Douek Jacob, Amar Keren-Or, Rinkevich Baruch
Israel Oceanographic and Limnological Research, National Institute of Oceanography, Tel-Shikmona, Haifa, Israel.
Genetica. 2011 Dec;139(11-12):1531-42. doi: 10.1007/s10709-012-9653-x. Epub 2012 May 3.
Aspects of maternal-planula larval genetics in the monoecious scleractinian coral Stylophora pistillata (Red Sea, Eilat) were studied by amplified fragment length polymorphism (AFLP) methodology in two successive reproductive seasons. In total, 293 planulae and 10 adult colonies were analyzed. In June 2006, 147 planulae were collected from 10 shallow water colonies. In March, April and June 2007, 146 additional planulae were sampled from five of the ten 2006 sampled colonies. All AFLP products showed unalike band profiles indicating a fully sexual production pattern. We used 181 and 210 putative AFLP loci, of which the overall level of polymorphism in 2006 was 92 and 99 % in 2007 (respectively). Differences were also observed between 2006 and 2007 reproductive seasons in terms of total average gene diversity (0.191 vs. 0.247, respectively), suggesting fast turnover of sperm donor genotypes. In addition, increased numbers of potential sperm donor colonies in the vicinity of gravid females showed no impact on genetic differentiation levels in released larvae. UPGMA tree revealed clustering of maternal genotypes and their offspring, suggesting, as expected, high relatedness between planulae and their mothers. In addition, the average heterozygosity of each group of siblings was persistently lower than heterozygosity calculated for the respective maternal colony, suggesting the possibility of partial inbreeding. This trend of reduced genetic heterogeneity in Stylophora pistillata is an alarming sign for populations residing in the northern Red Sea coral reefs.
在两个连续的繁殖季节，采用扩增片段长度多态性（AFLP）方法，对雌雄同体的石珊瑚细指鹿角珊瑚（红海埃拉特）的母体-浮浪幼虫遗传学方面进行了研究。总共分析了293个浮浪幼虫和10个成年群体。2006年6月，从10个浅水群体中采集了147个浮浪幼虫。2007年3月、4月和6月，从2006年采样的10个群体中的5个群体中又采集了146个浮浪幼虫。所有AFLP产物均显示出不同的条带图谱，表明是完全有性生殖模式。我们使用了181个和210个推定的AFLP位点，其中2006年的多态性总体水平为92%，2007年为99%。在2006年和2007年繁殖季节之间，在总平均基因多样性方面也观察到差异（分别为0.191和0.247），这表明精子供体基因型的快速更替。此外，在妊娠雌性附近潜在精子供体群体数量的增加对释放幼虫的遗传分化水平没有影响。UPGMA树显示母体基因型及其后代聚类，正如预期的那样，表明浮浪幼虫与其母亲之间有高度的亲缘关系。此外，每组同胞的平均杂合度一直低于为各自母体群体计算的杂合度，这表明存在部分近亲繁殖的可能性。细指鹿角珊瑚遗传异质性降低的这种趋势对于红海北部珊瑚礁中的种群来说是一个令人担忧的迹象。
