A populational survey of 45S rDNA polymorphism in the Jefferson salamander Ambystoma jeffersonianum revealed by fluorescence in situ hybridization(FISH)
A populational survey of 45S rDNA polymorphism in the Jefferson salamander Ambystoma jeffersonianum revealed by fluorescence in situ hybridization(FISH)作者机构:Department of Integrative BiologyUniversity of GuelphGuelphOntario N1G 2W1Canada
出 版 物:《Current Zoology》 (动物学报(英文版))
年 卷 期:2009年第55卷第2期
页 面:145-149页
核心收录:
学科分类:0710[理学-生物学] 07[理学] 0905[农学-畜牧学] 09[农学] 071007[理学-遗传学] 090501[农学-动物遗传育种与繁殖]
基 金:supported by NSERC discovery grants
主 题:rDNA Polymorphism Jefferson salamander Ambystoma jeffersonianum Fluorescence in situ hybridization FISH-rDNA
摘 要:The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among *** populations in terms of number,location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of *** that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation,low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.