Bugrov Alexander G, Karamysheva Tatiana V, Perepelov Eugeny A, Elisaphenko Eugeny A, Rubtsov Denis N, Warchałowska-Sliwa Elzbieta, Tatsuta Haruki, Rubtsov Nikolay B
Novosibirsk State University, 630090, Novosibirsk, Russia.
Chromosome Res. 2007;15(3):315-25. doi: 10.1007/s10577-007-1128-z. Epub 2007 May 10.
A DNA library derived from the B chromosome of Podisma kanoi was obtained by chromosome microdissection. A total of 153 DNA clones were isolated from the microdissected DNA library. Twenty of them were sequenced. A comparison of B chromosome DNA sequences with sequences of other species from the DDBJ/GenBank/EMBL database ( http://www.ddbj.nig.ac.jp/ ) was performed. Different patterns of signals were observed after FISH with labeled cloned DNA fragments. FISH signals with cloned DNA fragments painted either whole Bs or their different regions. Some clones also gave signals in pericentromeric regions of A chromosomes. Other cloned DNA fragments gave only background-like signals on A and B chromosomes. Comparative FISH analysis of B chromosomes in Podisma kanoi and P. sapporensis with DNA probes derived from the Bs of these species revealed homologous DNA that was confined within pericentromeric and telemetric regions of the B chromosome in P. kanoi. In contrast to the B chromosomes in P. sapporensis containing large regions enriched with rDNA, only a small cluster of rDNA was detected in one of the examined B chromosomes in P. kanoi. The data strongly suggest an independent origin of B chromosomes in two closely related Podisma species.
通过染色体显微切割获得了源自斑腿蝗科斑腿蝗B染色体的DNA文库。从显微切割的DNA文库中总共分离出153个DNA克隆。对其中20个进行了测序。将B染色体DNA序列与DDBJ/GenBank/EMBL数据库（http://www.ddbj.nig.ac.jp/ ）中其他物种的序列进行了比较。用标记的克隆DNA片段进行荧光原位杂交（FISH）后观察到不同的信号模式。克隆DNA片段的FISH信号标记了整个B染色体或其不同区域。一些克隆在A染色体的着丝粒周围区域也产生信号。其他克隆的DNA片段在A染色体和B染色体上仅产生类似背景的信号。用源自这些物种B染色体的DNA探针，对斑腿蝗科斑腿蝗和北海道蝗的B染色体进行比较FISH分析，结果显示同源DNA局限于斑腿蝗科斑腿蝗B染色体的着丝粒周围和端粒区域。与北海道蝗的B染色体含有大片富含核糖体DNA（rDNA）的区域不同，在斑腿蝗科斑腿蝗的一条被检测B染色体中仅检测到一小簇rDNA。这些数据有力地表明，两个近缘斑腿蝗物种的B染色体起源独立。
