Showing papers in "Cytogenetic and Genome Research in 1970"
TL;DR: Cytogenetic studies were made in dark-colored wild mice, previously described as M .
Abstract: Cytogenetic studies were made in dark-colored wild mice, previously described as M . poschiavinus Fatio, 1869. These mice are found only at a single locality, a Sw
84 citations
TL;DR: The somatic karyotypes of the 21 surviving species of the order Crocodilia are presented and the population surveyed totals 71 animals, with representatives of both sexes in 13 species.
Abstract: The somatic karyotypes of the 21 surviving species of the order Crocodilia are presented. The population surveyed totals 71 animals, with representatives of both sexes in 13 species. No karyotypic dif
80 citations
TL;DR: Tetraploid and octoploid species were described in amphibians of the family Ceratophrydidae (Procoela) and resulted apparently by duplication of ancestral genome.
Abstract: Polyploid species were described in amphibians of the family Ceratophrydidae (Procoela). Tetraploid (4N = 44) and octoploid (8N = 104) karyotypes resulted apparently by duplication of ancestral genome
75 citations
TL;DR: The results emphasize the importance of the heterozygous state, and particularly structural heterozygosity within a Robertsonian system of karyotypic variation, in inducing meiotic nondisjunction.
Abstract: Nondisjunction in the first meiotic division was evaluated by the frequency of aneuploid metaphase II (M II) figures in secondary spermatocytes of Mus musculus (N = 40; FN = 40), M. poschiaυinus (N = 26; FN = 40) and M. musculus × M. poschiavinus F1-hybrids (N = 33; FN = 40), whose karyotypes are related by Robertsonian-type centric fusions. Regular anaphase I disjunction prevailed in M. musculus and M. poschiavinus, where 92.8% and 94.0% of the M II figures examined had a complete haploid chromosome complement. In the F1-hybrids, however, less than one half of the M II figures examined were euploid (FN/2 = 20), whereas the frequency of hypomodal (FN/2 = 15 to 19; 31.2%) and hypermodal (FN/2 = 21 to 25; 24.2%) was high. These results emphasize the importance of the heterozygous state, and particularly structural heterozygosity within a Robertsonian system of karyotypic variation, in inducing meiotic nondisjunction. From the standpoint of methodology, M. musculus × M. poschiavinus hybrids of different generations should make possible stepwise analysis of the involvement of specific chromosomes in meiotic nondisjunction.
73 citations
TL;DR: Somatic chromosomes obtained from corneal squash preparations of nine species representing four genera of the anuran family Leptodactylidae were analyzed and compared.
Abstract: Somatic chromosomes obtained from corneal squash preparations of nine species representing four genera of the anuran family Leptodactylidae were analyzed and compared. Batrachyla leptopus, Cr
66 citations
TL;DR: The five North American species of the stickleback family Gasterosteidae were studied karyologically and one diploid-count groups; one with 46 includes Λpeltes quadracus.
Abstract: The five North American species of the stickleback family Gasterosteidae were studied karyologically. They constitute two diploid-count groups; one with 46 includes Λpeltes quadracus
60 citations
TL;DR: The proposal that the quadripartite centromere of the metacentric chromosomes has resulted from the fusion of two telocentric chromosomes with bipartite centromeres is interpreted.
Abstract: Whole-mount electron microscopy of metaphase mouse L-cells showed that in many cases the region of the centromere was located at one extreme end of the chromosome with no evidence for short arms of any significant size. In such telocentric chromosomes there was only a single area of chromatid association. By contrast, the region of the centromere in mouse metacentric chromosomes was much longer. When well dispersed, it was seen to consist of two distinct areas of chromatid association, each of which was comparable in length to that of the telocentric chromosomes. In the region between these two areas there was a decrease in the density of the chromatin fibers. A similar quadripartite morphology was seen in human, Chinese hamster, and sheep metacentric chromosomes. These findings are most simply interpreted by the proposal that the quadripartite centromere of the metacentric chromosomes has resulted from the fusion of two telocentric chromosomes with bipartite centromeres.
58 citations
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TL;DR: A triploid male infant, born after 39 weeks gestation, suffered from severe physical retardation, syndactyly, microphthalmia with coloboma, macroglossia, hypospadias, and a small number of other malformations.
Abstract: A triploid male infant, born after 39 weeks gestation, is described. Malformations included severe physical retardation, syndactyly, microphthalmia with coloboma, macroglossia, hypospadias, a small pe
58 citations
TL;DR: Meiotic and histological studies have been carried out on testicular biopsies from an azoospermic human male who exhibited normal secondary sex characteristics and a failure in the formation of chiasmata.
Abstract: Meiotic and histological studies have been carried out on testicular biopsies from an azoospermic human male who exhibited normal secondary sex characteristics. A failure in the formation of chiasmata
54 citations
TL;DR: In the course of examining about 5000 mouse oocytes maturing in vitro, three types of errors of first polar body formation, presumably spontaneous in origin, were observed.
