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Showing papers in "Journal of Genetics in 2006"


Journal ArticleDOI
TL;DR: It is concluded that antioxidant enzymes protect halophytes from deleterious ROS production during salt stress, and genetic information from mangroves and otherHalophytes would be helpful in defining the roles of individual isoforms in oxidative stress defence.
Abstract: Normal growth and development of plants is greatly dependent on the capacity to overcome environmental stresses. Environmental stress conditions like high salinity, drought, high incident light and low or high temperature cause major crop losses worldwide. A common denominator in all these adverse conditions is the production of reactive oxygen species (ROS) within different cellular compartments of the plant cell. Plants have developed robust mechanisms including enzymatic or nonenzymatic scavenging pathways to counter the deleterious effects of ROS production. There are a number of general reviews on oxidative stress in plants and few on the role of ROS scavengers during stress conditions. Here we review the regulation of antioxidant enzymes during salt stress in halophytes, especially mangroves. We conclude that (i) antioxidant enzymes protect halophytes from deleterious ROS production during salt stress, and (ii) genetic information from mangroves and other halophytes would be helpful in defining the roles of individual isoforms. This information would be critical in using the appropriate genes for oxidative stress defence for genetic engineering of enhanced stress tolerance in crop systems.

294 citations


Journal ArticleDOI
TL;DR: It is suggested that the Kherigarh breed has not experienced a genetic bottleneck in the recent past, and allelic and genotypic frequencies, heterozygosities and gene diversity were estimated, and genetic bottleneck hypotheses were explored.
Abstract: We report a genetic diversity study of Kherigarh cattle, a utility draught-purpose breed of India, currently declining at a startling rate, by use of microsatellite markers recommended by the Food and Agriculture Organization. Microsatellite genotypes were derived, and allelic and genotypic frequencies, heterozygosities and gene diversity were estimated. A total of 131 alleles were distinguished by the 21 microsatellite markers used. All the microsatellites were highly polymorphic, with mean (+/- s.e.) allelic number of 6.24 +/- 1.7, ranging 4-10 per locus. The observed heterozygosity in the population ranged between 0.261 and 0.809, with mean (+/- s.e.) of 0.574 +/- 0.131, indicating considerable genetic variation in this population. Genetic bottleneck hypotheses were also explored. Our data suggest that the Kherigarh breed has not experienced a genetic bottleneck in the recent past.

64 citations


Journal ArticleDOI
TL;DR: The heritability, the number of segregating genes and the type of gene interaction of nine agronomic traits were analysed based on F2 populations of synthetic oilseedBrassica napus produced from interspecific hybridization of B. campestris andB.
Abstract: The heritability, the number of segregating genes and the type of gene interaction of nine agronomic traits were analysed based on F2 populations of synthetic oilseed Brassica napus produced from interspecific hybridization of B. campestris and B. oleracea through ovary culture. The nine traits-plant height, stem width, number of branches, length of main raceme, number of pods per plant, number of seeds per pod, length of pod, seed weight per plant and 1000-seed weight-had heritabilities of 0.927, 0.215, 0.172, 0.381, 0.360, 0.972, 0.952, 0.516 and 0.987 respectively, while the mean numbers of controlling genes for these characters were 7.4, 10.4, 9.9, 12.9, 11.5, 21.7, 20.5, 19.8 and 6.4 respectively. According to estimated coefficients of skewness and kurtosis of the traits tested, no significant gene interaction was found for plant height, stem width, number of branches, length of main raceme, number of seeds per pod and 1000-seed weight. Seed yield per plant is an important target for oilseed production. In partial correlation analysis, number of pods per plant, number of seeds per pod and 1000-seed weight were positively correlated with seed yield per plant. On the other hand, length of pod was negatively correlated (r = -0.69) with seed yield per plant. Other agronomic characters had no significant correlation to seed yield per plant. In this experiment, the linear regressions of seed yield per plant and other agronomic traits were also analysed. The linear regression equation was y = 0.074x8 + 1.819x9 + 6.72x12- 60.78 (R2= 0.993), where x8, x9 and x12 represent number of pods per plant, number of seeds per pod and 1000-seed weight respectively. The experiment also showed that erucic acid and oil contents of seeds from F2 plants were lower than those of their maternal parents. However, glucosinolate content was higher than that of the maternal plants. As for protein content, similar results were found in the F2 plants and their maternal parents. It was shown that the four quality traits, i.e. erucic acid, glucosinolate, oil content, and protein content, had heritability values of 0.614, 0.405, 0.153 and 0.680 respectively.

