Studies On The Cloning Of Neuromedin S And Its Receptor In Rabbit And Effects Of Heat Stress On Expression Of Nms Mrna In The Hpa Axis

Neuromedin S is a polypeptide initially found in rat brain in2005by Mori. Evidence has revealed that neuromedin S are expressed in the central nervous system,spleen and testis.The neuropeptides NMS and neuromedin U (NMU) were identified as the same two endogenous ligands for two orphan G protein-coupled receptors (NMUR1and NMUR2). It was reported that NMS has many important physiological roles in the circadian oscillation systems,feeding,reproduct regulation and endocrine and so on, but the data were got mostly from rat and human.Studies on NMS and its receptor of rabbit have not been reported in the literature.Therefore,We studied the cloning and distribution of NMS and its receptor genes,and investigated the effect of heat stress of expressions of NMS mRNA in rabbit’s hypothalamus-pituitary-adrenal axis by RT-PCR.The results are as follows:(1) We first cloned NMS and NMUR2sequence of rabbit by RT-PCR, and submited to the Genebank (ID:GQ167047、GQ167048) via RT-PCR.(2) The cloned rabbit NMS sequence contains123amino acids,and was99.0%,97.6%,95.1%and79.7%identical to those of the corresponding pig, goat, cattle, and human homologues, resoectively.The cloned rabbit NMUR2sequence contains164amino acids,and was92.7%,89.6%,87.5%and80.5%identical to those of the corresponding goat, cattle, pig and human homologues, resoectively.(3)Analysis and forecast the NMS and NMUR2fragment by bioinformatics showed that theoretical isoelectric point pI of NMS is10.57and is mainly made up by helix and coil, while theoretical isoelectric point pI of NMUR2is9.91and is mainly made up by sheet and helix.(4) NMS mRNA was expressed in the hypothalamus, mesencephal, medulla oblongata,trachea,spleen and so on. NMUR2mRNA was expressed in the hypothalamus, mesencephal, medulla oblongata, hippocampus, cerebral cortex, pituitary, heart, spleen, uterus, ovaries and so on.(5) We established rabbit model of heat stress (42℃) using water-resisting type electric thermostat.The effect of heat stress (at0.5h,1h and2h) on NMS mRNA expression in rabbit hypothalamus-pituitary-adrenal axis was studied using relative quantity RT-PCR. In the hypothalamus, NMS mRNA expression increased at1h after heat stress (p<0.05) and was the highest lever in the2h(p<0.05). In the pituitary, expression of NMS mRNA decreased at1h after heat stress(p<0.05) and was the lowest at2h(p<0.05). In the adrenal gland, expression of NMS mRNA expression was the highest in the1h after heat stress (p<0.01) and decreased at2h (p<0.05).These results suggest that NMS and NMUR2genes are conserved in evolution; The change in expressions of NMS mRNA in rabbit’s hypothalamus-pituitary-adrenal gland axis after heat stress showed it might play a role in heat stress. The study provide the experimental data for studing the physiological function of rabbits NMS gene.