146 resultados para 149-897D


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Mitotic and meiotic chromosome preparations of the tufted deer (Elaphodus cephalophus) were studied to elucidate the sex-chromosomal polymorphism evidenced by this species. Females had 2n = 46 or 47 chromosomes, whereas males had 2n = 47 or 48 chromosomes. An X;autosome translocation was identified by synaptonemal complex analysis of spermatocytes at pachytene and confirmed by the presence of a trivalent at diakinesis/metaphase I. The present work, in combination with earlier observations by others, indicates that E. cephalophus possesses a varied X-chromosome morphology involving an X;autosome translocation and addition of varying amounts of heterochromatin. It is speculated that sex-chromosome polymorphism may be responsible for the observed differences in diploid chromosome number of tufted deer.

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We have used a combination of chromosome sorting, degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), chromosome painting and digital image capturing and processing techniques for comparative chromosome analysis of members of the genus Muntiacus. Chromosome-specific ''paints'' from a female Indian muntjac were hybridised to the metaphase chromosomes of the Gongshan, Black, and Chinese muntjac by both single and three colour chromosome painting. Karyotypes and idiograms for the Indian, Gongshan, Black and Chinese muntjac were constructed, based on enhanced 4', 6-diamidino-2-phenylindole (DAPI) banding patterns. The hybridisation signal for each paint was assigned to specific bands or chromosomes for all of the above muntjac species. The interspecific chromosomal homology was demonstrated by the use of both enhanced DAPI banding and comparative chromosome painting. These results provide direct molecular cytogenetic evidence for the tandem fusion theory of the chromosome evolution of muntjac species.

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中国西南地区分布有许多重要的珍稀濒危动物,对它们的保护举世瞩目,其中一些动物的分类进化地位还存在着争议。我们实验室多年来致力于这些物种的进化遗传和保护遗传学研究,旨在阐明这些物种的进化地位,确定野生或圈养群体的遗传结构,为制定科学的保护计划提供不可缺少的遗传学资料。

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矮马在国内重新发现后,我们对云南矮马历经7年的调查研究,取得如下主要结果:(1)据史料记述,考古物证,血液蛋白多态测定,云南极可能是矮马渊源地;(2)对全省12个地(州)实地调查及5个地(州)的了解,证明云南全省均有矮马,其数量占全国矮马总数的85%~90%,表明云南为矮马的中心产区。矮马的分布密度与生态环境、社会经济、文化、交通状况密切相关,与海拔、气温关系不大;(3)对正常的成年矮马和普通马,屠测69项指标,其差异达显著和极显著水平的占52.27%;(4)对头骨形态和105项尺度观测,两种马间差异达显著和极显著水准的占72.38%,表明二者为独立的品种。通过臼齿大小及齿面雏褶形态鉴别,两者间存在明显差异,并确认两种马均为古老品种;(5)测定矮马、普通马的血液生理生化指标28项46个指标,有7个指标存在显著和极显著差异。(6)两种马的染色体数均为2n=64,C带结构异染色质存在明显差异,反映出两种马间遗传进化上的差异;(7)对矮马、普通马的6种血液蛋白和同功酶测定,测到9个多态位点,结果在TF上两者有明显差异。对矮马、普通马样本,测定44个遗传座位,10个多态遗传座位中PGM及TF在两品种间差异显著.

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The black muntjac (Muntiacus crinifrons) has an unusual karyotype of 2n = 8 in females and 2n = 9 in males. We have studied the evolution of this karyotype by hybridising chromosome-specific paints derived from flow-sorted chromosomes of the Chinese muntjac (M. reevesi, 2n = 46) to chromosomes of the black muntjac. The hybridisation pattern allowed us to infer chromosomal homologies between these two species. Tandem and centromeric fusions, reciprocal translocations, and insertions are involved in the reduction of the diploid number from 2n = 46 to 2n = 8, 9. The painting patterns further show complex chromosomal rearrangements in the male black muntjac which involve more than half the karyotype, including both sex chromosomes. Since early meiosis is reported to be normal without any visible inversion loops of the synaptonemal complex, the observed chromosomal rearrangements would lead to heterosynapsis and, therefore, leave a large fraction of the male black muntjac karyotype balanced between the two sexes.

