Disruption of entire Cables2 locus leads to embryonic lethality by diminished Rps21 gene expression and enhanced p53 pathway

In vivo function of CDK5 and Abl enzyme substrate 2 (Cables2), belonging to the Cables protein family, is unknown. Here, we found that targeted disruption of the entireCables2locus (Cables2d) caused growth retardation and enhanced apoptosis at the gastrulation stage and then induced embryonic lethality in mice. Comparative transcriptome analysis revealed disruption ofCables2, 50% down-regulation ofRps21abutting on theCables2locus, and up-regulation of p53-target genes inCables2dgastrulas. We further revealed the lethality phenotype inRps21-deleted mice and unexpectedly, the exon 1-deletedCables2mice survived. Interestingly, chimeric mice derived fromCables2dESCs carrying exogenousCables2and tetraploid wild-type embryo overcame gastrulation. These results suggest that the diminished expression ofRps21and the completed lack ofCables2expression are intricately involved in the embryonic lethality via the p53 pathway. This study sheds light on the importance ofCables2locus in mouse embryonic development.