ABSTRACT

The freshwater bivalve Lamellidens marginalis is native to Southeast Asia and one of the most widely used mussels for pearl production in the region. No studies have been carried out on stock characterisation of L. marginalis due to the lack of molecular markers. In the present study, the genome of L. marginalis was sequenced at low coverage using an Illumina paired-end approach. A total of 268,403 contigs with a size range of 258–13,308 bp was assembled from 2.5 million high quality reads. The contigs were mined and 26, 877 simple sequence repeats (SSRs) were identified using MIcroSAtellite identification tool software. Among SSRs, di-nucleotide repeats (15,633 total) were more frequent than the tri- (6306), tetra- (4768), penta- (146) or hexa-nucleotide (24) repeats. Eighteen loci representing di- (eight), tri- (seven) and tetra- (four) nucleotide repeats were characterised using 30 individuals of L. marginalis. All loci showed moderate to high Polymorphic Information Content values. There was no linkage disequilibria between any pair of loci. Fourteen microsatellites were successfully amplified in the closely related species Lamellidens corrianus. These polymorphic microsatellite markers will be useful for genetic selection programs, as well as for studying the population and conservation genetics of L. marginalis and L. corrianus.

摘要

淡水双壳类Lamellidens marginalis原产于东南亚，是该地区珍珠生产中使用最广泛的贻贝之一。由于缺乏分子标记，尚未对边缘乳杆菌的种群特征进行研究。在本研究中，边缘乳杆菌的基因组使用Illumina的配对末端方法以低覆盖率测序。从250万个高质量读段中组装了268,403个重叠群，大小范围为258-13,308 bp。开采重叠群，并使用MIcroSAtellite识别工具软件识别了26、877个简单序列重复（SSR）。在SSR中，二核苷酸重复（共15633个）比三（6306），四（4768），五（146）或六核苷酸（24）重复更频繁。利用30个边缘乳杆菌个体表征了代表二（八个），三（七个）和四（四个）核苷酸重复的十八个基因座。所有基因座均显示中等至较高的多态信息含量值。任何一对基因座之间都没有连锁不平衡。在紧密相关的物种Lamellidens corrianus中成功扩增了14个微卫星。这些多态性微卫星标记将可用于遗传选择程序，以及用于研究边缘L.coralis和L.corrianus的种群和保护遗传学。