致倦库蚊的有丝分裂染色体核型和种内多态性研究

On Metaphase Karyotype and Intraspecific Polymorphism of Culex Pipiens Quinquefasciatus

对致倦库蚊有丝分裂核型和种内多态性进行了观察,目的在于探明尖音库蚊复合体各亚种间的遗传差异.方法:选取三龄晚期或四龄早期幼虫,在0.086%的秋水仙素溶液中饲养3.5～4h,取出脑神经节放入0.075mol/LKCl溶液中低渗30min,固定液中固定,空气干燥法制片,Giemsa染色.结果表明,致倦库蚊的染色体数目为2n=6,XY型,Ⅱ、Ⅲ号染色体为常染色体,Ⅰ号为性染色体,全部为中着丝粒染色体.在有丝分裂核型中观察到了大量四倍体现象,它在进化上的意义有待进一步探讨.另外在致倦库蚊中是否存在性染色体多态也有待进一步研究.

This paper studies the metaphase karyotype and intraspecific polymorphism of culex pipiens quinquefasciatus. It aims at probing into the differences of heredity in each subspecies of culex pipiens complex. The method is as follows: third-instar larvae at senior stage or fourth-instar larvae at junior stage are selected. The larvae are reared in 0.086% colchicines for 3.5～4 hours, the brain ganglia of the larvae are put into 0.075mol/L KCL fluid for 30 minutes and fixed in fixation fluid, the air-dired slides are stained with Giemsa. The result show that the number of culex pipiens quiquefasciatus karyptype is 6 (2n=6) with XY type. No. II and No. III belong to autosome. No. I belong to chromosome. All of chromosomes are metacentric. Many 4n cells have been observed in metaphase karyotypes. Its significance of evolution still needs to be further studied. Still more research work is needed to be done on whether culex pipiens quinquefasciatus has polymorphism of sex chromosome or not.