63 citations


Journal ArticleDOI
TL;DR: A large deletion, referred to as del(GJB6-D13S1830), was found to be located in trans in about 50% of Spanish individuals with nonsyndromic congenital or prelingual hearing loss with only one heterozygous mutation in GJB2, and significant differences in the frequency of this deletion among probands with sensorineural hearing loss have been reported in different populations.
Abstract: Congenital hearing loss is the most common sensorial problem, affecting approximately one in 500 children. Genetic factors are believed to be causative in at least half of these children. Although significant genetic heterogeneity exists as the cause of sensorineural hearing loss, one locus, DFNB1, comprising the GJB2 and GJB6 genes, is responsible for up to 20–50% of cases with congenital nonsyndromic hearing loss in many populations (Kelsell et al. 1997; Kenneson et al. 2002). Homozygous or compound heterozygous mutations in GJB2 are detected in most cases with DFNB1-related hearing loss. It was, nevertheless, evident in some studies that up to 50% of deaf subjects with GJB2 mutations carried only one mutant allele. During the search for an accompanying mutation in these heterozygotes, a large deletion of about 342 kb (later corrected to be 309 kb), which does not include GJB2 but truncates the neighboring GJB6, was discovered (Lerer et al. 2001; Del Castillo et al. 2002; Pallares-Ruiz et al. 2002). This large deletion, referred to as del(GJB6-D13S1830), was found to be located in trans in about 50% of Spanish individuals with nonsyndromic congenital or prelingual hearing loss with only one heterozygous mutation in GJB2 (Del Castillo et al. 2002). Significant differences in the frequency of this deletion among probands with sensorineural hearing loss have been reported in different populations. It was found to be common in Spain, France, the United Kingdom, Israel and Brazil, less frequent in the United States, Belgium and Australia, and detected in only a few individuals in Germany and the Czech Republic (Gabriel et al. 2001; Del Castillo et al. 2005; Seeman et al. 2005). It was not found in Austria and China (Gunther et al. 2002; Liu et al. 2002). It is remarkable that different frequencies have

53 citations


Journal ArticleDOI
TL;DR: In this paper, the authors report chromosome numbers and meiotic behaviour in 21 accessions of Brachiaria jubata as a tool in selecting promising ones for crossing in Brazil.
Abstract: The production of new genetic variability through hybridization has been undertaken in Brachiaria, an important forage grass genus of African origin widely used in pastures in the Brazilian tropics. Although the genus comprises about 100 species, only a few of them present favourable agronomic attributes and are explored. In the genus Brachiaria, the majority of species and accessions are polyploid and apomictic, which makes breeding through hybridization more complex. Sexuality has been found in diploids and eventually among tetraploids with normal meiosis. Brachiaria jubata presents good forage value and adaptation to riverbanks and lake margins, and is therefore relevant to pasture systems i n the tropics. Furthermore, the most interesting form of resistance to spittlebugs—antibiosis—was identified in one a ccession of B. jubata. Thus its interest in the Brazilian breeding programme lies in the possibility of using hybridization to transfer high resistance to this insect to susceptible ac cessions. This paper reports chromosome numbers and meiotic behaviour in 21 accessions of this species as a tool in selecting promising ones for crossing. Only one accession was found to be diploid; the others were tetraploid. Microsporogenesis was normal in the diploid accession, while among the tetraploid ones, irregular chromosome segregation leading to unbalanced gamete formation was common but variable. Pollen fertility among tetraploid accessions was hig h. Cytogenetic studies were carried out on accessions of Brachiaria jubatafrom the Brachiaria germplasm collection at Embrapa Beef Cattle kept in the field in Campo Grande (state of Mato Grosso do Sul, Brazil), which comprises 475 accessions of 15 species collected in Africa in the mid-1980s by CIAT (Colombia). Inflorescences were collected and

47 citations


Journal ArticleDOI
TL;DR: The results show that the mean values of the traits and their variance are both plastic, but react in different ways along a temperature gradient, while extreme low or high temperatures decrease the size but increase the variability.
Abstract: A natural population ofDrosophila melanogaster in southern France was sampled in three different years and 10 isofemale lines were investigated from each sample. Two size-related traits, wing and thorax length, were measured and the wing/thorax ratio was also calculated. Phenotypic plasticity was analysed after development at seven different constant temperatures, ranging from 12‡C to 31‡C. The three year samples exhibited similar reaction norms, suggesting a stable genetic architecture in the natural population. The whole sample (30 lines) was used to determine precisely the shape of each reaction norm, using a derivative analysis. The practical conclusion was that polynomial adjustments could be used in all cases, but with different degrees: linear for the wing/thorax ratio, quadratic for thorax length, and cubic for wing length. Both wing and thorax length exhibited concave reaction norms, with a maximum within the viable thermal range. The temperatures of the maxima were, however, quite different, around 15‡C for the wing and 19.5‡C for the thorax. Assuming that thorax length is a better estimate of body size, it is not possible to state that increasing the temperature results in monotonically decreasing size (the temperature-size rule), although this is often seen to be the case for genetic variations in latitudinal clines. The variability of the traits was investigated at two levels—within and between lines—and expressed as a coefficient of variation. The within-line (environmental) variability revealed a regular, quadratic convex reaction norm for the three traits, with a minimum around 21‡C. This temperature of minimum variability may be considered as a physiological optimum, while extreme temperatures are stressful. The between-line (genetic) variability could also be adjusted to quadratic polynomials, but the curvature parameters were not significant. Our results show that the mean values of the traits and their variance are both plastic, but react in different ways along a temperature gradient. Extreme low or high temperatures decrease the size but increase the variability. These effects may be considered as a functional response to environmental stress.

43 citations


Journal ArticleDOI
TL;DR: The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae, and agrees with morphological and cytological data.
Abstract: We have examined the molecular-phylogenetic relationships between nonmulberry and mulberry silkworm species that belong to the families Saturniidae, Bombycidae and Lasiocampidae using 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit I (coxI) gene sequences. Aligned nucleotide sequences of 16S rRNA andcoxI from 14 silk-producing species were used for construction of phylogenetic trees by maximum likelihood and maximum parsimony methods. The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae. Weighted parsimony analysis weighted towards transversions relative to transitions (ts, tv4) forcoxI resulted in more robust bootstrap support over unweighted parsimony and favours the 16S rRNA tree topology. Combined analysis reflected clear biogeographic pattern, and agrees with morphological and cytological data.

