The sea lamprey meiotic map improves resolution of ancient vertebrate genome duplications.
The sea lamprey meiotic map improves resolution of ancient vertebrate genome duplications.
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DOI：
10.1101/gr.184135.114
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发表时间：
2015-08
期刊：
影响因子：
7
通讯作者：
Keinath MC
中科院分区：
文献类型：
--
作者：
Smith JJ;Keinath MC
人们普遍认为，脊椎动物基因组中存在的许多基因的起源归功于发生在脊椎动物谱系祖先深处的两个全基因组复制。然而，关于这些重复的时间和结果的细节还没有得到很好的解决。我们提出了高密度的减数分裂和比较基因组图谱的海七鳃鳗（Petromyzon marinus），一个古老的血统的代表，从所有其他脊椎动物的分歧5.5亿年前。连锁分析共得到95个连锁群，与估计的生殖系染色体数（1n = 99）相似，总跨度为5570.25 cM。比较映射数据产生强有力的支持，一个单一的全基因组重复发生在基础脊椎动物谱系的假设，但不强烈支持假设的第二个事件。相反，这些比较地图揭示了在过去6亿多年的脊索动物进化中发生的几个进化上独立的节段复制。脊椎动物基因组复制的这一精确的历史应该允许对脊椎动物进化进行更精确的研究。
It is generally accepted that many genes present in vertebrate genomes owe their origin to two whole-genome duplications that occurred deep in the ancestry of the vertebrate lineage. However, details regarding the timing and outcome of these duplications are not well resolved. We present high-density meiotic and comparative genomic maps for the sea lamprey (Petromyzon marinus), a representative of an ancient lineage that diverged from all other vertebrates ∼550 million years ago. Linkage analyses yielded a total of 95 linkage groups, similar to the estimated number of germline chromosomes (1n ∼ 99), spanning a total of 5570.25 cM. Comparative mapping data yield strong support for the hypothesis that a single whole-genome duplication occurred in the basal vertebrate lineage, but do not strongly support a hypothetical second event. Rather, these comparative maps reveal several evolutionarily independent segmental duplications occurring over the last 600+ million years of chordate evolution. This refined history of vertebrate genome duplication should permit more precise investigations of vertebrate evolution.