果蝇(Drosophila melanogaster)唾腺染色体的制备与分析是果蝇细胞遗传研究的基本实验技术,也是非常流行的遗传学教学实验.国内绝大多数的实验教材介绍了这个实验的操作方法,但对于如何辨别染色体各条臂,并进而识别具体的带纹均未予以介绍.笔者详细介绍唾腺染色体的制备及拍摄、数码照片拼接方法;并着重介绍如何根据各条臂端粒端的形态特征,以及利用Lefevre的唾腺染色体照片图谱中指示的蓬突(puff)、缢缩及带纹组合特征识别染色体臂的方法,供研究和实验教学参考.
Polytene chromosome preparation is a basic technique in the Drosophila cytogenetics research,and is also a popular genetics laboratory investigation.Most laboratory menus provide protocols for polytene chromosome squash preparation,but they do not describe how to identify chromosome arms,and then to resolve the specific band(s).Here we provided detailed protocols for the polytene chromosome squash preparation,photography and the assemble of digital chromosome photos;and we described,especially for the beginner,how to recognize the chromosome arms of Drosophila melanogaster by the telomeric ends,landmark puffs,constrictions and the banding patterns indicated by Lefevre's photographic map of each of the chromosome limbs.