41 citations


Journal ArticleDOI
TL;DR: Among the diverse PRs,PR-1 is the dominant group, whose function is not well known, and the limited antifungal activity suggests function of PR-1 in plant defence.
Abstract: Plants are often threatened by pathogen attack or other external stresses during growth and development. To decrease loss in productivity, plants respond to biotic and abiotic stresses by triggering a series of biochemical reactions, termed hypersensitive reaction (HR), which is associated with synthesis of secondary metabolites, cell wall rigidification, lignin and suberin deposition, and induction of a variety of novel proteins. In the HR response, pathogenesis-related proteins (PRs) that are suggested to be effective in inhibiting growth, multiplication and/or spread of pathogens, and are responsible for the state of systemic acquired resistance (SAR; Van Loon 1997), are significantly induced and accumulated abundantly in host plants (Van Loon and Van Strien 1999). PR proteins can be divided into 17 groups on the basis of their sequence characteristics, immunological relationships and biological activities (Liu et al. 2005). However, only 14 distinct families of PR proteins have been found in plants (Sarowar et al. 2005). Not all families are found in any one plant species (Van Loon and Van Strien 1999). Among the diverse PRs, PR-1 is the dominant group, whose function is not well known. The limited antifungal activity suggests function of PR-1 in plant defence (Kitajima and Sato 1999). However, the mode of action and its relationship to other types of proteins still remain unknown. The first PR1 protein was discovered in 1970. Since then, a number of PR-1 proteins have been identified in Arabidopsis (Uknes et al. 1992), maize (Morris et al. 1998), wheat (Molina et al. 1999), tomato (Tornero et al. 1994), tobacco (Pfitzner and Goodman 1987), barley (Muradov et al. 1993), rice (Agrawal et al. 2000a,b; Kim et al. 2001) and pepper (Kim and Hwang 2000). Rice is a vitally important crop for human consumption. The completion of the Oryza sativa genome

35 citations


Journal ArticleDOI
TL;DR: Various average genetic variability measures showed substantial within-breed genetic variability in this major breed of Rajasthan, despite accumulated inbreeding as reflected by high average inbreeding coefficient (F1S = 0.39).
Abstract: The present study estimates genetic variability with a set of 25 microsatellite markers in a random sample of 50 animals of Tharparkar breed of Indian zebu (Bos indicus) cattle. Tharparkar is a dual-purpose breed, valued for its milk as well as draught utility, and is adapted to the inhospitable Thar desert conditions of Rajasthan typified by summer temperature hovering above 50°C, sparse rainfall and vegetation, and scarcity of even drinking water. The observed number of alleles ranged from 4 (ETH3, ILSTS030, INRA5, INRA63 and MM8) to 11 (HEL9 and ILSTS034), with allelic diversity (average number of observed alleles per locus) of 6.20. Observed and expected heterozygosity ranged from 0.25 (INRA63) to 0.77 (ETH10), and from 0.51 (HEL5 and HAUT27) to 0.88 (HEL9) respectively. Wide range of genetic variability supported the utility of these microsatellite loci in measurement of genetic diversity indices in other Indian cattle breeds too. Various average genetic variability measures, namely allele diversity (6.20), observed heterozygosity (0.57), expected heterozygosity (0.67) and mean polymorphism information content (0.60) values showed substantial within-breed genetic variability in this major breed of Rajasthan, despite accumulated inbreeding as reflected by high average inbreeding coefficient (F 1S = 0.39). The Tharparkar population has not experienced a bottleneck in the recent past.

32 citations


Journal ArticleDOI
TL;DR: The present study details meiotic and postmeiotic abnormalities related to cytokinesis observed in one accession of B. humidicola, a promising African genus of forage grass for the Brazilian savannas.
Abstract: Meiosis is controlled by a large number of genes, generally dominant, whose expression is stage-specific, site-specific and time-specific (Gottschalk and Kaul 1974, 1980a,b; Baker et al. 1976; Golubovskaya 1979, 1989). Among genes acting in the meiotic process, those responsible for the partitioning of the cytoplasm after nuclear division play a very important role in the formation of viable gametes. After two rounds of chromosome segregation (karyokinesis) and one simultaneous or two successive cytoplasmic divisions (cytokinesis), the final product of male meiosis in flowering plants emerges as a tetrad of haploid microspores enclosed in a callose wall. The timing of cytokinesis varies among angiosperms. In most monocot plants, cytokinesis is successive, i.e. one partitioning of the cytoplasm occurs after telophase I and another after telophase II, so that there is a distinct dyad stage. However, in most dicots, it is simultaneous and occurs after telophase II (Peirson et al. 1996). Many meiosis mutations affecting the pattern of cytokinesis have been reported in higher plants (Peirson et al. 1996). In Brachiaria, a promising African genus of forage grass for the Brazilian savannas, absence of cytokinesis leading to 2n microspores and binucleated or tetranucleated microspores have been reported in B. brizantha (Risso-Pascotto et al. 2003) and B. nigropedata (Utsunomiya et al. 2005). The present study details meiotic and postmeiotic abnormalities related to cytokinesis observed in one accession of B. humidicola.

