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1.
During mammalian spermatogenesis, spermatogenic cells undergo mitotic division and are subsequently divided into haploid spermatids by meiotic division, but the dynamics of sex chromosomes during spermatogenesis are unclear in vivo. To gain insight into the distribution of sex chromosomes in the testis, we examined the localization of sex chromosomes before and after meiosis in mouse testis sections. Here, we developed a method of fluorescence in situ hybridization (FISH) using specific probes for the X and Y chromosomes to obtain their positional information in histological testis sections. FISH analysis revealed the sex chromosomal position during spermatogenesis in each stage of seminiferous epithelia and in each spermatogenic cell. In the spermatogonia and leptotene spermatocytes, sex chromosomes were distantly positioned in the cell. In the zygotene and pachytene spermatocytes at prophase I, X and Y chromosomes had a random distribution. After meiosis, the X and Y spermatids were random in every seminiferous epithelium. We also detected aneuploidy of sex chromosomes in spermatogenic cells using our developed FISH analysis. Our results provide further insight into the distribution of sex chromosomes during spermatogenesis, which could help to elucidate a specific difference between X and Y spermatids and sex chromosome-specific behavior.  相似文献   

2.
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.  相似文献   

3.
Pre-conceptual sex selection is still a highly debatable process whereby X and Y chromosome bearing spermatozoa are isolated before oocyte fertilization. Recently, magnetic nanoparticles (MNP) have been used to determine X and Y chromosomes bearing spermatozoa as a result of searching for a cheap, highly efficient method using non-toxic materials. This study aimed to recover the sperm bearing X chromosomes in ram with different concentrations of MNP and then evaluate the success of this method using polymerase chain reaction (PCR). Ram sperms were divided into four groups, treated with 0 (control), 50, 100 and 200 μg/ml MNP, respectively. MNP was used to restore sperm cells bearing X chromosomes. Upon recovery, the PCR was performed to identify the X and Y sperms, Methyl ThiazoleTetrazolium (MTT), to assess MNP toxicity and sperm viability and acridine orange (AO) to evaluate sperm DNA integrity. The results of PCR revealed that the treatment of spermatozoa- bearing X chromosomes with 50 μg/ml MNP had the highest effects on the recovery of X sperm rather than the other concentrations of MNP. However, the concentrations of MNP did not have any toxic effects on spermatozoa, sperm viability and, DNA integrity, but the high concentration of MNP (200 μg/ml) significantly reduced DNA integrity. According to MTT and AO results, the concentrations of MNP used in this study had no toxic effects on spermatozoa and did not reduce the sperm viability and DNA integrity, except that 200 μg/ml MNP significantly reduced DNA integrity.  相似文献   

4.
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。  相似文献   

5.
In contrast to mammals and birds, fish display an amazing diversity of genetic sex determination systems, with frequent changes during evolution possibly associated with the emergence of new sex chromosomes and sex‐determining genes. To better understand the molecular and evolutionary mechanisms driving this diversity, several fish models are studied in parallel. Besides the medaka (Oryzias latipes Temminck and Schlegel, 1846) for which the master sex‐determination gene has been identified, one of the most advanced models for studying sex determination is the Southern platyfish (Xiphophorus maculatus, Günther 1966). Xiphophorus maculatus belongs to the Poeciliids, a family of live‐bearing freshwater fish, including platyfish, swordtails and guppies that perfectly illustrates the diversity of genetic sex‐determination mechanisms observed in teleosts. For X. maculatus, bacterial artificial chromosome contigs covering the sex‐determination region of the X and Y sex chromosomes have been constructed. Initial molecular analysis demonstrated that the sex‐determination region is very unstable and frequently undergoes duplications, deletions, inversions and other rearrangements. Eleven gene candidates linked to the master sex‐determining gene have been identified, some of them corresponding to pseudogenes. All putative genes are present on both the X and the Y chromosomes, suggesting a poor degree of differentiation and a young evolutionary age for platyfish sex chromosomes. When compared with other fish and tetrapod genomes, syntenies were detected only with autosomes. This observation supports an independent origin of sex chromosomes, not only in different vertebrate lineages but also between different fish species.  相似文献   

6.
The replicating patterns of bovine sex chromosomes were examined using the method of the alternate administration of BrdU and dT throughout the DNA synthesis of the cell cycle. It was clear that two X chromosomes of the female complement behaved in a different replicating patterns and that these differences were markedly shown in the last stage of the S period. The X chromosome of the male behaved in a similar replicating pattern to one of the two female X chromosomes. It was suggested that at the beginning of the S period, the X chromosomes replicated the DNA at the end of the short arm, in the central region, and at the distal region of the long arm. It was clear that the entire Y chromosome replicated in the last S period .  相似文献   

7.
In order to identify X‐ and Y‐bearing spermatozoa in water buffalo by fluorescence in situ hybridization (FISH), some available probes of closely related species were examined. An X‐ and Y‐specific probe set, made from flow sorted yak chromosomes, labelled in somatic metaphases of water buffalo the whole X and Y, respectively, except their centromere regions. A cattle Y‐chromosome repeat sequence (BC1.2) showed strong signal on the telomere region of the buffalo Y‐chromosome, demonstrating the evolutionary conservation of this locus in water buffalo. In hybridization experiments with spermatozoa from five buffaloes, the yak X‐Y paint set demonstrated clear signals in more than 92% (46.8% X and 45.8% Y) of the cells. Using the cattle Y‐chromosome specific BC1.2 probe, clear hybridization signal was detected in more than 48% of the cells. Statistical analysis showed that there was no significant difference between bulls or from the expected 50 : 50 ratio of X‐ and Y‐bearing cells. The probes presented here are reliable to assess separation of X‐ and Y‐bearing spermatozoa.  相似文献   

