This study examined the gametogenic cycle of Crassostrea gigas in controlled conditions over one year, with a focus on the initiation of gametogenesis. This work analysed also the role of temperature and photoperiod in the regulation of oyster reproduction. Broodstock were maintained in natural (NC), accelerated (AC) and perpetual winter (WC) conditions of temperature and photoperiod, with feed...

Seasonal changes in temperature and photoperiod are important environmental cues used by small birds to adjust their body mass (Mb) and thermogenesis. However, the relative importance of these cues with respect to seasonal adjustments in Mb and thermogenesis is difficult to distinguish. In particular, the effects of temperature and photoperiod on energy metabolism and thermoregulation are not w...

We measured the additive genetic variance within populations and the composite additive, dominance, and epistatic effects contributing to differentiation of photoperiodic response between two southern (ancestral) and each of four progressively more northern (derived) populations of the pitcher-plant mosquito, Wyeomyia smithii. Critical photoperiod and its additive genetic variance but not its h...

Juvenile songbirds rely on an endogenous program, encoding direction, distance, fueling, and timing of migration. Migratory distance is species-specific, expressed as a period migratory restlessness, for which the length correlated with while fueling modified to meet anticipated flight distances controlled by geomagnetic cues amount day-light available foraging. How daylength affect onset level...

Many small mammals respond to seasonal changes in photoperiod via alterations in morphology, physiology and behaviour. In the present study, we tested the hypothesis that the preweaning (from embryo to weaning) photoperiod experience can affect subsequent development in terms of body mass and thermogenesis. Brandt's voles (Lasiopodomys brandtii) were gestated and reared to weaning under either ...

Perinatal photoperiod is an important regulator of physiological phenotype in adulthood. In this study, we demonstrated that postnatal (0-4 weeks old) exposure of C57BL/6J mice to long photoperiod induced persistent increase in body weight until adulthood, compared with the mice maintained under short photoperiod. The expression of peroxisome proliferator-activated receptor δ, a gene involved i...

Photoperiod disruption, which occurs during shift work, is associated with changes in metabolism or physiology (e.g. hypertension and hyperglycaemia) that have the potential to adversely affect stroke outcome. We sought to investigate if photoperiod disruption affects vulnerability to stroke by determining the impact of photoperiod disruption on infarct size following permanent middle cerebral ...

ABSTRACT: The domestic canary (Serinus canaria) has been bred for hundreds of years to improve the quality its plumage and song. Reproduction in this species occurs seasonally, stimulated by a gradual increase day length. Although, occurrence seasonal breeding canaries is well known, whether reproduction can be manipulated remains unknown. Our objective was determine conditions captivity (photo...

In Channa punctatus testicular regression commonly observed during spawning and postspawing phases of reproductive cycle. In the present study testicular regression was frequently noticed in fish maintained under both long photoperiod-warm temperature (LD 16 : 8-30 degrees C) and short photoperiod-warm temperature (LD 8 : 16-30 degrees C) regimes. Testicular regression was characterized by dist...