PDF(Pubmed)
Abstract：
Only approximately 356 North Atlantic right whales (Eubalaena glacialis) remain. With extremely low levels of genetic diversity, limited options for mates, and variation in reproductive success across females, there is concern regarding the potential for genetic limitations of population growth from inbreeding depression. In this study, we quantified reproductive success of female North Atlantic right whales with a modified de-lifing approach using reproductive history information collected over decades of field observations. We used double-digest restriction site-associated sequencing to sequence approximately 2% of the genome of 105 female North Atlantic right whales and combined genomic inbreeding estimates with individual fecundity values to assess evidence of inbreeding depression. Inbreeding depression could not explain the variance in reproductive success of females, however we present evidence that inbreeding depression may be affecting the viability of inbred fetuses-potentially lowering the reproductive success of the species as a whole. Combined, these results allay some concerns that genetic factors are impacting species survival as genetic diversity is being retained through selection against inbred fetuses. While still far fewer calves are being born each year than expected, the small role of genetics underlying variance in female fecundity suggests that variance may be explained by external factors that can potentially be mitigated through protection measures designed to reduce serious injury and mortality from human activities.
摘要：
仅剩下大约356只北大西洋露脊鲸（Eubalaenaglacialis）。由于遗传多样性水平极低，配偶的选择有限，以及女性生殖成功的差异，人们担心近亲繁殖抑郁症可能导致人口增长的遗传限制。在这项研究中,我们使用数十年野外观测收集的生殖史信息，通过改良的去生方法量化了雌性北大西洋右鲸的繁殖成功率。我们使用双消化限制性位点相关测序对105只雌性北大西洋右鲸的基因组进行了约2％的测序，并将基因组近交估计值与个体繁殖力值相结合，以评估近交抑郁的证据。近交抑郁不能解释雌性繁殖成功的差异，然而，我们提供的证据表明，近亲繁殖抑郁症可能会影响近亲繁殖胎儿的生存能力，可能会降低整个物种的繁殖成功率。合并,这些结果减轻了一些担忧，即遗传因素正在影响物种的生存，因为遗传多样性正在通过对近交胎儿的选择得到保留。虽然每年出生的小牛比预期的少得多，遗传学潜在差异在女性繁殖力中的作用较小,这表明差异可能由外部因素解释,这些外部因素可能通过旨在减少人类活动造成的严重伤害和死亡率的保护措施得到缓解.
