Centromeric localization of an S-RNase gene in Petunia hybrida Vilm.
Centromeric localization of an S-RNase gene in Petunia hybrida Vilm.
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DOI：
10.1007/s001220051249
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发表时间：
1999-08-01
影响因子：
5.4
通讯作者：
Isogai, A
中科院分区：
文献类型：
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作者：
Entani, T;Iwano, M;Isogai, A
S核糖核酸酶已被鉴定为茄科植物自交不亲和反应中S等位基因特异的花柱决定基因。为确定S核糖核酸酶基因的物理位置，利用S核糖酶基因和S-B1核糖核酸酶基因探针进行了多色荧光原位杂交。S-B1-核糖核酸酶基因是位于第三染色体着丝粒附近的一对偶联信号。接下来，我们用从克隆SB1-311(20kb)制备的大基因组探针进行FISH。该探针与所有杂交杨染色体的着丝粒区域杂交。对Lambda SB1-311克隆的序列分析表明，存在一个由新的666bp单位序列组成的重复序列。含有该单位序列的亚克隆(PBS-SB1B5)也与所有着丝粒区域杂交，证实该单位是着丝粒特异重复序列。这些数据表明，S-B1-核糖核酸酶基因与着丝粒特异重复序列非常接近(在12kb以内)。同样，PBS-SB1B5探针与矮牵牛的所有染色体着丝粒区域杂交。然而，该探针没有与茄科其他物种的染色体着丝粒杂交。这些结果表明，该着丝粒重复序列可能是一个属特有的序列。
S-RNase has been identified to be an S-allele-specific stylar determinant contributing to the self-incompatibility response in Solanaceae. In order to examine the physical location of the S-RNase gene, multi-color fluorescence in situ hybridization (FISH) using the S-B1-RNase cDNA probe and ribosomal RNA gene (rDNA) probe was performed on an (SSB2)-S-B1 heterozygote of Petunia hybrids. The S-B1-RNase gene was detected as a doublet signal close to the centromere of chromosome III. Next, we performed FISH using a large genome probe prepared from a lambda SB1-311 clone (20 kb) which contains the SB1-RNase gene and its 3' flanking region. This probe hybridized to the centromeric regions of all P. hybrida chromosomes. Sequence analysis of the lambda SB1-311 clone revealed the presence of a repetitive sequence consisting of a novel 666 bp unit sequence. A subclone (pBS-SB1B5) containing this unit sequence also hybridized to all of the centromeric regions, confirming that this unit is the centromeric specific repetitive sequence. These data suggested that the S-B1-RNase gene is located very close to (within a distance of 12 kb from) the centromeric-specific repetitive sequence. Likewise, the pBS-SB1B5 probe hybridized to the centromeric regions of all chromosomes in P littoralis, another Petunia species. However, the probe did not hybridize to the centromere of the chromosomes from other species in Solanaceae. These results suggested that this centromeric repetitive sequence might be a genus-specific one.