29 citations


Journal ArticleDOI
TL;DR: The problems created by the massive data available since the decipherment of the first human genome, followed by in situ quantitation of RNA in the thousand or so cell varieties, in health and disease, are far from resolved.
Abstract: The problems created by the massive data available since the decipherment of the first human genome, followed by in situ quantitation of RNA in the thousand or so cell varieties, in health and disease, are far from resolved. Unlike astronomy , with its equivalent problems of evolution and data-drownin g, biology and medicine involve fewer units but a far greater variety: only sequence data can claim exemption from the fuzzy nouns on which most other descriptions depend. To make matters worse few observers of living organisms— well, sick or dead—can approach the average mathematical ability of astronomers. Unlike astronomy, biology is more than an observational study: we depend on plants and animals to concentrate and package our foods and medical services to ease the problems of birth, illness and death. Big problems need big books. This one, or rather pair— the first edition has twinned—certainly qualifies, weighing in at almost three kilograms and costing £230–£290 pounds (the amount seems to vary for new books according to supplier identified on the Internet, and some suppliers quote lower, changing prices for used copies). Blackwells declin to display such expensive books, possibly explaining their solitary order when last consulted. While the reputation of its contributors will ensure good sales to major libraries, ts cost will deprive them of the readership they deserve. It will rarely enter the shelves of small departmental librari es, where they exist, or are allowed to exist. Advances in genetics, as in its subject matter, are largely dependent on small departments: larger departments are essential for utilizing these advances. Additional chapters in the second edition are on ‘Evolutionary quantitative genetics’, ‘Bayesian methods in ge nomics’ and ‘Analysis of microarray gene expression data’: only the last is justified by technical advances since the firs t edition. There is more extensive indexing in the second edition. The reference index is deficient in giving the page of the reference rather than the page needing the reference. Th e glossary has many omissions and some unacceptable errors.

Journal ArticleDOI
TL;DR: The complementary use of morphological and yield analysis, molecular cytogenetic techniques and molecular markers allowed a more accurate evaluation and characterization of the hybrids analysed here.
Abstract: The morphological, yield, cytological and molecular characteristics of bread wheat x tritordeum F(1) hybrids (2n = 6x = 42; AABBDH(ch)) and their parents were analysed. Morphologically, these hybrids resembled the wheat parent. They were slightly bigger than both parents, had more spikelets per spike, and tillered more profusely. The hybrids are self-fertile but a reduction of average values of yield parameters was observed. For the cytological approach we used a double-target fluorescence in situ hybridization performed with total genomic DNA from Hordeum chilense L. and the ribosomal sequence pTa71. This technique allowed us to confirm the hybrid nature and to analyse chromosome pairing in this material. Our results showed that the expected complete homologous pairing (14 bivalents plus 14 univalents) was only observed in 9.59% of the pollen mother cells (PMCs) analysed. Some PMCs presented autosyndetic pairing of H(ch) and A, B or D chromosomes. The average number of univalents was higher in the wheat genome (6.8) than in the H(ch) genome (5.4). The maximum number of univalents per PMC was 20. We only observed wheat multivalents (one per PMC) but the frequency of trivalents (0.08) was higher than that of quadrivalents (0.058). We amplified 50 RAPD bands polymorphic between the F(1) hybrid and one of its parents, and 31 ISSR polymorphic bands. Both sets of markers proved to be reliable for DNA fingerprinting. The complementary use of morphological and yield analysis, molecular cytogenetic techniques and molecular markers allowed a more accurate evaluation and characterization of the hybrids analysed here.

Journal ArticleDOI
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, which aims to provide real-time information about the phytochemical properties of E.coliothorax, a substance which is a major raw material for rice cultivation.
Abstract: 1Plant Molecular Biology Lab, M. S. Swaminathan Research Foundation, Taramani, Chennai 600 113, India 2Tissue Culture and Genetic Engineering Laboratory, Plant Breeding, Genetics and Biotechnology Division, International Rice Research Institute (IRRI), DAPO BOX 7777, Metro-Manila, The Philippines 3Permanent address: Department of Botany, Goa University, Goa 403 206, India 4Present address: Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, India

Journal ArticleDOI
TL;DR: Sexual conflict has mainly been investigated in animals and the interlocus component has been the principal focus of past studies, however, among the very large diversity of reproductive systems of plants, it can be furtherbedivided into two components: inter locus and intralocus con-�ict.
Abstract: .2003). Sexualconflictcanfurtherbedividedinto two components: interlocus and intralocus conflict.Interlocus conflict designates the form of conflict inwhich the expression of a sex-limited locus results in a netfitness benefitto thesexexpressingit anda fitness costto theother sex, usually through direct reproductive interactions.Thisleadstostrongselectionforacounteractingmechanism,usually governed by a different locus, in the other sex. Theresult is rapid evolution of the loci involved and open-endedcycles of antagonistic coevolution between the sexes (Hol-land and Rice 1998).Intralocus conflict involves traits (and hence alleles) thatareexpressedinbothsexes,buthavedifferentoptimaineachsex (Rice and Chippindale 2001), thereby creating divergentselection pressures across sexes. However, because malesand females of the same species share the same genome, ge-netic correlations for the same trait between sexes impedethe independent evolution of the trait within each sex, lead-ing to a conflict between the sexes. A part of the conflict canpotentially be resolved by evolution of sex-limited gene ex-pression leading to sexual dimorphism. The unresolved partof the conflict maintains each sex away from its optimum,creating a gender load.Sexual conflict has mainly been investigated in animalsand the interlocus component has been the principal focusof past studies. However, among the very large diversityof reproductive systems of plants, dioecy gathers all the