Abstract: In the course of examining about 5000 mouse oocytes maturing in vitro, three types of errors of first polar body formation, presumably spontaneous in origin, were observed: (1) twen
49 citations
TL;DR: A sterile male German shorthair pointer with testicular hypoplasia and a ventricular septal defect was found to have a 79, XXY chromosome constitution in peripheral-blood leukocytes, bone marrow and bone marrow.
Abstract: A sterile male German shorthair pointer with testicular hypoplasia and a ventricular septal defect was found to have a 79, XXY chromosome constitution in peripheral-blood leukocytes, bone marrow and f
TL;DR: Satellite association (SA) in lymphocytes obtained from women was found in 89.9% of cells after 48 h in culture and in 66.1% in culture after 96 h.
Abstract: Satellite association (SA) in lymphocytes obtained from women was found in 89.9% of cells after 48 h in culture and in 66.1% of cells after 96 h. After 48 h, 33.7% of acrocentrics participate in SA, w
TL;DR: Two additional genera, Ametrida and Enchisthenes, and another species of Λrtibeus were found to have an XX/XYjY2 sex-chromosome syst.
Abstract: Two additional genera, Ametrida and Enchisthenes, and another species of Λrtibeus were found to have an XX/XYjY2 sex-chromosome syst
TL;DR: The late-replicating X of the mouse can be clearly identified in a large proportion of metaphase spreads as an unlabelled chromosome when labelling of cells is done early in the S period.
Abstract: The late-replicating X of the mouse can be clearly identified in a large proportion of metaphase spreads as an unlabelled chromosome when labelling of cells is done early in the S period. The Y chromosome follows this same pattern. Studies on Cattanach’s translocation are also reported, and it has been shown that the Xt can be distinguished from the normal X in early labelled material.
TL;DR: C-metaphase karyotypes from bone-marrow cells from 117 individuals representing 24 populations of the pocket gopher, Thomomys bottae, suggest interfertility between adjacent populations despite degrees of karyotypic disparity.
Abstract: C-metaphase karyotypes from bone-marrow cells from 117 individuals representing 24 populations of the pocket gopher, Thomomys bottae (Eydoux and Gervais), were studied. The geographic range of the populations sampled was California, Arizona, New Mexico and the Mexican states of Sonora and Sinaloa. No evidence of intrapopulation variation was recorded, but extensive inter-population variation in chromosome complement was observed. All individuals, excepting one, had a diploid number of 76, so that variation rested in the relative numbers of each morphological type of chromosome in the respective complements. Existing evidence suggests interfertility between adjacent populations despite degrees of karyotypic disparity.
TL;DR: Chromosomal analyses of several tissues of a bovine true hermaphrodite revealed a diploid XX/triploids XXY chimerism, believed to be the first report of an established triploid cell line in the world.
Abstract: Chromosomal analyses of several tissues of a bovine true hermaphrodite revealed a diploid XX/triploid XXY chimerism. This is believed to be the first report of an established triploid cell line in <
TL;DR: Somatic interphase nuclei of different tissues of heterogametic females of various species of snakes with a differentiated W chromosome possess a distinct, darkly stained chromocenter comparable to that of a venomous snake.
Abstract: Somatic interphase nuclei of different tissues of heterogametic females of various species of snakes with a differentiated W chromosome possess a distinct, darkly stained chromocenter comparable to th
TL;DR: The chromosomes of two phenotypically normal individuals of a family with a complex chromosome rearrangement were studied, and the apparently balanced karyotypes were interpreted as the result of reciprocal translocations between a B-, a C- and a D-group chromosome.
Abstract: The chromosomes of two phenotypically normal individuals of a family with a complex chromosome rearrangement were studied. Karyotype analysis and measurements of certain chromosomes showed three abnormal chromosomes, and the apparently balanced karyotypes were interpreted as the result of reciprocal translocations between a B-, a C- and a D-group chromosome. The B- and D-group chromosomes involved were identified as a No. 5 and a No. 13 by means of autoradiography and the C-group chromosome as a No. 9 on morphological grounds.
TL;DR: A pericentric inversion of a group D chromosome was found in a phenotypically normal nine-year-old boy in the course of a chromosome survey of children with behavioral disorders.
Abstract: A pericentric inversion of a group D chromosome was found in a phenotypically normal nine-year-old boy in the course of a chromosome survey of children with behavioral disorders. Family studies demons
TL;DR: Karyotypes of six members of a family in three generations consistently exhibited an additional minute centric chromosome, except for the mentally retarded propositus, which is typical of the remainder of the family.
Abstract: Karyotypes of six members of a family in three generations consistently exhibited an additional minute centric chromosome. Except for the mentally retarded propositus, the remainder of the family prov
TL;DR: For the first time a case of X-trisomy (XXX-gonosome aberration) in a Fleckvieh-heifer is reported and Cytogenetic examination of leukocytes and tissue cultures from the skin of this animal gave in 100%
Abstract: For the first time a case of X-trisomy (XXX-gonosome aberration) in a Fleckvieh-heifer is reported. Cytogenetic examination of leukocytes and tissue cultures from the skin of this animal gave in 100%
TL;DR: Evidence for genetic control of meiotic nondisjunction was not found in a religious isolate of Amish in northern Indiana, and mean inbreeding coefficients for the parents, grandparents, and great-grandparents were not significantly different between the two groups.
