Genetic control of a central pattern generator: rhythmic oromotor movement in mice is controlled by a major locus near Atp1a2.
Fluid licking in mice is a rhythmic behavior that is controlled by a central pattern generator (CPG) located in a complex of brainstem nuclei. C57BL/6J (B6) and DBA/2J (D2) strains differ significantly in water-restricted licking, with a highly heritable difference in rates (h(2)≥0.62) and a corresponding 20% difference in interlick interval (mean ± SEM = 116.3±1 vs 95.4±1.1 ms). We systematically quantified motor output in these strains, their F(1) hybrids, and a set of 64 BXD progeny strains. The mean primary interlick interval (MPI) varied continuously among progeny strains. We detected a significant quantitative trait locus (QTL) for a CPG controlling lick rate on Chr 1 (Lick1), and a suggestive locus on Chr 10 (Lick10). Linkage was verified by testing of B6.D2-1D congenic stock in which a segment of Chr 1 of the D2 strain was introgressed onto the B6 parent. The Lick1 interval on distal Chr 1 contains several strong candidate genes. One of these is a sodium/potassium pump subunit (Atp1a2) with widespread expression in astrocytes, as well as in a restricted population of neurons. Both this subunit and the entire Na(+)/K(+)-ATPase molecule have been implicated in rhythmogenesis for respiration and locomotion. Sequence variants in or near Apt1a2 strongly modulate expression of the cognate mRNA in multiple brain regions. This gene region has recently been sequenced exhaustively and we have cataloged over 300 non-coding and synonymous mutations segregating among BXD strains, one or more of which is likely to contribute to differences in central pattern generator tempo.
Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America. jboughter@uthsc.edu
John D
JD
Boughter
Megan K
MK
Mulligan
Steven J
SJ
St John
Kenichi
K
Tokita
Lu
L
Lu
Detlef H
DH
Heck
Robert W
RW
Williams
D000818:Animals; D002874:Chromosome Mapping; D033481:Chromosomes, Mammalian; D005260:Female; D005786:Gene Expression Regulation; D008040:Genetic Linkage; D055106:Genome-Wide Association Study; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009068:Movement; D010507:Periodicity; D040641:Quantitative Trait Loci; D015203:Reproducibility of Results; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D013045:Species Specificity
C401838:Atp1a2 protein, mouse; D000254:Sodium-Potassium-Exchanging ATPase