【摘要】 本研究采用流式细胞术,以公鸡(Gallusdomesticus)红血细胞DNA含量为标准,测定了23头长江江豚(Neophocaenaphocaenoidesasiaeorientali)的基因组大小(或称C值)。实验过程中采用了保存在3中不同条件下的长江江豚的全血样品,用3种不同的方法提取白细胞。为了获得本实验所用的公鸡红血细胞DNA含量的准确值,首先以人(Homosapiens)的C值为标准,对其进行了校正。然后其C值(2C=2.35pg)用于长江江豚的基因组大小测定。结果发现:长江江豚的单倍体DNA含量为3.27pg/C,由此得出其基因组大小为3.17×109bp;雌性和雄性的C值分别为3.25pg和3.29pg,野外长江江豚和豢养长江江豚的C值分别为3.30pg和3.05pg。对雌雄个体之间以及不同生长条件下长江江豚的C值应用独立样本t检验分析,发现:1)不同性别的长江江豚基因组大小之间没有明显的差异;2)豢养条件下的长江江豚和野生长江江豚之间的基因组大小有明显差异,豢养条件下的长江江豚的基因组明显小于野生条件下的长江江豚。据此推测必要环境因子的变化可能会对长江江豚的基因组DNA含量造成影响。更多还原

【Abstract】 The present study determined C-values of 23 individuals of Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis by flow cytometry using chicken erythrocyte DNA content as a standard.The Yangtze finless porpoise’s lymphocyte cells were extracted from whole blood samples stored at three different conditions.For determining the actual C-value of chicken erythrocyte,we firstly standardized its C-value controlled by human C-value of 3.50 pg/C,and then the chicken C-value of 2.35 pg/2C was used in the following determinations.Result shows that the C-value of the Yangtze finless porpoise is 3.27 pg with the genome size of 3.17×109 bp.The C-values for male and female are 3.29 pg and 3.25 pg,respectively.The C-values of Yangtze finless porpoises reared in captivity and wild are 3.06 pg and 3.30 pg,respectively.Analyzed by Independent-Samples T Test,it’s found that the C-values of different genders have no significant difference,whereas,the C-values of wild Yangtze finless porpoises and that reared in captivity have significant differences,the C-value of Yangtze finless porpoise in captivity is smaller than that of the wild ones.It’s assumed that the stability of environmental factors has certain influences on animal genome size variation.更多还原