Abstract: To study the location of serine protease 23(PRSS23) and the relationship between its mRNA expression in granulosa cells and progesterone(P4 ) secretion in laying hens follicles,large white follicles(LWF) with diameter of 3—5 mm and small yellow follicles(SYF) with diameter of 6—8 mm were selected for tissue localization of PRSS23 by immunohistochemical technology. Small white follicles(SWF),LWF,SYF and large yellow follicles (LYF) were selected,follicular fluid was extracted with a 1 mL syringe,and P4 content in follicular fluid of follicles with different size was measured,respectively.Granulosa cells which were located on the intima of follicles were scraped and the expression of PRSS23 mRNA in granulosa cells of follicles with different size in laying hens was detected by real-time quantitative PCR.Results showed that PRSS23 was expressed in the layer of follicular granulosa cells,membrane cells and cumulus cells of laying hens,with the highest expression level in SYF granulosa cells layer.PRSS23 mRNA content in SYF was significantly higher than that in other follicles (P<0.05).The content
of P₄ in SYF follicular fluid was significantly higher than that in other follicular fluid(P<0.05).The above results indicate that PRSS23 may influence the selection of follicles through promoting the secretion of P₄ by granulosa cells in SYF.

Key words: Laying hens, Follicles, PRSS23, Expression, Progesterone

摘要： 为研究丝氨酸蛋白酶23（PRSS23）在蛋鸡卵泡中的表达部位及其mRNA在颗粒细胞中的表达与孕激素（P₄）分泌的关系，选取直径为3~5 mm的大白卵泡（LWF）和直径为6~8 mm的小黄卵泡（SYF），应用免疫组织化学技术对PRSS23进行组织定位；分别选取小白卵泡（SWF）、LWF、SYF、大黄卵泡（LYF），用1 mL注射器抽取卵泡液，测定不同大小等级前卵泡卵泡液中P4的含量；刮取位于卵泡内膜上的颗粒细胞，利用实时荧光定量PCR技术检测PRSS23基因mRNA在蛋鸡不同大小等级前卵泡颗粒细胞中的表达情况。结果显示，PRSS23在蛋鸡卵泡颗粒细胞层、膜细胞层和卵丘细胞均有表达，在SYF颗粒细胞层表达量最高；PRSS23基因mRNA在SYF中的含量显著高于其他卵泡（P<0.05）；P₄在SYF卵泡液中的含量显著高于其他卵泡卵泡液（P<0.05）。以上结果表明，PRSS23在SYF中可能会通过促进颗粒细胞分泌P₄来影响卵泡的选择。

关键词: 蛋鸡, 卵泡, PRSS23, 表达, 孕激素