Preservation of common carp germ cells under hypothermic conditions: Whole tissue vs isolated cells

The aim of this study was to optimize the conditions for hypothermic storage of spermatogonial stem cells (SSCs) and oogonial stem cells (OSCs) of common carp Cyprinus carpio. This was conducted by storing gonadal tissue or isolated cells for 24 hr under hypothermic conditions in the first experiment and by testing two different storage media (L‐15 or DMEM supplemented with 10% FBS and 25 mM HEPES) and regular medium change (every 4 days) during two weeks of hypothermic storage in the second experiment. During the first 24 hr, isolated cells showed no decrease in viability, while cells obtained from hypothermically stored tissues displayed significantly lower viability after only 6 hr (Tukey's HSD, p < 0.01) indicating that hypothermic storage of isolated cells is superior to storing tissue pieces. The 2‐week trial demonstrated that storage media have a profound influence, while regular medium exchange does not have a positive effect on cell viability. Viability of SSCs and OSCs after two weeks was approximately 40% and 25%, respectively; however, survival of ~70% was obtained after 10 days of storage for SSCs and 7 days for OSCs. Hypothermic storage developed in this study has many practical applications during the development of surrogate broodstock technologies for common carp, but also in carp hatcheries and for the conservation of genetic resources of closely related cyprinid species.     

胎牛卵巢组织学结构研究

获体长8～15cm黑白花奶牛雌性胎犊5头,用光镜和电镜对其卵巢的组织结构进行了观察.生殖上皮呈单层或复层住状,其增殖能力极强,细胞突破基膜进入卵巢深部,与卵巢间质细胞相混.在光镜下,卵原细胞在卵巢的外区,分为由卵巢间质包围成大包囊状共质体、合胞体状细胞群和小包囊细胞簇以及密集裸露的卵母细胞,它们可明显地分出明暗两类.卵巢间质细胞核具有两种形态:一种为长梭形,数量较多;一种为纺锤形,数量较少,常见具纺锤形核的细胞包围的卵母细胞,而形成典泡.常见1～3个卵泡上皮细胞包围的卵母细胞形成原始卵泡;另一种是极性分布成帽状包围的卵母细胞卵泡.电镜下观察,有具共质体状结构和膜相隔的卵原细胞群两种情况.共质体状卵原细胞内的细胞器位于核旁;有膜相隔的卵原细胞核大,胞质少,胞质中膜泡结构明显.     

Study on features of female fetal reproductive system development in Chinese northeast fine-wool sheep

Some charaterasics of female fetal reproductive system were studied in different gestation phases of Chinese northeast fine-wool sheep.The results showed that reproductive system consisted of ovary,oviduct,uterus and genitalia.The fetal ovaries were granular in early phase and became elliptic in later phase.The functional formula of ovarian weight,length and volume was obtained. Primary oocyte was encapsulated by monolayer cells in 7-week fetal ovary cortex.Primordial follicles were formed in 8-week fetal ovary,the follicular cells were sporadically arranged and not always regular.Complete organization of primordial follicles appeared until 10-week gestation,most of them scattered in nests in the following weeks of gestation.Two types of follicular complexes were found in fetal.There were continuous and quick mitosis of oogonia in fetal ovaries,large complexes were formed by oogoniaes encapsulated by multilayer of follicular cells,then they differentiated into small complexes,one or more primary oocytes were formed by mitosis of oogonia,primordial follicles which were caused by follicular cell approaching into them developed.     

蒙古绵羊胎儿卵巢发育的组织学研究

对37-99 d胎龄的蒙古绵羊胎儿卵巢进行组织学观察。结果表明,绵羊胎儿在37 d,可以从外观上分辨雌雄,雌性胎儿的性腺初步出现卵巢的组织学特征;37-51 d为卵原细胞的共质体期,卵原细胞数量增长加快;55~76 d卵巢中逐渐充满大量的合胞体样卵母细胞群;从58 d开始卵巢皮质深层出现少量的形态不典型的原始卵泡。胎龄73 d时,皮质深层出现真正的原始卵泡;81 d时皮质中层出现大量原始卵泡;99 d时皮质深层中可看到一些初级卵泡。与成体卵母细胞相比,胎儿时期的生殖细胞有活跃的增殖分裂特征;生殖细胞发育按卵原细胞增殖→卵母细胞分化→形成原始卵泡的步骤发育,在位置分布上由卵巢皮质外层逐渐向皮质里层分步发育。