To effects of sex maturation in olive flounder by regulating long photoperiod, gonadal development and GTH mRNA expression in the pituitary were investigated. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from September 2011 to March 2012. The results showed that natural photoperiodic group showed a higher gonadosomatic index (GSI) than long photoperiodic ...

This study investigated the growth rate, proximate composition, and fatty acid profile in juvenile of kutum Rutilus frisii kutum in different dark-light cycles. Fish were stocked randomly in eighteen 2000-L fiberglass tanks and received six photoperiod regimes: natural photoperiod, 24L (light):0D (day), 16L:8D, 12L:12D, 8L:16D and 0L:24D. Application of continuous dark (0L:24D) and an intermedi...

Relative to a short daily (24-h) photoperiod, exposure to a long daily photoperiod increases the milk yield of dairy cows. However, the endocrine basis for this phenomenon is unknown. The present study was designed to test the hypothesis that a long daily photoperiod is associated with increased circulating insulin-like growth factor (IGF)-I, a hormone that is galactopoietic in ruminants. Forty...

In natural populations, genetic variation in seasonal male sexual behaviour could affect behavioural ecology and evolution. In a wild-source population of white-footed mice, Peromyscus leucopus, from Virginia, U.S.A., males experiencing short photoperiod show high levels of genetic variation in reproductive organ mass and neuroendocrine traits related to fertility. We tested whether males from ...

This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural ...

Chirostoma jordani is a native annual species inhabiting lacustrine waters of the Central Mexico Plateau. It is widely distributed and is currently facing high environmental pressures. Five experiments were performed to study the reproductive performance of this species. Four of the experiments were conducted in 270-L indoor recirculation tanks. Two males and one female at the first stage of re...

The maternal photoperiod at the time of seed maturation can predict the seasonal conditions of newly dispersed seeds. We investigated the effects of maternal photoperiod on seasonal dormancy in Arabidopsis thaliana using a set of F6 recombinant inbred lines derived from a cross between individuals from two natural populations (Cal-0 and Tac-0) differing in cold requirements for germination. We ...

Recent studies have shown that the waveform of the rhythm of c-Fos photoinduction in the ventrolateral (vl) part of the suprachiasmatic nucleus (SCN) and that of the rhythm in the spontaneous c-Fos production in the dorsomedial (dm) part of the SCN in rats released into constant darkness depend on the photoperiod under which the animals were previously maintained. The aim of the present study w...

ten male merghoz goats with initial live weights of 29.2 ± 1.2 kg (mean±se) were used to investigate the effect of natural changes in photoperiod on dry matter intake (dmi) and reproductive activity during a 365 day study. the bucks were housed in individual pens, under natural daylength condition at west of iran, kermanshah (34˚ 18¢n and 47˚ 3¢e and 1420 m above sea level). a diet was offered ...