Genetic mediation of body weight, serum cholesterol concentration, cholesterol absorption, and lipoprotein cholesterol concentration in the baboon (Papio cynocephalus)

Abstract

Total serum cholesterol concentration, high density lipoprotein cholesterol, low density lipoprotein cholesterol, percent of dietary cholesterol absorbed, and body weight were analyzed in three separate genetic studies. Hypercholesterolemic and hypocholesterolemic lines of baboons were developed by selective breeding. Significant differences were observed between serum cholesterol concentration of the high and low lines at birth and all intervals through one year of age. Serum cholesterol concentration at birth was not closely correlated with serum cholesterol concentration at other ages. Total serum cholesterol concentration of the sires was a better indicator of the mean serum cholesterol concentration of the progeny than were the sire response values. The correlation between an individual's estimated breeding value and true breeding value for serum cholesterol concentration was estimated. Repeatability estimates of .44, .70, and .91 were observed for serum triglyceride concentration, serum cholesterol concentration, and body weight, respectively, while on a challenge diet. Variance component, regression coefficient, correlation coefficient, and realized heritability procedures were used to estimate heritability. Heritability estimates for total serum cholesterol concentration ranged from .11 to .87; however, a range of .25 to .55 was observed for most estimates of the heritability of total serum cholesterol concentration in infant and juvenile baboons. Estimates for the heritability of body weight in infant and juvenile baboons ranged from .01 to .74 but most estimates were within a range of .30 to .50. Heritability estimates of .14 and .53 were observed for the percent of dietary cholesterol absorbed. Heritability estimates of lipoprotein cholesterol concentration were inconsistent between age periods. A response in lipoprotein cholesterol concentration was observed as a correlated effect of selection for total serum cholesterol concentration. Genetic and phenotypic correlations are presented for all characters...