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紫云英根瘤菌107菌株exo基因簇非连锁突变位点的克隆

曾维清, 宋鸿遇

中科院上海植物生理研究所.上海 200032

摘要

用鸟枪法从3株紫云英根瘤菌107菌株的胞外多糖合成缺陷变种(Exo~(-))NA-05、NA-07和NA-08中克隆获得含有107菌株exo基因及Tn5的exo::Tn5片段。以pRK415为载体构建107菌株EcoRⅠ酶切后DNA片段的部分基因库,用exo::Tn5做探针原位杂交得到一个阳性克隆。该克隆的外源片段4.2kb能恢复3个变种的多糖表及结瘤固氮能力。酶切分析和Southern杂交表明,3株变种中Tn5插入位点相近。

关键词： 鸟枪法; 紫云英根瘤菌; Exo基因克隆; 物理图谱

Cloning of an unlinked exo site from EPS synthesis deficient mutants of Rhizobium astragali strain 107

Zeng Weiqing, Song Hongyu

Shanghai Institute of Plant Physiology,The Chinese Academy of Sciences.Shanghai 200032

Abstract

By complementation test of NA-05, NA-07 and NA-08 with plasmids carrying exo genes of R. meliloti and Rhizobium sp. NGR234, the function of the exo gene cloned in pRK415 (the pRKM578) was identified as encoding for UDP-glucose-4-epimerase, as the exoB of R. meliloti and exoC of R. sp. NGR234.

Key words: Shtgun method;Rhizobium astragali;Exo gene cloning;Physical mapping

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引用本文：

曾维清, 宋鸿遇. 紫云英根瘤菌107菌株exo基因簇非连锁突变位点的克隆[J]. 生理学报 1997; 49 (4): .

Zeng Weiqing, Song Hongyu. Cloning of an unlinked exo site from EPS synthesis deficient mutants of Rhizobium astragali strain 107. Acta Physiol Sin 1997; 49 (4): (in Chinese with English abstract).