经营田鼠染色体核型与G带分析

采用骨髓法制备经营田鼠染色体标本片,并对其染色体核型和G带进行分析。结果表明,经营田鼠体细胞染色体数为2n=38,雄性染色体核型由18对常染色体和1对异配型性染色体XY组成,雌性为18对常染色体和1对同配型性染色体XX组成。1～9号为端着丝粒（t）染色体（包括Y染色体）,10号为近端着丝粒（st）染色体,11～18号为中央着丝粒（m）染色体（包括X色体）。19对染色体共分布有370条G带（雄性365条）,其中深带190条,浅带180条。因此,经营田鼠的染色体数目、G带具有明显种的特征,与其他鼠类不同。     

Use of molecular markers for the identification of River Buffalo chromosomes: chromosome one

A standard karyotype for the River Buffalo has recently been established. The largest five chromosomes are biarmed and, based on the banding homology between cattle and buffalo chromosomes, were suggested to originate from the fusion of cattle acrocentric chromosomes. The origin of buffalo chromosome 1 is controversial due to the difficulty in differentiating between the small acrocentric cattle chromosomes. Using molecular markers assigned to cattle chromosomes, synteny between CD18, a marker for BTA1, and markers for small acrocentric cattle chromosomes BTA 24 to BTA 29 was investigated in buffalo/hamster somatic cell hybrids. The investigation revealed that CD18 is syntenic with ANT1, a marker for cattle chromosome 27. The present results confirm that buffalo BBU1 results from fusion of cattle BTA 1 and BTA 27. They also underline the importance of biarmed buffalo chromosomes for the identification of small cattle acrocentrics.     

云南圭山山羊及红骨圭山山羊的染色体核型及带型研究

作者采用外周血淋巴细胞培养及染色体分带技术,分析了云南圭山山羊和红骨圭山山羊的染色体核型和C-带带型及G-带带型。结果表明,两种山羊的染色体形态较相似,二倍体染色体众数为2n=60,其中常染色体29对全部为端着丝粒,X染色体相对长度介于1号与2号染色体之间为端着丝粒,Y染色体最小且为唯一的中端着丝粒染色体。两种山羊中都发现一定比例的体细胞染色体多倍体,比例分别为6.8%、9.4%。对2种山羊C-显带及G-显带的带型分析显示没有明显差异。     

藏獒染色体核型分析

采用外周血淋巴细胞培养法和常规染色体分析技术,对青海省藏獒的染色体核型进行了分析。结果表明：藏獒二倍体染色体数目为2n=78,NF=80,按形态可分为39对,除性染色体X和Y为中着丝粒（M）染色体外,其它38对常染色体均为端着丝粒（T）染色体。     

Chromosomes of gaur cross domestic cattle hybrids

The chromosomes of five gaur (Bos gaurus hubbacki) domestic cattle (B indicus cross B taurus) hybrids (three females, two males) were studied using the leucocyte culture method and centromeric (C) banding technique. All the hybrids had a diploid chromosome number of 2n = 58, made up of two submetacentric autosomes (different in size) and 54 acrocentric autosomes, most of which could be arranged in pairs in descending order of size. The sex (X) chromosomes in females were a pair of submetacentric chromosomes smaller than the submetacentric autosomes. The Y chromosome in males was a small submetacentric chromosome. The C banding patterns were useful in identifying the X and Y chromosomes and the inherited submetacentric autosomes from the gaur sire. Phenotypically, the hybrids resembled normal B indicus cross B taurus calves except for the presence of a distinct hump-like dorsal ridge containing the spinous processes of the third to 11th thoracic vertebrae, upright 'deer-like' ears and long lean legs. The potential of these hybrids as important genetic resources for meat production is stressed.     

西藏自治区日喀则市白草核型分析

白草（Pennisetum centrasiaticum）广泛分布于世界各地，被牛羊所采食。本试验采用常规根尖压片法对采自西藏日喀则市的白草进行染色体数目统计及核型分析。结果表明：白草染色体总长度为45.87 μm，平均臂比为1.23，核型不对称指数为54.83；所有染色体的臂比在1.08至1.70范围内，其中近中部着丝粒染色体（sm）为1对，其余17对均为中部着丝粒染色体（m），所有染色体未观测到随体出现；白草染色体基数为9，核型为2n=4x=36=34 m+2 sm，属于四倍体植物，核型类型为1A，是进化较原始的物种。     

A centric fission and heterochromatin polymorphism in Equus asinus Spanish breeds

In this work a chromosomal study in Equus asinus is presented. Forty‐two specimens, belonging to five different Spanish breeds in risk of disappearing, have been analysed. Metaphases have been sequentially stained (uniform, G‐banded and C‐banded) and analysed. All specimens, except one, presented 2n = 62 chromosomes. Variation in chromosome number (2n = 63) is because of a fission in one chromosome of pair no. 3, resulting in two acrocentric chromosomes. Polymorphisms affecting the size of heterochromatic C+ bands and the presence of hetrochromatic 1p and 4p arms are also analysed. The results show no polymorphisms which can be attributed to a particular breed. From the chromosomal point of view, all Spanish asinine specimens correspond to a single population. Rearrangements detected suggest a fission tendency in the homologous E. asinus no. 3 chromosome in Equidae species.     