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本试验采用水平式淀粉凝胶电泳法,对版纳斗鸡、武定鸡的60个样本,32个遗传位点的血液蛋白多态性进行了检测。这两个品种只在ES-1、AKp-1、AKp-2、LAP四个座位显示多态。其余25个位点均为单态,尚有CP、XDH和IDH三个座位染色后未出现谱带。试验结果表明:两鸡种之间虽呈现一定的遗传差异,但平均基因杂合度较小(0.0607;0.0648),两者间遗传距离较近(0.0778)。

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Chromosomal homologies were established between human and two Chinese langurs (Semnopithecus francoisi, 2n=44, and S. phayrei, 2n=44) by chromosome painting with chromosome-specific DNA probes of all human chromosomes except the Y. Both langur species showed identical hybridization patterns in addition to similar G-banding patterns. In total, 23 human chromosome-specific probes detected 30 homologous chromosome segments in a haploid langur genome. Except for human chromosomes 1, 2, 6, 16 and 19 probes, which each gave signals on two non-homologous langur chromosomes respectively, all other probes each hybridized to a single chromosome. The results indicate a high degree of conservation of chromosomal synteny between human and these two Chinese langurs. The human chromosome 2 probe painted the entire euchromatic regions of langur chromosomes 14 and 19. Human chromosome 1 probe hybridized to three regions on langur autosomes, one region on langur chromosome 4 and two regions on langur chromosome 5. Human 19 probe hybridized on the same pattern to one region on chromosome 4 and to two regions on langur chromosome 5, where it alternated with the human chromosome 1 probe. Human 6 and 16 probes both hybridized to one region on each of the two langur autosomes 15 and 18. Only two langur chromosomes (12 and 21) were each labelled by probes specific for two whole human chromosomes (14 and 15 and 21 and 22 respectively). Comparison of the hybridization patterns of human painting probes on these two langurs with the data on other Old World primates suggests that reciprocal and Robertsonian translocations as will as inversions could have occurred since the divergance of human and the langurs from a common ancestor. This comparison also indicates that Asian colobines are karyotypically more closely related to each other that to African colobines.

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采用水平式淀粉胶电泳技术 ,对云南龙陵黄山羊、宁蒗黑头山羊、马关无角山羊和路南圭山羊等 4个保种山羊的 1 2 0个个体共 3 9个基因座位的基因多态性进行了研究。结果显示 ,云南 4个保种山羊品种在AKP、CES - 1、ESD、GOI、LAP、MDH、ME和NP基因座位出现多态。多态座位基因在不同保种山羊中分布不同。多态基因座位百分比 (P)在 4个保种山羊中分别为 0 .2 0 51 ,0 .1 53 8,0 .1 2 82和 0 .1 53 8。平均杂合度 (H)分别为 0 .0 95,0 .0 61 4 ,0 .0 4 67和 0 .0 662。用UPGMA法对由基因频率计算得到的Nei氏标准遗传距离进行聚类分析 ,结果表明云南保种山羊具地理分布及品种特点 ,龙陵黄山羊和其它 3个品种的遗传距离最远。

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Domestic cats and dogs are important companion animals and model animals in biomedical research. The cat has a highly conserved karyotype, closely resembling the ancestral karyotype of mammals, while the dog has one of the most extensively rearranged mammalian karyotypes investigated so far. We have constructed the first detailed comparative chromosome map of the domestic dog and cat by reciprocal chromosome painting. Dog paints specific for the 38 autosomes and the X chromosomes delineated 68 conserved chromosomal segments in the cat, while reverse painting of cat probes onto red fox and dog chromosomes revealed 65 conserved segments. Most conserved segments on cat chromosomes also show a high degree of conservation in G-banding patterns compared with their canine counterparts. At least 47 chromosomal fissions (breaks), 25 fusions and one inversion are needed to convert the cat karyotype to that of the dog, confirming that extensive chromosome rearrangements differentiate the karyotypes of the cat and dog. Comparative analysis of the distribution patterns of conserved segments defined by dog paints on cat and human chromosomes has refined the human/cat comparative genome map and, most importantly, has revealed 15 cryptic inversions in seven large chromosomal regions of conserved synteny between humans and cats.

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对6只笼养滇金丝猴(Rhinopithecus bieti)进行了随机扩增多态DNA(RAPD)及遗传多样性分析.用45个10bp随机短引物对每只滇金丝猴的基因组DNA进行了扩增,平均每个个体观察到的RAPD标记约为130个左右,单个引物获得的标记在1~7个之间.80%的RAPD标记表现为无多态的单型性.个体间的遗传距离为0.052,表明笼养滇金丝猴群体的遗传多样性很低.此研究结果与在蛋白多态研究中得到的一致.贫乏的遗传多样性一方面使目前处于濒危境地的滇金丝猴生存情况更加危险,同时其本身也可能是造成目前滇金丝猴濒危的原因之一.另外,通过成对的遗传距离分析,构建了这一群滇金丝猴的谱系关系图,提出了让遗传距离较远的个体间进行交配的笼养繁育计划.

