S locus-linked F-box genes expressed in anthers of Hordeum bulbosum
S locus-linked F-box genes expressed in anthers of Hordeum bulbosum
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DOI：
10.1007/s00299-009-0745-8
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发表时间：
2009-07
影响因子：
6.2
通讯作者：
K. Kakeda
中科院分区：
文献类型：
--
作者：
K. Kakeda
二倍体球茎大麦是栽培大麦的野生近缘种，其配子体表现为两个座位的自交不亲和(SI)系统，其配子体受不连锁的多等位基因SandZ控制。这一独特的SI系统在禾本科(Poaceae)包括小麦族(Triticeae)中观察到。本文介绍了球茎海棠中与Socus共分离的两个F-box基因，命名为Hordeum Slocus-Linked F-box 1(HSLF1)和HSLF2，这两个基因是从AMF(基于AFLP的mRNA指纹分析)获得的S3单倍型特异克隆(HAS175)衍生而来的。序列分析表明，这两个基因都编码富含亮氨酸重复序列(LRR)结构域的F-box蛋白，而不同于在以S核糖核酸酶为基础的配子体SI系统中被鉴定为花粉决定簇的F-box蛋白。在水稻基因组中发现了许多具有LRR结构域的同源F-box基因，尽管该基因家族的功能尚不清楚。HSLF1基因的一个等位基因(HSLF1-S3)在成熟花药中特异表达，而其他两个等位基因均未检测到表达。虽然3个HSLF1等位基因之间的序列多态程度较低，但在其中一个未表达的等位基因中发现了移码突变。HSLF2基因表达水平低，无组织特异性，3个等位基因间序列多态性较小。与S核糖核酸酶为基础的SI系统中发现的F-box基因的多样性进行了比较，并对其多样性进行了讨论。
DiploidHordeum bulbosum(a wild relative of cultivated barley) exhibits a two-locus self-incompatibility (SI) system gametophytically controlled by the unlinked multiallelic lociSandZ. This unique SI system is observed in the grasses (Poaceae) including the tribe Triticeae. This paper describes the identification and characterization of two F-box genes cosegregating with theSlocus inH.bulbosum, namedHordeumSlocus-linked F-box 1 (HSLF1) andHSLF2, which were derived from anS3haplotype-specific clone (HAS175) obtained by previous AMF (AFLP-based mRNA fingerprinting) analysis. Sequence analysis showed that both genes encode similar F-box proteins with a C-terminal leucine-rich repeat (LRR) domain, which are distinct fromSlocus (orShaplotype-specific) F-box protein (SLF/SFB), a class of F-box proteins identified as the pollenSdeterminant in S-RNase-based gametophytic SI systems. A number of homologous F-box genes with an LRR domain were found in the rice genome, although the functions of the gene family are unknown. One allele of theHSLF1gene (HSLF1-S3) was expressed specifically in mature anthers, whereas no expression was detected from the other two alleles examined. Although the degree of sequence polymorphism among the threeHSLF1alleles was low, a frameshift mutation was found in one of the unexpressed alleles. TheHSLF2gene showed a low level of expression with no tissue specificity as well as little sequence polymorphism among the three alleles. The multiplicity ofSlocus-linked F-box genes is discussed in comparison with those found in the S-RNase-based SI system.