Suppressor mutants of Neurospora crassa that tolerate allelic differences at single or at multiple heterokaryon incompatibility loci.
Suppressor mutants of Neurospora crassa that tolerate allelic differences at single or at multiple heterokaryon incompatibility loci.
复制标题
粗糙脉孢菌的抑制突变体，可耐受单个或多个异核不相容位点的等位基因差异。
DOI：
10.1093/genetics/137.3.731
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发表时间：
1994
期刊：
影响因子：
3.3
通讯作者：
Akins,RA
中科院分区：
文献类型：
--
作者：
Arganoza,MT;Ohrnberger,J;Min,J;Akins,RA
粗糙脉孢菌至少11个异核体不亲和性(HET)基因座中任何一个的等位基因差异都会引发不亲和性反应：菌丝融合部位的局部细胞死亡。我们已经分离出了自发的和插入的抑制突变体，它们是异核体相容的，尽管在一个或几个het基因座上存在等位基因差异。一些基因内和基因外突变体仅在单个het基因座上耐受等位基因差异。通过同时选择对het-c、-d和-e或这些加交配型中的每一个的差异的耐受性，分离出多耐受的自发突变体。一些抑制突变体在受影响的het基因座上只针对一个等位基因；另一些突变体抑制了两个等位基因。插入突变是从转化子库中分离出来的，每个转化子都有一个整合到染色体上随机位置的质粒。1个突变体在het-d耐受等位基因差异。来自脉孢霉基因组库的同源粘粒补充了突变的表型。第二个插入失活突变体耐受het-c差异。与整合位点对应的野生型基因座的失活是通过重复诱导点突变(RIP)完成的。RIP后代和最初的突变体一样，对het-c的差异具有耐受性。在病原真菌中使用这种抑制突变体作为低毒性的通用供体是可能的。
Allelic differences at any one of at least 11 heterokaryon incompatibility (het) loci in Neurospora crassa trigger an incompatibility response: localized cell death at sites of hyphal anastomosis. We have isolated spontaneous and insertional suppressor mutants that are heterokaryon-compatible in spite of allelic differences at one or at several het loci. Some intra- and extragenic mutants tolerated allelic differences only at single het loci. Multi-tolerant spontaneous mutants were isolated by selecting simultaneously for tolerance of differences at het-c, -d and -e, or at each of these plus mating-type. Some suppressor mutants were specific for only one allele at the affected het locus; others suppressed both alleles. Insertional mutations were isolated from banks of transformants, each having a plasmid integrated into a random position in the chromosome. One mutant tolerated allelic differences at het-d. A homologous cosmid from a Neurospora genomic bank complemented the mutant phenotype. A second insertional inactivation mutant was tolerant of het-c differences. Inactivation of the wild-type locus corresponding to the integration site was accomplished by repeat-induced point mutation (RIP). The RIP progeny, like the original mutant, were tolerant of differences at het-c. It may be possible to use such suppressor mutants as universal donors of hypovirulence in pathogenic fungi.