Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom.
PLoS One. 2010 Jan 25;5(1):e8875. doi: 10.1371/journal.pone.0008875.
Mytilus species are important in marine ecology and in environmental quality assessment, yet their molecular biology is poorly understood. Molecular aspects of their reproduction, hybridisation between species, mitochondrial inheritance, skewed sex ratios of offspring and adaptation to climatic and pollution factors are priority areas.
METHODOLOGY/PRINCIPAL FINDINGS: To start to address this situation, expressed genetic transcripts from M. galloprovincialis were pyrosequenced. Transcripts were isolated from the digestive gland, foot, gill and mantle of both male and female mussels. In total, 175,547 sequences were obtained and for foot and mantle, 90% of the sequences could be assembled into contiguous fragments but this reduced to 75% for the digestive gland and gill. Transcripts relating to protein metabolism and respiration dominated including ribosomal proteins, cytochrome oxidases and NADH dehydrogenase subunits. Tissue specific variation was identified in transcripts associated with mitochondrial energy metabolism, with the digestive gland and gill having the greatest transcript abundance. Using fragment recruitment it was also possible to identify sites of potential small RNAs involved in mitochondrial transcriptional regulation. Sex ratios based on Vitelline Envelop Receptor for Lysin and Vitelline Coat Lysin transcript abundances, indicated that an equal sex distribution was maintained. Taxonomic profiling of the M. galloprovincialis tissues highlighted an abundant microbial flora associated with the digestive gland. Profiling of the tissues for genes involved in intermediary metabolism demonstrated that the gill and digestive gland were more similar to each other than to the other two tissues, and specifically the foot transcriptome was most dissimilar.
Pyrosequencing has provided extensive genomic information for M. galloprovincialis and generated novel observations on expression of different tissues, mitochondria and associated microorganisms. It will also facilitate the much needed production of an oligonucleotide microarray for the organism.
贻贝种类在海洋生态和环境质量评估中很重要，但它们的分子生物学知识还很欠缺。它们繁殖的分子方面、物种间的杂交、线粒体遗传、后代偏斜的性别比例以及对气候和污染因素的适应等都是优先研究领域。
方法/主要发现：为了开始解决这一问题，我们对来自厚壳贻贝（Mytilus galloprovincialis）的表达遗传转录物进行了焦磷酸测序。从贻贝的消化腺、足部、鳃和套膜中分离出转录物，这些贻贝包括雄性和雌性。总共获得了 175547 条序列，对于足部和套膜，90%的序列可以组装成连续的片段，但对于消化腺和鳃，这一比例降低到 75%。与蛋白质代谢和呼吸有关的转录本占主导地位，包括核糖体蛋白、细胞色素氧化酶和 NADH 脱氢酶亚基。与线粒体能量代谢有关的转录本存在组织特异性变化，消化腺和鳃的转录本丰度最高。利用片段招募，还可以鉴定参与线粒体转录调控的潜在小 RNA 位点。基于卵黄蛋白受体溶菌酶和卵黄蛋白溶菌酶转录本丰度的性别比例表明，维持了均等的性别分布。厚壳贻贝组织的分类 profiling 突出了与消化腺相关的丰富微生物菌群。中间代谢相关基因的组织分析表明，鳃和消化腺彼此之间更为相似，而与其他两个组织则不太相似，特别是足部转录组与其他组织差异最大。
焦磷酸测序为厚壳贻贝提供了广泛的基因组信息，并对不同组织、线粒体和相关微生物的表达产生了新的观察结果。它还将促进为该生物体生产急需的寡核苷酸微阵列。
