Seasonal environmental changes modulate the prolactin receptor expression in an eurythermal fish

Abstract

Eurythermal fish have evolved compensatory responses to the cyclical seasonal changes of the environment. The complex adaptive mechanisms include the transduction of the physical parameters variations into molecular signals. Studies in carp have indicated that prolactin and growth hormone expression is associated with acclimatization, suggesting that the pituitary gland is a relevant physiological node in the generation of the homeostatic rearrangement that occurs in this adaptive process. Here, we report the cloning and characterization of a full-length carp prolactin receptor cDNA, which codes for the long form of the protein resembling that found in mammalian prolactin receptors. We identified up to three receptor transcript isoforms in different tissues of the teleost and assessed cell- and temporal-specific transcription and protein expression in carp undergoing seasonal acclimatization. The distinctive pattern of expression that carp prolactin receptor (cPRLr) depicts upon seasonal acclimatization supports the hypothesis that prolactin and its receptor are clearly involved in the new homeostatic stage that the eurythermal fish needs to survive during the cyclical changes of its habitat.

Eurythermal fish acclimatization and nucleolar function: a review

“…Research on the complex adaptive mechanisms underlying fish acclimatization have indicated that sensing of the changes in physical parameters (e.g. temperature, photoperiod) and the corresponding transduction into molecular signals occurs by triggering a neuroendocrine cascade which at the same time entails transcriptional modulation in the hypothalamic-pituitary axis Kausel et al, 1999;Fletcher et al, 2001;San Martin et al, 2004). Prolactin, the well-known osmoregulatory hormone in fish appears to be also an essential coordinating molecule for temperature acclimatization San Martin et al, 2004).…”

Cloning and expression of a unique short form of the porcine prolactin receptor

“…These data are consistent with our observations. A discrepency between PRLR-SF mRNA levels and protein levels has also been observed in carp, where the PRLR-SF is the predominant protein even though the PRLR-LF mRNA is more abundant than the PRLR-SF mRNA (San Martin et al 2004Martin et al , 2007. The discrepancy between pPRLR-SF mRNA and protein levels could be due to increased stability of the mRNA or protein relative to the pPRLR-LF.…”