Haplotype Analysis in Multiple Crosses to Identify a QTL Gene

HDL concentrations in inbred mouse strains with five types of APOA2. The 43 strains were separated into five types (24 “a,” 12 “b,” 4 “c,” 2 “d,” and 1 “e”) according to amino acids located at nine different APOA2 positions (see Table 1). Plasma HDL concentrations (mean ± SEM, mg/dL) were obtained from groups of 7- to 10-week-old males (A) and females (B) fasted for 4 h (all the strains in Table 1 except CASA, MRL, and NZO; Mouse Phenome Database). Each group consisted of between 10 and 40 mice (24 ± 7 males and 22 ± 6 females, mean ± SD). Plasma concentrations of HDL in male (C) and female (D) mice with Ala⁶¹ (all the strains except APOA2^b mice) and those with Val⁶¹ (APOA2^b mice) were also compared.