PARENT SESSION

(T359) INTERACTIONS OF INDOL ACETIC ACID WITH EGF AND FSH IN THE CULTURE OF OVINE PREANTRAL FOLLICLES.

Seneda, Marcelo¹, Andrade, Evelyn^{1, 2}, Alfieri, Amauri¹, Oliveira, Joao ³, Bracarense, Ana Paula¹, Figueiredo, Jose ², Toniolli, Ricardo², ¹ University of Londrina, Londrina, PR, Brazil² State University of Ceara, Fortaleza, CE, Brazil³ UNESP, FCAVJ, Jaboticabal, SP, Brazil

ABSTRACT- The mechanisms that regulate the gradual exit of ovarian follicles from the non-growing, primordial pool are very poorly understood. The aim of this work was to evaluate the effect of exogenous addition of indol acetic acid (IAA), epidermal growth factor (EGF) and follicle stimulating hormone (FSH) on the activation and growth rate of ovine preantral follicles after in vitro culture of ovarian fragments. The ovarian cortex was divided into small fragments and one fragment was immediately fixed in Bouin (control Day 0). The other fragments were cultured for 2 or 6 d in culture plates with: Minimum Essential Medium (MEM) supplemented with ITS (insulin-transferrin-selenium), pyruvate, glutamine, hypoxantine, bovine serum albumine and antibiotics (MEM+); MEM+ plus IAA (40 ng/mL); MEM+ plus EGF (100 ng/mL); MEM+ plus FSH (100 ng/mL); MEM+ plus IAA+EGF; MEM+ plus IAA+FSH, MEM+ plus EGF+FSH or MEM+ plus IAA+EGF+FSH. After 2 or 6 d of culture in each treatment, the pieces of ovarian cortex were fixed in Bouin for histological examination. The follicles were classified according to the stage of development as primordial or developing follicles (primary and secondary follicles). Percentages of primordial follicles was reduced in Days 2 and 6 of culture, with an increase in the percentages of developing follicles in all media tested (P<0.05) when compared to control. We also observed that the culture of ovarian cortex for 6 d, in all tested media, reduced the percentages of healthy follicles when compared with control (P<0.05), except for culture in IAA+EGF and EGF+FSH. We conclude that the interaction between IAA and EGF as well as EGF and FSH were the most effective to activated ovine primordial follicles in vitro.

KEY WORDS: indol acetic acid, ovine, preantral, follicles