Krzysik-Walker Susan M, Ocón-Grove Olga M, Maddineni Sreenivasa B, Hendricks Gilbert L, Ramachandran Ramesh
Department of Poultry Science, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Biol Reprod. 2007 Oct;77(4):626-35. doi: 10.1095/biolreprod.106.054957. Epub 2007 Jun 20.
Calcitonin (CALCA), a hormone primarily known for its role in calcium homeostasis, has recently been linked to reproduction, specifically as a marker for embryo implantation in the uterus. Although CALCA expression has been documented in several tissues, there has been no report of production of CALCA in the ovary of any vertebrate species. We hypothesized that the Calca gene is expressed in the chicken ovary, and its expression will be altered by follicular maturation or gonadal steroid administration. Using RT-PCR, we detected Calca mRNA and the calcitonin receptor (Calcr) mRNA in the granulosa and theca layers of preovulatory and prehierarchial follicles. Both CALCA and Calca mRNA were localized in granulosa and thecal cells by confocal microscopy. Using quantitative PCR analysis, F1 follicle granulosa layer was found to contain significantly greater Calca mRNA and Calcr mRNA levels compared with those of any other preovulatory or prehierarchial follicle. The granulosa layer contained relatively greater Calca and Calcr mRNA levels compared with the thecal layer in both prehierarchial and preovulatory follicles. Progesterone (P(4)) treatment of sexually immature chickens resulted in a significantly greater abundance of ovarian Calca mRNA, whereas estradiol (E(2)) or P(4) + E(2) treatment significantly reduced ovarian Calca mRNA quantity. Treatment of prehierarchial follicular granulosa cells in vitro with CALCA significantly decreased FSH-stimulated cellular viability. Collectively, our results indicate that follicular maturation and gonadal steroids influence Calca and Calcr gene expression in the chicken ovary. We conclude that ovarian CALCA is possibly involved in regulating follicular maturation in the chicken ovary.
降钙素（CALCA）是一种主要因其在钙稳态中的作用而闻名的激素，最近它与生殖联系在一起，特别是作为子宫内胚胎着床的标志物。尽管CALCA的表达已在多种组织中得到记录，但尚未有关于任何脊椎动物卵巢中产生CALCA的报道。我们推测Calca基因在鸡卵巢中表达，并且其表达会因卵泡成熟或性腺类固醇给药而改变。使用逆转录聚合酶链反应（RT-PCR），我们在排卵前和等级前卵泡的颗粒层和卵泡膜层中检测到了Calca信使核糖核酸（mRNA）和降钙素受体（Calcr）mRNA。通过共聚焦显微镜观察，CALCA和Calca mRNA均定位于颗粒细胞和卵泡膜细胞中。使用定量PCR分析发现，与任何其他排卵前或等级前卵泡相比，F1卵泡颗粒层中Calca mRNA和Calcr mRNA水平显著更高。在等级前和排卵前卵泡中，颗粒层中的Calca和Calcr mRNA水平相对于卵泡膜层而言都相对更高。对性未成熟鸡进行孕酮（P(4)）处理导致卵巢Calca mRNA丰度显著增加，而雌二醇（E(2)）或P(4)+E(2)处理则显著降低卵巢Calca mRNA数量。在体外使用CALCA处理等级前卵泡颗粒细胞可显著降低促卵泡生成素（FSH）刺激的细胞活力。总体而言，我们的结果表明卵泡成熟和性腺类固醇会影响鸡卵巢中Calca和Calcr基因的表达。我们得出结论，卵巢CALCA可能参与调节鸡卵巢中的卵泡成熟。