Journal ArticleDOI
TL;DR: Clinical evaluation showed presence of corneal defects with variations in both age of onset and severity of amyloid deposits in these patients, and sequence analysis identified a novel A-to-C transversion at position 1612 in the TGFBI gene in a pedigree with LCDI.
Abstract: Lattice corneal dystrophy (LCD), characterized by the accu mulation of amyloid within the cornea, is one of the most common inherited corneal diseases. Mutations in the human transforming growth factor beta-induced gene ( TGFBI), formerly designatedBIGH3, have been shown to be associated with different forms of LCD, including LCD type I (LCDI) and type IIIA (LCDIIIA) (Munier et al. 2002). Here we report the clinical and molecular-genetic analysis of LCD in Chinese patients. Clinical evaluation showed presence of corneal defects with variations in both age of onset and severity of amyloid deposits in these patients. Sequence analysis identified a novel A-to-C transversion at position 1612 (A1612C) in theTGFBI gene in a pedigree with LCDI. The A1612C mutation is expected to result in a Thr538Pro (T538P) substitution in TGFBI protein. Our study showed that P501T mutation with its disequilibrium-linked polymo rphism IVS10-3T→ C, previously identified only in Japanese LCDIIIA patients (Tsujikawaet al. 2002), was also present in Chinese LCDIIIA patients.

Journal ArticleDOI
TL;DR: Although the mtDNA D-loop sequence has a rapid rate of evolution, the 287-bp Numts are highly conserved; they are nearly identical in tiger subspecies and only 1.742% different between tiger and leopard, indicating that such sequences represent molecular 'fossils' that can shed light on evolution of the mitochondrial genome and may be the most appropriate outgroup for phylogenetic analysis.
Abstract: Using oligonucleotide primers designed to match hypervariable segments I (HVS-1) ofPanthera tigris mitochondrial DNA (mtDNA), we amplified two different PCR products (500 bp and 287 bp) in the tiger (Panthera tigris), but got only one PCR product (287 bp) in the leopard (Panthera pardus). Sequence analyses indicated that the sequence of 287 bp was a D-loop-like nuclear mitochondrial sequence (Numts), indicating a nuclear transfer that occurred approximately 4.8–17 million years ago in the tiger and 4.6–16 million years ago in the leopard. Although the mtDNA D-loop sequence has a rapid rate of evolution, the 287-bp Numts are highly conserved; they are nearly identical in tiger subspecies and only 1.742% different between tiger and leopard. Thus, such sequences represent molecular ‘fossils’ that can shed light on evolution of the mitochondrial genome and may be the most appropriate outgroup for phylogenetic analysis. This is also proved by comparing the phylogenetic trees reconstructed using the D-loop sequence of snow leopard and the 287-bp Numts as outgroup.

Journal ArticleDOI
TL;DR: The strength and success of molecular biology came from the many interactions between geneticists, physicists, chemists and biochemists, and was also characterized by a powerful combination of theoretical and experimental approaches.
Abstract: Bohr, Delbruck and Schrodinger were physicists who had important influences on biology in the second half of the twentieth century. They thought that future studies of the gene might reveal new principles or paradoxes, analogous to the wave/particle paradox of light propagation, or even new physical laws. This stimulated several physicists to enter the field of biology. Delbruck founded the bacteriophage group which provided one of the roots of molecular biology. Another was X-ray crystallography which led to the discovery of DNA structure. The strength and success of molecular biology came from the many interactions between geneticists, physicists, chemists and biochemists. It was also characterized by a powerful combination of theoretical and experimental approaches.

Journal ArticleDOI
TL;DR: Results of cross-amplification of 63 microsatel-lite loci, originally developed for Xiphophorus, tested in the Amazon molly and its two parental species P. mexicana and P. latipinna are reported, finding eight microsatellite loci were found to be poly-morphic.
Abstract: The Amazon molly Poecilia formosa is a model system forstudying the evolution of sex (Turner 1980; Schartl 1995)and skin cancer development (Schartl et al. 1997). Only veryfew variable microsatellites are known for this species. Mi-crosatellites, however, have already proven to be very usefultools for diverse genetic analyses (Lampert et al. 2005). Herewe report the results of cross-amplification of 63 microsatel-lite loci, originally developed for Xiphophorus, tested in theAmazon molly and its two parental species P. mexicana andP. latipinna. Eight microsatellite loci were found to be poly-morphic. Sixteen primers allowed species identification an deight primers allowed diagnosis of different ploidy levels inP. formosa. These microsatellites will be useful to gain newinsights into the population structures, clonal variability andreproductive biology of a mixed species reproductive com-plex, and also into the genetic mechanism underlying cancerformation.P. formosa, the Amazon molly, is a small freshwa-ter fish species that occurs in the northeastern part ofMexico and extends into the USA (Texas). It is an all-female species and was the first vertebrate discovered toreproduce clonally (Hubbs and Hubbs 1932). Its repro-ductive mode is gynogenesis:females produce unreducedeggs, but need sperm from a closely related sexual speciesto trigger the onset of oocyte development. The male’s