8.
利用加入氨甲喋呤和胸苷使细胞分裂同步化并结合胰酶G带技术,分析了猪前中期染色体高分辨G带。单套染色体的G带数目,包括x和y染色体,前中期为503条,中期为300条。绘制了前中期和中期G带带型图。  相似文献   

9.
Chromosomes of gaur cross domestic cattle hybrids   总被引:1,自引:0,他引:1  
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.  相似文献   

10.
采用常规细胞遗传学分析手段,对青海省西宁动物园饲养的马鹿染色体核型进行分析,结果:马鹿染色体数目为2n=68,染色体臂数NF=70(♀)、71();常染色体类型为2条中(M)着丝粒,64条近端或端(A)着丝粒;性染色体类型X为近端(A),Y为近中(sM)着丝粒;公母鹿核型式为68,XY和68XX。  相似文献   

11.
贵州香猪染色体核型研究   总被引:1,自引:0,他引:1  
以贵州香猪(久仰香猪、剑白香猪、从江香猪)为试验组,长白猪为对照组,用外周血淋巴细胞培养对其染色体核型进行研究。结果表明,各香猪类型及长白猪淋巴细胞染色体数均为2n=38;香猪染色体核型组成为10sm 4st 12m 12t,长白猪则为8sm 4st 14m 12t;性染色体雌性均为XX,雄性均为XY,X、Y属中着丝粒染色体,Y是中着丝粒染色体相对长度最短的一条;3,5,6,7和9号染色体的臂比值各香猪类型与长白猪相比,差异显著(P<0.05)或极显著(P<0.01);1,5,6,8,9和11号染色体的相对长度各香猪类型与长白猪相比,差异显著(P<0.05)或极显著(P<0.01);香猪类型间也存在一定差异。  相似文献   

12.
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。  相似文献   

13.
An 18‐month‐old European shorthair cat was subjected to genetic studies due to ambiguous external genitalia (underdeveloped both penis and scrotum). Further anatomic and histopathological studies revealed the presence of abdominal, atrophic testes and uterus. Cytogenetic analysis showed two cell lines, one with X monosomy—37,X [90% of the analysed metaphase spreads], and other line had 38 chromosomes with normal X chromosome and abnormally small Y‐derived chromosome—38,X,der(Y) [10%]. Further fluorescence in situ hybridization study with telomeric probe revealed a ring structure of the der(Y). Eight Y chromosome‐specific genes, SRY, TETY1, TETY2, CUL4BY, CYORF15, HSFY, FLJ36031Y and ZFY, were detected. We conclude that the described abnormality of the reproductive system, leading to sterility, was caused by a very rare type of chromosomal mosaicism—37,X/38,X,r(Y).  相似文献   

14.
采用常规及分带技术,对Wistar系大鼠染色体研究的结果如下:2n=42;1;X号染色体为亚端着丝点染色体;2~10;Y号为端部着丝点染色体;11~13号为亚中部着丝点染色体;14~20号为中部着丝点染色体.染色体G-带与天津Ⅰ系大鼠G-带基本一致.染色体Ag—NORs定位于11,12,13以及X号染色体上,分布范围为1~7个,众数为6个.染色体C-带明显者为4~8,10~12,14~19,X号染色体,C-带不明显者为1~3,9,13,20,Y号染色体.  相似文献   

15.
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.  相似文献   

16.
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。  相似文献   

17.
采用外周血淋巴细胞培养及染色体分带技术分析了徐淮白山羊的染色体核型、C-带。结果表明,徐淮白山羊二倍体染色体数为2N=60,常染色体和X染色体均为端部着丝粒染色体.X染色体的大小介于1号和2号染色体之间,Y染色体最小.为中部着丝粒染色体,公羊核型为60.XY.母羊为60.XX。大部分常染色体和性染色体着丝粒部位显示阳性C带。  相似文献   

18.
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、三代测序技术在Y染色体测序中的应用,并展望了基于CRISPR-dCas9可视化系统的流式染色体分离技术,以及高精度的三代测序技术在Y染色体测序中的应用前景。  相似文献   

19.
布尔山羊的染色体核型分析   总被引:6,自引:1,他引:5  
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。  相似文献   

20.
The standard procedure of artificial insemination with fresh equine spermatozoa involves short‐term storage (to 48 h at 5°C). This procedure is accompanied by a gradual loss of sperm viability. The aim of this study was to investigate whether the X/Y ratio of equine spermatozoa is affected by short‐term storage and the swim‐up procedure. We used a standard protocol, for short‐term storage (0, 24 and 48 h at 5°C) of stallion semen diluted in the commercial extender EquiPro? (Minitüb GmbH, Tiefenbach, Germany). After each set‐up storage period, the motile fraction of sperm cells was selected by the swim‐up method. The X/Y ratio was evaluated by fluorescence in situ hybridization (FISH) in the fresh, non‐selected sperm, and in motile spermatozoa selected after each of the storage periods. Molecular probes for the equine chromosomes X and Y were used. The X/Y ratio in all sperm samples analysed in this study (fresh and stored) was not different from the theoretical 1 : 1 value. The incidence of chromosomally abnormal sperm cells in the fresh (0.28%) and motile (0.13%) sperm samples was not significantly different. The two approaches (sperm storage up to 48 h and the swim‐up procedure) applied to this study did not affect the X/Y ratio in the motile fraction of equine spermatozoa. This finding does not conform to phenomena described for human and cattle. For this reason, the finding may imply species‐related differences.  相似文献   

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