Profiling Of Functional Long Noncoding Rnas Affecting Oogenesis In Fish

Reproductive development and gametogenesis are the basis of species continuity.Ovogenesis is a multi-step dynamic process involving intricate regulation of gene expression.Long non-coding RNAs(lncRNAs)have been shown to participate in and regulate various signaling pathways and biological processes in recent studies.Existing studies have shown that lncRNAs act as key regulators in oogenesis and spermatogenesis in mammalian mice and pigs[1-3].Therefore,systematic mining and analysis of the role of lncRNAs in oogenesis has a profound impact on exploring the regulatory mechanisms of reproductive development.The oogenesis process of fish tends to have higher environmental adaptability and is more complex than that of higher vertebrates.There are many and complex factors regulating oogenesis and egg quality in fish.Overall,the collection of various maternal substances in the egg determines the quality of the egg.These maternal substances lnclude not only proteins,lipids,hormones,vitamins,etc.,but also various maternal RNAs,such as coding RNA(coding),small RNA(small RNA),and long non-coding RNA(lncRNA).At present,whether and how lncRNAs are involved in the regulation of oogenesis and egg quality in fish remains unclear.The functional study of lncRNAs during oogenesis not only provides theoretical guidance for the evaluation and improvement of fish egg quality,but also provides new ideas for promoting the sustainable development of aquaculture.In this study,the zebrafish,a teleost fish model organism,was used as the research object.The oocytes of the five stages of zebrafish oogenesis were collected from five stages:Ⅰ,Ⅱ,Ⅲ,Ⅳ and egg for RNA transcriptome sequencing.In-depth mining and functional analysis of the lncRNAs.Through time-series analysis,5769 gene elements dynamically expressed during zebrafish oogenesis were identified,lncluding 202 lncRNAs.GO and KEGG analysis showed that these genes were mainly enriched in oogenesis,eggshell formation,fatty acid elongation,fatty acid metabolism,sperm-egg recognition and other pathways highly related to oogenesis.In addition,based on the sequence and expression characteristics of dynamically expressed lncRNAs and dynamically expressed coding genes,we constructed a network of competing endogenous regulatory RNAs during oogenesis to predict the possible regulation and functions of lncRNAs.We screened lncRNAs ENSDARG00000117632 and ENSDARG000000117778 that are dynamically expressed during zebrafish oogenesis,and found that they were specifically expressed in oocytes.Competitive endogenous regulatory RNA network analysis revealed that ENSDARG00000117632 and ENSDARG000000117778 were able to bind to dre-miR-17a-3p to regulate the expression of Piwi,a known key regulator of gametogenesis.This study provides the expression profiles of gene elements at various stages during zebrafish oogenesis,and further analyzes and predicts the regulation of lncRNAs on coding genes through competitive endogenous networks.The research on the function of each gene element in zebrafish oogenesis has laid the foundation.