七种雀形目鸟类染色体组型的比较研究

A COMPARATIVE STUDY OF THE KARYOTYPES FROM SEVEN SPECIES OF PASSERINE BIRDS

鸟类的核型由于制作上的困难和核型中含有大量的微小染色体,在脊椎动物中是研究得最少的一个类群。迄今,已记载过核型的不到500种,尚不及世界鸟类总数的5%,其中大多数是观尝鸟类或家禽。在我国,除家鸡和家鸭外,均未见有报道。染色体的数目和形态一般具有种的特性。染色体核型的比较研究,对于了解物种的特性、探索物种的分类、遗传、进化和系统发育都有一定的意义。本文报道七种野生雀形目鸟类的染色体组型。

This paper present the comparative studies of the karyotpes of 7 species of passerine birds. The karyotypcs were made from metaphase of bone marrow by the colchicinc-hypotonic-air drying technique. The results were given as follows. Motacillidac Anthus h. hodgsoni Richmond 2n=±74, AN±92 Anthus roseatus Blyth 2n=±80, AN =±92 Muscicapidac (Sylvinae) Phylloscopus fuscatus (Blyth) 2n=±76, An =±86 Phylloscopus a/finis (Tickell) 2n=±76, AN =±84 Phylloscopus p. pulcher Blyth 2n=±8, AN =±0 Fringillidae Cardnclis a. ambigua (Oustalet) 2n=±80, AN=±92 Emberiza pusilla Pallas 2n=±80, AN=±94 By a comparative study, we had tound that the five species of them (A. h. hodgsoni, A. roseatus, P. p. pulcher, C. a. ambigua and E. pusilla) had more metacenlric or submctaccntric chromosomes than their allies. These birds were distributed only or mainly over the Qinghai-Xizang Plateau, the region of the Tanshymalaya and the Himalaya. It was probable that these birds were relatively more, specialized. The phenomenon of parallel evolution of the chromosomes was been found in the karyotypcs of five passerine birds distributing these region, which was been evolved from tcloccntric chromosomes to metace-ntric ones. The result of the evolutions showed that the numbers ot rne-or sub-mctaccnlric chromosomes were been increased.