藏鸡的有丝分裂观察及染色体核型分析简

试验采用直接骨髓法制备林芝藏鸡染色体,通过显微自动成像系统观察藏鸡细胞有丝分裂全过程,包括间期、早前期、前期、中期、后期和末期,并分析了藏鸡有丝分裂过程染色体的形态变化规律。通过比较有丝分裂各期的形态,结果发现藏鸡有丝分裂的前期染色体伸展最长,碱基暴露最多,适合于做基因定位工作。同时进行了藏鸡染色体的核型分析,数据统计结果发现林芝地区藏鸡染色体数目2n=78,其中前5对染色体和性染色体中有3对中央着丝粒（m）染色体、1对近中着丝粒（sm）染色体、2对端着丝粒（t）染色体。与前人试验结果进行了比较,结果显示存在一定差异,原因仍需进一步试验验证。     

A note on the somatic Y chromosome of reindeer (Rangifer tarandus L.)

Recently a report on the reindeer chromosomes was published (Nes et al. 1965). The chromosome complement was described as consisting of 70 autosomes and a sex chromosome set of the XY-type. All autosomes were acrocentric except one pair which was submetacentric. The X was found to be submetacentric and also the largest chromosome of the complement. The Y was characterized as being the smallest acrocentric chromosome, and the authors stated that the Y chromosome could only occasionally be distinguished from the autosomes by its shorter length.In our studies of the same species we have found a quite different appearance concerning the Y chromosome.     

中国野蚕染色体结构及其变异的研究

采用细胞生物学的电离辐射方法研究了中国野蚕染色体形态和结构变异。结果表明 :中国野蚕 2 8条染色体粗线期大小在 1～ 3 μm之间 ,而且变异范围小 ,在生物界属于小染色体类。在电离辐射作用下 ,野蚕染色体结构异常的表现主要为易位、缺失、倒位等 ,其中易位的类型为相互易位和简单易位 ;缺失的类型为中间缺失和顶端缺失。本文从染色体变异角度对蚕的起源与分化作了探讨     

C- AND G- BANDING PATTERNS AND CHROMOSOMAL MORPHOLOGY OF SOME BREEDS OF AUSTRALIAN CATTLE

A cytogenetical study using metaphase chromosomes from cultured lymphocytes, was made of 2 Banteng (Bibos banteng) steers and 218 bulls representing 13 purebreeds (Bos taurus type, Bos indicus type and Sanga) and 7 cross-breeds. Studies were made of photographic karyotypes of Giemsa stained and C-banded chromosomes of bulls of each breed and of B-banded chromosomes from 3 breeds of Bos indicus and one cross-breed Australian Friesian Sahiwal) cattle. The relative lengths of chromosomes of Bos taurus and Bos indicus bulls were compared and significant difference in relative lengths of the X chromosomes were noted between these two species. There was a differences in morphology of the Y chromosomes; Sanga, Banteng and Bos taurus type breeds had a small submetacentric Y chromosome, except for the Jersey which had a metacentric Y chromosome. All Bos indicus type bulls had an acrocentric Y chromosome but the Droughtmaster breed had two forms of the Y chromosome (submetacentric and acrocentric). The C-banding patterns of the autosomes and X chromosomes were similar for all breeds while those of the Y chromosomes of Bos indicus type cattle allowed their accurate identification. G-banding patterns of Bos indicus resembled those of Bos taurus and enabled pairing of homologous chromosomes. Centromeres of the autosomes were unstained but those of the sex chromosomes were darkly stained.     

Roles of Cohesin and Condensin in Chromosome Dynamics During Mammalian Meiosis

Meiosis is a key step for sexual reproduction in which chromosome number is halved by two successive meiotic divisions after a single round of DNA replication. In the first meiotic division (meiosis I), homologous chromosomes pair, synapse, and recombine with their partners in prophase I. As a result, homologous chromosomes are physically connected until metaphase I and then segregated from each other at the onset of anaphase I. In the subsequent second meiotic division (meiosis II), sister chromatids are segregated. Chromosomal abnormality arising during meiosis is one of the major causes of birth defects and congenital disorders in mammals including human and domestic animals. Hence understanding of the mechanism underlying these unique chromosome behavior in meiosis is of great importance. This review focuses on the roles of cohesin and condensin, and their regulation in chromosome dynamics during mammalian meiosis.     

Y CHROMOSOME MORPHOLOGY OF CATTLE

Metaphase chromosomes from cultured lymphocytes were prepared from 246 bulls including Bos indicus, Bos taurus. Bos (Bibos) banteng, Sanga and interspecific and intra-specific breed crosses. Morphology and karyotype position of the Y chromosome for each bull were noted. Karyotype position of the Y chromosome varied between bulls from 25th to 29th pair and the Y chromosomes of Bos indicus and breeds derived from Bos indicus bulls were acrocentric while those of Bos taurus, Sanga and breeds derived from these bulls were metacentric/submetacentric. Two forms of Y chromosome were noted in the Droughtmaster breed. C-banding patterns of the acrocentric Y chromosome were characteristic and enabled easy identification.     

