The Effects Of Ocean Acidification On Manila Clam Ruditapes Philippinarum

The suitable culture environment is one of the determining factors of marine organisms.Carbon dioxide and other industrial affluent increasingly altering the environment through mixing with sea water resulting in acidification.Acidification poses a threat to the ecological landscape of intertidal communities.Consequently,calcifying organism Manila clam Ruditapes philippinarum is particularly at high risk,as increased levels of atmospheric CO2 intensify the partial pressure in the oceans.Manila clam,an important commercial species cultured in Asia,need to adapt in order to cope with the adverse effects of ocean acidification or else production may decrease severely.In order to get a better understanding of the effect of ocean acidification,we studied the transcriptomic response of manila clam using RNA sequencing and investigate the deleterious effect as well as clam resistance to the ocean acidification.p H 8.0,7.4 and wild population of manila clam were used in this study and 8.0 p H treated as the control group.The clams were cultured for 3 months in the experimental condition with sufficient food supply.Aftermath,total RNA was extracted from each treatment group 8.0 and 7.4 p H.Subsequently,c DNA libraries were prepared using Illumina Hiseq 2000 and total 378541600 clean reads were generated after sequencing where,197912472 reads were mapped with an average mapping efficiency of 51.204%.Approximately,27,652 genes were found to be affected by acidification.Comparison of all unigene to GO,KEGG,SWISSPROT and nr database using BLAST for functional annotation revealed alienation of 625,67,62 and 72 genes respectively.Among the affected genes,84 genes were expressed differently(q < 0.005)between treatment and control group.A further comparison showed,48 genes were Up-regulated at low p H condition and 36 genes downregulated.Functional annotation of the differentially expressed genes in GO and KEGG pathway reveal diverse biological functions and processes.According to GO annotation,the genes that change expression significantly were denoted in cellular processes and regulation of biological process,molecular function,binding,transport and ribosomal activity.While KEGG highlighted the gene involved in some important pathways like amino acid metabolism,osmoregulation,signal and interaction,biosynthesis of unsaturated fatty acid pancreatic secretion,ECM-receptor interaction.Our results provide insight into the gene affected by ocean acidification and functional pathways and molecular mechanism effected genes reveal potential marker of tolerance to acidic stress in Manila clam.These information can be used to create cultivars with enhanced levels of potential to deal with the acidification through studying the expression of various defense relevant genes.