Showing papers in "Caryologia in 1974"
TL;DR: A method is described which, through the combined use of warm phosphate saline and a Giemsa-trypsin mixture, consistently produces G-bands in metaphase chromosomes of human leukocytes.
Abstract: SUMMARYA method is described which, through the combined use of warm phosphate saline and a Giemsa-trypsin mixture, consistently produces G-bands in metaphase chromosomes of human leukocytes.
75 citations
TL;DR: The Leguminosae family unity in discussed on the basis of chromosome numbers among its species, and the relation of polyploidy to geographic distribution is discussed.
Abstract: SUMMARYThis study is an attempt to analyse the variation in chromosome numbers of Leguminosae and its relation to evolution. Cytological observations were made on forty two species of Brazilian leguminous plants belonging to 25 genera. Chromosome numbers in 36 species are reported for the first time. Data from literature show marked chromosome variation among the 2,953 cytologically studied species of Leguminosae. The relation of polyploidy to geographic distribution is discussed. Tropical and woody Leguminosae are generally polyploid. The Leguminosae family unity in discussed on the basis of chromosome numbers among its species.
41 citations
TL;DR: Melanophryniscus moreirae, of the Brachycephalidae family, presents a karyotype related to those of the Bufonidae, which is not morphologically distinguishable sex chromosomes.
Abstract: SUMMARYKaryotypes of twelve species of Leptodactylidae and one Brachycephalidae were studied. They were: Eleutherodactylus unistrigatus (2n=20), Holoaden bradei (2n=18), Paralelmatobius lutzi (2n=24), Physalaemus aguirrei, P. cicada, P. gracilis, P. kroyeri, P. sp. (1), P. sp. (2), P. olfersi, P. signiferus, P. soaresi (2n=22) and Melanophryttiscus moreirae (2n=22). Centric fusion and pericentric inversions are the most important mechanisms of karyotype differentiation in Leptodactylidae. Melanophryniscus moreirae, of the Brachycephalidae family, presents a karyotype related to those of the Bufonidae. No morphologically distinguishable sex chromosomes could be observed.
41 citations
TL;DR: The karyologic finding is discussed with regard to the position of the Mugilidae in systematic studies and 3 cytotaxonomic groups are proposed: a) Mugil cephalus, all the chromosomes of which are acrocentric; b) Liza and Chelon with one pair of subtelocentrics; c) Oedalechilus with one Pair of telocentrics with a very small arm.
Abstract: SUMMARYThe karyotypes of six species of Mediterranean mullets have been studied: Mugil cephalus, Liza aurata, Liza saliens, Liza ramada, Chelon labrosus and Oedalechilus labeo. The diploid number in all these species is 2n=48. On the basis of the morphology of the karyotype, 3 cytotaxonomic groups are proposed: a) Mugil cephalus, all the chromosomes of which are acrocentric; b) Liza and Chelon with one pair of subtelocentrics; c) Oedalechilus with one pair of telocentrics with a very small arm. The karyologic finding is discussed with regard to the position of the Mugilidae in systematic studies.
32 citations
TL;DR: The karyologic analysis of three strains of the callus cultures of Allium sativum L. var.
Abstract: SUMMARYThe karyologic analysis of three strains of the callus cultures of Allium sativum L. var. sativum derived from leaf tissues of three cultivars is presented. The explants were removed from virus-free plants and cultivated on the synthetic medium. A frequency of individual chromosomal types as related to the length of cultivation in vitro was studied in individual strains of the cultures.
32 citations
TL;DR: Ch Chromatin lenght in various taxa of Cucumis and the categories of chromosomes in each have been utilised critically in discussing the primitive and advanced nature of various species, which indicates twelve as the primitive base number from which seven has been derived.
Abstract: SUMMARYThe relationship between the base number seven and twelve, i.e., which is the prime number from which the other has been derived, has been discussed. The chromatin lenght in various taxa of Cucumis and the categories of chromosomes in each have been utilised critically in discussing the primitive and advanced nature of various species. The trend indicates twelve as the primitive base number from which seven has been derived. C. callosus (x = 7) appears to be primitive on these considerations. In the other group of species with x = 12 C. anguria and C. dipsaceus show primitive karyological features. Further C. hardwickii appears to be nearer to C. sativus than the later is to C. callosus. Thus chromosomal alterations, namely karyotypic variations appears to be main factor responsible for speciation.
27 citations
TL;DR: It is concluded that the basic number x = 9 which is so common in Astereae and Anthemideae is perhaps of ancient polyploid origin and may have been derived ultimately from x = 5 of the ancestral stock throughpolyploidy and aneuploidal reduction.
Abstract: Cytotaxonomic observations have been made on 71 Indian taxa of the tribes Astereae, Anthemideae, Heliantheae and Helenieae (family Compositae). Cytological races have been reported in 5 species. It...
27 citations
TL;DR: It is proposed that chromosome pairing may result from the fortuitous juxtaposition of homologues by the congressive adjustments of chromosome positions during mitotic metaphase alignment and that numerous elastic physical connections are formed between corresponding sites of homology.
Abstract: SUMMARYIt is proposed that chromosome pairing may result from the fortuitous juxtaposition of homologues by the congressive adjustments of chromosome positions during mitotic metaphase alignment. (Some unknown mechanism for stirring of chromosomes may exist in organisms with zygotic meiosis). During this juxtaposition it is suggested that numerous elastic physical connections are formed between corresponding sites of homologues and that these persist through later stages or even many cell cycles, often so stretched that little or no evidence of pairing can be found, until meiotic prophase. At this time these hypothetical elastic physical connections may function to bring the chromosomes they connect sufficiently close together for the formation of the synaptonemal complex.Photomicrographs of the premeiotic mitosis in maize illustrate peculiar features typical of this division and in support of the hypothesis outlined above.
22 citations
TL;DR: The West Malaysian taxon was compared with the taxa reported in India.
Abstract: SUMMARYThree males and two females of the West Malaysian house shrew, Suncus murinus (Linnaeus), collected from Malacca appeared to be monomorphic. All individuals had 2n=40 comprising 12 pairs acrocentric, 4 pairs meta-/submeta-centric and 3 pairs subacrocentric autosomes, and meta/submeta-centric X and submetacentric Y sex chromosomes. The autosome complement and the duplicate type X chromosome were similar to those with 2 n = 40 reported previously in West Malaysia. The Y chromosome, however, was larger and also differed in its morphology viz. submetacentric instead of metacentric. The West Malaysian taxon was compared with the taxa reported in India. Japan and South Vietnam, and the geographic variations discussed.
16 citations
TL;DR: Six more species of Indian Pill-millipedes investigated reveal a highest diploid chromosome number for the group and an XY sex-chromosome mechanism in the male and the sex-bivalent is the largest pair in the complement.
Abstract: SUMMARYThe chromosome studies in six more species of Indian Pill-millipedes have been made for the first time. The species investigated reveal a highest diploid chromosome number for the group (2n=30) and an XY sex-chromosome mechanism in the male. The sex-bivalent is the largest pair in the complement.
16 citations
TL;DR: It has been suggested that natural selection which is main cause of maintaining non-random association of inversions, is not acting against recombinant arrangements in D. ananassae and it is unexpected in the light of results from other species of Drosophila.
Abstract: SUMMARYThe chromosomal analysis of many natural populations and laboratory stocks of the cosmopolitan species Drosophila ananassae has shown that there is no evidence of non-random association of two independent inversions occurring in the opposite arms of the third chromosome. This conclusion is based on an abundance of repulsion combinations. In certain laboratory stocks, only parental combinations (coupling) were found. This is attributable to the suppression of recombination between heterozygous inversions as it has been evidenced by crossover studies. Thus it has been suggested that natural selection which is main cause of maintaining non-random association of inversions, is not acting against recombinant arrangements in D. ananassae and it is unexpected in the light of results from other species of Drosophila.
TL;DR: It is suggested that the endoplasmic reticulum traverses the plasmodesma, constituting the inner structure of Tillandsia usneoides L, which is useful better to understand the activity regulating the passage of substances from one cell to another.
Abstract: SUMMARYAn interpretation is reported on the ultrastructure of plasmodesmata that traverse in very large numbers the walls which separate the four central cells of the hair shield from the underlying dome-shaped cell in Tillandsia usneoides L. It is suggested that the endoplasmic reticulum traverses the plasmodesma, constituting the inner structure. This structure, owing to the sizes the reticulum should assume, would be granular (measures of the components are reported). This interpretation is useful better to understand the activity regulating the passage of substances from one cell to another.
TL;DR: Upon backcrossing to maize, a hybrid combining 20 Zea + 36 Tripsacum chromosomes gave rise to a cytologically and morphologically variable population that had the capacity of games to function sexually as well as apomictically.
Abstract: SUMMARYUpon backcrossing to maize, a hybrid combining 20 Zea + 36 Tripsacum chromosomes gave rise to a cytologically and morphologically variable population. Twenty-five different chromosome combinations, five of which were capable of apomixis, were obtained after three backcrosses to maize. The variation in chromosome combinations may be attributed to (1) unequal segregation during anaphase I due to the presence of univalents and/or multivalents (2) the presence or absence of cytokinesis during the second meiotic division and (3) the capacity of games to function sexually as well as apomictically. Essentially pure maize with 2n=20 was recovered via three chromosome lines. One of the recovered maize exhibited low chromosome pairing and may indicate that intergenomic exchange between maize and Tripsacum had taken place.