Wapl localization on the synaptonemal complex, a meiosis-specific proteinaceous structure that binds homologous chromosomes, in the female mouse.

The wings apart-like (Wapl) protein is required to hold sister chromatids together in mitotic heterochromatin in Drosophila melanogaster. It is localized on the synaptonemal complex (SC), a meiosis-specific structure connecting one pair of sister chromatids to the homologous pair in mouse pachytene spermatocytes. The human Wapl is a cohesin-binding protein that facilitates cohesin's timely release from chromosome arms during prophase. The objective of the present study was to determine the subcellular localization of the mouse Wapl on female meiotic chromosomes at pachynema. The pachytene oocytes were isolated from foetal ovaries at 18.5 dpc and double immunostained with anti-synaptonemal complex protein 2 (SYCP2) and anti-Wapl. In the pachytene oocytes examined, mouse Wapl was colocalized with SYCP2 on the SC. Our results further implicated that Wapl might play a crucial role in meiotic chromosome remodelling at early meiosis.     

加州野大麦染色体C-分带、荧光原位杂交及其核型分析

以二倍体加州野大麦(Hordeum californicum)及普通小麦中国春(Chinese spring,CS)-加州野大麦的双二倍体为材料,进行依次染色体C-分带和荧光原位杂交(FISH)分析.结果表明:小麦背景中的加州野大麦染色体都显示较强的末端带,7对染色体之间带的数目和强弱均存在明显差异,可以和普通小麦染色体相互区分开来;以45s rDNA为探针进行荧光原位杂交发现,二倍体和双二倍体中加州野大麦的NOR位点均位于第7对染色体短臂上;基于根尖细胞有丝分裂中期染色体C-分带和原位杂交结果,利用Motic images plus 2.0 ML软件"数码显微图像处理系统"进行核型分析,确定加州野大麦的核型为2n=2x=10 m(2SAT) 4 sm,属于较为对称性核型(Ⅱ A);加州野大麦染色体核型的建立,为利用远缘杂交和染色体工程转移加州野大麦的有利基因奠定了基础.     

哺乳动物Y染色体的测序进展

哺乳动物的性染色体由一对常染色体演化而来,其中X染色体在物种间相对保守,而Y染色体则存在很大的变异,包括染色体的大小、结构和基因数量等.研究Y染色体的遗传结构与变异,对于理解哺乳动物的起源进化、性别决定以及动物繁殖都具有重要意义.因此,文章综述了哺乳动物Y染色体的结构与变异,以及Sanger测序技术、二代测序技术、三代...     

Trisomy 2 in three cases of canine haemangiopericytoma.

Two female (12 and 14 years old) and one male dog (10 years old) developed haemangiopericytomas. Three copies of chromosome 2 were present in the tumours of all three dogs. Additional alterations were an interstitially deleted chromosome 1, centric fusions 3/34 and 8/15, isochromosome 32 and two unidentified marker chromosomes (M1, M2) in one bitch. In the other bitch, the additional alterations were trisomy 37, centric fusions 8/38 and 30/31, and a derivative chromosome 13 (der13). In the male dog, tandem fusion 2/19 was present in addition to two structurally normal chromosomes 2.     

哈白兔×日本大耳兔F1的染色体核型分析

采用常规细胞遗传学手段,对青海省畜牧兽医科学院饲养的哈白兔×日本大耳兔Ｆ１的染色体核型进行分析,结果表明,Ｆ１的染色体数目２ｎ＝４４,染色体臂数ＮＦ＝７８（♂）;常染色体类型１～７对为中着丝粒染色体（Ｍ）,８～１０对为亚中着丝粒染色体（ＳＭ）,１１～１６对为近端着丝粒染色体（ＳＴ）,１７～２１对为端着丝粒染色体（Ｔ）,性染色体Ｘ为亚中着丝粒染色体（ＳＭ）,Ｙ为中着丝粒染色体（Ｍ）,公兔核型式为４４,ＸＹ（♂）。     

番红花染色体核型分析

通过对番红花根尖细胞进行染色体常规制片,并进行核型分析.结果显示,番红花为2倍体(2n=2x=24)植物,核型公式为K(2n)=2x=24=2t+2st+8sm+12m,其中,中部着丝粒染色体(m)6对,近中部着丝粒染色体(sm)4对,近端着丝粒染色体(st)1对,端着丝粒染色体(t)1对.核型类型为2B,并且倍性不是...     

布尔山羊的染色体核型分析

采用外周血淋巴细胞培养法，对布尔山羊的染色体核型进行了分析。结果表明，布尔山羊的二倍体染色体数目为2n=60，公羊核型为60，XY；母羊核型为60，XX。共有29对常染色体和1对性染色体。所有常染色体均为端部着丝点染色体；X染色体为第二大的端部着丝点染色体，Y染色体为最小的天是唯一的中部着丝点染色体。研究发现，布尔山羊存在1.7％的三倍体和5.9％的四倍体。