| Beef is popular among consumers.Increasing the intramuscular fat content can improve the quality of beef and bring higher economic benefits to the beef market.LncRNA is a class of non-coding RNA that can regulate beef intramuscular fat deposition by regulating the expression of gene on the same chromatin.In order to compare the quality,intramuscular fat and fatty acid contents of Xianan cattle at different ages of newborn,12 months and 24 months,provide relevant theoretical guidance for the breeding of Xianan cattle,reveal the function of FABP3 AU(fatty acidbinding protein 3 antisense upstream)in adipogenic differentiation,and provide molecular theoretical basis for FABP3 AU in regulating intramuscular fat deposition of beef.The quality,intraminomuscle fat and long-chain fatty acid contents of Xianan cattle at different ages were compared and their correlation with lncRNA FABP3 AU was analyzed,and the function of overexpressed FABP3 AU in 3T3-L1 cell proliferation and differentiation was detected.The results are as follow.(1)The results of meat quality,intramuscular fat content and long chain fatty acid were as follows: The p H of 12-month-old Xianan longissimus dorsi muscle was significantly higher than that of newborn cattle(P < 0.05)and the cooking loss of 24-month-old Xianan cattle’s longissimus dorsi muscle was significantly lower than that of newborn cattle(P < 0.05).The content of total protein in the back muscle of 24-month-old Xianan cattle was significantly higher than that of newborn cattle(P < 0.05).The water content of the longissimus dorsi muscle of newborn Xianan cattle was significantly higher than that of 12-month-old and 24-month-old(P < 0.05).The intramuscular fat of Xianan cattle gradually increases with age,the intramuscular fat content in longissimus dorsi muscle of Xianan cattle at 24-month-old was significantly higher than that of newborn cattle,but there was no significant difference in other periods,and there was no significant difference in muscle triglyceride(TG)concentration between different months of Xianan cattle(P > 0.05).The contents of total unsaturated fatty acids and total polyunsaturated fatty acids in longissimus dorsi muscle of Xianan cattle at different months increased with the increase of months,and there were significant differences in the contents of palmitoleic acid,oleic acid,linoleic acid,arachidonic acid and docotrienoic acid among different months(P < 0.05).(2)Bioinformatics analysis predicted that FABP3 AU was mainly located in the nucleus with very low coding ability.The results of Real Time Quantitative PCR(RTq PCR)showed that FABP3 AU was expressed in multiple tissues of Xianan cattle at different months,and the highest expression was found in spleen.The expression of FABP3 AU in Xianan cattle liver increased with the increase of age,and there was a significant difference between newborn and 24 months of age(P < 0.05);Pearson correlation analysis results show that there was no significant correlation between the expression of FABP3 AU and meat quality,intramuscular fat content and triglyceride(TG)concentration(P > 0.05).The expression of FABP3 AU was significantly correlated with the content of some long-chain fatty acids in the muscle of newborn and24 months old Xianan cattle(P < 0.05).The expression of FABP3 AU was significantly correlated with some long-chain fatty acids in subcutaneous fat of Xianan cattle at different months(P < 0.05).There was a significant positive correlation between FABP3 AU and FABP3 expression in muscle of newborn Xianan cattle(P < 0.05).(3)After overexpression of FABP3 AU in 3T3-L1 precursor adipocytes,the expression of key genes for cell proliferation was inhibited and the cell proliferation status was decreased.After FABP3 AU was overexpressed in differentiated 3T3-L1 precursor adipocytes,key genes of adipogenic differentiation were inhibited,cell triglyceride(TG)concentration decreased,and cell lipid droplet formation was inhibited.During adipogenic differentiation of 3T3-L1 cells,overexpression of FABP3 AU promoted the m RNA expression level of FABP3.In a conclusion,this reserch found that there were significant differences in the quality,intramuscular fat content and long-chain fatty acid content of Xianan beef of different months.The individual meat quality indicators of newborn Xianan cattle were excellent,while the content of intramuscular fat and unsaturated fatty acids in muscles of 24-month-old Xianan cattle was higher,which was more in line with human health standards.The expression of lncRNA FABP3 AU in the muscle of Xianan cattle in different periods was not significantly correlated with meat quality,intramuscular fat content and triglyceride(TG)concentration,but was significantly correlated with the content of some long-chain fatty acids.Overexpression of FABP3 AU inhibited the proliferation and differentiation of 3T3-L1 cells.This study would provide an important theoretical reference for the production of high-grade Xianan beef,and made a preliminary exploration of the effect of FABP3 AU on intramuscular fat deposition in beef cattle. |
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