Clock基因在不同繁殖时期雌性马岗鹅中的组织表达

Tissue expression of Clock gene in female magang goose at different reproductive stages

为研究Clock基因对鹅繁殖周期的影响,选取产蛋高峰期、休产期和就巢期的2.5年龄雌性马岗鹅各6只,采集下丘脑、垂体和卵巢组织样品,克隆鹅的Clock基因,并采用实时荧光定量PCR的方法检测其在不同繁殖周期的表达水平.通过克隆获得马岗鹅Clock基因cDNA序列2905bp,基因组序列全长41039bp,含22个外显子,21个内含子.比对分析发现该序列包含了Clock基因的全部编码序列,共2574bp,编码857个氨基酸.氨基酸序同源性比对发现,鹅Clock基因与其他禽类的同源性均超过96%,在物种间的保守性高.产蛋高峰期时Clock基因表达水平在下丘脑、垂体和卵巢组织中均高于休产期和就巢期,其中在下丘脑(P<0.01)和卵巢组织(P<0.05)中差异均显著,而休产期和就巢期的表达水平差异无统计学意义(P>0.05).研究发现Clock基因在产蛋高峰期的下丘脑和卵巢中高表达,说明该基因可能参与鹅繁殖节律的调控.

To study the effect of Clock gene on the geese reproductive cycle, six 2.5-year-old female Magang geese were selected during the peak laying period, the restoration period and the broodiness period, and samples of hypothalamus, pituitary and ovary were collected. The goose Clock gene was cloned and its expression level in different reproductive cycles was detected by real-time fluorescence quantitative PCR. In this study, 2 905 bp cDNA sequence of the Clock gene of Magang goose was cloned, and its genome sequence was 41 039 bp in length, including 22 exons and 21 introns. Blast analysis showed that the sequence contained all the coding sequences of Clock gene, a total of 2 574 bp, encoding 857 amino acids. Homology analysis of amino acid sequence showed that the Clock gene of goose shared more than 96% homology with other birds clock gene, and was highly conservative among species. The expression level of Clock gene was higher in hypothalamus, pituitary and ovarian tissues during the peak period than that in the restoration period and the broodiness period, and the difference was significant in hypothalamus ( P<0.01) and ovarian tissues ( P<0.05), but there was no significant difference in the expression level between the restoration period and the broodiness period ( P>0.05). Clock gene was highly expressed in hypothalamus and ovary during the peak egg laying period, indicating that the gene may be involved in the regulation of goose reproduction rhythm.