The Study Of Molecular Evolution On GPR50 And PPARα Gene Of Primates

Nonhuman primates are widely distributed, under the Mammalia （Mammalia） primates （Primates）, is the highest of the animal kingdom and other groups. Wide variety of non-human primates in our country, about 15 percent of the world’s species, a total of 4 families 7 genera 23 species with 39 subspecies. However, due to the expansion of human activities in the region, excessive hunting and habitat destruction, primate species living environment is under serious threat in recent years. Some primate species on the verge of extinction, the number of rare species decreased significantly, distribution smaller. Because of the closely related in primate and human to genetic, so often used in genetics research, the study of primates will help strengthen understanding of human genetic diseases, and energy metabolism, but also conducive to the protection and use of primates animal genetic resources. GPR50 gene and PPARa gene play an important role in lipid metabolism, involved in the expression of lipid metabolism, as well as important factors of fatty liver, diabetes, atherosclerosis and other diseases. Molecular evolution study of PPARa and GPR50 gene in primates will help to understand primates respond to this natural selection, showing how the adaptation and evolution.The study through PCR amplification and sequencing, access the complete coding sequence of 4 primates GPR50 and PPARa, which is golden monkey （Rhinopithecus roxellana）, Tibetan macaque（Macaca thibetana）, flat-topped monkey（Macaca leonina） and douc langur（Pygathrix nemaeus）,13 primates complete coding region of the GPR50 gene and PPARa gene downloaded from public databases. On the basis of these species GPR50 and PPARa gene coding sequences, using MEGA6.0 and Lasergene software package for sequence analysis of nucleotide and amino acid sequences, The similarity of sequences using the built-in software program Bioedit to compute, SMART Online prediction of protein domains. The reconstruction of two gene phylogenetic tree using the adjacent （NJ） and maximum likelihood （ML） method respectively. The evolution of PPARa gene GPR50 gene in primate animal was discussed in the theoretical knowledge related to molecular evolution. Some of the main results are as follows:（1） This study successfully amplified out GPR50 and PPARa complete coding region of the gene sequence of four primate, which are golden monkey, Tibetan macaque, flat- topped monkey, and douc monkey.The complete sequence length of GPR50 coding region were 1866bp,1887bp,1887bp, and 1866bp,The complete sequence length of PPARa coding regions were 1407bp,1404bp,1404bp,1407bp.Get sequences of other primate species from GenBank.（2）Using the measured sequence comparise the database sequence which have been reported on homology primates, showed homology, sequence homology are high, GPR50 nucleotide homology In more than 67%, amino acid homology over 77%; PPARa nucleotide homology in more than 88%, amino acid homology in more than 89%.（3）Through an online prediction of protein domains of GPR50 and PPARa, the results shows, GPR50 and PPARa protein has strong conservative structure, GPR50 typically belongs to seven transmembrane structure, PPARa contains a ZnF₄C domain and a HOL1 domain.（4） Through the construction of a phylogenetic tree, this study chose two ways to construct phylogenetic tree of primates, NJ tree and ML tree with the same topological structure, consistent with recognized primate phylogenetic relationships. Divided into people, great apes, small, Old World monkeys, New World monkeys and prosimians 6 cluster, all the primates species is well clustered into single group With high degree of confidence.（5）Using PAML platform to estimate the primates’s rate of evolution, selection pressure display GPR50 and PPARa subjected to different selective pressures among species. May be related to the function associated with them, In each branch, the main is subjected to purifying selection, a selective pressure to relax the trend part of branches. GPR50 and PPARa gene in human evolution rate, great apes, small apes, Old World monkeys, New World monkeys and prosimians 6 categories that have significant difference, indicating that GPR50 and PPARa gene have different evolutionary rates in all major categories.This study based on the molecular evolutionary perspective, explore the GPR50 gene and PPARa phylogenetic and selection pressure in primates. Provide the basis for the evolution of primate research lipid metabolism-related genes, and has certain help for better understanding the impact of GPR50 and PPARa gene in a variety of diseases.