Significant loss of genetic diversity and accumulation of deleterious genetic variation in a critically endangered azalea species, Rhododendron boninense, growing on the Bonin Islands
Significant loss of genetic diversity and accumulation of deleterious genetic variation in a critically endangered azalea species, Rhododendron boninense, growing on the Bonin Islands
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小笠原群岛上生长的极度濒危杜鹃花品种博宁杜鹃遗传多样性显着丧失，有害遗传变异不断积累
DOI：
10.1111/1442-1984.12270
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发表时间：
2020
影响因子：
1.4
通讯作者：
Mayu Shibabayashi
中科院分区：
文献类型：
--
作者：
Yuji Isagi;Takashi Makino;Tomoko Hamabata;Ping-Lin Cao;Satori Narita;Yoshiteru Komaki;Kazuki Kurita;Akiyo Naiki;Yoshiaki Kameyama;Toshiaki Kondo;Mayu Shibabayashi
遗传多样性的丧失会增加近亲繁殖导致种群灭绝的风险。此外，有害的遗传变异的数量可能通过遗传漂变而在小种群中积累，也可能使种群变得脆弱。博宁杜鹃是一种极度濒危的杜鹃花品种，生长在联合国教科文组织世界遗产小笠原群岛；它在野外的种群数量下降到只有一个个体。尽管政府实施了物种保护计划，但没有成功实现自然再生或种群增长。我们假设遗传多样性的减少和有害遗传变异的积累可能导致物种的脆弱性，并在R.博宁及其同类。微卫星标记遗传分析表明R.的遗传多样性。博尼尼斯最终处于低水平；该物种的微卫星位点都是固定的，而同源物则保持较高的等位基因多样性。基于综合转录组分析，R 的有害变异量。 boninense 明显大于 R。天井。 R 的小种群的重复代际转变。海洋岛屿上的博宁尼翁可能导致遗传多样性较低以及基因组中更多有害变异，我们推测累积的有害变异可能导致R的脆弱性。博尼尼塞。这项研究表明可以根据极度濒危物种基因组的遗传多样性和累积的有害变异量来评估有效保护计划的可行性。
Loss of genetic diversity increases the risk of extinction of a population through inbreeding depression. In addition, the number of deleterious genetic variations, which might accumulate in a small population through genetic drift, can also make the population vulnerable.Rhododendron boninenseis a critically endangered azalea species, which grows on the Bonin Islands, a UNESCO World Heritage Site; its population size in the wild dropped to only a single individual. Although a governmental program for species conservation has been conducted, no successful natural regeneration or population growth was achieved. We hypothesized that the reduced genetic diversity and accumulated deleterious genetic variation might cause the vulnerability of the species, and conducted comparative genetic and genomic analyses betweenR. boninenseand its congeners. Genetic analysis using microsatellite markers indicated that the genetic diversity ofR. boninensewas ultimately low; microsatellite loci of this species were all fixed, whereas the congeners maintain high allelic diversity. Based on comprehensive transcriptome analysis, the amount of deleterious variation ofR. boninensewas significantly greater than that ofR. amanoi. Repeated generation transitions of the small population ofR. boninenseon the oceanic islands is likely to have resulted in low genetic diversity as well as more deleterious variations in the genome, and we speculated that the accumulated deleterious variation might result in vulnerability ofR. boninense. This study indicates the possibility of evaluating the feasibility of effective conservation programs based on the genetic diversity and the amount of accumulated deleterious variation in the genome of critically endangered species.