Journal ArticleDOI
TL;DR: Two identified PCR fragments of the promoter region in PCR-SSCP were used and it was demonstrated that the lowest primer concentration in PCR product affecting SSCP banding patterns is around 6 nM, and that primer-concentration-dependent intermediate SSCP patterns appear in unpurified PCR product amplified with regular amounts of primers.
Abstract: Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) is a widely utilized screening method for detection of mutations. In this method, the target sequence of interest is amplified by PCR and separated as single-stranded molecules by electrophoresis in a nondenaturing polyacrylamide gel (Orita et al. 1989). However, the sensitivity and resolution of PCR-SSCP can be influenced by many parameters, including size and GC content of the PCR product (Li et al. 2003); gel temperature during electrophoresis (Chen et al. 1995); buffer composition (e.g. ionic strength, pH; Kukita et al. 1997); buffer additives, mainly glycerol, formamide, polyethylene glycol (Markoff et al. 1997; Paccoud et al. 1998); gel matrix composition and concentration (Savov et al. 1992), as well as primer concentration in PCR product (Cai and Touitou 1993). It is generally considered that specific PCR amplification is important in detection of mutations by using PCR-SSCP (Orita et al. 1989; Li et al. 2003). Moreover, it has been noted that addition of either forward or reverse primer in PCR product may apparently alter SSCP banding patterns, which is presumably caused by the interaction between primer(s) and single-strand DNAs (ssDNA) (Almeida et al. 1998; Hennessy et al. 1998). Previously, Cai and Touitou (1993) demonstrated that the lowest primer concentration in PCR product affecting SSCP banding patterns is around 6 nM, and that primer-concentration-dependent intermediate SSCP patterns appear in unpurified PCR product amplified with regular amounts of primers (30–150 nM). In the present study, we used two identified PCR fragments of the promoter region in

Journal ArticleDOI
TL;DR: 1Behaviour, Ecology and Evolution Laboratory, Biology Department, Poornaprajna Institute of Scientific Research, P.O. box No.
Abstract: 1Behaviour, Ecology and Evolution Laboratory, Biology Department, Poornaprajna Institute of Scientific Research, P.O. Box No. 18, Devanahalli, Bangalore 562 110, India 2Present Address: National Institute of Malaria Research (ICMR), 22 Sham Nath Marg. New Delhi 110 054, India 3Evolutionary Biology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560 064, India 4Present Address: Department of Biology, Queen’s University, Kingston, Ontario K7L 3N6, Canada 5Department of Environmental Biology, University of Delhi, University Road, Delhi 110 007, India 6Present Address: Evolutionary Biology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560 064, India 7Present Address: School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India

Journal ArticleDOI
TL;DR: The results suggest that the homeotic-like changes in floral patterning leading to petaloid stamens in Og2 and OgRLM may be associated with aberrant mitochondrial gene expression.
Abstract: We have previously reported correction of severe leaf chlorosis in the cytoplasmic male sterile Ogura (also called Ogu) Brassica juncea line carrying Ogura cytoplasm by plastid substitution via protoplast fusion. Two cybrids obtained from the fusion experiment, Og1 and Og2, were green and carried the plastid genome of B. juncea cv. RLM198. While Og1 displayed normal flower morphology comparable to that of its euplasmic B. juncea counterpart except for sterile anthers, Og2 retained homeotic-like floral modification of stamens to petal-like structures and several other floral deformities observed in the chlorotic (Ogu) B. juncea cv. RLM198 (or OgRLM). With respect to the mitochondrial genome, Og1 showed 81% genetic similarity to the fertile cultivar RLM while Og2 showed 93% similarity to OgRLM. In spite of recombination and rearrangements in the mitochondrial genomes in the cybrids, expression patterns of 10 out of 11 mitochondrial genes were similar in all the three CMS lines; the only exception was atp6, whose expression was altered. While Og1 showed normal atp6 transcript similar to that in RLM, in Og2 and OgRLM weak expression of a longer transcript was detected. These results suggest that the homeotic-like changes in floral patterning leading to petaloid stamens in Og2 and OgRLM may be associated with aberrant mitochondrial gene expression.

Journal ArticleDOI
TL;DR: Special mention is made of horses of the Zanskar region for their exceptional ability to survive and perform under the harsh climatic conditions of their high-altitude habitat.
Abstract: Indiaisendowedwithsomemagnificentbreedsofhorsesthathave evolved and adapted to different geographical and eco-logical conditions. Special mention is made of horses of theZanskar region for their exceptional ability to survive andperform under the harsh climatic conditions of their high-altitude habitat (between 3000 and 5000 metres). Thesehorses, with small, strongly built and compact bodies, areknown for their ability to survive on scarce food in the win-ter snow-bound months and yet have incredible stamina andstrength. However, poor management of these animals hasled to dilution of their characteristic features to some ex-tent. The ever-increasing road network and mechanizationhave also led to steep decline in their population and imme-diate conservation measures are required (Bhat

Journal ArticleDOI
TL;DR: In cytoraces the parental chromosomes are not just differentially represented but there is evidence for introgression even at the gene level, and quantitative analysis shows lack of correlation between the chromosomal pattern of inheritance and overall quantity of the major glue protein fractions in the cytorace.
Abstract: Glue proteins are tissue-specific proteins synthesized by larval salivary gland cells ofDrosophila. InDrosophila nasuta nasuta andD. n. albomicans of thenasuta subgroup, the genes that encode the major glue protein fractions are X-linked. In the present study, these X-linked markers have been employed to trace the pattern of introgression ofD. n. nasuta andD. n. albomicans genomes with respect to the major glue protein fractions in their interracial hybrids, called cytoraces. These cytoraces have inherited the chromosomes of both parents and have been maintained in the laboratory for over 400–550 generations. The analysis has revealed that cytoraces withD. n. albomicans X chromosome show eitherD. n. nasuta pattern or a completely novel pattern of glue protein fractions. Further, quantitative analysis also shows lack of correlation between the chromosomal pattern of inheritance and overall quantity of the major glue protein fractions in the cytoraces. Thus, in cytoraces the parental chromosomes are not just differentially represented but there is evidence for introgression even at the gene level.

