Deletion of a 236 kb region around S4-RNase in a stylar-part mutant S4sm-haplotype of Japanese pear
Deletion of a 236 kb region around S4-RNase in a stylar-part mutant S4sm-haplotype of Japanese pear
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DOI：
10.1007/s11103-007-9277-1
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发表时间：
2008-03-01
影响因子：
5.1
通讯作者：
Takasaki-Yasuda, Takeshi
中科院分区：
文献类型：
--
作者：
Okada, Kazuma;Tonaka, Nozomi;Takasaki-Yasuda, Takeshi
日本梨（Pyrus pyrifolia Nakai）具有配子体自交不亲和（GSI）机制，其由具有多个S-单倍型的单个S-位点控制，每个S-单倍型包含决定雌蕊和花粉的等位基因身份的独立基因。雌蕊S基因是S-核糖核酸酶（S-RNase）基因，而花粉S基因的良好候选者是F-box蛋白基因。自交亲和品种"Osa-Nijisseiki"是“Nijisseiki”（S_2S_4）的芽突变体，其花柱部分突变体为S-4（sm）-单倍型，缺失S-4-RNase基因，但保留花粉S基因。为了描绘S-4（sm）单倍型中的缺失断点，我们从S-4纯合子构建了细菌人工染色体（BAC）文库，并在S-4-RNase周围组装了570 kb的BAC重叠群。对S-4-和S-4（sm）-纯合子的DNA和BAC重叠群的DNA序列进行基因组PCR，可以鉴定S-4-RNase上游48 kb至下游188 kb的236 kb缺失。S-4（sm）-单倍型缺少34个预测的开放阅读框（ORF），包括S-4-RNase和花粉特异性F-box蛋白基因（称为S4 F-box 0）。基因组PCR与引物对设计的缺失路口产生了一个产品的S-4（SM）-单倍型。该产物可作为早期选择具有S-4（sm）单倍型的SC品种的标记。
Japanese pear (Pyrus pyrifolia Nakai) has a gametophytic self-incompatibility (GSI) mechanism controlled by a single S-locus with multiple S-haplotypes, each of which contains separate genes that determine the allelic identity of pistil and pollen. The pistil S gene is the S-ribonuclease (S-RNase) gene, whereas good candidates for the pollen S gene are the F-box protein genes. A self-compatible (SC) cultivar, 'Osa-Nijisseiki', which is a bud mutant of 'Nijisseiki' (S2S4), has a stylar-part mutant S-4(sm)-haplotype, which lacks the S-4-RNase gene but retains the pollen S gene. To delineate the deletion breakpoint in the S-4(sm)-haplotype, we constructed a bacterial artificial chromosome (BAC) library from an S-4-homozygote, and assembled a BAC contig of 570 kb around the S-4-RNase. Genomic PCR of DNA from S-4- and S-4(sm)-homozygotes and the DNA sequence of the BAC contig allowed the identification of a deletion of 236 kb spanning from 48 kb upstream to 188 kb downstream of S-4-RNase. The S-4(sm)-haplotype lacks 34 predicted open reading frames (ORFs) including the S-4-RNase and a pollen-specific F-box protein gene (termed as S4F-box0). Genomic PCR with a primer pair designed from the deletion junctions yielded a product specific for the S-4(sm)-haplotype. The product could be useful as a maker for early selection of SC cultivars harboring the S-4(sm)-haplotype.