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Showing papers on "Karyotype published in 1968"



Journal ArticleDOI
TL;DR: The chromosome morphology of about 50 species of Bovoidea indicates an almost exclusive use of the Robertsonian fusion mechanism of karyotype evolution in this group of species which represent 30 different genera.
Abstract: The chromosome morphology of about 50 species of Bovoidea has now been investigated. Although the diploid number varies from 30 to 60 among these species, the fundamental number (NF) varies only (with but three exceptions) from 58 to 62. This indicates an almost exclusive use of the Robertsonian fusion mechanism of karyotype evolution in this group of species which represent 30 different genera. All known cytogenetic information on the Bovoidea has been summarized and a complete bibliography is presented for each species. Karyotypes and data on a number of previously unstudied species are presented.

187 citations


Journal ArticleDOI
TL;DR: According to this study, diploid members of Ostariophysi underwent extensive chromosomal rearrangements as well as steady increases in DNA contents by regional duplication of chromosomal segments.
Abstract: Our previous study on the order Ostariophysi was limited to members of the family Cyprinidae, suborder Cyprinidea. It was shown that the carp and the goldfish with 104 chromosomes and a DNA value of 50% that of mammals are tetraploid, as the diploid species of this family has 50–52 chromosomes and a 25% DNA value. In order to obtain some idea as to how many changes in DNA values and chromosome complements have occurred among diploid members of Ostariophysi, the study was expanded to cover members of the families Cobitidae and Characinidae of the suborder Cyprinidea as well as members of the families Ictarulidae and Loricaridae of the suborder Siluroidea. Diploid chromosome numbers varied from 50 to 98 and DNA values from 27–51% that of mammals. Apparently, diploid members of Ostariophysi underwent extensive chromosomal rearrangements as well as steady increases in DNA contents by regional duplication of chromosomal segments.

93 citations


Journal ArticleDOI
TL;DR: Variation of number and shape of chromosomes in Hylidae and Leptodactylidae suggests that the mechanism of centric fusion played a role in karyotype differentiation, which could not be evidenced in the Bufonidae.
Abstract: SUMMARYKaryotypes of eighteen species of Anura from Brazil have been studied (Bufonidae, Leptodactylidae, Hylidae, and Pseudidae).Leptodactylidae show a variation of chromosomal number from 2 n = 18 to 2 n = 26. Hylidae presents also variations from 2 n = 22 to 2 n = 30. These differences were correlated to morphological alterations of the karyotypes. Bufonidae, however, disclosed a great chromosomal uniformity, showing the same diploid number, 2 n = 22. In Pseudidae one species showed 2 n = 24 chromosomes. Pseudopaludicola falcipes has 2 n = 18. It seems to be the lowest chromosome number described in Anura.Variation of number and shape of chromosomes in Hylidae and Leptodactylidae suggests that the mechanism of centric fusion played a role in karyotype differentiation. This mechanism could not be evidenced in the Bufonidae.Centric fusion however is not the only mechanism in amphibian evolution. Indeed, the occurence of natural bisexual polyploid species in the family Ceratophrydidae (BECAK M. L. et al. ...

77 citations


Journal Article
TL;DR: Cytogenetic studies were carried out on bone marrow and spleen cells of 40 rats of Long-Evans strain with primary leukemia induced by pulse doses of 7,12-dimethylbenz(α)anthracene, finding consistent chromosomal abnormalities, believed to be the first so far reported for an experimental leukemia.
Abstract: Summary Cytogenetic studies were carried out on bone marrow and spleen cells of 40 rats of Long-Evans strain with primary leukemia induced by pulse doses of 7,12-dimethylbenz(α)anthracene. Chromosomal abnormalities were detected in 26 cases, of which 21 were characterized by abnormal constitution of two specific chromosomes, C-1 (longest telocentric chromosome), and A-6 (6th group of metacentrics). Most of the leukemias represented the hepatic type. Sixteen rats had modal or nonmodal cells with trisomic C-1 chromosome, 5 among them containing stem-line cells with both C-1 and A-6 trisomy. Unassociated A-6 trisomy was found in modal cells of 4 other leukemias, one of them chloroleukemia, and in the stemline of one of the trisomic C-1 positive leukemia. Modal hypodiploid cells of 41 chromosomes with A-6 monosomy was also detected in one case. These consistent chromosomal abnormalities appear to be the first so far reported for an experimental leukemia. The presence of a marker chromosome, metacentric or submetacentric, was recognized in cells of 4 other leukemias. The remaining one had tetraploid cells. No chromosomal anomaly could be detected in 12 other hepatic type leukemias, one lymphoblastic and another thymic. The possible interpretation for the presence of consistent chromosomal abnormalities in the given type of leukemia is discussed.

