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Updated: Aug 16, 2026

Aip1p Dynamics Are Altered by the R256H Mutation in Actin
Published on: July 30, 2014
The t complex-encoded GTPase-activating protein Tagap1 acts as a transmission ratio distorter in mice
Hermann Bauer1, Jürgen Willert, Birgit Koschorz
1Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 73, 14195 Berlin, Germany. herrmann@molgen.mpg.de
Abstract:
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.
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