Ghatnekar Lena, Jaarola Maarit, Bengtsson Bengt O
Department of Cell and Organism Biology, Genetics, Lund University, Sölvegatan 29, 223 62 Lund, Sweden.
Proc Biol Sci. 2006 Feb 22;273(1585):395-9. doi: 10.1098/rspb.2005.3355.
In sheep's fescue, Festuca ovina, genes coding for the cytosolic enzyme phosphoglucose isomerase, PGIC, are not only found at the standard locus, PgiC1, but also at a segregating second locus, PgiC2. We have used PCR-based sequencing to characterize the molecular structure and evolution of five PgiC1 and three PgiC2 alleles in F. ovina. The three PgiC2 alleles were complex in that they carried two gene copies: either two active genes or one active and one pseudogene. All the PgiC2 sequences were very similar to each other but highly diverged from the five PgiC1 sequences. We also sequenced PgiC genes from several other grass species. Phylogenetic analysis of these sequences indicates that PgiC2 has introgressed into F. ovina from the distant genus Poa. Such an introgression may, for example, follow from a non-standard fertilization with more than one pollen grain, or a direct horizontal gene transfer mediated by a plant virus.
在羊茅属植物羊茅(Festuca ovina)中,编码胞质酶磷酸葡萄糖异构酶(PGIC)的基因不仅存在于标准位点PgiC1,还存在于一个分离的第二位点PgiC2。我们利用基于PCR的测序技术对羊茅中五个PgiC1等位基因和三个PgiC2等位基因的分子结构及进化进行了表征。三个PgiC2等位基因很复杂,因为它们携带两个基因拷贝:要么是两个活性基因,要么是一个活性基因和一个假基因。所有PgiC2序列彼此非常相似,但与五个PgiC1序列高度不同。我们还对其他几种禾本科植物的PgiC基因进行了测序。对这些序列的系统发育分析表明,PgiC2已从远缘的早熟禾属渗入到羊茅中。例如,这种渗入可能是由于不止一个花粉粒的非标准受精,或者是由植物病毒介导的直接水平基因转移导致的。