Growth curves for MMU2 B6.CAST and HG.CAST speed congenic strains. Body weight LSMEANS ± SEM are plotted as a function of time (weeks). Top plot, growth curves in male B6 (+/+) and HG (hg/hg) speed congenic strains; bottom plot, growth curves in female B6 (+/+) and HG (hg/hg) speed congenic strains.