Degeneration of the nonrecombining regions in the mating-type chromosomes of the anther-smut fungi.
Degeneration of the nonrecombining regions in the mating-type chromosomes of the anther-smut fungi.
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DOI：
10.1093/molbev/msu396
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发表时间：
2015-04
影响因子：
10.7
通讯作者：
Giraud T
中科院分区：
文献类型：
--
作者：
Fontanillas E;Hood ME;Badouin H;Petit E;Barbe V;Gouzy J;de Vienne DM;Aguileta G;Poulain J;Wincker P;Chen Z;Toh SS;Cuomo CA;Perlin MH;Gladieux P;Giraud T
真菌中的二态交配型染色体是理解重组抑制的基因组后果的极好模型。它们被抑制的重组和减少的有效群体大小预计会限制自然选择的效力，导致基因组退化。我们的目的是鉴定花药黑穗病真菌的交配型染色体（a1和a2）的序列，并研究其非重组区域的退化。我们使用了单倍体a1 lychnidis-dioicae Microbotryum参考基因组序列。对a1和a2配对型染色体进行了电泳分离和测序。结合限制-消化光学图谱，鉴定了交配型染色体的重组和非重组区域。此外，还获得了其他12种微生物的基因组序列数据。我们发现了强有力的证据表明，在交配型染色体的非重组区，整个属的退化，与非交配型染色体或交配型染色体的重组区相比，具有显著更高的非同义替换率（dN/dS）。交配型染色体的非重组区也表现出转座因子含量高、基因表达弱和基因丢失的现象。与X/Y或Z/W性染色体相比，a1和a2交配型染色体的退化程度没有差异，这与它们之间缺乏同质/异质不对称是一致的。
Dimorphic mating-type chromosomes in fungi are excellent models for understanding the genomic consequences of recombination suppression. Their suppressed recombination and reduced effective population size are expected to limit the efficacy of natural selection, leading to genomic degeneration. Our aim was to identify the sequences of the mating-type chromosomes (a1 and a2) of the anther-smut fungi and to investigate degeneration in their nonrecombining regions. We used the haploid a1 Microbotryum lychnidis-dioicae reference genome sequence. The a1 and a2 mating-type chromosomes were both isolated electrophoretically and sequenced. Integration with restriction-digest optical maps identified regions of recombination and nonrecombination in the mating-type chromosomes. Genome sequence data were also obtained for 12 other Microbotryum species. We found strong evidence of degeneration across the genus in the nonrecombining regions of the mating-type chromosomes, with significantly higher rates of nonsynonymous substitution (dN/dS) than in nonmating-type chromosomes or in recombining regions of the mating-type chromosomes. The nonrecombining regions of the mating-type chromosomes also showed high transposable element content, weak gene expression, and gene losses. The levels of degeneration did not differ between the a1 and a2 mating-type chromosomes, consistent with the lack of homogametic/heterogametic asymmetry between them, and contrasting with X/Y or Z/W sex chromosomes.
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DOI：
10.1093/bioinformatics/btp348
发表时间：
2009-08-01
期刊：
Bioinformatics (Oxford, England)
影响因子：
--
作者：
Capella-Gutiérrez S;Silla-Martínez JM;Gabaldón T
通讯作者：
Gabaldón T
影响因子：
10.7
作者：
Bachtrog, D
通讯作者：
Bachtrog, D
影响因子：
9.8
作者：
Fraser JA;Diezmann S;Subaran RL;Allen A;Lengeler KB;Dietrich FS;Heitman J
通讯作者：
Heitman J
影响因子：
10.7
作者：
Filatov, DA;Charlesworth, D
通讯作者：
Charlesworth, D
影响因子：
56.9
作者：
CHARLESWORTH, B
通讯作者：
CHARLESWORTH, B