Multiple genes, whose functions or expression are overlapping, compensate for the loss of one gene. A gene cluster in the mouse genome encodes five seminal vesicle proteins (SVS2, SVS3, SVS4, SVS5, and SVS6). SVS2 plays an essential role in the successful internal fertilization by protecting the sperm membrane against a uterine immune attack. We hypothesized that the four remaining proteins of this gene cluster may compensate for the deficiency of SVS2. For confirming that, we generated mice

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... king the entire Svs gene cluster and compared their fecundity with Svs2-deficient (Svs2 KO) alone. Svs2 KO mice has a single loxP site, thus we inserted another loxP by combining the CRISPR/Cas9 system with ssODN. Male mice lacking the entire Svs gene cluster (Svs2-6 KO mice), generated by the deletion of 100kbp genomic DNA, showed low fecundity. However, the fecundity level was comparable with that from Svs2 KO male mice. Our results show SVS3, SVS4, SVS5, and SVS6 do not function in the protection of sperm against a uterine immune attack in the absence of SVS2. Thus, Svs2 is the critical gene in the SVP gene cluster. Center Chromosomal rearrangements are the cause of many hereditary disorders and play a role in the pathogenesis of diseases such as cancer. To study these molecular pathologies, in vivo models of chromosomal rearrangement are indispensable, but producing them requires substantial effort and prudent technique. Recently, we used i-GONAD method to introduce chromosomal inversions of several Mb in length in mouse zygotes (Iwata et al., Sci Rep 2019). However, our result suggests that the larger the target region, the higher the risk to cause lethality. In this study, we established an efficient chromosomal engineering system by using the i-GONAD in a genome stability mutant. Our methods provide a simple and efficient approach for engineering chromosomal rearrangements and contribute to the study of disease caused by chromosomal rearrangements. Abstract | 489