62 citations


Journal ArticleDOI
TL;DR: The XX component apparendy had little modifying effect on short stature in this series but did have some effect on gonadal development, whereas mental retardation was seen most frequently in patients with an isochromosome X component.

61 citations


Journal ArticleDOI
TL;DR: Chromosome material of mitotic bone marrow cells from 59 individuals representing 16 populations of Thomomys talpoides was studied and karyotype differences coincided with populations that co-exist without interbreeding.
Abstract: Chromosome material of mitotic bone marrow cells from 59 individuals representing 16 populations of Thomomys talpoides was studied. These populations were found in southern Wyoming, Colorado, northern New Mexico and northern Arizona. A limited amount of intrapopulation variation in form but not number of chromosomes was found. Bight distinct karyotypes were observed. These can be characterized by the following diploid numbers and fundamental numbers of chromosomes: 40(70), 44(70), 56(70), 60(70), 58(76), 48(78), 56(78) and 46(82). Among the six populations with 48 chromosomes some interpopulation variation was noted. In several instances karyotype differences coincided with populations that co-exist without interbreeding.

59 citations


Journal ArticleDOI
TL;DR: The chromosome karyotypes are described and scale diagrams prepared of 35 species representing 8 genera of the “cycad” families Stangeriaceae and Zamiaceae and it is suggested that telocentric chromosomes may be of ancient origin in the cycads and that there may have been a progression from Telocentric to mesocentric karyotype.
Abstract: The chromosome karyotypes are described and scale diagrams prepared of 35 species representing 8 genera of the “cycad” families Stangeriaceae and Zamiaceae. The karyotype patterns, chromosome types and characteristics of the nucleolar organisers and heterochromatin are discussed in relation to their evolution in this ancient group of plants. A possible path of chromosome evolution is suggested by the concurrence in some genera of terminal heterochromatic knobs on chromosome arms and a single pair of telocentric homologues which in the remaining genera are replaced by complex partially heterochromatic nucleolar-organising chromosomes. — It is suggested that telocentric chromosomes may be of ancient origin in the cycads and that there may have been a progression from telocentric to mesocentric karyotypes. The paucity of genera today and the taxonomic isolation of the cycads from the remainder of the present-day flora renders impossible the corroboration of this theory by direct cytological comparisons with other groups.

58 citations


Journal ArticleDOI
TL;DR: In this paper, the association pattern was studied in 1182 mitoses of 21 patients with trisomy 13 and in a control group, and 173 trisomic mitoses were compared with the same number of diploid mitoses in a case of mosaicism.
Abstract: The association pattern was studied in 1182 mitoses of 21 patients with trisomy 13 and in a control group. In addition, 173 trisomic mitoses were compared with the same number of diploid mitoses in a case of mosaicism.

58 citations


Journal ArticleDOI
TL;DR: Karyological examination of 26 species of bats from the family Phyllostomidae revealed two Y chromosomes (XY1Y2) in six species involving three genera, and all females are of the XX.
Abstract: Karyological examination of 26 species of bats from the family Phyllostomidae revealed two Y chromosomes (XY1Y2) in six species involving three genera All females are of the XX

56 citations


Journal ArticleDOI
TL;DR: Relationships between the A and B genomes of the tetraploid Avena species and between these and the AS genome of the diploid A. hirtula and strigosa were studied in triploid (AS) species.
Abstract: Relationships between the A and B genomes of the tetraploid Avena species (A. magna excluded) and between these and the AS genome of the diploid A. hirtula and strigosa were studied in triploid (ASAB) and tetraploid (ASASAB) hybrids. Chromosome affinities were estimated on the basis of the karyotypes and the pairing behaviour of the chromosomes.The main findings were:1. The AS karyotype of the 2x and the A of the 4x species were identical and the chromosomes of the genomes A and B were similar. No difference was noticeable in the karyotypes of the 4x species studied. A nucleolar chromosome appeared from the B set in the 3x hybrids. It was concluded that the B genome is probably a modified form of A.2. All the chromosomes were capable of pairing in the ASAB and ASASAB hybrids. High degree of homology between the AS and A genomes was indicated by the high frequency of ring bivalents and ring-rod trivalents. The synaptic success of the B genome chromosomes (up to six trivalents) was interpreted as homoeology...

