Department of Anatomy, Histology and Embryology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China,
Cytotechnology. 2008 Mar;56(3):187-95. doi: 10.1007/s10616-008-9147-y. Epub 2008 May 11.
Healthy 90-day-old ostrich chicks were used in the present study. The ultrastructure and melatonin 1a receptor (MT1) distribution in the ovaries of ostrich chicks was observed by transmission electron microscope and light microscope. The results showed that the ostrich chick ovary contained primordial follicles, primary follicles and secondary follicles, but no mature follicles. There are some unique ultrastructural characteristics observed in the secondary follicle, such as the cortical granule, which was located in cytoplasm beside the nucleus and appeared first in the oocyte. The zona radiata appeared in the secondary follicle, and there was an obvious vitelline membrane. There were intraovarian rete, connecting rete, and extraovarian rete in the ovaries of ostrich chicks. This is the first study that provides immunohistochemical evidence for the localization of the melatonin MT1 in the ostrich chick ovary. The germinal epithelium, follicular cell layer of every grade of follicle, cytoplasm of the oocyte and interstitial cells all expressed MT1. The expression of positive immunoreactivity materials was the strongest in the follicular cell layer of the primordial follicle and germinal epithelium, was weaker in the follicular cell layer of the primary follicle and secondary follicle, and was weakest in the oocytes of all grades of follicle. In addition, the extraovarian rete displayed strong positive expression of MT1, while there was no positive expression in the intraovarian rete or connecting rete. The positive expression of MT1 immunoreactivity in the ovary was very strong, implying that the ovary is an important organ for synthesizing MT1.
本研究选用 90 日龄健康鸵鸟雏鸡。应用透射电镜和免疫组织化学技术，观察了鸵鸟雏鸡卵巢的超微结构和褪黑素 1a 受体（MT1）的分布。结果表明，鸵鸟雏鸡卵巢内有原始卵泡、初级卵泡和次级卵泡，但无成熟卵泡。次级卵泡中有一些独特的超微结构特征，如皮质颗粒，位于核旁胞质中，首先出现在卵母细胞中。次级卵泡中出现了放射冠，并有明显的卵黄膜。鸵鸟雏鸡卵巢内有卵巢内网、连接网和卵巢外网。这是首次在鸵鸟卵巢中定位褪黑素 MT1 的免疫组织化学证据。生殖上皮、各级卵泡的卵泡细胞层、卵母细胞的细胞质和间质细胞均表达 MT1。原始卵泡的卵泡细胞层和生殖上皮中阳性免疫反应物质的表达最强，初级卵泡和次级卵泡的卵泡细胞层较弱，各级卵泡的卵母细胞最弱。此外，卵巢外网显示出强烈的 MT1 阳性表达，而卵巢内网和连接网没有阳性表达。卵巢中 MT1 免疫反应的阳性表达非常强烈，这表明卵巢是合成 MT1 的重要器官。
