Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not M-NM-^TNp73KO mice, display a M-bM-^@M-^Xnear-empty seminiferous tubuleM-bM-^@M-^Y phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation. 3 mice each for control wildtype and TAp73 knockout mice.
Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not M-NM-^TNp73KO mice, display a M-bM-^@M-^Xnear-empty seminiferous tubuleM-bM-^@M-^Y phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation. 3 mice each for control wildtype and TAp73 knockout mice
Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not ΔNp73KO mice, display a ‘near-empty seminiferous tubule’ phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation.
Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not ΔNp73KO mice, display a ‘near-empty seminiferous tubule’ phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.