Vallenback Pernilla, Jaarola Maarit, Ghatnekar Lena, Bengtsson Bengt O
Department of Cell and Organism Biology, Lund University, Genetics Building, Sölvegatan 29, SE-223 62 Lund, Sweden.
Mol Phylogenet Evol. 2008 Mar;46(3):890-6. doi: 10.1016/j.ympev.2007.11.031. Epub 2007 Dec 10.
A segregating second locus, PgiC2, for the enzyme phosphoglucose isomerase (PGIC) is found in the grass sheep's fescue, Festuca ovina. We have earlier reported that a phylogenetic analysis indicates that PgiC2 has been horizontally transferred from the reproductively separated grass genus Poa. Here we extend our analysis to include intron and exon information on 27 PgiC sequences from 18 species representing five genera, and confirm our earlier finding. The origin of PgiC2 can be traced to a group of closely interrelated, polyploid and partially asexual Poa species. The sequence most similar to PgiC2 is found in Poa palustris with a divergence, based on synonymous substitutions, of only 0.67%. This value suggests that the transfer took place less than 600,000 years ago (late Pleistocene), at a time when most extant Poa and Festuca species already existed.
在羊茅属植物羊茅（Festuca ovina）中发现了一个与磷酸葡萄糖异构酶（PGIC）相关的分离的第二基因座PgiC2。我们之前曾报道，系统发育分析表明PgiC2是从生殖隔离的早熟禾属植物水平转移而来的。在此，我们扩展了分析范围，纳入了来自五个属的18个物种的27个PgiC序列的内含子和外显子信息，并证实了我们之前的发现。PgiC2的起源可以追溯到一组密切相关、多倍体且部分无性繁殖的早熟禾物种。与PgiC2最相似的序列存在于泽早熟禾（Poa palustris）中，基于同义替换，其分歧度仅为0.67%。这一数值表明该转移发生在不到60万年前（晚更新世），当时大多数现存的早熟禾属和羊茅属物种已经存在。
