Levels of BMP-6 mRNA in goat ovarian follicles and in vitro effects of BMP-6 on secondary follicle development.
Expression of BMP-6 mRNA was quantified by real-time polymerase chain reaction (PCR) and the BMP-6 protein was demonstrated by immunohistochemistry in the primordial, primary, secondary, small and large antral follicles of goat. Furthermore, the influence of BMP-6 on increase in diameter, antrum formation and expression of BMP-6 and FSH-R in in vitro cultured secondary follicles was studied. Therefore, goat primordial, primary and secondary follicles, as well as small and large antral follicles were obtained and the mRNA levels of BMP-6 were quantified by PCR in real time. Expression of BMP-6 protein in goat follicles was demonstrated by immunohistochemistry. The influence of BMP-6 in the presence or absence of follicle-stimulating hormone (FSH) on both the development of secondary follicles and the expression of mRNA for BMP-6 and FSH-R was evaluated after 6 days of culture. Furthermore, the follicular diameter and the formation of the antrum were evaluated before and after 6 days of culture and compared by Kruskal-Wallis and chi-squared tests (P < 0.05), respectively. The results show that the level of mRNA for BMP-6 in primary and secondary follicles was significantly higher than in the primordial follicles (P < 0.05). Similar levels of BMP-6 mRNA were observed in cumulus-oocyte complexes and mural granulosa/theca cells from small and large antral follicles, respectively. BMP-6 protein was expressed in oocytes of all categories of follicles and in granulosa cells from secondary follicles onwards. Addition of BMP-6 to the culture medium increased the diameter of secondary follicles mainly by antrum formation after 6 days' culture, in the presence or absence of FSH (P < 0.05). Furthermore, addition of FSH resulted in increased levels of BMP-6 mRNA in these follicles (P < 0.05). Simultaneous administration of FSH and BMP-6 enhanced the levels of FSH receptor (FSH-R) mRNA (P < 0.05). It is concluded that BMP-6 mRNA is increased during transition from primordial to primary/secondary follicles in the goat ovaries and that BMP-6 enhances the growth of cultured secondary follicles.
Biotechnology Nucleus of Sobral - NUBIS, Federal University of Ceara, Sobral, CE, Brazil.
Isana M A
IM
Frota
Cintia C F
CC
Leitão
José J N
JJ
Costa
Robert
R
van den Hurk
Márcia V A
MV
Saraiva
José R
JR
Figueiredo
José R V
JR
Silva
D000818:Animals; D055418:Bone Morphogenetic Protein 6 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D054885:Cumulus Cells / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D006107:Granulosa Cells / Q000187:drug effects / Q000502:physiology; D006080:Ovarian Follicle / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D010053:Ovary / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D011962:Receptors, FSH / Q000235:genetics; D046509:Tissue Culture Techniques
D055418:Bone Morphogenetic Protein 6; D003470:Culture Media; D012333:RNA, Messenger; D011962:Receptors, FSH; D005640:Follicle Stimulating Hormone