A self-compatible mutant S allele conferring a dominant negative effect on the functional S allele in Ipomoea trifida
A self-compatible mutant S allele conferring a dominant negative effect on the functional S allele in Ipomoea trifida
复制标题
自交亲和突变体 S 等位基因对三裂叶薯功能性 S 等位基因产生显性负效应
DOI：
10.1007/s004970000048
复制
发表时间：
2000
影响因子：
--
通讯作者：
Y. Kowyama
中科院分区：
文献类型：
--
作者：
K. Kakeda;H. Tsukada;Y. Kowyama
摘要：在三裂叶薯（Ipomoea trifida）中鉴定出自发发生的自交亲和突变体，该物种具有由单个多等位基因 S 基因座控制的孢子体自交不亲和性。对自交亲和突变体自交和杂交后代的亲和/不亲和表型分离分析表明，自交亲和性状是由S位点突变引起的；因此，突变的 S 等位基因被指定为 Sc。使用 SSP 基因（与 I. trifida 的 S 基因座紧密连锁的基因）作为探针，对分离 Sc 等位基因的后代植物进行 RFLP 分析，证实突变存在于 S 基因座。在自交亲和突变体与三个 S 等位基因 S1、S3 和 S22 之一纯合的自交不亲和植物之间杂交获得的 F1 后代中检查了自交不亲和反应，其中显性关系是 S22>S1>S3。与 S22 和 S1 纯合子杂交的所有 F1 后代植物都是自交不亲和的，并且在柱头和花粉上都表现出每个自交不亲和亲本（S22 或 S1）各自的表型。然而，在与S3纯合子杂交的F1后代植物中，携带基因型ScS3的那些均作为与S3纯合子的雌性和雄性亲本自交亲和和交叉亲和。这些结果表明四个S等位基因之间的显性关系是：S22>S1>Sc>S3，因此揭示了突变的Sc等位基因比功能性S3等位基因显性的意外发现。对于这一观察结果的一个可能的解释是，Sc 等位基因编码的基因产物对 S3 基因产物产生显性负效应。
Abstract A spontaneously occurring self-compatible mutant has been identified in Ipomoea trifida, a species possessing sporophytic self-incompatibility controlled by a single multiallelic S locus. Analysis of the segregation of compatibility/incompatibility phenotypes in selfed and crossed progenies of the self-compatible mutant plant indicated that the self-compatibility trait was caused by a mutation at the S locus; the mutated S allele was therefore designated Sc. RFLP analysis of progeny plants segregating for the Sc allele using the SSP gene (a gene linked closely to the S locus of I. trifida) as a probe confirmed that the mutation was present at the S locus. Self-incompatibility responses were examined in F1 progenies obtained from crosses between the self-compatible mutant and self-incompatible plants homozygous for one of three S alleles, S1, S3 and S22, where the dominance relationship is S22>S1>S3. All F1 progeny plants from crosses with S22 and S1 homozygotes were self-incompatible and exhibited the respective phenotypes of each self-incompatible parent (either S22 or S1) in both stigma and pollen. However, of the F1 progeny plants from the cross with the S3 homozygote, those carrying the genotype ScS3 were all self-compatible and cross-compatible as both female and male parents with the S3 homozygote. These results indicate that the dominance relationship between the four S alleles is: S22>S1>Sc>S3 and so reveal the unexpected finding that the mutated Sc allele is dominant over a functional S3 allele. A possible explanation for this observation is that the gene product encoded by the Sc allele confers a dominant negative effect on the S3 gene product.
影响因子：
56.9
作者：
Schopfer, CR;Nasrallah, ME;Nasrallah, JB
通讯作者：
Nasrallah, JB