Chromosome Structure and Function Laboratory, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466, Gatersleben, Germany,
Cell Mol Life Sci. 2014 Feb;71(3):467-78. doi: 10.1007/s00018-013-1437-7. Epub 2013 Aug 3.
B chromosomes (Bs) are dispensable components of the genome exhibiting non-Mendelian inheritance and have been widely reported on over several thousand eukaryotes, but still remain an evolutionary mystery ever since their first discovery over a century ago [1]. Recent advances in genome analysis have significantly improved our knowledge on the origin and composition of Bs in the last few years. In contrast to the prevalent view that Bs do not harbor genes, recent analysis revealed that Bs of sequenced species are rich in gene-derived sequences. We summarize the latest findings on supernumerary chromosomes with a special focus on the origin, DNA composition, and the non-Mendelian accumulation mechanism of Bs.
B 染色体(Bs)是基因组中可缺少的成分,表现出非孟德尔遗传特性,已经在几千多种真核生物中广泛报道,但自一个多世纪前首次发现以来,它们仍然是一个进化之谜[1]。近年来,基因组分析的进展极大地提高了我们对 Bs 起源和组成的认识。与 Bs 不携带基因的普遍观点相反,最近的分析表明,已测序物种的 Bs 富含基因衍生序列。我们总结了关于额外染色体的最新发现,特别关注 Bs 的起源、DNA 组成和非孟德尔积累机制。