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Bovine embryonic myogenic cells: Conditions for culture and response of protein turnover and ribosome populations with either insulin or dexamethasone
Abstract
The objective of this research was to optimize the bovine embryonic growth conditions and determine protein turnover and ribosome population dynamics, when these cells were incubated with either insulin or dexamethasone. In the first study, myoblast proliferation was measured in cultures on plates treated with collagen, gelatin, or plastic, and no differences in cell proliferation were observed with the different substrata. Myoblast proliferation and differentiation was determined in different media (balanced salt solution BSS, DMEM/F12, McCoy's 5A, or 70% DMEM/20% M-199) and 10% fetal bovine serum. Cell proliferation was greatest (P $<$.001) in the medium: DMEM $>$ McCoy's SA $>$ DMEM/F12 $>$ BSS). Cell differentiation was greatest (p $<$.05) for DMEM/F12 followed by McCoy's, DMEM/M-199, and BSS. Cell proliferation was greatest (p $<$.05) in iron-supplemented serum followed by FBS=newborn calf, horse (HS), and serum-free. In the second study, protein synthesis and degradation were determined over ten levels of either dexamethasone (DEX) (0-1000 nM) or insulin (INS) (0-1000 ng/mL). Protein degradation in bovine myotubes increased quadratically (p $<$.01) with DEX concentrations and decreased linearly (p $<$.01) with INS. Protein synthesis increased quadratically (p $<$.05) with INS, but DEX had no effect. Polysome population shifts were measured in bovine myotubes incubated with either DEX (0-200 nM) or INS (0-100 ng/ml) with or without 2% HS serum. Monosome and polysome peak areas were greater (p $<$.01) in myotubes treated with serum. The 80S subunit peak height was greater (P $<$.01) in serum-treated cultures. Increased INS levels quadratically decreased (P $<$.01) 40S peak height, while the polysome percent increased quadratically (P $<$.01). Increasing DEX levels increased (P $<$.01) monosome peak areas, while decreasing (p $<$.01) the polysome percent. Protein and RNA were not different between the hormone concentrations used. Bovine embryonic myogenic cells proliferate best with DMEM/M-199 and 10% Fe-CS and differentiate best with McCoy's 5A. Both DEX and INS may influence ruminant fetal development by regulating protein synthesis through translation.
Subject Area
Livestock|Cellular biology
Recommended Citation
Woods, Timothy Lee, "Bovine embryonic myogenic cells: Conditions for culture and response of protein turnover and ribosome populations with either insulin or dexamethasone" (1997). ETD collection for University of Nebraska-Lincoln. AAI9736961.
https://digitalcommons.unl.edu/dissertations/AAI9736961