真菌植物病原体基因组中一个重复DNA序列家族的宿主物种特异性保守性。

Host species-specific conservation of a family of repeated DNA sequences in the genome of a fungal plant pathogen.

作者信息

Hamer J E, Farrall L, Orbach M J, Valent B, Chumley F G

机构信息

Central Research and Development Department, E. I. du Pont de Nemours and Company, Inc., Wilmington, DE 19880-0402.

出版信息

Proc Natl Acad Sci U S A. 1989 Dec;86(24):9981-5. doi: 10.1073/pnas.86.24.9981.

We have identified a family of dispersed repetitive DNA sequences in the genome of Magnaporthe grisea, the fungus that causes rice blast disease. We have named this family of DNA sequences "MGR" for M. grisea repeat. Analysis of five MGR clones demonstrates that MGR sequences are highly polymorphic. The segregation of MGR sequences in genetic crosses and hybridization of MGR probes to separated, chromosome-size DNA molecules of M. grisea shows that this family of sequences is distributed among the M. grisea chromosomes. MGR sequences also hybridize to discrete poly(A)+ RNAs. Southern blot analysis using a MGR probe can distinguish rice pathogens from various sources. However, MGR sequences are not highly conserved in the genomes of M. grisea field isolates that do not infect rice. These results suggest that host selection for a specific pathogen genotype has occurred during the breeding and cultivation of rice.

我们在引起稻瘟病的真菌——稻瘟病菌（Magnaporthe grisea）的基因组中鉴定出了一个分散的重复DNA序列家族。我们将这个DNA序列家族命名为“MGR”，即稻瘟病菌重复序列。对五个MGR克隆的分析表明，MGR序列具有高度多态性。MGR序列在遗传杂交中的分离以及MGR探针与稻瘟病菌分离的染色体大小的DNA分子的杂交表明，这个序列家族分布在稻瘟病菌的染色体之间。MGR序列也与离散的聚腺苷酸加尾（poly(A)+）RNA杂交。使用MGR探针进行的Southern印迹分析可以区分来自不同来源的水稻病原体。然而，MGR序列在不感染水稻的稻瘟病菌田间分离株的基因组中并不高度保守。这些结果表明，在水稻的育种和栽培过程中，已经发生了针对特定病原体基因型的宿主选择。