Correlation Studies Between Fat Mass And Obesity Associated Gene Expression And Fat Deposition In Altay Sheep

Xinjiang Altay sheep, which with fine meat quality, have big tail(full of fat). Tail fat of some breedsaccounted for more than17%of body weight. How to reduce fat without affecting the tail intramuscularbeen a key issue to Xinjiang sheep meat quality traits and excellent breeds resource utilization, while thekey is to understand the differences of sheep fat deposition in various parts of the body and relatedregulating factor expression changes, to explore the mechanism of the differences of formation. FTO genewhich associated with fat deposition and metabolism of hormones, and have significantly differences in theexpression of muscle and fat. Currently, the specificity of sheep FTO expression in spatial and temporal andcorrelation with fat deposition has not been reported. This study was designed to illustrate the differencesand relationship in FTO expression and developmental of fat deposition in different parts of Altay sheep,meanwhile measuring the fat metabolism of hormone and gene; To explore the correlation between FTOgene and fat deposition.1. Morphology studies in different parts of adipocytesIn order to study the variation in different parts of adipose tissues deposition in Altay sheep, perirenalfat, tail fat and subcutaneous fat were sampled from90and270days Altay sheep, using the drop method ofoil red O staining on adipose tissue frozen section and Motic microscopic digital image processing systemto measure area of adipocytes. The results showed that: the area of adipocyte in tail was significantly higherthan in perirenal adipocytes in90days (P <0.01), and the area of adipocyte in tail fat, peripheral fat wassignificantly higher than that of perirenal fat in270days. From90days to270days, perirenal dipocyte areashowed an increasing trend, while the tail dipocyte area showed a decreasing trend.2. Detecting lipid metabolism related enzymes and hormones in serumTo study the relationship between blood lipid level and fat deposition in different growth stages, lipidmetabolism related enzymes and hormones were measured using radioimmunoassay and ELISA method.The results showed that: leptin of90days Altay sheep was significantly higher than that of270days (6.22ng/mL,4.72ng/mL); concentrations of AST, ALT at90days were significantly lower than the270days(80.56U/L,103.03U/L;22.49U/L,45.58U/L); while the concentrations of HSL of90days wassignificantly higher than270days (104.18mmol/L,70.86mmol/L).3. Relationship of FTO gene expression and fat depositionTo study the correlation between temporal specificity of FTO gene expression and its correlation withfat deposition, FTO mRNA and protein expression levels of different parts of the organs and adipose tissueswas assayed using RT-PCR and Western blot method. The results showed that: FTO gene was expressed inthe all kinds of tissues. FTO gene highly expressed in the hippocampus at90days, followed in the pituitarygland,which was significantly higher than the expression level of longissimus muscle, myocardial, kidney,liver and other tissues(P <0.01). In ages comparison, there was consistent expression levels when comparison of270days and90days, while expression level of FTO in kidney and liver was significantlylower than longissimus muscle(P <0.01), and expression level of hippocampus and pituitary wassignificantly higher than longissimus muscle(P <0.01). However, the expression level of FTO gene in thehypothalamus was significantly higher than that in all parts of the adiposes. FTO expression in tail fatwas significantly higher than perirenal fat, myocardial fat and subcutaneous fat in270days sheep. In agescomparison, there was no significantly differences between difference organs at90days and270days.Meanwhile, the expression level of FTO gene is significantly higher than the perirenal fat, myocardial fatand subcutaneous fat in the week of the FTO gene expression levels. By comparing the90days and270days Altay sheep in the same organ FTO gene expression levels found in various organs was nosignificantly differences. In comparison90days and270days, tail fat FTO gene expression found at270days in tail fat was significantly higher than90days.270days adipose tissues detected the levels of FTOprotein in tail fat was found higher than those in perirenal fat and subcutaneous fat at270days old (P<0.05).4. Distribution of FTO protein in adipocytesTo determine the distribution of FTO proteins in cells, using immunofluorescence staining techniquesfor different parts of the adipose tissue frozen sections were fluorescently labeled and confocal microscopyto observe its positioning. The results showed that FTO protein was located on the perirenal fat and tail fatadipocyte membranes and the edge of cytoplasm.Conclusion:1. Altay sheep exist in different parts of the area of spatial and temporal differences in the adipocyte,the adipocyte area of fat tail was significantly higher than other parts of the adipose tissues. Adipocyte areashows a decreasing trend compared in ages, while adipocyte area is increasing with the growth of adiposetissue.2. Comparison serum parameters of Altay sheep in different ages, there are concentrations differencesamong the levels of LEP, AST, ALT and HSL.3. FTO mRNA and protein are in the presence of spatial and temporal specificity in different organsand in different ages, levels of FTO mRNA and protein expression in tail fat was significantly higher thanin other parts of adipose tissue in270days.4. FTO protein is located on the perirenal fat and tail fat adipocyte membranes and the edge ofcytoplasm.