七星瓢虫精母细胞减数分裂观察研究

Study on Spermatocyte Meiosis in Coccinella Septempuctata

研究昆虫染色体一般选择在生殖细胞减数分裂阶段.七星瓢虫初级精母细胞的染色体计数为2n=16+X,减数分裂中期,n=8、n=8+X,染色体形态多为短棒状(参见照片).其性染色体是属XD型,雌性XX,为同配性别,雄性为异配性别,即X0(2n—1).昆虫染色体数量、组型,以及减数分裂的配对情况均与分类学亲缘关系有相关性,是昆虫正确鉴定和系统分类的重要参考.

The stage of meiosis in the generative cell is chosen in studying insect chromosome. The number of chromosome in coccinella septempunctata of primary spermatocyte is 2n=16+x. In metaphase of meiosis is n = 8 and n=8+x. The most shape of chromosomes are short bar (refer to photographs). The type of sex chromosome is xo, female is xx belonging to homoganetic sex. Male is xo (2n-1) belonging to heterogametic sex. The chromosomes in insects of number karytype and pairing have something to do with kindred and taxonomy. It is an important references that insects is identified and classified.