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:Diploidy is a fundamental genetic feature in mammals, in which haploid cells normally arise only as post-meiotic germ cells that serve to insure a diploid genome upon fertilization. Gamete manipulation has yielded haploid embryonic stem (ES) cells from several mammalian species, but as of yet not from humans. Here we analyzed a large collection of human parthenogenetic ES cell lines originating from haploid oocytes, leading to the successful isolation and maintenance of human ES cell lines with a normal haploid karyotype. Haploid human ES cells exhibited typical pluripotent stem cell characteristics such as self-renewal capacity and a pluripotency-specific molecular signature. Although haploid human ES cells resembled their diploid counterparts, they also displayed distinct properties including differential regulation of X chromosome inactivation and genes involved in oxidative phosphorylation, alongside reduction in absolute gene expression levels and cell size. Intriguingly, we found that a haploid genome is compatible not only with the undifferentiated pluripotent state, but also with differentiated somatic fates representing all three embryonic germ layers, despite a persistent dosage imbalance between the autosomes and X chromosome. We expect that haploid human ES cells will provide novel means for studying human functional genomics, development and evolution.
Project description:Clonal cellular variance often confounds reproducibility of forward and reverse genetic studies. We developed combinatorial approaches for whole genome saturated mutagenesis using haploid murine ES cells to permit induction and reversion of genetic mutations. Using these systems, we created a biobank with over 100000 individual ES cell lines with repairable and genetically bar coded mutations targeting 16950 genes. This biobank termed “Haplobank” is freely available. In addition, we developed a genetic color coding system for rapid repair of mutations and direct functional validation in sister clones. Using this system, we report functional validation of essential ES cell genes. We also identified phospholipase16G as a key pathway for cytotoxicity of human rhinoviruses, the most frequent cause of the common cold. Moreover, we derived 3D blood vessel organoids from haploid ES cells, combining conditional mutagenesis in haploid ES cells with tissue engineering. We identified multiple novel genes, such as Connexin43/Gja1, in blood vessel formation and tip cell specification in vitro and also in vivo. Taken together, we develop a conditional homozygous ES cell resource for the community to empower controlled genetic studies in murine ES cells and tissues derived from it.
Project description:Diploidy is a fundamental genetic feature in mammals, in which haploid cells normally arise only as post-meiotic germ cells that serve to insure a diploid genome upon fertilization. Gamete manipulation has yielded haploid embryonic stem (ES) cells from several mammalian species, but as of yet not from humans. Here we analyzed a large collection of human parthenogenetic ES cell lines originating from haploid oocytes, leading to the successful isolation and maintenance of human ES cell lines with a normal haploid karyotype. Haploid human ES cells exhibited typical pluripotent stem cell characteristics such as self-renewal capacity and a pluripotency-specific molecular signature. Although haploid human ES cells resembled their diploid counterparts, they also displayed distinct properties including differential regulation of X chromosome inactivation and genes involved in oxidative phosphorylation, alongside reduction in absolute gene expression levels and cell size. Intriguingly, we found that a haploid genome is compatible not only with the undifferentiated pluripotent state, but also with differentiated somatic fates representing all three embryonic germ layers, despite a persistent dosage imbalance between the autosomes and X chromosome. We expect that haploid human ES cells will provide novel means for studying human functional genomics, development and evolution.
Project description:Diploidy is a fundamental genetic feature in mammals, in which haploid cells normally arise only as post-meiotic germ cells that serve to insure a diploid genome upon fertilization. Gamete manipulation has yielded haploid embryonic stem (ES) cells from several mammalian species, but as of yet not from humans. Here we analyzed a large collection of human parthenogenetic ES cell lines originating from haploid oocytes, leading to the successful isolation and maintenance of human ES cell lines with a normal haploid karyotype. Haploid human ES cells exhibited typical pluripotent stem cell characteristics such as self-renewal capacity and a pluripotency-specific molecular signature. Although haploid human ES cells resembled their diploid counterparts, they also displayed distinct properties including differential regulation of X chromosome inactivation and genes involved in oxidative phosphorylation, alongside reduction in absolute gene expression levels and cell size. Intriguingly, we found that a haploid genome is compatible not only with the undifferentiated pluripotent state, but also with differentiated somatic fates representing all three embryonic germ layers, despite a persistent dosage imbalance between the autosomes and X chromosome. We expect that haploid human ES cells will provide novel means for studying human functional genomics, development and evolution.