Journal ArticleDOI
TL;DR: To take right measures to protect wild resources of L. longituba, it is important to study the range of genetic variation, genetic structure, diversification trend and other factors affecting genetic structure of the populations of this important and sparsely distributed species.
Abstract: Lycoris longituba Y. Hsu et Q. J. Fan is a perennial, bulbiferous, herbaceous plant of the family Amaryllidaceae. It is endemic in China, with a very limited distribution, being found only at Langyashan in Anhui province, and Baohuashan and Xuyi city in Jiangsu province, all located about 50 km from one another (see figure 1 and table 1 in electronic supplementary material at http://www.ias.ac.in/jgenet/). A unique biological characteristic of this plant is that its leaves come out in spring and die in early summer, followed by flowering. Thus, its vegetative growth and reproduction are discrete, which is rare in angiosperms. With a vigorous and long scape, its flowers are diverse in both colour and floral form, and fragrant in smell, and have high ornamental value. Also called Chinese tulip, this species is ideal for ikebana, and its bulb has medicinal properties. We have collected more than 70 variants of this species in our laboratory with different floral colours and forms. Population-genetic structure is considered as spatiotemporal distribution of genetic variation (Ge 1997), and reflects evolutionary processes in populations (Hamrick and Loveless 1989). To take right measures to protect wild resources of L. longituba, it is important to study the range of genetic variation, genetic structure, diversification trend and other factors affecting genetic structure of the populations of this important and sparsely distributed species. Presently, many biochemical and DNA-based markers are used in studies of population structure. The random amplified polymorphic DNA (RAPD) method (Williams et al. 1990) is frequently applied to reveal population-genetic variation, divergence and biogeography (Schaal and Leverich 2001). A large number of studies have successfully applied this method to study genetic variation in plants owing to

Journal ArticleDOI
TL;DR: Overall, the preliminary findings suggest that Australian feral pigs are genetically diverse, with heterozygosity and allelic diversity at 0.758 and 11.0 alleles per locus on average, respectively.
Abstract: In many regions in the world the reduction in population sizes of native pigs is a conservation concern (Li et al. 2000; Martinez et al. 2001). However, in Australia, feral (or wild) pigs are a significant invasive species, and there are upwards of 10 million feral pigs present, inhabiting over 40% of the continent (Choquenot et al. 1996). Coupled with these large numbers and advances made in marker technology, there is an increasing awareness of the value in quantifying (and understanding) the biodiversity retained in non-commercial livestock breeds (e.g. Hall and Bradley, 1995). Well-characterized microsatellite markers, such as those recommended by the Food and Agriculture Organization and International Society for Animal Genetics (FAO-ISAG), are ideal for such studies. There is an increasing amount of data being generated from indigenous pigs, including Asian (Li et al. 2000; Kaul et al. 2001), American (Lemus-Flores et al. 2001) and wild European (Laval et al. 2000; Martinez et al. 2000; Vernesi et al. 2003) breeds. However, there is no such information available on the diversity of wild pigs in Australia or Papua New Guinea. Overall, the preliminary findings suggest that Australian feral pigs are genetically diverse, with heterozygosity and allelic diversity at 0.758 and 11.0 alleles per locus on average, respectively.

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TL;DR: This poster presents a probabilistica guide to the construction and operation of the biologia Animale workshop at the University of Palermo, designed to assist in the design and construction of the buildings and equipment for this and other similar workshops.
Abstract: 1Istituto di Scienze Marine, Sezione di Venezia, CNR, Castello 1364/a, 30122 Venezia, Italy 2Dipartimento di Biologia Animale, Universita di Palermo, Via Archirafi 18, 90123 Palermo, Italy 3Dipartimento di Scienze Ambientali, Universita “Ca’ Foscari”, Castello 2737/b 30122 Venezia, Italy 4Istituto di Ecologia e Biologia Ambientale, Universita di Urbino “Carlo Bo”, Via I. Maggetti 22, 61029 Urbino (PU), Italy

Journal ArticleDOI
TL;DR: The group has successfully cloned three new human testis apoptosis-related genes and twohuman testis-specific expressed genes by using suppression subtractive hybridization (SSH) and their role is of great importance in understanding the biology of spermatogenesis.
Abstract: Infertility is a common problem which a ffects 13% of couples; both female and male factors are known to contribute to it. Although several external factors have been claimed t o affect male reproduction, evidence that genetic factors play important roles is accumulating (Bourrouillou et al. 1985; Adamset al. 1995). Idiopathic azoospermia or severe oligozoospermia accounts for about 20% of male infertility cases . In these cases, systematic analysis of molecular deletions of Y chromosome indicates that three nonoverlapping regions, AZFa, AZFb andAZFc, in band Yq11, are involved in male spermatogenesis (Vogt e al. 1996). A series of genes including DAZ andRBM genes have been identified in these AZF regions as candidate genes for azoospermia. They are categorized as a testis-specific type and a multiple-tissue expression type (Ma et al. 1993; Reijoet al. 1995). However, gene-specific mutations causing the azoospermia phenotype have only been found in the USP9Y gene (Sunet al. 1999). Some autosomal genes are also associated with spermatogenesis in mouse and human, including DAZLA, CREM and HSP70 with its human homologueHSPA2 (Dix et al. 1996; Ruggiuet al. 1997) The products of many genes are essential for spermatogenesis, but a small number a ffect spermatogenesis exclusively. Identification of these new genes and their role is of great importance in understanding the biology of spermatogenesis (Cooket al. 1998). Our group has successfully cloned three new human testis apoptosis-related genes and two human testis-specific expressed genes by using suppression subtractive hybridization (SSH) (Liu et al. 2002, 2004; Xinget al. 2003). In an attempt to

