| Popis: |
Fishes exert stress response in a various ways depending on the type of the stressor. The stress responses are activated through a cascade mechanism stimulated by the stressor which involves the hypothalamus–hypophyseal–interrenal (HHI) axis, catecholamines (CA), and gonadotropins. Adaptive stress responses may positively impact the fish survival and reproduction, while continuous or prolonged stress causes adverse effects on the fish reproduction. Corticotropin-releasing factor and adrenocorticotropic hormone are the principal hormones responsible for producing corticosteroids through the HHI axis. Cortisol acts differentially on the stress response as it helps at the early developmental stage; conversely, it impairs the gonadal function. CA have a critical role in maintaining body homeostasis and intermediary metabolism, and they also have a predominant role in reproductive function. Besides hormones, few genetic and epigenetic factors have been identified to understand the molecular responses to stress however, genome-wide associated studies will be initiated to investigate a complete picture of the stress mechanism. Further, recent evidence suggests a growing concern in determining the correlation between the stress hormone level and its associated gene function. Hence, this review highlights the regulation of stress responses in different axes, genetic and epigenetic factors related to stress, and the integration of recent technologies and novel hypotheses to unravel the stress response mechanism in fish reproduction. |
