Sequence characterization of microsatellites in diploid and polyploid Ipomoea
Sequence characterization of microsatellites in diploid and polyploid Ipomoea
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DOI：
10.1007/s001220051216
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发表时间：
1999-07-01
影响因子：
5.4
通讯作者：
LaBonte, DR
中科院分区：
文献类型：
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作者：
Buteler, MI;Jarret, RL;LaBonte, DR
本研究的目的是评估六倍体甘薯[Ipomoea batatas（L.）拉姆。]及其推定的四倍体和二倍体祖先，并通过等位基因直接测序来测试多倍体中可能的微卫星突变机制。从I.甘薯和测序。设计PCR引物，对两个六倍体I. batatas群体、四倍体Ipomoea trifida群体和二倍体I. trifida种群。测试的63个引物对中有9个产生了清晰可辨的可遗传的带型; 5个表现出孟德尔分离。所有其它引物对要么产生模糊的带型，这不能被标记，要么在I中完全没有带。红薯所有引物均能从I.在四倍体和二倍体I.三裂叶属的加入。在三个物种的几个等位基因的序列分析表明，由于在重复区域的突变与重复数的小差异一致的差异。然而，在某些情况下，微卫星侧翼区的插入/缺失和碱基替换负责多倍体和二倍体物种的多态性。这些结果提供了强有力的经验证据，复杂的遗传机制是负责SSR等位基因变异在番薯。四岛甘薯微卫星位点表现为符合四倍体分离比例的多体分离。据我们所知，这是第一次报告的分离率的微卫星标记在多倍体。
The objectives of the present study were to evaluate the inheritance and nucleotide sequence profiles of microsatellite genetic markers in hexaploid sweetpotato [Ipomoea batatas (L.) Lam.] and its putative tetraploid and diploid ancestors, and to test possible microsatellite mutation mechanisms in polyploids by direct sequencing of alleles. Sixty three microsatellite loci were isolated from genomic libraries of I. batatas and sequenced. PCR primers were designed and used to characterize microsatellite loci in two hexaploid I. batatas populations, a tetraploid Ipomoea trifida population, and a diploid I. trifida population. Nine out of the sixty three primer pairs tested yielded a clearly discernible, heritable banding pattern; five showed Mendelian segregation. All other primer pairs produced either smeared banding patterns, which could not bt: scored, or no bands at all in I. batatas. All of the primers which produced discernible banding patterns from I. batatas also amplified products of similar size in tetraploid and diploid I. trifida accessions. The sequence analysis of several alleles in the three species showed differences due to mutations in the repeat regions consistent with small differences in the repeat number. However, in some cases insertions/deletions and base substitutions in the microsatellite flanking regions were responsible for polymorphisms in both polyploid and diploid species. These results provide strong empirical evidence that complex genetic mechanisms are responsible for SSR allelic variation in Ipomoea. Four I. batatas microsatellite loci showed polysomic segregation fitting tetraploid segregation ratios. To our knowledge this is the first report of segregation ratios for microsatellites markers in polyploids.