Effects Of Ex Situ Feeding On Plateau Adaptability Of Tibetan Pigs(sus Scrofa)and Analysis Of Gene Expression

Tibetan pig(Sus scrofa)is a unique local breed in Sichuan,Yunnan,Gansu and Tibet,and is also the only national protected high altitude pigs.Pork of Tibetan pig is one of the most popular products in the meat market.In order to explore the molecular mechanism of Tibetan pig’s adaptation to high altitude hypoxia,the blood physiological indexes of Tibetan pig and Banna small ear pig ex situ fed were measured,and then the transcriptome of lung and heart tissues of ex situ fed pigs were studied by using differential expression analysis and WGCNA.The specific research contents are as follows:1.The differences of blood physiological indexes were compared between Tibetan pigs from high altitude to low altitude for one month and Banna small ear pigs from low altitude to high altitude for one month.It was found that the number of RBC and HGB of Tibetan pigs at high altitudes were significantly higher than those of Banna small ear pigs at low altitudes.However,there was no significant difference in the number of RBC and HGB of Tibetan pigs after one month from ex situ to low altitude areas.The results indicated that compared with low altitude pigs,the blood physiological indexes of Tibetan pigs were not affected by the change of altitude,which may be the embodiment of their strong adaptability.2.Compared with low altitude Banna small ear pigs,564 differentially expressed genes in lung tissue of Tibetan pigs in high altitude were screened by differential expression analysis,including 310 up-regulated and 254 down regulated genes;,and 4253 differentially expressed genes in heart tissue including 3134 up-regulated and 1119 down regulated genes were screend.Gene ontology and KEGG enrichment analysis of differentially expressed genes showed that CCL2,IL1 B and ITGA2 genes may be actively involved in angiogenesis in lung tissue.In heart tissue,PIK3 CA and PIK3 CB genes involved in PI3K/Akt/m TOR signaling pathway,which play an important role in regulating the expression of HIF-1α and activating genes of hypoxia pathway.These results indicate that PI3K/Akt/m TOR signaling pathway is one of the main pathways involved in the regulation of Tibetan pigs’ adaptation to high altitude hypoxia.3.The WGCNA analysis was constructed based on the standardized expression profile data of lung and heart tissues,and 38 and 13 modules were enriched in lung and heart tissues respectively.EPAS1,EDN1 and hub genes ROBO4 were significantly enriched in the positive brown module in the high altitude Banna small ear pig group of lung tissue,which indicated thses genes may play the key regulatory roles in stress of high altitude of Banna small ear pigs.The genes AGT and ACE in the negative blue module of lung tissue of high altitude Tibetan pig group were found,and AGT,NOS3 and hub genes GAS6 involved in hypoxia related pathways were also observed in the negatively correlated blue module of cardiac tissue high altitude Tibetan pig experiment group,which indicated these genes may play the regulatory role in the process of Tibetan pigs stress of normoxia.Tibetan pigs adapt to high altitude hypoxia mainly by regulating the volume and surface area of red blood cells;CCL2,IL1 B and HIF-1α were found in the transcriptome data of heart tissue And ITGA2 gene may be involved in angiogenesis of Tibetan pigs;In the lung tissue transcriptome data,EPAS1,EDN1 and ROBO4 genes may be involved in the angiogenesis of Banna small ear pigs.