摘要
采用骨骼细胞直接制备染色体标本法和BSG及Ag-NORs显带技术,研究了小山蛙(Rana minimus)和中国雨蛙(Hyla chinensis)的常规核型、C-带和Ag-NORs。小山蛙2n=26,有5对大型和8对小型染色体。第6对染色体短臂近着丝点处具次缢痕,并为C-带染色阳性,银带显示此次缢痕处,即是标准NORs。C-带显现于几乎所有染色体的着丝点区,插入型C-带少且弱,无端位带。中国雨蛙2n=24,有6对大型和6对小型染色体。次缢痕在第10对染色体长臂上,亦为C-带染色阳性,并与银染显示的标准NORs相一致。C-带分析表明,亦以着丝点C-带为主,插入型C-带少,无端位带。本文初步讨论了蛙科和雨蛙科的核学特征以及它们间的演化关系。
Using bone marrow preparing chromosome method.BSG technique and a quick Ag-stained NORs method,the conventional,C-banded and Ag-stained karyotypes of Rana minimus Ting et Ts'ai and Hyla ckinensis Guenther were studied.The diploid number of R.minimus is 2n=26,consisting of 5 pairs of large and 8 pairsof small chromosomes.A secondary constriction is observed at a position near the centromere on the short arm of chromosome No.6 and it is also the position of the 'standard NORs' Chromosome C-banding shows that the heteroch.romations of R.minimimus are located in the centromeric and pericentrorneric regions,with comparatively few lightly-stained interstitial C-bands and no telomeric ones.And the secondary constriction is C-banding positively stained.H.chinensis has 24 chromosomes which divide into a group of 6 large pairs and a group of 6 small pairs.A secondary constriction appears at a position on the long arm of chromosome No.10.It is also the position of the 'standard NORs' and C-banding positively stained.The C-banding pattern is mainly composed of centiomeric C-bands with few interstitial ones and no telomeric ones.The karyotypic characters of Ranidae and Hylidae and the relationship to the evolution are also discussed.
关键词
核型
C带
银染
山蛙
雨蛙
Karyotype,C-banding,Ag-NORs,Amphibians