TL;DR: Pollen grains with variable chromosome numbers have been observed in two species of Cypripedium and four of Paphiopedilum and the implication of these in the evolution of new forms is discussed.
Abstract: Two species of Cypripedium and four of Paphiopedilum have been cytologically investigated. Polysomaty and aneusomaty has been noticed in C. cordigerum, a diploid species, in the root-tip squashes. ...
TL;DR: Karyotype constitution of three breeds of Bos taurus taurus (Charolais, Chianina and Jersey, and four ones coming from the Bos tarus indicus crosses) mean there will be a possibility of distinguishing some breeds of Bosnia taurusTaurus through the Y chromosome.
Abstract: SUMMARYKaryotype constitution of three breeds of Bos taurus taurus (Charolais, Chianina and Jersey), three breeds of Bos taurus indicus (Gyr, Guzerat and Red Shindi) and four ones coming from the Bos taurus taurus Bos taurus indicus crosses, were studied and on the basis of this preliminary data there will be a possibility of distinguishing some breeds of Bos taurus taurus through the Y chromosome.
TL;DR: Fertilization has been shown to be contributing to seed setting though chances of apomixis are not ruled out and high percentage of sterile grains in plants from seeds has been attributed to their homogeneity allowing undesirable combinations of the zygote to be fixed.
Abstract: SUMMARYA study of the floral characters, meiotic behaviour as influenced by temperature, pollen grain analysis, development of the embryo and seed setting has been carried out on plants grown from old bulbs and young seeds of tetraploid Allium tuberosum L.High polymorphism in flower character of plants grown from old bulbs as compared to those from seeds in the first generation, has been suggested as due to the accumulation of somatic variations through successive years.High percentage of sterile grains in plants from seeds has been attributed to their homogeneity allowing undesirable combinations of the zygote to be fixed. Such undesirable combinations are also reflected in pollen grains, where it has been shown that sixteen chromosomed gametes may contain deficiencies and duplication. In bulbs, the accumulation of variations provide with a choice for selection.Fertilization has been shown to be contributing to seed setting though chances of apomixis are not ruled out. Seed setting and seed viability are...
TL;DR: An attempt was made, by studying the kinetics of the production of multipolar anaphases in the meristematic population, to determine the sequence of events by which colchicine affects the mitotic spindle.
Abstract: A study was made of the effect of colchicine on the mitotic spindle in onion root tips.The influence of temperature and time of exposure of dividing cells to the drug on the formation of multipolar...
TL;DR: In Pedicularis and Melampyrum disturbed mitoses and formation of restitution nuclei are characteristic, in the remaining genera endomitoses (exact sense) regularly occur, and therefore in the Pedicularieae there exist two different types of the cellur plurinucleate tapetum.
Abstract: SUMMARYThe karyological events in the anther tapetum during the premeiotic and meiotic period of development have been studied in Pedicularis, Barista, Odontites, Euphrasia, Bel-lardia, Melampyrum, Tozzia, and Lathraea. The one-layered inner tapetum becomes bi- or plurinucleate already prior to the onset of meiosis, with the exception of Pedicularis where it remains uninucleate diploid during this period. The outer tapetum always persists in the uninucleate diploid level until meiosis starts. Chromosome augmentation during the meiotic period follows two different ways: in Pedicularis and Melampyrum disturbed mitoses and formation of restitution nuclei are characteristic, in the remaining genera endomitoses (exact sense) regularly occur. In Barista and Lathraea restricted to the outer tapetum additionally to the endomitoses always undisturbed acytokinetic mitoses during the early meiotic period take place. Therefore in the Pedicularieae there exist two different types of the cellur plurinucleate tapetum: a...
TL;DR: The epidermis nuclei showed, in almost all the ages, a 2C value, whilst the fat body nuclei were mostly in 4C; from these results it is inferred that the epidermal cells are in G1 and thefat body cells in G2, when they display their highest activity.
Abstract: SUMMARYCytophotometric analyses were done on nuclear DNA of epidermis, fat body and Malpighian tubes of S. gregaria hoppers of different ages within the 4th and 5th instars.The epidermis nuclei showed, in almost all the ages, a 2C value, whilst the fat body nuclei were mostly in 4C; from these results it is inferred that the epidermal cells are in G1 and the fat body cells in G2, when they display their highest activity.In the Malpighian tubes a wide range of DNA values were found, which are assumed to be related to differences in growth and differentiation of different segments composing each tube.