Journal ArticleDOI
TL;DR: The unique structural organization of the terminal chromosome regions, which is never observed at any other location of the genome supports the idea that they are morphological manifestations of the postulated telomeres.
Abstract: The submicroscopic organization of terminal chromosome regions of Drosophila hydei polytene chromosomes is described. A compact region composed of tightly packed fibrils of 100 to 125 A diameter embedded in an amorphous material is located at each of the chromosome ends of the 5 long chromosome arms. From this compact region, sometimes containing cavities, fibrils extend onto the nearest normal band region. The diameter of the extending fibrils is 100–125 A, 200–250 A or 400 A. Pronase digestion of fixed and squashed chromosomes reduced the electron density of the amorphous matrix in the compact regions but failed to affect the diameter of the fibrils. The extending fibrils, however, showed a decrease in diameter after pronase digestion. The most frequently observed diameter values were 100–125 A. — The volume of the terminal structures, including the compact region as well as the extending fibrils, is characteristically different for the various elements of the karyotype. Chromosome 2 displays the largest terminal structure, whereas chromosome 4 only occasionally shows the presence of compact regions. — End to end association of the long chromosome arms involves the fusion of the compact terminal structures. The non-random distribution of end to end association seems to be correlated with the volume of the terminal structures. Chromosome 2 which contains the largest compact terminal region is more frequently involved in end to end associations than any other chromosome arm. — The terminal regions show replication of DNA. They belong to the group of regions which display a discontinuous labeling pattern along the chromosomes, representing a late phase of the replication cycle. — The unique structural organization of the terminal chromosome regions, which is never observed at any other location of the genome supports the idea that they are morphological manifestations of the postulated telomeres.

Journal ArticleDOI
B. Chiarelli1
TL;DR: The hypothesis is suggested that the variation in the number of the chromosomes of the genus Cercopithecus is originated by the reduplication of single chromosomes.
Abstract: The chromosomes of 27 animals belonging to 11 species of the genus Cercopithecus were studied.The number of chromosomes for the different species studied, varies from a minimum of 2n=54 to a max. of 2n=72. In individuals belonging to the same species, a different number of chromosomes has been noted.The morphological analysis did not reveal any clear relation between the total number of chromosomes and the number of acrocentric chromosomes.The total length of the caryotype measured on 20 metaphase plates, increases with the increase of the number of the chromosomes.On the basis of these two data I suggest the hypothesis that the variation in the number of the chromosomes of the genus Cercopithecus is originated by the reduplication of single chromosomes.

Journal ArticleDOI
TL;DR: During the course of propagation the long-surviving hybrid clones show progressive loss of telocentric chromosomes associated in at least one case with loss of mouse enzyme.
Abstract: Somatic hybrids of drug-resistant mutant hamster and mouse cell lines have been isolated and propagated in long-term culture and have been studied in respect to karyotype and three enzymes. During the course of propagation the long-surviving hybrid clones show progressive loss of telocentric chromosomes associated in at least one case with loss of mouse enzyme. Hybrid clones showed hybrid molecules for malate dehydrogenase (MDH), lactate dehydrogenase (LDH), and 6-phosphogluconate dehydrogenase (6PGD) made up by recombination of parental subunits.

Journal ArticleDOI
TL;DR: The ability of acrocentric chromosomes to form associations was found to be changed with the age of the individual and the ability of nuclei of the primary culture of embryonic fibroblasts and in the culture of peripheral blood leucocytes is weakest.

Journal ArticleDOI
TL;DR: A new karyotype of Vicia faba with all 12 chromosomes easily interdistinguishable has been used to study the interchromodomal distribution of chromatid aberrations induced by ethyl alcohol and maleic hydrazied.
Abstract: A new karyotype of Vicia faba with all 12 chromosomes easily interdistinguishable has been used to study the interchromodomal distribution of chromatid aberrations induced by ethyl alcohol and maleic hydrazied. The distribution patterns of intra- and interchanges induced by ethyl alcohol and maleic hydrazide are non-random and agent-specifc. These patterns are neither changed by pretreatment with EDTA which sensitizes the cells to both agents nor by scoring aberrations after different recovery times. The preferential participation in aberrations of individual chromosome segments which is responsible for the non-random and agent-specific distribution of aberrations between chromosomes is a transposable feature of the segments in question. The transfer of such a segment to another position within the karyotype is accompanied by a corresponding shift in aberration distribution. In addition to ethyl alcohol- and maleic hydrazide-specific patterns of distribution of chromatid aberrations, particular chromosomes and chromosome segments have been found to be involved with differing frequencies in particular types of aberration after both ethyl alcohol and maleic hydrazide treatment. This is understood as being due to factors which, secondarily and differentially, influence the type of interaction of lesions preferentially induced in the relevant chromosomes and chromosome segments.

