RRC ID |
31334
|
著者 |
Satou Y, Hirayama K, Mita K, Fujie M, Chiba S, Yoshida R, Endo T, Sasakura Y, Inaba K, Satoh N.
|
タイトル |
Sustained heterozygosity across a self-incompatibility locus in an inbred ascidian.
|
ジャーナル |
Mol Biol Evol
|
Abstract |
Because self-incompatibility loci are maintained heterozygous and recombination within self-incompatibility loci would be disadvantageous, self-incompatibility loci are thought to contribute to structural and functional differentiation of chromosomes. Although the hermaphrodite chordate, Ciona intestinalis, has two self-incompatibility genes, this incompatibility system is incomplete and self-fertilization occurs under laboratory conditions. Here, we established an inbred strain of C. intestinalis by repeated self-fertilization. Decoding genome sequences of sibling animals of this strain identified a 2.4-Mbheterozygous region on chromosome 7. A self-incompatibility gene, Themis-B, was encoded within this region. This observation implied that this self-incompatibility locus and the linkage disequilibrium of its flanking region contribute to the formation of the 2.4-Mb heterozygous region, probably through recombination suppression. We showed that different individuals in natural populations had different numbers and different combinations of Themis-B variants, and that the rate of self-fertilization varied among these animals. Our result explains why self-fertilization occurs under laboratory conditions. It also supports the concept that the Themis-B locus is preferentially retained heterozygous in the inbred line and contributes to the formation of the 2.4-Mb heterozygous region. High structural variations might suppress recombination, and this long heterozygous region might represent a preliminary stage of structural differentiation of chromosomes.
|
巻・号 |
32(1)
|
ページ |
81-90
|
公開日 |
2015-1-1
|
DOI |
10.1093/molbev/msu268
|
PII |
msu268
|
PMID |
25234703
|
MeSH |
Animals
Animals, Inbred Strains / genetics*
Animals, Inbred Strains / physiology
Chromosomes
Ciona intestinalis / genetics*
Ciona intestinalis / physiology
Genetic Loci
Genetic Variation
Heterozygote*
Self-Fertilization
Sequence Analysis, DNA
|
IF |
11.062
|
引用数 |
3
|
WOS 分野
|
GENETICS & HEREDITY
BIOCHEMISTRY & MOLECULAR BIOLOGY
EVOLUTIONARY BIOLOGY
|
リソース情報 |
カタユウレイボヤ・(ニッポンウミシダ) |
Wild C. int |