The Self-incompatibility (S) Locus of Antirrhinum Resides in a Pericentromeric Region  

金鱼草自交不亲和位点位于着丝粒的周边区(英文)

作　　者：马闻师[1] 周君莉[1] 赖钊[1] 张燕生[1] 薛勇彪[1] 

机构地区：[1]中国科学院遗传与发育研究所,北京100080

出　　处：《Acta Botanica Sinica》2003年第1期47-52,共6页Acta Botanica Sinica（植物学报：英文版）

基　　金：中国科学院和国家自然科学基金(39825103)~~

摘　　要：The self-incompatibility ( S) loci from the Solanaceae, Rosaceae and Scrophulariaceae encode a class of ribonucleases, known as S RNases, which have been shown to control the pistil expression of self-incompatible reaction. In the former two families, the S loci have been shown to be located near centromere. However, the chromosomal location of the S locus in Antirrhinum, a species of the Scrophulariaceae, is not known. To determine its chromosomal location and genomic organization, an S-2 RNase gene and its corresponding 63 kb BAC clone were separately used for fluorescence in situ hybridization (FISH) of mitotic metaphase chromosomes of a self-incompatible Antirrhinum line Of S2S5. The results showed that the S-2 RNase detected a doublet signal near the centromere of the smallest chromosome (2n = 16). Two separate doublet signals of the tested BAC sequence were shown on both sides of the centromeres of all eight pairs of the chromosomes, suggesting that the Antirrhinum S locus is located in a pericentromeric region. Furthermore, a retrotransposon, named RIS1 (retrotransposon in the S locus), which has not been identified yet in. Antirrhinum, was found next to S-2 RNase. Taken together, the centromeric location of the S locus from the three S-RNase-based self-incompatible families provides a further support on a common origin of their evolution as well as suppressed recombination.在蔷薇科、茄科和玄参科配子体自交不亲和中,编码花柱的S RNase控制花柱的自交不亲和性。在前两科植物中,自交不亲和(S)位点定位于着丝粒的附近,但在玄参科植物金鱼草(Antirrhinum)中自交不亲和位点至今未知。为了确定它在染色体上的位置和基因组结构,以基因型S2S5金鱼草根尖为材料,进行染色体的制备观察,利用地高辛标记的S2 RNase和含有其全长的BAC克隆(s2 BAC)为探针进行荧光染色体原位杂交(FISH),发现S2RNase杂交信号位于染色体的着丝粒附近,而S2 BAC的杂交信号位于每条染色体的着丝粒的周边区,呈对称的4个,表明金鱼草S位点位于着丝粒的周边区。对S2BAC预测基因的分析表明,发现一个金鱼草新的反转座子(RIS1)。结果显示,金鱼草S位点位于染色体着丝粒的周边区,富含转座子和反转座子,和其他两类配子体自交不亲和的位置类似,预示它们的共同起源和具有抑制重组的功能。

关 键 词：ANTIRRHINUM self-incompatibility (S) locus pericentromere RETROTRANSPOSON FISH 

分 类 号：Q945.5[生物学—植物学]