多浪羊Lin28A基因克隆及其在初情期启动过程中的表达研究

Cloning and Expression of Lin28A Gene in the Onset of Puberty in Duolang Sheep

旨在克隆绵羊Lin28A基因cDNA序列,探讨其在初情期启动过程中的表达规律和调控特性。本研究分别在初情期前(第1次发情前1周)、初情期、初情期后(第1次发情后1周)屠宰多浪羊各5只。采集下丘脑、垂体、卵巢组织,对其Lin28A基因cDNA进行克隆,利用DNAman 6.0软件对多浪羊Lin28A氨基酸与其他物种的Lin28A氨基酸序列进行同源性比较。采用Real-time PCR技术分析下丘脑、垂体、卵巢中Lin28A基因、let-7a、let-7b在初情期启动过程中表达的变化规律。结果表明,多浪羊Lin28AcDNA序列为3 581bp,包括2 963bp的3′UTR和618bp CDS;多浪羊Lin28A氨基酸与人、家鼠、牛和绵羊的同源性分别是87.56%、88.52%、92.68%和89.95%,与鸡、斑马鱼的同源性分别是76.10%、61.84%。在初情期前至初情期的过程中,下丘脑、卵巢中Lin28A表达显著降低(P<0.05),let-7a、let-7b的表达没有显著变化(P>0.05)。本研究结果对于揭示Lin28A基因在绵羊初情期启动中的作用及机制提供了科学依据。

The objectives of the present study were to clone the Lin 28 A cDNA of sheep,investigate its expression patterns and regulation properties during the onset of puberty in sheep.In this study,5 Duolang sheep were slaughtered in the prepuberty(1 week before the first estrus),puberty and postpuberty(1 week after the first estrus),respectively,hypothalamus,pituitary and ovarian tissues were collected.The Lin28A cDNA of these tissues was cloned,the homology of the amino acids of Lin28A between Duolang sheep and other species were compared by DNAman 6.0.The expression patterns of Lin28A,let-7a and let-7b in hypothalamus,pituitary and ovary during the puberal transition in Duolang sheep were detected by real-time PCR.The results showed that the fragment of Lin28A cDNA was 3581 bp which contained 2963 bp of 3′UTR and 618 bp of the coding region.The deduced protein sequence of the Lin28A coding region shared 87.56%,88.52%,92.68%,89.95%,76.10% and 61.84% to that of human,house mouse,cattle,sheep,original chicken and zebrafish.The expression of Lin28A was significantly decreased in the hypothalamus and ovary from prepuberty to puberty(P<0.05),the expression levels of let-7a and let-7b did not change significantly(P>0.05).The results provided a foundation for revealing the function of Lin28A gene and its role in the onset of puberty in sheep.