摘要
采用相对定量反转录多聚酶链式反应 (RT PCR)的方法 ,以 β actin为内标 ,测定绍鸭排卵前卵泡F1 、F3、F5及大白卵泡 (LWF)颗粒层与膜层中GH受体 (GHR)、IGF I型受体 (IGF IR)和FSH受体 (FSHR)、LH受体 (LHR)mRNA表达水平 ,以分析生长轴和生殖轴激素对绍鸭卵泡发育的协同调节作用。结果表明 :在所测定的各级卵泡中 ,GHRmRNA在膜层的表达水平均显著高于颗粒层 ,膜层中大白卵泡表达量最高 ,而颗粒层中GHRmRNA水平在各级卵泡之间没有明显差异 ;相反 ,IGF IRmRNA在同级卵泡颗粒层的表达水平显著高于膜层 ,颗粒层和膜层中IGF IRmRNA表达在各级卵泡之间的差异均不显著 ,只是大白卵泡的膜层与其他等级卵泡的膜层相比 ,IGF IR的表达量呈现较高的趋势 ;FSHRmRNA表达的变化趋势类似于IGF IR ,同级卵泡颗粒层中的表达量高于膜层 ;LHRmRNA在各级卵泡膜层中表达没有明显差异 ,而颗粒层中LHRmRNA随着卵泡发育成熟逐级显著增加 ,且F5和LWF卵泡膜层的LHRmRNA显著高于颗粒层 ,与GHRmRNA的表达相似。结果提示 ,GH和IGF I调节卵巢功能的优势作用位点和机制不尽相同 ;GHR和LHR协同表达与IGF IR和FSHR协同表达可能对卵泡发育起到精细的调节作用 ;而LHR在卵泡颗粒层中表达的逐级显著增加可能与卵泡等级的建立和排卵有关。
Expression of genes encoding growth hormone receptor (GHR),type I insulin like growth factor receptor (IGF IR),follicle stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) was measured in granulosa and theca layers of the largest (F 1),third largest (F 3),fifth largest (F 5) preovulatory follicles and large white follicles (LWF) in the ovary of Shaoxing ducks,with relative quantitative reverse transcription polymerase chain reaction (RT PCR) using β actin as an internal standard.The results showed that GHR mRNA was more abundant in theca layer than in granulosa layer in all the follicles investigated,in theca layer,the LWF follicle expressed highest the level of GHR mRNA,while no differences in granulosa layer were observed among follicles at different stages of development.In contrast,the expression of IGF IR mRNA in theca layer was evidently lower than that in granulosa layer,but no significant changes were found among different stages of follicles in either layers,except that LWF trended to express higher IGF IR mRNA in the theca layer compared to other preovulatory follicles.Similar to IGF IR mRNA,FSHR mRNA was more abundant in granulosa layer and no significant differences were found among different stages of follicles in either layers.In contrast,the expression of LHR mRNA followed a different pattern.In the theca layer,the expression level maintained consistent,while in the granulosa layer,a significant stepwise increase was observed as the follicles matured,resulting in higher mRNA level of LHR in the granulosa layer of largest follicles (F 1),but lower mRNA level of LHR in the granulosa layer of smaller follicles (F 5 and LWF).These results suggest that GH and IGF I regulate ovary function by respective dominant sites in the follicles,and they cooperate with LH and FSH to regulate the follicle development via their respective receptors.The high expression of LHR mRNA in granulosa layer of large follicles might be related to the establishment of the follicle hierarchy and ovulation.
基金
国家自然科学基金 ( 3 9770 5 40 )项目资助~~
