【摘要】 本文报道了中华大蟾蜍(Bufo bufo gargartzans)的C带和BrdUrd-Hoechst-Giemsa复制带,并以中华大蟾蜍为代表确立了两栖类体细胞的姐妹染色单体差别染色(SCD)方法。BrdUrd-Hoechst-Giemsa技术在两栖类的中期染色体上能显示可重复的复合带型。用这种方法我们鉴定中华大蟾蜍第10对同型染色体为ZZ/ZW型性染色体,所有雄性动物两个Z染色体的复制型是完全相同的(同步复制的),而雌性动物的Z和W染色体显示出异型复制型(不同步复制的)。在W染色体长臂近着丝粒处有一个较早的复制带,Z染色体则缺乏这个复制带。这些性染色体用C带和其他方法不能区分。此外,我们还测定了中华大蟾蜍淋巴细胞的SCE频率,发现其SCE频率比哺乳动物高,为7.83±0.49(m±S.E.)。更多还原

【Abstract】 The C-banding and BrdUrd-Hoechst-Giemsa replication pattern in somatic chromosomes in Bufo bufo gargarizans and sister chromatid differential staining technique of the somatic cells in Amphibia are presented in this article.Metaphase chromosomes showing multiple banding pattern were easily reproducible using BrdUrd-Hoechst-Giemsa technique in Amphibia.With this method the homomorphic chromosome pair No.10 in Bufo bufo gargarizans could be identified as sex-specific chromosomes of the ZZ/ZW-type.The Z chromosomes in all male animals replicated synchronously,but Z chromosome and W chromosome of females revealed heteromorphic replication pattern.There was anearlier replication band in the broad,late replication legion on W chromosome’s long arm,whilst Z chromosome lacked this earlier replication band.The sex chromosomes could not be identified using C-banding and other techniques we used.We found that the SCE frequency of somatic cells in Bufo bufo gargarizans was 7.83 + 0.49 (m + S.E.),which was higher than that of mammals in general.更多还原