奥利亚罗非鱼和尼罗罗非鱼核型及DNA含量的比较研究

STUDIES ON KARYOTYPES AND CELLULAR DNA CONTENT OF SAROTHERODON AUREA AND S.NILOTICA

采用ＰＨＡ体内培养法，取鱼体肾细胞用空气干燥法制备奥利亚罗非鱼（Ｓａｒｏｔｈｅｒｏｄｏｎａｕｒｅａ）和尼罗罗非鱼（Ｓ．ｎｉｌｏｔｉｃａ）的染色体，经核型分析，奥利亚罗非鱼为２ｎ＝４４，６ｓｍ＋２４ｓｔ＋１４ｔ；ＮＦ＝５０。尼罗罗非鱼为２ｎ＝４４，６ｓｍ＋２４ｓｔ＋１４ｔ；ＮＦ＝５０。经流式细胞仪测量外周血红血球的ＤＮＡ含量，奥利亚罗非鱼为２Ｃ＝２．２２ｐｇ（２．２２ｐｇ／Ｎｕｃｌ．）；尼罗罗非鱼为２Ｃ＝２．２７ｐｇ（２．２７ｐｇ／Ｎｕｃｌ．）。经对比分析，两种鱼的核型和ＤＮＡ含量之间的差异不显著，在分类地位上非常接近。

Adopted the PHA intra-cultivation, the kidney cells of Sarotherodon aurea and S.nilotica were taken out to make the metaphase chromosome specimens by air-drying method. The idiograms were established on the basis of their karyotypes. The results indicate that the chromosome number of S. aurea is 2n=44,chromosome formula is 6 st+24 st+14 t, NF= 50, and the chromosome number of S. nilotica is 2n=44, chromosome formula is 6 sm+24 st+14 t, NF= 50. Flow cytometric was used to determine the DNA content of peripheral red blood cells of these two fish. The absolute DNA content determined is that in S. aurea it is 2c=2. 22 pg (2. 22 pg/Nucl) and in S. nilotica 2c=2. 27 pg (2. 27 pg/Nucl). The result of comparison is that the difference between these two species is not apparent in karyotype and DNA content, Which shows that they are quite close to each other in terms of classification status.