Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, RS, Brasil.
Braz J Med Biol Res. 2010 Sep;43(9):816-20. doi: 10.1590/s0100-879x2010007500074. Epub 2010 Jul 30.
The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande), both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop) was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7), with OFA1 being the most frequent (47.54%). Nucleotide diversity was moderate (π = 0.62%) and haplotype diversity was relatively low (67%). Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.
南美海狮（Otaria flavescens）广泛分布于南美洲太平洋和大西洋沿岸。然而，在巴西沿海，该物种仅有两个非繁殖地（位于南里奥格兰德州的拉各斯岛野生动物保护区和巴伊亚州的里奥格兰德东沙嘴野生动物保护区）。在该地区，该物种持续受到人为活动的影响，主要是与有机和无机化学物质污染以及渔业相互作用有关的活动。本文首次报道了在巴西南部沿海发现的南美海狮的遗传多样性。分析了线粒体 DNA 控制区（D 环）的 287-bp 片段。在 56 个个体中发现了 7 个新的单倍型（OFA1-OFA7），其中 OFA1 最为常见（47.54%）。核苷酸多样性适中（π = 0.62%），单倍型多样性相对较低（67%）。此外，中位连接网络分析表明，与太平洋沿岸秘鲁种群的单倍型相比，巴西种群的单倍型形成了相互单系分支。这两个种群没有共享单倍型，可能在一段时间以前就已经隔离了。为了更好地理解这里报告的结果对南美海狮管理和保护的生物学意义，需要对整个物种分布进行进一步的遗传研究。
