The Mediterranean monk seal (Monachus monachus) is one of the world’s most endangered marine mammals. Centuries of human persecution along with recent expansion of the fishing industry and intensive shoreline development, have isolated Mediterranean monk seals into small populations in the eastern Mediterranean Basin and eastern North Atlantic. We developed 19 microsatellite loci from the species’ genome and investigated genetic patterns within the two existing populations from the North Atlantic (Cabo Blanco and Madeira; N = 50). Microsatellite characterization was conducted on the Cabo Blanco population before the massive die-off that happened in 1997 (N = 30). Four loci deviated from the Hardy–Weinberg equilibrium and six loci showed an excess of homozygotes, suggesting that both nonequilibrium conditions (small-size, bottlenecked population subject to inbreeding) and null alleles are at stake. We could not detect any linkage disequilibrium among locus pairs. The genetic diversity observed in the population was low (mean number of alleles per locus = 2.68) but higher than reported in previous studies using cross-species amplification for the same population. Observed levels of genetic diversity in the post-crash population (N = 16) were slightly lower than in the precrash population (A_R = 2.14 vs. 2.39), but the loss of 10 rare alleles in the post-crash population likely reflects the deleterious impact of the 1997 die-off. The Madeiran individuals (N = 4) were fully homozygous (A_R = 1.11). Although they were genetically differentiated from Cabo Blanco, allelic distribution showed that Madeira is a genetically depauperate subpopulation of Cabo Blanco, suggesting that translocations from the latter may be considered beneficial. The newly developed microsatellites shall prove useful in managing populations at the individual level, and will be used to further investigate on the genetic structure and historical demography of past and present populations of Mediterranean monk seals.

中文翻译：

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濒临灭绝的地中海和尚海豹Monachus monachus的十九个微卫星基因座的开发和表征

地中海和尚海豹（Monachus monachus）是世界上最濒危的海洋哺乳动物之一。几个世纪以来，随着人类迫害的不断发展，捕捞业的发展和海岸线的密集发展，地中海和尚海豹被隔离在地中海盆地东部和北大西洋东部的少数人群中。我们从该物种的基因组中开发了19个微卫星基因座，并研究了北大西洋现有的两个种群（卡波布兰科和马德拉群岛；N  = 50）内的遗传模式。在1997年大规模死亡之前，对Cabo Blanco人群进行了微卫星表征（N = 30）。偏离哈迪-温伯格平衡的四个基因座和六个基因座显示纯合子过量，这表明非平衡条件（小规模，受瓶颈限制的近交种群）和无效等位基因都处于危险之中。我们无法检测到基因座对之间的任何连锁不平衡。在种群中观察到的遗传多样性较低（每个基因座的等位基因平均数= 2.68），但高于以前对同一种群进行跨物种扩增的研究报告。灾后种群（N  = 16）的遗传多样性水平略低于灾前种群（A _R = 2.14 vs. 2.39），但是在灾后种群中丢失10个稀有等位基因可能反映了1997年死亡的有害影响。Madeiran个体（N  = 4）是完全纯合的（A _R  = 1.11）。尽管它们与卡波布兰科有遗传区别，但等位基因分布表明马德拉岛是卡波布兰科的遗传上无遗传的亚群，这表明从卡波布兰科的易位可能是有益的。新开发的微卫星将被证明可用于管理个人层面的种群，并将被用于进一步研究地中海和尚海豹过去和现在种群的遗传结构和历史人口统计学。