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Forty chromosome-specific paint probes of the domestic dog (Canis familiaris, 2n = 78) were used to delineate conserved segments on metaphase chromosomes of the American mink (Mustela vison, 2n = 30) by fluorescence in situ hybridisation. Half of the 38 canine autosomal probes each painted one pair of homologous segments in a diploid mink metaphase, whereas the other 19 dog probes each painted from two to five pairs of discrete segments. In total, 38 canine autosomal paints highlighted 71 pairs of conserved segments in the mink. These painting results allow us to establish a complete comparative chromosome map between the American mink and domestic dog. This map demonstrates that extensive chromosome rearrangements differentiate the karyotypes of the dog and American mink. The 38 dog autosomes could be reconstructed from the 14 autosomes of the American mink through at least 47 fissions, 25 chromosome fusions, and six inversions. Furthermore, comparison of the current dog/mink map with the published human/dog map discloses 23 cryptic intrachromosomal rearrangements in 10 regions of conserved synteny in the human and American mink genomes and thus further refined the human/mink comparative genome map. Copyright (C) 2000 S. Karger AG, Basel.

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本文通过细胞遗传学、mtDNARFLP(线粒体DNA、限制性片段长度多态性)和血液蛋白及同工酶3个方面的研究,分析了云南文山黄牛和迪庆黄牛的遗传多样性和遗传分化关系。结果:(1)细胞遗传学云南两个地方黄牛品种的Y染色体形态及其C一带具有显著多态性。文山黄牛和迪庆黄牛分别为一小的近端部和亚申部(或中部)着丝位Y染色体,并分别在Y染色体的臂端部和短臂的臂端部显示弱阳性C一带,说明文山黄牛的父系起源可能是瘤牛(Bosindicus),而迪庆黄牛是普遍牛(Bostaurus)。推测两种Y染色体可能是臂问倒位的结果。(2)mtD-NARFLP两个黄牛品种的111个个体的mtDNA经8种限制性内切酶酶切后,有个酶表现出多态,共检测到17种限制性态型。归结出的3种基因单倍型,分别是A-A-A-A-A-A-A型(瘤斗)、B-B-B-B-B—B-B型(普通型)和A-C-B-B-C-A-A型(耗半Bosgrunniens)。从基因单倍型在群体中的表现可看出,文山黄牛和迪庆黄牛都具有瘤牛和普通牛两种母系起源。但文山黄牛以瘤牛血统为主,迪庆黄牛以普通牛血统为主,而且还可能含有部价耗牛的血统。(3)血液蛋白及同工酶分析了两个黄牛品种的...

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A complete comparative chromosome map of the white-browed gibbon (Hylobates hoolock, 2n = 38), white-cheeked gibbon (Hylobates leucogenys, 2n = 52), and human has been established by hybridising H. leucogenys chromosome-specific paints and human 24-colour paints onto H. hoolock metaphase chromosomes. In the 18 H. hoolock autosomes, we identified 62 conserved segments that showed DNA homology to regions of the 25 H. leucogenys autosomes, Numerous interchromosomal rearrangements differentiate the karyotypes of H. leucogenys and H. hoolock. Only H. hoolock chromosome 10 showed homology to one entire autosome of H. leucogenys. The hybridisation of human 24-colour paints not only confirmed most of the chromosome correspondences between human and H. hoolock established previously but also helped to correct five erroneous assignments and revealed three new segments. Our results demonstrate that the karyotypes of the extant gibbons have arisen mainly through extensive translocation events and that the karyotype of H. hoolock more closely resembles the ancestral karyotype of Hylobates, rather than the karyotype of H. leucogenys. Copyright (C) 2001 S. Karger AG, Basel.

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 采用水平板淀粉胶电泳技术对来自云南保种宁蒗黑头山羊的31 个个 体的39 个基因座位的血液同功酶进行了分析, 结果得到A KP, CES- I, ESD, GO I, M E 和N P 共6 个座位出现多态, 多态座位A KPO , CES- I2, ESDB , GO IA ,M EB 和 N PB 的基因频率较高; 多态座位百分比P = 0. 1538, 平均杂合度H = 0. 0679 ± 0. 0241。本研究首次得到了该羊的遗传多样性特征, 为该羊的保种和利用提供了基础 数据。

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Chromosome homologies between the Japanese raccoon dog (Nectereutes procyonoides viverrinus, 2n = 39 + 2-4 B chromosomes) and domestic dog (Canis familiaris, 2n = 78) have been established by hybridizing a complete set of canine paint probes onto high-res