Developmental expression of skeletal muscle heparan sulfate proteoglycans in turkeys with different growth rates

Heparan sulfate proteoglycans (HSPG) are a group of extracellular matrix molecules that link skeletal muscle cells to their extrinsic environment. To investigate if HSPG expression is affected by muscle growth and gender, a turkey line (F) selected for increased 16-wk BW and its unselected random-bred control line, RBC2, were used in the present study. Heparan sulfate (HS) and HSPG levels were measured in embryonic and posthatch pectoralis major muscle. HS levels plateaued at embryonic day (ED) 16 in both lines. A significant decrease of HS occurred at ED 18 in F males and females, and at ED 20 and 22 in the RBC2 males and females, respectively. Embryonic HSPG levels peaked at ED 18, and were significantly higher from ED 14 through 18 in F males and females compared with those of the RBC2 line. Male pectoralis major muscle had more HSPG at early embryonic stages than female muscle in both lines. During 1 to 16 wk posthatch, F male and female pectoralis major muscle contained more HSPG than the RBC2 samples, and HSPG levels in F males were higher than those of the females. Myogenic satellite cells derived from F and RBC2 male and female pectoralis major muscle were cultured to measure HSPG expression during proliferation and differentiation. No significant difference in HSPG level was found between the RBC2 and F line cells. However, in both lines, male-derived satellite cells had more HSPG than the female cells during proliferation and differentiation. These data show that HS and HSPG expression are affected by muscle growth properties and sex.