利用雌核发育尼罗罗非鱼鉴定性别分化相关MicroRNA

Fish as low vertebrates has more complex sex differentiation compared to high vertebrates. The sex differentiation of fish is becoming hotspot of fish physiology. The exactly mechanism of miRNA in fish sex differentiation is still not elucidate. Our research group would use sex - reversed gynogenesis Nile tilapia to illustrate the effects of miRNA on sex differentiation of tilapia with same genotypes but different phenotypes. The project would use artificial induction to obtain gynogenesis Nile tilapia by inhibition of the first cleavage. We would choose a portion of fry to form sex – reversed male fish and the genotype is identical to the female gynogenesis fish. By comparing the result of miRNA and transcriptome sequencing from male and female Nile tilapia, we would filter the miRNA which is related to sex differentiation and analyze the key related gene which participates the sex differentiation to elucidate the mechanism of miRNA in sex differentiation. The present project would use artificial breeding technologies including gynogenesis and sex reversal to clarify molecular mechanism of miRNA affecting sex differentiation through regulation of transcriptome from a new perspective.

鱼类是低等脊椎动物，其性别决定方式较高等脊椎动物更为复杂，已成为当今鱼类生理学研究的热点。微小RNA（miRNA）在鱼类性别分化中的确切机制目前尚未阐明。本课题组拟通过性反转雌核发育罗非鱼，以阐明miRNA对同基因型不同表现型罗非鱼性别分化的影响。本项目希望利用人工诱导获得抑制第一次卵裂的雌核发育尼罗罗非鱼，取一部分鱼苗进行人工性反转得到雄性个体，这部分雄性与未进行性反转处理的雌性在基因型上是同基因型的。通过对比同基因型雌性和雄性尼罗罗非鱼的miRNA测序和转录组测序结果，筛选与性别分化高度有关的差异表达miRNA，并分析鉴定两性雌核发育尼罗罗非鱼性腺中的关键性别分化相关基因，阐明其在性别决定分化中的表达机制。本课题利用雌核发育和性反转这两种人工育种技术，从新的视角阐明miRNA从转录水平影响性别决定的分子机制。

鱼类是低等脊椎动物，其性别决定方式较高等脊椎动物更为复杂，已成为当今鱼类生理学研究的热点。微小RNA（miRNA）在鱼类性别分化中的确切机制目前尚未阐明。本课题组通过制备人工性反转罗非鱼与正常雄性和雌性罗非鱼对比，以阐明miRNA对同基因型不同表现型罗非鱼性别分化的影响。通过对比同基因型雌性和雄性尼罗罗非鱼的miRNA测序和环状RNA测序结果，筛选与性别分化高度有关的差异表达miRNA和环状RNA，并分析鉴定尼罗罗非鱼性腺中的关键性别分化相关基因。结果表明在性反转后，miRNA的表达倾向于雄性。进一步的功能分析鉴定了多个与生殖有关系的miRNA，这些miRNA可能与关键时期的性反转机制有关；同时，有趣的是，性反转的样品其环状RNA表达和雌性的卵巢也不大，仅仅有1个表达下降。这说明在性反转后，虽然miRNA的表达倾向于雄性，但环状RNA的变化并不大。这些差异表达的环状RNA在性反转过程中起到重要作用。这些结果有助于我们阐明罗非鱼性别决定分化中的分子机制。