Localization of two new X-linked quantitative trait loci controlling corpus callosum size in the mouse.
Corpus callosum (CC) size is a complex trait, characterized by a gradation of values within a normal range, as well as abnormalities that include a small or totally absent CC. Among inbred mouse strains with defects of the CC, BTBR T(+)tf/J (BTBR) mice have the most extreme phenotype; all animals show total absence of the CC and severe reduction of the hippocampal commissure (HC). In contrast, the BALB/cByJ (BALB) strain has a low frequency of small CC and consistently normal HC. Reciprocal F(1) crosses between BTBR and BALB suggest the presence of X-linked quantitative trait loci (QTLs) affecting CC size. Through linkage analysis of backcross male progeny, we have localized two regions on the X chromosome, having peaks at 68.5 Mb (approximately 29.5 cM) and at 134.5 Mb (approximately 60.5 cM) that are largely responsible for the reciprocal differences, with the BTBR allele showing X-linked dominant inheritance associated with CC defects.
Kusek
G K
GK
Genomics Institute, Wadsworth Center, Troy, and Department of Biomedical Sciences, University at Albany, Albany, NY, USA.
Wahlsten
D
D
Herron
B J
BJ
Bolivar
V J
VJ
Flaherty
L
L
D061085:Agenesis of Corpus Callosum; D000704:Analysis of Variance; D000818:Animals; D002874:Chromosome Mapping; D000013:Congenital Abnormalities / Q000235:genetics; D003337:Corpus Callosum / Q000033:anatomy & histology* / Q000196:embryology; D050172:Genes, X-Linked / Q000235:genetics*; D008040:Genetic Linkage; D006624:Hippocampus / Q000002:abnormalities / Q000033:anatomy & histology / Q000196:embryology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008818:Mice, Neurologic Mutants; D009929:Organ Size; D038081:Organogenesis / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics*; D013045:Species Specificity; D014960:X Chromosome / Q000235:genetics