TL;DR: The chromosomal instability of I. chamaeiris s.l. Bertol.
Abstract: SUMMARYThe investigation of Iris chamaeiris Bertol. s.l. (Maugini and Bini Maleci 1973), is extended to other specimens from Morteto (Ponte a Moriano—Lucca).Following certain general observations, the karyotype of these plants is described in detail. Most of them show a normal karyotype, but two of them show an abnormal one. The two karyotypes observed in the specimens from Morteto are compared with each other and each of them is also compared with the previously studied karyotypes from M. Morello, M. Argentario and Quercianella-Le Forbici.The chromosomal instability of I. chamaeiris s.l. is revealed and justified both by the active vegetative reproduction and by the probable hybrid origin of these plants.
TL;DR: The chromosome number in 223 metaphases of the kidney of colchicine pretreated 6 males and 7 females of Heteropneustes fossilis has been determined and the chromosome formula was determined to be n=7m + 13sm + 8st.
Abstract: SUMMARYThe chromosome number in 223 metaphases of the kidney of colchicine pretreated 6 males and 7 females of Heteropneustes fossilis has been determined. The diploid number of 56 chromosomes was found in 90.67% metaphases in males and 81.75% in females. Some metaphases were aneuploid and polyploid in constitution in both the sexes.The karyotypes in both the sexes consisted of 7 pairs of metacentric, 13 pairs of submetacentric and 8 pairs of acrocentric chromosomes. The longest pair of metacentric chromosomes has been demarcated as the ‘marker pair’ while the rest were gradually seriated.The mean length in micra of the haploid set of 28 chromosomes ranged between 4.15 and 1.52 in male, 3.99 and 1.42 in female. On the basis of the centromeric index the chromosome formula has been determined to be n=7m + 13sm + 8st.The spermatogonial metaphase complements contained mostly 56 chromosomes. Very few were tetraploid and aneuploid in constitution. Metaphase I contained 28 stumpy rod-like bivalents. The sex chro...
TL;DR: Analysis of the degree of homology of the chromosomes confirmed that, in the derived polyploid lines, part of the genome is in a triploid condition (Oliveri et al. 1972) even if in some cases only parts of the chromosome are in aTriploids condition as a result of deletions.
Abstract: SUMMARYThe authors have examined the « banding pattern », revealed by the Seabright method (1972), of chromosomes of an aneuploid-diploid line (C-125) and of certain lines of various degrees of ploidy derived from it. It was found that the line C-125 has preserved a large proportion of normal chromosomes, similar to those of the species, some in a diploid and others in a haploid condition.Analysis of the degree of homology of the chromosomes confirmed that, in the derived polyploid lines, part of the genome is in a triploid condition (Oliveri et al. 1972) even if in some cases only parts of the chromosome are in a triploid condition as a result of deletions. This last type of chromosome rearrangement is the one that has had the greatest importance in the evolution of the karyogram of the induced polyploid lines. The results are discussed in relation to problems of « dosage compensation ».
TL;DR: The necessity for aeration is demonstrated by using a synchronous binucleate population, induced by 1-hour treatment of caffeine, and in the experiments at 15°C and 25°C the effects of non-aeration on the cell cycle were still more drastic.
Abstract: SUMMARYOnion root meristems are a frequently used material for the study of cell cycle and the effects of several treatments. For such works as many enviromental factors (light, temperature, aeration,…) as possible must be controlled.In this paper we studied the effect of aeration at two different temperatures, 15°C and 25°C. In the experiments carried out at each temperature and with aeration we obtained very similar mitotic indices (about 13%).In bulbs whose roots were grown into nonaerated water, but renewed every day, we obtained different results: at 15°C the mitotic index was 12.4% and at 25°C the mitotic idex was 9.7%.By using a synchronous binucleate population, induced by 1-hour treatment of caffeine, we demonstrated the necessity for aeration. In the experiments at 15°C, the B-Interphase is 10% longer in the nonaerated roots, and we also observed a desynchronization of the binucleate population. In the experiments at 25°C the effects of non-aeration on the cell cycle were still more drastic. The...
TL;DR: Tetra and octoploids were perfectly seed sterile despite good pollen fertility in tetraploids, and efforts to overcome ploidy barriers have been discussed.