Journal ArticleDOI
TL;DR: The three chromosomes of Poa annua that could be identified with certainty existed in homologous pairs, indicating that the species could have originated from Poa exilis or Poa supina and one other hitherto unidentified species.
Abstract: From a karyotype analysis of Poa annua (2n = 28) two large chromosomes, I and II, and one small chromosome, XIV, as well as three chromosome groups containing two, four and five chromosomes have be...

Journal ArticleDOI
TL;DR: Chromosome rearrangements that have been described in malignant processes are structural and numerical, and the most remarkable instance is the rearrangement that produces marker chromosomes.
Abstract: Chromosome rearrangements that have been described in malignant processes are structural and numerical. Structural rearrangements produce marker chromosomes. The most remarkable instance i...

Journal ArticleDOI
TL;DR: Cebocephaly, one of the more severe forms of this type of malformations, characterized by a single nostril and monoventricular arrhinencephaly has also been observed with a normal karyotype (De Myer, 1964).
Abstract: Bilateral harelip, cleft palate, and some form of arrhinencephalic malformation of the brain are among the more common striking features of trisomy 13-15. These cranio-facial malformations are attributable to a defect of the prechordal mesoderm, and the most extreme form consists of cyclopia associated with a monoventricular brain. The facial and cerebral malformations do not necessarily correspond to each other in severity. For example, in a recent analysis of seven cases of trisomy 13-15, one child (Case 4) showed no cleft of the lip or palate but had an extreme form of monoventricular arrhinencephaly (Snodgrass, Butler, France, Crome, and Russell, 1966). Arrhinencephaly, with various degrees of involvement of the face and brain, is by no means confined to children with an abnormal karyotype. Landau, Barry, and Koch (1963) described severe cleft lip and palate associated with monoventricular arrhinencephaly in an infant with normal chromosomes. Cebocephaly, one of the more severe forms of this type of malformations, characterized by a single nostril and monoventricular arrhinencephaly has also been observed with a normal karyotype (De Myer, 1964). It is probable that such cases are reported less frequently than those with chromosomal abnormalities. N. E. France (personal communication, 1966) found that 4 out of 12 children with various types of arrhinencephaly had normal chromosomes; 6 showed trisomy 13-15, one trisomy 17-18, and one had a deficiency of part of the short arm of chromosome 5. De Myer, Zeman, and Palmer (1963) reported 2 sibs with median harelip, cleft palate, and monoventricular arrhinencephaly; the chromosomes of

Journal ArticleDOI
TL;DR: Images courtesy of AFP, EPA, Getty Images and Reuters.
Abstract: ImagesFig. 4Fig. 5Fig. 6Fig. 8Fig. 9Fig. 10Fig. 1Fig. 2Fig. 7Fig. 3


Journal ArticleDOI
TL;DR: L'esame condotto dall'Autore sul cariotipo di 7 Microchirotteri (3 Rinolofidi e 4 Vespertilionidi) fa ritenere che nell'evoluzione del cariotIPo di questo sottordine sia implicato il fenomeno robertsoniano di fusione centrica.
Abstract: L'esame condotto dall'Autore sul cariotipo di 7 Microchirotteri (3 Rinolofidi e 4 Vespertilionidi) fa ritenere che nell'evoluzione del cariotipo di questo sottordine sia implicato il fenomeno robertsoniano di fusione centrica.

