The Developmental Changes Of LPL And HSL MRNA Expression And Genetic Variation Of LPL Gene And Association With Intramuscular Fat In Pigs

Laiwu Black pigs with fine meat quality and high intramuscular fat (IMF) content is one of the excellent local breeds in China, but the mechanism of IMF deposition is not clear until now. To investigate the molecular mechanism of IMF deposition, we explored the expression patterns of lipoprotein lipase (LPL) gene, hormone sensitive lipase (HSL) gene and the polymorphism of LPL gene. This paper included two experiments. Experiment one: thirty-six Laiwu Black (LW) and thirty-six Lulai Black (LL) (weight of 40-90kg) were used in this experiment, we explored the expression pattrens of LPL gene and HSL gene with semi-quantitative RT-PCR method. Experiment two: to explore the gene polymorphism in intron 5 of LPL gene, 68 Laiwu Black, 75 Lulai Black, 49 Yantai Black and 40 Large White were used. The results were as follows:The developmental tendencies of muscle LPL mRNA in LW and LL pigs were similar. With gaining of body weight, the LPL mRNA abundance decreased from 50kg to 70kg (P<0.05), but increased and presented a peak at 80kg phase for LW. For LL The LPL mRNA abundance decreased gently, and from 70kg to 90kg the LPL mRNA abundance is lower than the phase from 40kg to 70kg. On the whole, the expression level of LPL mRNA in muscle of LW tended to be higher than that of LL (P>0.05). Correlation analysis showed that the expression of LPL mRNA in muscle has no obvious correlation with the IMF. But were positively correlated with the ratio of IMF to bodyfat for LW(P<0.05) and LL pig (P<0.01). The developmental tendencies of muscle HSL mRNA in LW and LL pigs were similar. With gaining of body weight, the HSL mRNA abundance decreased. The HSL mRNA abundance decreased rapidly from 60kg to 70kg for LW. In contrast, The HSL mRNA abundance decreased gently from 60kg to 90kg for LL. In the phase from 60kg to 80kg, the expression level of HSL mRNA in muscle of LL tended to be higher than that of LW (P<0.05). Correlation analysis showed that the expression of HSL mRNA in muscle were negatively correlated with the IMF for both LW and LL...