Comparative analysis of reproductive cycles in female persian gazelle (Gazella subgutturosa subgutturosa) (Central Asia) and sand gazelle (Gazella subgutturosa marica) (Arabian Peninsula)

This study was conducted at the Bukhara breeding centre (Ouzbekistan, Centr al Asia) on Persian gazelles (Gazella subgutturosa subgutturosa) and at Thu mammah (Saudi Arabia) on sand gazelles (Gazella subgutturosa marica). Plasm a prolactin (PRL) and progesterone were determined in groups of females. Be cause these females were under two different photoperiods (20 degreesN in S audi Arabia and 40 degreesN in Uzbekistan), some Persian females were treat ed with melatonin implants. Both groups of females living in natural enviro nment in Uzbekistan and in Saudi Arabia exhibited an estrus (autumn and ear ly winter) and an anestrus season (spring and summer). Both groups of femal es exhibited estrous and anestrous seasons. The estrous season was shorter in females from Uzbekistan. During the anestrous season, progesterone conce ntrations remained at basal levels in Persian gazelles (Uzbekistan) while i n sand gazelles (Saudi Arabia) hormonal concentrations were higher than in Persian gazelles until August and decreased to similar concentrations in Se ptember-October. Moreover, the pattern of PRL significantly differed in the two groups. Persian gazelles exhibited a clear seasonal pattern with signi ficantly high levels of PRL in June whereas in the sand gazelle PRL did not rise significantly in summer and fluctuated widely. Melatonin treatment si gnificantly depressed PRL concentrations but did not affect the length of t he estrous season in Persian gazelles, suggesting that the reproductive cyc le was entrained by an endogenous rhythm, (C) 2001 Academic Press.