Abstract: Evidence for genetic control of meiotic nondisjunction was not found in a religious isolate of Amish in northern Indiana. Sixteen mongols were ascertained, and each had 47 chromosomes without evidence of mosaicism. Through the use of detailed family records, pedigrees were assembled for the propositi. The 16 comparison sibships were matched for maternal age and sibship size and selected at random from the same population. Mean inbreeding coefficients for the parents, grandparents, and great-grandparents were not significantly different between the two groups.
TL;DR: Comparison between the standard maps of the Triturus vulgaris meridionaiis lampbrush chromosomes and the lampbrush karyotype of an adult female belonging to the same subspeci is compared.
Abstract: Comparison between the standard maps of the Triturus vulgaris meridionaiis lampbrush chromosomes and the lampbrush karyotype of an adult female (♀-IX) belonging to the same subspeci
TL;DR: Half-chromatids have often been observed by light microscopy and similar structures were looked for by electron microscopy of whole-mount preparations of mitotic cells from seven different species of mam.
Abstract: Half-chromatids have often been observed by light microscopy. Similar structures were looked for by electron microscopy of whole-mount preparations of mitotic cells from seven different species of mam
TL;DR: A malformed infant and her phenotypically normal relatives were studied cytogenetically and Mosaicism consisting of normal cells and cells carrying an abnormally long chromosome 16 was detected in member.
Abstract: A malformed infant and her phenotypically normal relatives were studied cytogenetically. Mosaicism consisting of normal cells and cells carrying an abnormally long chromosome 16 was detected in member
TL;DR: A computer system to both measure and classify human chromosomes with good accuracy compared to manual methods is described and applications for the system may depend on cytogeneticists exploiting its advantages and avoiding the drawbacks described.
Abstract: A computer system to both measure and classify human chromosomes with good accuracy compared to manual methods is described. Using a 35-mm photomicrographic negative, the system, while measuring the chromosomes automatically, requires a human operator’s interaction for about 15% of the chromosomes. Results for an initial 45 spreads are given. Using the interactively measured arm lengths and arm areas, the system classified over 99% of the chromosomes correctly into 10 classes without any assistance; two chromosomes, or 0.1% of the initial sample, were misclassified (from group D to E). For the remaining 1%, interaction after classification was requested by the computer, and, with the information available to the operator, a correct classification can be made in these cases by him. The system uses a computer-controlled flying spot scanner connected to a medium-size general purpose computer, an IBM 360 Series, Model 30, and takes 25 min per spread. An annual capacity of 7500 analyzed spreads will be available in 1971 after installation of an RCA Spectra 70/46, operating under a multi-programmed system, in October 1970. Applications for the system may depend on cytogeneticists exploiting its advantages and avoiding the drawbacks described.
TL;DR: Replication patterns of the duplicate-type sex chromosomes have been studied in bone-marrow cells in vivo and fetal cells in vitro of the Indian house shrew.
Abstract: Replication patterns of the duplicate-type sex chromosomes have been studied in bone-marrow cells in vivo and fetal cells in vitro of the Indian house shrew, <
TL;DR: A cell line from a female Microtus agrestis has been established in vitro, with most cells showing the normal female complement with two entire X chromosomes.
Abstract: A cell line from a female Microtus agrestis has been established in vitro, with most cells showing the normal female complement with two entire X chromosomes. Clo
TL;DR: A cytogenetic study has been made from leukocyte cultures of the peripheral blood of 10 males and 16 females of L·emur catta, an endemic species of Madagascar.
Abstract: A cytogenetic study has been made from leukocyte cultures of the peripheral blood of 10 males and 16 females of L·emur catta, an endemic species of Madagascar. The animals had been
TL;DR: It is concluded that, in contrast to several older reports but in agreement with some recent reports, the vast majority of endometrial and decidual cells possess a full chromosome complement, even after several cell divisions in vitro.
Abstract: Chromosome studies of cultured cells derived from endometrial biopsies obtained from 56 healthy women undergoing normal menstrual cycles and two women in the menopause and from five decidual biopsies revealed that 85.0% of the total cells counted (3602) had the modal chromosome number, 11.9% were hypomodal and 3.1% were hypermodal. These results varied only very slightly from counts of cells of chromosomally normal embryos cultured under identical conditions. This distribution of the counts and the fact that karyotype analyses of 608 cells revealed random losses (or, very rarely, gains) of chromosomes in cells from 61 of the 63 cases studied strongly suggest that most of the aneuploid cells result from technical artifacts. Therefore, it is concluded that, in contrast to several older reports but in agreement with some recent reports, the vast majority of endometrial and decidual cells possess a full chromosome complement, even after several cell divisions in vitro.