论文标题:羊驼染色体核型的研究
Study on the Chromosomal Karyotype of Alpacas
论文作者 张巧灵
论文导师 董常生,论文学位 硕士,论文专业 动物遗传育种与繁殖
论文单位 山西农业大学,点击次数 97,论文页数 51页File Size3896k
2003-07-01论文网 http://www.lw23.com/lunwen_110311807/ 羊驼;染色体;核型;C-带;G-带
Huacaya alpaca;Chromosome;Karyotype;C-banding;G-banding
为了从选种、杂交改良、疾病诊断以及性别决定的遗传机制等方面为羊驼的繁育与推广提供更为有效的细胞遗传学资料，本试验采用外周血淋巴细胞培养法制备染色体，分析了23只胡阿基亚型羊驼(Huacaya alpaca，雌20只，雄3只)的染色体及其核型，并通过BSG法(Barium hydroxide／Saline／Giemsa，氢氧化钡-盐溶液-吉姆萨，也即Sumner BSG法)与胰酶-EDTA法分别对羊驼的C-分带和G-分带进行分析，结果表明： (1)羊驼二倍体染色体数目为2n=74，雄性羊驼核型为74，XY；雌性羊驼核型为74，XX。其中，1～20对常染色体为亚端着丝粒染色体，21～36对常染色体为亚中着丝粒染色体和中着丝粒染色体，X为中着丝粒染色体，Y为端着丝粒染色体。 (2)C-带分析表明，阳性带分布于所有染色体的着丝粒部位，即所有染色体的着丝粒部位被深染，其余部位均浅染。 (3)G-带分析表明，羊驼G带明暗相间，显现出不同的带纹。且羊驼每对染色体都有其独特的带纹特征，其带纹的数目和精细程度随着染色体长度的增加而增加。 此外，本研究还观察到正常羊驼染色体畸变类型，包括数目畸变和结构畸变，数目畸变如三倍体、四倍体；结构畸变如环状染色体，不过畸变类型的频率很低。
Blood samples from 23 Huacaya alpacas ,3 males and 20 females ,were used to study chromosome karyotype ,so as to provide some effective cytogenetics basis for the selectioiymprovement by crossing and disease diagnosis of alpacas ,and genetic mechanisms of sex determination. Peripheral blood lymphocyte culture was used to prepare chromosome. Methods of trypsase-EDTA and BSG (Barium hydroxide / Saline / Giemsa)were used for G-banding and C-banding respectively . The results showed as follows:Firstly , the number of diploid chromosomes was in the alpacas 2n=74,with the karyotype 74, XY and 74, XX for males and females respectively. Thirty six homologous pairs of chromosomes were autosomes , in which chromosomes ,pairs of 1 to 20 were acrocentric-subterminal , 21 to 36 metacentric-submetacentric . And X chromosome was metacentric, Y chromosome terminal.Secondly , observation to C-bands indicated that positive bands distributed in the centromeres of all chromosomes ,id. all centromeres of chromosomes were densely dyed , but two arms lightly dyed .Thirdly , the analysis of G-bands showed that bright and dark bands appeared by turn. It showed different bands. And every pair of chromosomes had its distinct band ,and the longer the chromosomes, the more the . number of bands, and the more clear the bands.Additionally, several types of chromosome aberrations were observed in somatic cells of the normal alpacas .These aberrations involved triploid, tetraploid and ring chromosomes . But their aberration frequencies were very low.
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