Htet Aung Htut, Makabe So, Takahashi Hiroko, Samuel Poku Aduse, Sato Yo-Ichiro, Nakamura Ikuo
Graduate School of Horticulture, Chiba University, Matsudo, Chiba 271-8510, Japan.
BEX Co. Ltd., Itabashi-ku, Tokyo 173-0004, Japan.
Breed Sci. 2022 Jun;72(3):267-273. doi: 10.1270/jsbbs.21075. Epub 2022 Jul 12.
AA-genome complex comprises five wild species, , , , , and . Evolutionary relationships among these five wild species have remained contentious and inconclusive. We found that intron 20 of , a single-copy nuclear gene, was short (S-type: 141-142 bp) in , , and , while long (L-type: 1.5 kb) introns were apparent in and . Because species containing BB, CC, EE, FF, and GG genome showed L-type introns, the S-type intron was probably derived from the L-type intron by the deletion of a 1.4 kb fragment through intramolecular homologous recombination between two tandem TTTTGC repeats. Excluding the large deletion sequence, intron 20 sequence of was identical to that of . As more than 3,470 accessions of and also contained the same intron 20 sequence with except for single T-nucleotide deletion, which was shared with , the deletion of the T-nucleotide probably occurred in the L-type intron 20 of . Deletions of a large 1.4 kb fragment and single T-nucleotide within the intron 20 of gene were considered as useful DNA markers to study the evolutionary relationships among AA-genome species.
AA基因组复合体由五个野生种组成，即[物种名称1]、[物种名称2]、[物种名称3]、[物种名称4]和[物种名称5]。这五个野生种之间的进化关系一直存在争议且尚无定论。我们发现，单拷贝核基因[基因名称]的第20内含子在[物种名称1]、[物种名称2]和[物种名称3]中较短（S型：141 - 142 bp），而在[物种名称4]和[物种名称5]中明显为长内含子（L型：1.5 kb）。由于含有BB、CC、EE、FF和GG基因组的物种显示为L型内含子，S型内含子可能是通过两个串联的TTTTGC重复序列之间的分子内同源重组缺失1.4 kb片段而从L型内含子衍生而来。排除大的缺失序列后，[物种名称6]的第20内含子序列与[物种名称7]的相同。由于除了与[物种名称8]共有的单个T核苷酸缺失外，超过3470份[物种名称9]和[物种名称10]的材料也含有与[物种名称6]相同的第20内含子序列，T核苷酸的缺失可能发生在[物种名称11]的L型第20内含子中。[基因名称]第20内含子内1.4 kb大片段和单个T核苷酸的缺失被认为是研究AA基因组物种间进化关系的有用DNA标记。
