Molecular Identification Of Candidate Genes For Locomotion In Mongolian Horses

China is one of the oldest countries to have horse raising, but the quantity andquality of horse have declined seriously because of the popularity of mechanization andserious lagging of other horse industries. In recent years, horse racing and leisure horseriding have became emerging industries around the world, so horse industry have beenaroused attention again by a great of states, and some relevant supporting policies havebeen introduced. Many places started to build racing courses and city saddle horse clubsand imported many thoroughbred horses from abroad. Most of the foreign racing horsesare thoroughbred horses which are too expensive to buy and breed. It’s necessary to dignational horse breeds which have good motion performance by fully understanding theirlocomotion, and to breed our national racing horse and develop Chinese racing horseindustry.Mongolian horse is one of the oldest horse breeds in the world, and has powerfulendurance, strong resistance to chilliness, rough feeding and disease. And it has beenused for racing from the13th century to nowadays. Along with the progress of molecularbiology methods and continuous studying of thoroughbred horses on their locomotion byforeign countries, it’s extremely urgent to study the area of sports of Mongolian horsewhich is unique local breed in our country.In this study, we studied the expression of muscle development and energymetabolism related genes including MSTN, PDK4, CKM, COX411, COX412,PPARGC1A, CAV-1, FABPpm and LDHA gene in gluteus medius of Mongolian horse;PCR-SSCP and sequencing technology were used to carry out polymorphism scanningfor genes which showed significantly different expression; Two-dimensionalelectrophoresis and mass spectrometry were used to identify differential expressiveproteins in muscular tissues of Mongolian horses from different periods of movement.We got the following results:1. Studying the expressive pattern of muscle development related genes includingMSTN, PDK4, CKM, COX411, COX412, PPARGC1A, CAV-1, FABPpm and LDHA genein gluteus medius of Mongolian horses.(1) Studying the expression of candidate genes in gluteus medius at stationary phaseT0, movement immediately postexercise phase T1and recovery phase T2from movementand measuring the relative expression of these candidate genes. The results showed that: the mRNA expressions of PDK4and PPARGC1A gene were up regulate at phase T1andsignificantly up regulate (P<0.05) at phase T2, the both have significant relativity; themRNA expression of CAV-1gene was significantly up regulate (P<0.05) at phase T2,while expression at phase T1was lower than phase T0.(2) After measuring the mRNA expressions of the candidate genes in gluteus mediusof trained Mongolian horses and untrained Mongolian horses at stationary condition, wefound training had effects on mRNA expressions of all candidate genes, within raletivegenes the mRNA expressions of PDK4, MSTN and COX412gene increased significantly(P<0.05) and COX412gene was significant higher (P<0.01).(3) Western blotting was used to measure the protein expressions of PDK4, PGC-1and CAV-1gene of Mongolian horses at different periods of movement, the resultsshowed protein expressions of PDK4, CAV-1and PGC-1gene were higher at phase T1and T2than phase T0, and protein expression of PDK4gene was significant higher(P<0.05) at phase T2than phase T0, while the other two genes didn’t reach significantlevel.2. Choosing CAV-1, PDK4and PPARGC1A gene as candidate genes for enduranceexercise of Mongolian horses because the mRNA expressions of these genes weresignificantly different before and after endurance exercise. SSCP-PCR was used to studythe polymorphisms in exons of the genes, the results showed the three genes were highlyconserved in Mongolian horses and just found single nucleotide polymorphisms in thefifth exon of PPARGC1A gene. And then we detected PCR-SSCP of PPARGC1A gene infour horse populations, and found allele A was the dominant allele.3. Two-dimensional electrophoresis was used to study proteomics of skeletal muscleof Mongolian horses at different periods of movement, we found44different proteinpoints at different movement phases, within there were31different protein pointsbetween phase T1and phase T0,30different protein points between phase T2and phaseT0. We successfully identified44different protein points in different movement stagesand got28different proteins by MALDI-TOF/MS mass spectrometry. These proteins areGO noted and WEGO analysied. The results showed that there are16classes accodingbiology processes, consist metabolic processes (35.7%), mainly include10proteins, suchas ACADVL、HSPB1、HSP70、LARS、TNNT3、Rab-40c, and so forth.