Journal ArticleDOI
TL;DR: It is found that processing time had little effect on chromosomal ultrastructures, but that trypsin digestion had a large effect, and the results indicate that the grain size distribution of CHO chromosomes was larger than that of human.
Abstract: DNA and associated proteins, such as histones, form complex structures known as chromatin fibres (about 30 nm in diameter); these further aggregate into chromosomes. Researchers have long sought to fully understand the structure and structure–function relationships of chromosomes. Many three-dimensional chromosome structures have been investigated by scanning electron microscopy (SEM) (Harrison et al. 1982; Wanner and Formanek 1995; Sumner 1996), but use of SEM is limited by sample staining, embedding, vacuum, etc. Recently, atomic force microscopy (AFM) (Binning et al. 1986) has been utilized for analysis of chromosome structures. AFM has an ultrahigh resolution that enables researchers to observe nanometre-scale structures (Hansma et al. 1992). In addition, the technique allows imaging of samples in air or liquid, and does not require the complex treatments needed for SEM. Thus, AFM facilitates observation of chromosomal ultrastructures at nearly physiological conditions. To date, a number of studies have investigated chromosomal structures using AFM (Liu et al. 2003; Tamayo 2003; Sugiyama et al. 2004). However, few previous studies have investigated factors influencing chromosome ultrastructures or species-specific ultrastructural characteristics. We studied the effects of several factors on AFM imaging of chromosomal ultrastructures. We found that processing time had little effect on chromosomal ultrastructures, but that trypsin digestion had a large effect. In addition, we compared the chromosomal surface ultrastructure of human and CHO cells. The results indicate that the grain size distribution of CHO chromosomes was larger than that of human

Journal ArticleDOI
TL;DR: TDT is a test of both linkage and association; the null hypothesis is linkage and/or association and it was shown that the expectation of TDT under the alternative hypothesis is proportional to (1−2θ)δ, where θ is the recombination fraction between the candidate locus and the disease loci and δ the linkage disequilibrium between the two loci.
Abstract: One of the most common designs for identification of genes involved in complex human diseases is the transmission disequilibrium test (TDT) design (Spielmann et al. 1993). This design consists in the collection of cases (affected individuals) and their two parents (commonly called triads of case– parents). The analysis of such data is based on comparison of the numbers of transmissions and nontransmissions of alleles for a candidate locus from parents to affected child. Here we mean by a candidate locus any variant or marker near or within the coding sequence of a candidate gene, whose function or position (or both) suggest its involvement in disease aetiology. Differential transmission of alleles, if any, indicates linkage and association between the candidate locus and the disease. Consider, without loss of generality, a candidate locus with two alleles A and a (in the case of multiple alleles such as for STR markers, one would consider testing each allele A against all others pooled in one non-A (a) allele). The expression of the TDT statistic is T = (b − c)2/(b + c), where b (respectively c) is the number of heterozygous parents who transmit the A (respectively a) allele to their affected child. Thus, for a triad to be informative (contribute to T value), at least one parent needs to be heterozygous for the candidate locus. TDT is a test of both linkage and association; the null hypothesis is linkage and/or association and it was shown that the expectation of TDT under the alternative hypothesis is proportional to (1−2θ)δ, where θ is the recombination fraction between the candidate locus and the disease locus and δ the linkage disequilibrium between the two loci. Under the null hypothesis, heterozygous parents transmit either allele (A, a) to an affected offspring with equal probability. For a large number of triads (>20), the distribution of T can be approximated by a chi-square distribution with one degree of freedom (d.f.). Many approximations have been

Journal ArticleDOI
Jing Liu1, Yonghua Sun1, Na Wang1, Yaping Wang1, Zuoyan Zhu1 
TL;DR: The results show that the upstream sequence of 500 bp can direct highly efficient and tissue-specific expression of eGFP in zebrafish embryos, whereas a fragment of 200 bp containing the TATA box and a partial suppressor of hairless paired site sequence (SPS) is not sufficient to driveeGFP expression in zbrafish embryos.
Abstract: Some members ofhairy/Enhancer-of-split-related gene (HES) family have important effects on axial mesoderm segmentation and the establishment and maintenance of the somite fringe. In fishes, theher6 gene, a member of the HES family, is the homologue ofhes1 in mammals and chicken. In this study, theher6 gene and its full-length cDNA from the common carp (Cyprinus carpio) were isolated and characterized. The genomic sequence of common carpher6 is approximately 1.7 kb, with four exons and three introns, and the full-length cDNA of 1314 bp encodes a putative polypeptide of 271 amino acids. To analyse the promoter sequence of common carpher6, sequences of various lengths upstream from the transcription initiation site ofher6 were fused to enhanced green fluorescent protein gene (eGFP) and introduced into zebrafish embryos by microinjection to generate transgenic embryos. Our results show that the upstream sequence of 500 bp can direct highly efficient and tissue-specific expression ofeGFP in zebrafish embryos, whereas a fragment of 200 bp containing the TATA box and a partial suppressor of hairless paired site sequence (SPS) is not sufficient to driveeGFP expression in zebrafish embryos.