Molecular genetic analysis of the self-incompatibility locus in a wild species of sweet potato

野生甘薯自交不亲和位点的分子遗传学分析

基本信息

批准号：
13460003
负责人：
KOWYAMA Yasuo
金额：
$ 9.34万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13460003/
关键词：
ipomoea trifida self-incompatibility genome analysis molecular genetics S-locus 遺伝子地図 BACライブラリー

项目摘要

Self-incompatibility (SI) in flowering plants is an elaborate genetic system that prevents self-fertilization and thereby promotes out-crossing to maintain generic diversity within a species. In a plant family, Convolvulaceae, several species of the genus ipomoea possess a sporophytic type of SI that causes a complete failure of pollen germination on the stigma surface after self-pollination. The SI system of Ipomoea is regulated by a single multiallelic locus called the S-locus. To identify the S-locus genes in Ipomoea, we used a positional cloning strategy based on a fine linkage map of DNA markers. Several genomic clones covering the S-locus were screened from bacterial artificial chromosome (BAC), λ and fosmid libraries that were constructed in the present study. Using the terminal end sequences of these clones, the S-locus region was further delimited within 0.6 cM, spanning ca. 300kb. Remarkable suppression of genetic recombination was detected in the S-locus region. From sequence analysis of the 313-kp region, 43 open reading frames (ORFs), many repetitive sequences and 5 transposable elements were predicted. Northern blot analysis of mRNAs isolated from reproductive and vegetative organs showed that five and four genes were specifically expressed in the stigma and anther-pollen, respectively. The present study made clear that these reproductive specific genes showed no homologies with the SI genes reported to date from other plants and suggests that a unique molecular mechanism is involved in the SI system of Convolvulaceae family.

开花植物中的自我兼容（SI）是一种精致的遗传体系，可防止自我受精，从而促进越过，以维持物种内的通用多样性。在植物家族中，腹膜科的几种物种具有一种孢子虫类型的Si，在自花线后会导致花粉发芽在污名表面上的完全失败。 ipomoea的Si系统由一个称为S-cocus的单个多层基因座调节。为了识别依属息护物中的S-cocus基因，我们使用了基于DNA标记的精细链接图的位置克隆策略。从本研究中构建的细菌人工染色体（BAC），λ和Fosmid库中筛选了几个覆盖S-Ocus的基因组克隆。使用这些克隆的末端序列，S-Ocus区域在0.6厘米内进一步划定，跨越大约。 300kb。在S-Ocus区域检测到了遗传重组的明显抑制。从313-KP区域的序列分析，43个开放式阅读帧（ORF），预测了许多重复序列和5个可转座元素。从生殖和植物器官中分离出的mRNA的北印迹分析表明，分别在污名和其他菌毛中特别表达了五个和四个基因。本研究明确指出，这些生殖特异性基因尚未与其他植物报告的SI基因同源，这表明Chordolvulaceae家族的SI系统中有一种独特的分子机制。