| Follicular development is characterized by a morphological change in the growth process, accompanied by functional differentiation of follicular. Primordial follicle growth, once started, is a continuous process of development and differentiation, or become a dominant follicle, making egg emitted and matured, or half-way latch. Within each sexual cycle, there lives a group of primordial follicular, and most of the growing follicular will not reach the ovulation stage, but die in the developing process of apoptosis in different periods. The regulation of follicle development process is a complex process, including endocrine factors and regulatory factors within the ovary, dominating the growth and development of oocytes together.PDE3A is mainly expressed in ovary phosphodiesterase subtypes of ovarian development in the growth process, which can degrade cAMP, making cAMP levels decrease, and thereby lowered the potency of FSH and LH to achieve the maintenance of the normal function of cells. In addition, oocytes emitted from PDE3A gene of knocking-down mouse can not be spontaneous in vitro meiotic maturation, and has still been in GV period, unless inhibiting PKA activity to make oocytes become mature. It means that, PDE3A have effects on the content of cAMP by regulating the level of PKA activity in mouse oocytes, thus it plays an important role in regulating oocyte maturation.In this study, Erhualian sows was used as the experimental animals. Erhualian sow is a fine local pig breeds in China, which belongs to the outstanding Taihu pig populations. It has a high reproductive ability and is world-famous as "Pigs within a national treasure " and "King of the world’s breeds litter". The average litter Erhualian of Aberdeen is15.93, and the Litter size of Survival is14.12. And the puberty age is64th day and the weight of puberty age are15kilograms; the heterosis performance of hybrid breeding sows F1is particularly significant, at the same time it also has some other advantages, such as their resistance to crude feed, strong adaptability and tasty meat. Therefore, Erhualian sows were selected as the experimental animals, which also can acted as the representative of a certain significance.This study used pig ovaries in different periods, observing the changes in the organizational learning process through the staining of porcine ovaries at different developmental stages, which aims to explore the porcine ovarian follicular dynamics characteristics; and study the PDE3A in the regulation of follicular development and maturation process of the special significance by measuring the PDE3A age of sows in different subtypes of ovarian tissue. So it will improve the rate of birth and provide a theoretical basis for the breeding improvement and speed up the breeding and increase the effectiveness of livestock production.In order to study the histological changes of ovaries at different developmental stages and explore biological significances of PDE3A during the processes of ovarian occurrence, development and maturation, we choose ovaries from Erhualian pigs of90days postcoitum,1day postpartum,20,120and180days postpartum for histological observation and RT-PCR of PDE3A in the present experiment. The results show that ovaries at90days postcoitum are mainly composed of primordial follicles, the development of1day postpartum,20,120and180days postpartum ovaries is obvious (P<0.01)and morphological characteristics. The expression level of PDE3A mRNA at the time of20days postpartum decreases significantly compared to the other stages. The significant decrease of PDE3A mRNA may imply some biological functions in the follicular recruitment. |
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