Data from: Microsatellite evidence for high frequency of multiple paternity in the marine gastropod Rapana venosa

Background: Inferring of parentage in natural populations is important in understanding the mating systems of a species, which have great effects on its genetic structure and evolution. Muricidae, a large group (approximately 1,600 species) of marine gastropods, are poorly investigated in patterns of multiple paternity and sperm competition based on molecular techniques. The veined Rapa whelk, Rapana venosa, a commercially important muricid species with internal fertilization, is an ideal species to study the occurrence and frequency of multiple paternity and to facilitate understanding of their reproductive strategies. Methodology/Principal Findings: We developed five highly polymorphic microsatellites in R. venosa and applied them to identify multiple paternity in 19 broods (1381 embryos) collected from Dandong, China. Multiple paternity was detected in 17 (89.5%) of 19 broods. The number of sires per brood ranged from 1 to 7 (4.3 on average). Of the 17 multiply sired broods, 16 (94.1%) were significantly skewed from equal paternal contributions, and had a dominant sire which was also dominant in each assayed capsule. Conclusions: Our results indicate that a high level of multiple paternity occurs in the wild population of R. venosa. Similar patterns of multiple paternity in the 2–6 assayed capsules from each brood imply that fertilization events within the body of a female occur mostly (but not entirely) as random draws from a “well-but-not-perfectly blended sperm pool” of her several mates. Strongly skewed distributions of fertilization success among sires also suggest that sperm competition and/or cryptic female choice might be important for post-copulatory paternity biasing in this species.背景：对自然种群开展亲权推断，对于解析物种的交配系统至关重要，而交配系统对物种的遗传结构与演化具有深远影响。骨螺科（Muricidae）是一类包含约1600个物种的大型海洋腹足类群，目前基于分子技术对其多重父权（multiple paternity）与精子竞争（sperm competition）模式的研究仍较为匮乏。脉纹红皱岩螺（Rapana venosa）是一种具有重要经济价值的体内受精骨螺科物种，亦是研究多重父权的发生与频率、进而解析其繁殖策略的理想实验材料。 方法与主要结果：本研究在红皱岩螺中开发了5个高度多态性的微卫星（microsatellites）标记，并利用这些标记对采自中国丹东的19个育幼群（共包含1381枚胚胎）开展多重父权鉴定。结果显示，19个育幼群中有17个（占比89.5%）检测到多重父权现象；每窝幼体的父本数量范围为1至7，平均为4.3。在这17个存在多重父权的育幼群中，有16个（占比94.1%）的父本贡献显著偏离均等模式，且存在一个优势父本，该优势父本在每个被检测的育幼囊中均占据主导地位。 结论：本研究结果表明，红皱岩螺野生种群中存在高水平的多重父权现象。对每窝幼体中2~6个育幼囊的检测结果呈现出一致的多重父权模式，这意味着雌体内的受精过程主要（但并非完全）是从其多位配偶的"混合良好但并非完全均匀的精子库"中随机抽取精子完成的。父本间受精成功率的显著偏态分布，同样暗示精子竞争和/或隐蔽性雌体选择（cryptic female choice）可能在该物种的交配后父权偏向调控中发挥重要作用。