Histological Study On Reproductive System Of Female Badger (Meles Meles)

In order to explore the histological changes of ovaries, oviduct, uterus and vagina of female badger during the reprocuctive cycle, we observed the ovary of badger, which were harvested respectively in December, the following April and June, using optical microscopes and electron microscopes, and oviduct,uterus and vagina were observed by optical microscopes. The results were mainly the following aspects:1.The characteristic of morphological changes of the follicles of badger were studied. The follicles in the different developmental stages could be seen during December, April and June. The number of primordial follicles which were in single or in small groups was much. Such number of follicles with larger folliclular cavity could be seen in the three periods, while the number of follicles with larger folliclular cavity were much more, and the diameter of follicle was up to1043.25μm. The zona pellucida appeared when the follicular cells were1or2layers, and the thickness of the zona pellucida was increased with the increase of the diameter of oocytes.2. The histology of atretic follicles were studied. The study found that badger atretic follicles came from the various developmental stages of follicular atresia, but the most common was the antral follicle atresia. The atretic follicles formed by stage Ⅰ showed that oocyte presented shrinking, follicle cells arranged in irregular and the nucleus of follicular cells became pycnotic. Atretic follicles, which mainly formed by stage Ⅱ and stage Ⅲ, performed that oocyte began to deform and shrink and nuclear became pycnotic, and the zona pellucida collapsed, loose granular cell layer and the basal membrane disappeared. The antral follicles’s atresia divided into early, middle and late.3. The histology of corpus luteum was studied. The badger ovaries, which were harvested in December, April and June, were found luteal structure. The corpus luteum were constituted by small luteal cells and large luteal cells. The study found that there were much corpus luteums in the ovary of June badger compared with December or April, and larger diameter corpus luteum mainly distributed in the ovary of June badger. The average diameter of the corpus luteums, which were harvested in December, April or June, was no significant difference (P>0.05).4. The histology of Interstitial gland was studied. The interstitial gland from various periods of the badger’s ovary are extremely well developed, widely distributed in the ovarian stroma, the connective tissue and blood vessels dispersed cell populations separated into different sizes.5. The histology of oviduct, uterus and vagina were studied. The oviduct tissue of badger from April and June were developed better than that of December, and the tubal mucous layer inward formed a number of primary folds, many of which can form2or3folds differentiation. The uterine horn, uterine body of December, April and June had a wealth of adenomyosis. The adenomyosis in the uterine horn was developed well. The vaginal epithelial was stratified into squamous cells. Vaginal epithelial keratinization of April and June was obvious, but the horny phenomenon was unseen in December6. The ultrastructure of the follicle of the badger were studied. The cell organelle in the oocyte was changed accompanied by the development of the oocyte. The mitochondria, which were roundness in the stage I, became rod-shaped and dumbbell-shaped, and flocked together in he stage IV. The number of cortical granules in the stage I was small, while in the stage IV, the number of cortical granules had increased and lined up in the plasma membrane. The appearance of lipid droplets in the oocytes was earlier. A large number of lipid droplets existed in the stage I, where the sizes of lipid droplets were different and the color are dull,while in the stage IV, the number of lipid droplets increased and the color became lighter. Follicle cells which were spindly became cubic and the number of follice cells had increased. The organelles in the cytoplasm increased with the development of follicles, and the link between the organelles became more closer. Some vacuoles with posterior wall can be seen in the follicular cytoplasmic. Micro filaments widely lied in the outside of the basal membrane.