大熊猫系我国特产的世界珍稀动物,素有“活化石”和“国宝”之称。限于材料来源,虽有核型的少数报道(邓承宗等,1980;陈文元等,1984;Newnham et al.,1966),但研究尚不够深入。1980年,Wurster-Hill和Bush首先报道了大熊猫(♂)的显带核型,并与杂交熊等比较,探讨了大熊猫的分类地位。本文对四只大熊猫的G带、C带核型和Ag-NORs作了分析,绘制了G带核型模式图,并提出了某些商榷的意见。
We amplified the 197 bp HMG box sequence by using Polymerase Chain Reaction (PCR) with primers according to the known SRY sequence from male raccoon genomic DNA, and then cloned and sequenced. The nucleic acid and amino acid sequence comparison between raccoon and other mammals revealed high conservation of the SRY HMG box in mammals (about 80%), which implied that the DNA binding activity was crucial to mediate the action of SRY in sex determination. The variation of raccoon HMG box sequence mainly occurred on purine by replacement and missense mutation, which implicated that only the HMG box protein with advanced structure had efficient activity. The homology and difference between mammals HMG box was accorded to the evolution systematic tree.
