Longitudinal muscle gene expression patterns associated with differential intramuscular fat in cattle

The activity-dependent neuroprotective protein (ADNP), a double-edged sword, sex-dependently regulates multiple genes and was previously associated with the control of early muscle development and aging. Here we aimed to decipher the involvement of ADNP in versatile muscle gene expression patterns in correlation with motor function throughout life. Using quantitative RT-PCR we showed that Adnp+/− heterozygous deficiency in mice resulted in aberrant gastrocnemius (GC) muscle, tongue and bladder gene expression, which was corrected by the Adnp snippet, drug candidate, NAP (CP201). A significant sexual dichotomy was discovered, coupled to muscle and age-specific gene regulation. As such, Adnp was shown to regulate myosin light chain (Myl) in the gastrocnemius (GC) muscle, the language acquisition gene forkhead box protein P2 (Foxp2) in the tongue and the pituitary-adenylate cyclase activating polypeptide (PACAP) receptor PAC1 mRNA (Adcyap1r1) in the bladder, with PACAP linked to bladder function. A tight age regulation was observed, coupled to an extensive correlation to muscle function (gait analysis), placing ADNP as a muscle-regulating gene/protein.

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Using muscle gene expression to estimate triacylglyceride deposition, and relative contributions of fatty acid synthesis and fatty acid import in intramuscular fat in cattle

Animal Production Science ◽

10.1071/an14247 ◽

2014 ◽

Vol 54 (9) ◽

pp. 1436 ◽

Cited By ~ 4

Author(s):

B. P. Dalrymple ◽

B. Guo ◽

G. H. Zhou ◽

W. Zhang

Keyword(s):

Gene Expression ◽

Fatty Acid ◽

De Novo ◽

Acid Synthesis ◽

Intramuscular Fat ◽

Muscle Gene Expression ◽

Expression Of Genes ◽

Genes Encoding ◽

Muscle Gene ◽

The Impact

Intramuscular fat content (IMF%) in cattle influences the value of individual animals, especially for higher marbling markets. IMF is triacylglyceride (TAG) in lipid droplets in the intramuscular adipocytes. However, there are many different pathways from feed intake to the final common process of TAG synthesis and storage as IMF. To evaluate the relative importance of different pathways we compared changes in the expression of genes encoding proteins involved in the TAG and fatty acid (FA) synthesis pathways in the longissimus muscle of Piedmontese × Hereford (P×H) and Wagyu × Hereford (W×H) crosses. Based on these changes we have estimated the relative contributions of FA synthesised de novo in the intramuscular adipocyte and the uptake of circulating FA (both free and from TAG), from the diet or synthesised de novo in other tissues, to TAG deposition as IMF. We have analysed the impact of different developmental times and different diets on these processes. Increased de novo FA synthesis in intramuscular adipocytes appeared to contribute more than increased FA uptake from circulation to the additional TAG deposition in W×H compared with P×H cattle between 12 and 25 months (forage diet). Changing diet from forage to concentrate appeared to increase the importance of FA uptake from circulation relative to de novo FA synthesis for TAG synthesis in intramuscular adipocytes. These results are consistent with the literature based on analysis of lipid composition. Gene expression appears to provide a simple assay for identification of the source of FA for the deposition of IMF.

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