Abstract: SUMMARYArtificially raised tetraploids in Tropaeolum majus enhanced its ornamental value. Octoploids, though had smaller flowers but umbrella shaped appearance of leaves make them quite charming. Ploidy barrier exists in the species. Tetra and octoploids were perfectly seed sterile despite good pollen fertility in tetraploids. Lack of dehiscence of anthers was noted in tetraploids but artificial pollination also failed to achieve seed setting. The pollen grain germinated normally on 4n stigma and also pollen tube travelled down through the stylar tissue. In rare cases fruit formation was initiated but after some growth they aborted and their study revealed total absence of developing embryos. Efforts to overcome ploidy barriers have been discussed.
TL;DR: A technique which differentially stains segments of the meiotic chromosomes of Cepaea nemoralis differentially for analysing variation in chiasma position in Cepcea is described.
Abstract: SUMMARYA technique which differentially stains segments of the meiotic chromosomes of Cepaea nemoralis is described. Slides of the ovotestis prepared by a heat-drying technique are incubated in a urea-buffer solution at 37°C for 10–20 minutes and then stained with giemsa. The usefulness of this technique for analysing variation in chiasma position in Cepcea is discussed.
TL;DR: A study has been made of the labelling pattern produced by tritiated actinomycin-D in various cell stages of spermatogenesis and spermiohistogenesis and in nurse cells of the testicle of Asellus aquaticus and the following results were obtained.
Abstract: SUMMARYA study has been made of the labelling pattern produced by tritiated actinomycin-D in various cell stages of spermatogenesis and spermiohistogenesis and in nurse cells of the testicle of Asellus aquaticus.Five series of experiments were carried out: the first two series in vivo: i.e. the actinomycin-D was injected into the living animal and the testicles were fixed 1) with 10% neural formalin, 2) with 45% acetic acid; the other three series in vitro: i.e. the3H-actino-mycin-D was supplied to the tissue already previously fixed with 3) 10% neural formalin or 4) 45% acetic acid or 5) 45% acetic acid followed by treatment with H2SO4 for 30' at 0°C.The following results were obtained: 1) actinomycin-D binds with the transcriptionally active chromatin; 2) the bindings of actinomycin-D to DNA is conditioned by the presence of histones.
TL;DR: The presence of between 5–16 abnormal meta and submetacentric chromosomes suggests a mechanism of centric fusion in canine neuroblastoma cultivated in vitro.
Abstract: SUMMARYThe chromosomic analysis of a canine neuroblastoma cultivated in vitro was carried out. The majority of the cells were hypodiploid, most frequendy having between 44–57 chromosomes. The presence of between 5–16 abnormal meta and submetacentric chromosomes suggests a mechanism of centric fusion.
TL;DR: The karyology of thaliaceans appears to be well differenciated from that of other tunicates and, although ascidians and thaliACEans are the most akin to each other, it is not possible to establish a meaningful probable relationship between their chromosomes.
Abstract: SUMMARYThe chromosomes of six species of thaliaceans have been examined. The haploid number 11 was determined for Pyrosoma atlanticum and Doliolum denticolatum; the haploid number 12 was found for Pegea confoederata, Salpa fusiformis, Thalia democratica; the haploid number 13 was found in Salpa maxima.Salpa fusiformis and Thalia democratica are strikingly akin with respect to both number and morphology of diakinetic chromosomes whereas the other species of Salpida all possess distinguishing peculiarities. Pegea confoederata takes a place apart among the thaliaceans by virtue of the minute dimension of its chromosomes.The karyology of thaliaceans appears to be well differenciated from that of other tunicates and, although ascidians and thaliaceans are the most akin to each other, it is not possible to establish a meaningful probable relationship between their chromosomes.
TL;DR: Dermatobia hominis karyotype was studied in 118 larvae and 115 laboratory raised pupae and found that « Brain » and gonad cells possess twelve chromosomes, the sexual being the smallest pair.
Abstract: SUMMARYDermatobia hominis karyotype was studied in 118 larvae and 115 laboratory raised pupae. « Brain » and gonad cells possess twelve chromosomes, the sexual being the smallest pair. The Y chromosome is a little shorter than the X. Salivary glands, Malpighian tabules, intestines and fat cells possess six isolated polytene chromosomes, which do not form a chromocenter.
TL;DR: Structures, satellite association, autoradiography and appearance of the marker chromosome were employed to show that the secondary constriction of the so-called « satellited 17 » was not of the satellite stalk type but instead identical to Schmid'S type 4 « heterochromatic chromosome section ».
Abstract: SUMMARYA 17p marker or variant chromosome 17 was observed in nine of twenty-four members of a family. Structure, satellite association, autoradiography and appearance of the marker chromosome were employed to show that the secondary constriction of the so-called « satellited 17 » was not of the satellite stalk type but instead identical to Schmid'S type 4 « heterochromatic chromosome section ».