Abstract
Most ovarian follicles begin to grow and develop but fail to reach
ovaulatory status. It is widely accepted that apoptosis is the driving force behind
follicle loss with ageing but age-related molecular changes in ovarian follicle are still
poorly understood. The purpose of this study was to examine the age and stage
dependent changes in expression of cellular FLICE-like inhibitory protein (cFLIP),
in neonatal and adult goat ovary through reverse-transcribed polymerase chain
reaction (RT-PCR) and immunostaining analyses. The mRNA expressions of cFLIPs
and CFLIPL were found significantly (P < 0.05) lower in adult than neonatal group.
CFLIP protein was strongly localized in primordial follicles of neonatal and the
granulosa cells of healthy follicle for adult group. The luteal cells were also
positively immunostained. However, primordial follicles for neonatal and granulosa
cells of healthy follicle for adult were shown strong PCNA immunostained similar
with cFLIP protein localization pattern. TUNEL positive cells were found in the
granulosa cells of atretic follicle in adult ovary. There was no or a very few TUNEL
positive cells in primordial follicles of neonatal ovary and in corpus luteum. In
addition, to test the survival ability of goat ovarian implants and to investigate the
localization of cFLIP protein in rescued tissue, neonatal ovarian cortex was
transplanted to immunodeficient SCID mouse kidney. Treatment with FSH was
increased the number of follicles and follicular size in both male and female mice but
there was non-significant difference found among them. Similar with normal
conditions, CFLIP protein was strongly expressed in granulosa cells of healthy
follicles. Thus, it may be concluded that cFLIP expression and localization in caprine
ovary depend on age and stages of follicular development.