Journal ArticleDOI
TL;DR: The chromosomes of the reindeer (2n = 70) were studied with special reference to the chronology of DNA replication of the sex chromosomes.
Abstract: The chromosomes of the reindeer (2n = 70) were studied with special reference to the chronology of DNA replication of the sex chromosomes. The X chromosome was metacentric and nearly of the duplicate

Journal ArticleDOI
29 Jun 1968-BMJ
TL;DR: The marked reduction in tolerance was found principally in patients in whom the original investigations had shown obviously diabetic glucose and glucose-cortisone tolerance, but it was not found only in the patients who had the longest duration of treatment.
Abstract: improvement in the results of the glucose tolerance test in 14 out of 15 patients (93%). There was a reversible reduction of tolerance in only one patient. During long-term treatment with chlorthalidone in therapeutic doses the glucose tolerance was found to be unchanged in 10 out of the 16 patients (55%). In three patients there was only slightly reduced tolerance, while in the remaining three there was severely reduced tolerance, which on follow-up was found to be irreversible in two cases and reversible in the third. The marked reduction in tolerance was found principally in patients in whom the original investigations had shown obviously diabetic glucose and glucose-cortisone tolerance, but it was not found only in the patients who had the longest duration of treatment. Though the two groups of patients were not identical in all respects, it must be emphasized that 12 of them were treated with the two diuretics alternately. Where glucose tolerance was concerned the two groups were comparable. In order to avoid deterioration in latent diabetes mellitus it would seem practicable to determine the two-hour value in the glucose tolerance test. Increased values in this test indicate a necessity for caution in the use of diuretics, particularly chlorthalidone.

Journal ArticleDOI
TL;DR: Karyotype studies revealed 47 chromosomes with the extra chomosome closely resembling a normal A3 chromosome in a malignant ovarian teratoma with many sex chromatin-positive cells.

Journal ArticleDOI
TL;DR: The study of the karyotype in Spalax microphthalmus has proved that this species has a constant number of chromosomes (2n = 62), no matter of the animals' origin.
Abstract: SUMMARYThe authors have studied the karyotype of the Spalax leucodon species living in Romania, and they have found that on each side of the Carpathian mountains (North and South) the animals have a different number of chromosomes, i.e. 2n = 56 and 2n = 50. This considerable variation in the number of chromosomes may be due to a Robertsonian process of karyotype evolution which is favoured by the lack of migration possibilities.The study of the karyotype in Spalax microphthalmus has proved that this species has a constant number of chromosomes (2n = 62), no matter of the animals' origin.

Journal ArticleDOI
TL;DR: A new deletion involving slightly more than half of one arm of chromosome No. 1 is reported, identified as the arm which terminates DNA replication early in the synthetic period.
Abstract: Until recently, the only congenital condition that was known to be due to an actual loss of chromosome material was XO Turner's syndrome. No case of complete monosomy for an autosome has as yet been reported. However, it is now well established that partial deletion of an autosome is compatible with life. The deletion most frequently encountered involves the short arm of chromosome 5 (Lejeune et al., 1963), and the deletion which is probably next in frequency involves the short arm of chromosome 18 (de Grouchy et al., 1963). Partial monosomy for the long arm of chromosome 18 (de Grouchy et al., 1964), the short arm of chromosome 4 (Wolf et al., 1965), or the long arm of a G group chromosome (Lejeune et al., 1964) have also been reported repeatedly. Isolated case reports of deletions have involved the terminal segment of one arm of chromosome 3 (Patau, Opitz, and Dewey, 1964); part of the long arm of a D chromosome (Lele, Penrose, and Stallard, 1963); and the terminal segment of the long arm of chromosome 4 (Ockey et al., 1967). The purpose of the present paper is to report a new deletion involving slightly more than half of one arm of chromosome No. 1. By means of autoradiography, the deleted arm was identified as the arm which terminates DNA replication early in the synthetic period.

Journal ArticleDOI
TL;DR: A psychiatric-cytogenetic investigation of a 67-year-old woman with a chromosome mosaic of 45/46/47 chromosomes and sex chromosomes XO/xx/XXX is part of a more comprehensive study of intelligence, personality and mental disorders in patients with different chromosome abnormalities.
Abstract: The present study with a psychiatric-cytogenetic investigation of a 67-yearold woman with a chromosome mosaic of 45/46/47 chromosomes and sex chromosomes XO/xx/XXX is part of a more comprehensive study of intelligence, personality and mental disorders in patients with different chromosome abnormalities. Such studies may add to our knowledge of the genetic influence of specific chromosomes on personality, intelligence and mental disorders.

Journal ArticleDOI
M. Fraccaro1, Anna Mannini1, Luciano Tiepolo1, Gerli M1, C. Zara1 
TL;DR: The chromosomal finding and the histological appearance of the tumour agree in indicating that this case illustrates the cytogenetic basis for the beginning of an evolution towards malignancy.