Expression of Melanocortin Receptor 2 Involved in the Stress Response Pathway in Different Tissues of Broad-snouted Caiman (Caiman latirostris).

PARACHÚ MARCÓ, VIRGINIA; AMWEG, AYELEN N.; ORTEGA, HUGO H.; SIROSKI, PABLO

Skukuza

Congreso; The IUCN Species Survival Commission (SSC). Crocodile Specialist Group. 24th Working Meeting.; 2016

The interaction between melanocortin and reproduction isassociated with various processes related to metabolism, stress, immunity, andneuroendocrine signaling pathways. Melanocortin receptors (MCRs) are involvedin a diverse number of physiological functions, including pigmentation,steroidogenesis, energy homeostasis, exocrine secretion, sexual function,analgesia and inflammation. There are five MCR subtypes (termed MC1R to MC5R) thateach has a different melanocortin peptide and different patterns of tissueexpression. While other receptors are promiscuous for different peptides, the melanocortinMC2 receptor (MC2R) is a specific receptor that mediates different tissue responsesto ACTH. Their identification, sequencing and expression were previouslyanalyzed in mammal (human, bovine, rabbits and rodents), avian (Gallus gallus), reptilian (Anolis carolinensis), and amphibian (Xenopus tropicalis) tissues; however,there are no reports regarding their detection in crocodilians. In order to identifythe mRNA coding C. latirostris MC2R, wedesigned a set of primers from sequence alignments of phylogenetically relatedspecies obtained from NCBI. We detected MC2R mRNA expression in C. latirostris adrenal, gonad, liver,and spleen tissues by reverse transcription PCR (RT-PCR) and real time PCR. Thisstudy is the initial step to performing an evaluation of the reproductiveimpact of the ACTH pathway in steroid secretion and function in C. latirostris gonads. Since theneuroendocrine system is an essential component of reproduction, any responseof this system to stress might influence reproductive success.