Project description:The mammalian genome contains two ERK/MAP kinase kinase genes, Map2k1 and Map2k2, encoding dual-specificity kinases responsible for ERK/MAP kinase activation. Loss of Map2k1 function in mouse causes embryonic lethality due to placental defects, while Map2k2 mutant mice survive with a normal lifespan. The Map2k1 mutation interferes with the growth of the labyrinthine region of the placenta and its vascularization. Map2k1+/-Map2k2+/- embryos also die during gestation of underdevelopment of the labyrinth. In Map2k1+/-Map2k2+/- mutants, the vascularization of the labyrinth is reduced and defects in SynT-II formation lead to the accumulation of multinucleated trophoblasts giant cells (MTG). Deletion of both Map2k1 alleles in allantoïs-derived tissues in Map2k1+/ Map2k2+/- placenta (Map2k1flox/-Map2k2+/-Tg+/Sox2Cre) increases the penetrance and the expressivity of the MTG placental phenotype. Microarray analysis with RNA extracted from placentas of E12.5 wt, Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos was performed to evaluate the molecular impact of the loss of Map2k alleles on placenta development. Total RNA was isolated from placentas of E12.5 Map2k1+/+Map2k2+/+(control), from E12.5 Map2k1+/-Map2k2+/- embryos (experimental) and from E12.5 and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos (experimental). Four specimens were analyzed per genotype.
Project description:The mammalian genome contains two ERK/MAP kinase kinase genes, Map2k1 and Map2k2, encoding dual-specificity kinases responsible for ERK/MAP kinase activation. Loss of Map2k1 function in mouse causes embryonic lethality due to placental defects, while Map2k2 mutant mice survive with a normal lifespan. The Map2k1 mutation interferes with the growth of the labyrinthine region of the placenta and its vascularization. Map2k1+/-Map2k2+/- embryos also die during gestation of underdevelopment of the labyrinth. In Map2k1+/-Map2k2+/- mutants, the vascularization of the labyrinth is reduced and defects in SynT-II formation lead to the accumulation of multinucleated trophoblasts giant cells (MTG). Deletion of both Map2k1 alleles in allantoïs-derived tissues in Map2k1+/ Map2k2+/- placenta (Map2k1flox/-Map2k2+/-Tg+/Sox2Cre) increases the penetrance and the expressivity of the MTG placental phenotype. Microarray analysis with RNA extracted from placentas of E12.5 wt, Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos was performed to evaluate the molecular impact of the loss of Map2k alleles on placenta development.
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.