The t complex-encoded GTPase-activating protein Tagap1 acts as a transmission ratio distorter in mice.
Transmission ratio distortion in the mouse is caused by several t-complex distorters (Tcds) acting in trans on the t-complex responder (Tcr). Tcds additively affect the flagellar movement of all spermatozoa derived from t/+ males; sperm carrying Tcr are rescued, resulting in an advantage for t sperm in fertilization. Here we show that Tagap1, a GTPase-activating protein, can act as a distorter. Tagap1 maps to the Tcd1 interval and has four t loci, which encode altered proteins including a C-terminally truncated form. Overexpression of wild-type Tagap1 in sperm cells phenocopied Tcd function, whereas a loss-of-function Tagap1 allele reduced the transmission rate of the t6 haplotype. The combined data strongly suggest that the t loci of Tagap1 produce Tcd1a. Our results unravel the molecular nature of a Tcd and demonstrate the importance of small G proteins in transmission ratio distortion in the mouse.
Bauer
Hermann
H
Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 73, 14195 Berlin, Germany. herrmann@molgen.mpg.de
Willert
Jürgen
J
Koschorz
Birgit
B
Herrmann
Bernhard G
BG
D000818:Animals; D033481:Chromosomes, Mammalian; D003433:Crosses, Genetic; D005260:Female; D020690:GTPase-Activating Proteins / Q000235:genetics* / Q000502:physiology; D006239:Haplotypes; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000502:physiology*; D009687:Nuclear Proteins / Q000737:chemistry / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology; D019076:Transgenes / Q000502:physiology; D056427:t-Complex Genome Region
D020690:GTPase-Activating Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins