Experiment
A (C57BL/6J x DBA/2J)F2 intercross and 35 BXD (C57BL/6J x DBA/2J) RI strains were used to identify QTLs associated with cerebellar weight and volume. C57BL/6J animals show increased cerebellar weight and volume compared to DBA/2J animals. F1 animals resemble C57BL/6J in cerebellar weight and volume phenotype, and the authors state that there is no significant difference between F1 and F2 animals with regard to cerebellar weight and volume. Total cerebellar size did not appear to vary significantly by age, sex, or body weight of the animals. Two QTLs linked to cerebellar weight and volume, Cbm1 (LRS = 15) and Cbm2 (LRS = 22.5), were mapped to Chromosome 1 (89 cM - 102 cM) and 8 (44 cM - 53 cM), respectively, in both the F2 cross and RI strains. Cbm1 on Chromosome 1 is associated with D1Mit150.Cbm2 on Chromosome 8 is also putatively linked to cerebellar fissure number (LRS = 8.3) at D8Mit312. Animals with DBA/2J alleles have on average one more fissure than animals with C57BL/6J alleles. Three QTLs linkedto cerebellar weight, Cbm3 (LRS = 22), Cbm4 (LRS = 30), and Cbm5 (LRS not given), mapped to Chromosome 14 (5 cM - 16 cM) and 19 (28 cM - 56 cM for Cbm4; 4 cM - 21 cM for Cbm5), respectively, in the F2 cross. All 5 QTLs mapped in this experiment do not appear to act epistatically.
Analysis Tools