Global Transcriptomes Analysis Provide Insights Into Genes Expression And Pathways Activated During Embryogenesis In Chinese Mitten Crab,eriocheir Sinensis

The Crustaceans are one of the largest and most diverse group of invertebrates,which evolved through a complex polymorphic life cycle.As a critical developmental period of crustaceans,embryonic development progresses through orderly and timely thousands of differentially genes activation and expression.However,the molecular genetic programs that respond to embryogenesis and control the process of nutrients utilization in the egg are little known in brachyuran decapods,such as Eriocheir sinensis which was a kind of high commercial aquaculture species in China.This study was systematically conducted to investigate molecular mechanisms at seven embryonic stages(zygote,E1;cleavage,E2;blastula,E3;gastrula,E4;egg-nauplius,E5;eyespot stage,E6;heart beating stage,E7)and one zoea stage(newly-hatched zoea Ⅰ,L1).With RNA-seq technology,the developmental transcriptome and expression profiling data of E.sinensis developing embryos provide a perspective on relate global patterns of comprehensive genes expressed and pathways activated of this species.The results generated de novo reference transcriptome and identified total 108 338 422 paired reads with assemble 60 985 genes including 17 004,20 091,21 657,20 887,21 041,15 899,13 466 and 20 402 genes at the eight developmental stages from E1 to Z1.Among the total genes from the eight development stages,we found that 14 738 genes(24.17%)were differentially expressed,7 049 genes(11.56%)showed stage-specificity expression and a larger subset,including 35 280 genes(57.85 %),exhibit constitutive expression in all the developmental stages.We annotated the embryo transcriptome by sequence homology analysis against nr and Uni Prot databases revealed 28 147 and 19 930 genes(46.15% and 32.68%)returned at least one Blast hit.We also analyze the expression dynamics of several development related signaling pathways,including Hedgehog,JAK-STAT,Notch,TGF-β,Ras/MAPK and Wnt and investigated metabolic networks during E.sinensis embryo development stages,which are consist of fatty acid degradation,glycerolipid metabolism,glycerophospholipid metabolism and yolk nutrient utilization and absorption pathway.We quantified gene expression and confirmed the reliability the expression profiles by q RT-PCR at the different developmental stages.In conclusion,this study provides a large-scale resource about global expression patterns and dynamic expression of E.sinensis,and enrich the information of molecular mechanism during embryo development.