Research Note: Effect of selection for body weight on the adipogenic conversion of turkey myogenic satellite cells by Syndecan-4 and its covalently attached N-glycosylation chains

Abstract

Adult myoblasts, satellite cells, will proliferate, and differentiate into myotubes in vitro. However, changes in environmental and nutritional conditions will result in the satellite cells differentiating into adipocyte-like cells synthesizing lipids. Prior research has shown that levels of N-glycosylation and heparan sulfate can promote or prevent the adipogenic conversion of myogenic satellite cells. Syndecan-4, an N-glycosylated heparan sulfate proteoglycan, has been shown to play key roles in satellite cell proliferation and migration. The objective of the current study was to determine if syndecan-4, and syndecan-4 N-glycosylation and heparan sulfate chain levels altered the conversion of satellite cells to an adipogenic cell fate and if growth selection affected the response of the satellite cells. Over-expression of syndecan-4, syndecan-4 without N-glycosylated chains but with its heparan sulfate chains attached, syndecan-4 without heparan sulfate chains with its N-glycosylation chains, and syndecan-4 without N-glycosylation and heparan sulfate chains was measured for lipid accumulation in pectoralis major muscle satellite cells isolated from the Randombred Control line 2 (RBC2) and 16 wk body weight (F line) turkeys. The F line was selected from the RBC2 line for only 16 wk body weight. Results from this study demonstrated that wild type levels of syndecan-4 and its covalently attached N-glycosylation chains play a key role in regulating the conversion of pectoralis major muscle satellite cells to an adipogenic lineage while selection for body weight was not a major contributing factor in this conversion.