Zhang Jing, Huang Jin-Qiang, Li Ya-Ya, Wang Na, Sun Jian, Wang Tian-Zi, Chen Song-Lin
Lab for Aquaculture Genomics and Cell Engineering, Yellow Sea Fisheries Research Institute, CAFS, Qingdao 266071, China.
Dongwuxue Yanjiu. 2013 Oct;34(5):464-70.
Over the past few decades, Medaka (Oryzias latipes) has become a model animal in teleost species research due both to its short reproductive cycle and efficient proliferate capacity. Unfortunately, however, systematic data of its sexual differentiation and development have yet to be obtained. In the present study, we observed Medaka gonad development from the earliest recognizable stages through differentiation to maturation under a light microscope, after paraffin sectioning and hematoxylin-eosin staining. The results showed that among juveniles aged 5 to 10 days, the gonad located on the right side of the dorsal abdominal cavity and the germ cells was significantly larger than the surrounding somatic cells. Ten days after hatching, sexual differences between females and males became obvious, and germline cysts derived from oogonium division were present in the gonad. At 50 days after hatching, ovarian cavities and mature sperm were observed. Moreover, during the study we also observed the coexistence of two sexual characteristics during a male's development. Together, these observations fill current gaps in developmental and genetic biology that will allow a more efficient use of Medaka as an experimental model.
在过去几十年里，青鳉（Oryzias latipes）因其短繁殖周期和高效增殖能力，已成为硬骨鱼物种研究中的一种模式动物。然而，不幸的是，其性别分化和发育的系统数据尚未获得。在本研究中，我们在石蜡切片和苏木精-伊红染色后，通过光学显微镜观察了青鳉性腺从最早可识别阶段到分化再到成熟的发育过程。结果显示，在5至10日龄的幼鱼中，位于腹腔背侧右侧的性腺以及生殖细胞明显大于周围的体细胞。孵化后10天，雌雄之间的性别差异变得明显，性腺中出现了由卵原细胞分裂产生的生殖细胞囊肿。孵化后50天，观察到卵巢腔和成熟精子。此外，在研究过程中，我们还观察到雄性发育过程中两种性别特征的共存。总之，这些观察结果填补了当前发育生物学和遗传生物学的空白，这将使青鳉作为实验模型得到更有效的利用。
