Project description:In mammals, pluripotent cells transit through a continuum of distinct molecular and functional states en route to initiating lineage specification. Capturing pluripotent stem cells (PSCs) mirroring in vivo pluripotent states provides accessible in vitro models to study the pluripotency program and mechanisms underlying lineage restriction. Here, we develop optimal culture conditions to derive and propagate post-implantation epiblast-derived PSCs (EpiSCs) in rats, a valuable model for biomedical research. We show that rat EpiSCs can be reset toward the naïve pluripotent state with exogenous Klf4, albeit not with the other five candidate genes (Nanog, Klf2, Esrrb, Tfcp2l1, and Tbx3) effective in mice. Finally, we demonstrate that rat EpiSCs retain competency to produce authentic primordial germ cell-like cells that contribute to functional gametogenesis leading to the birth of viable offspring. Our findings in the rat model uncover conserved principles underpinning pluripotency and germline competency across species.
Project description:In vitro generation of germ cells from pluripotent stem cells (PSCs) can crucially impact future reproductive medicine and animal breeding. A decade ago, in vitro gametogenesis was established in the mouse. However, induction of primordial germ cell-like cells (PGCLCs) to produce fertile gametes has not been achieved in any other species. Here, we demonstrate the induction of functional PGCLCs from rat PSCs. We show that epiblast-like cells in floating aggregates form rat PGCLCs. The gonadal somatic cells support maturation and epigenetic reprogramming of the PGCLCs. Notably, rat PGCLCs transplanted into the seminiferous tubules of germline-less rats produce spermatids, leading to the birth of viable offspring. Insights from our rat model will elucidate conserved and divergent mechanisms essential for the broad applicability of in vitro gametogenesis.
Project description:Pluripotent stem cells (PSCs) provide a powerful tool to produce transgenic animals for biomedical research. However, impaired PSC contribution to chimerism and most notably to the germline oftentimes impedes production of genetically modified animals, rendering techniques that expediate PSC contribution to the germline highly desirable. Blastocyst complementation denotes a technique which purposes to generate organs, tissues or cells in animal chimeras following microinjection of PSCs into genetically compromised blastocyst-stage embryos. Here, we report on successful blastocyst complementation of the male germline in adult chimeras via microinjection of mouse or rat PSCs into mouse blastocysts mutated for Tsc22d3, an essential gene for spermatozoa production. Microinjection of mouse embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) into Tsc22d3-KnockOut (KO) blastocyst-stage embryos gave rise to intraspecies chimeras embodying functional spermatozoa, which were solely derived from the microinjected PSCs. Furthermore, microinjection of rat ESCs into Tsc22d3-KO mouse embryos gave rise to viable mouse-rat chimeras that exhibited extensive contribution of rat cells to various tissues and organs. Notably, multiple mouse-rat chimeras showed contribution of rat ESCs to the male germline, solely harboring rat spermatids and spermatozoa that were rat ESC-derived and could fertilize rat oocytes. Collectively, this study reports on a method for exclusive germ cell production of one species in another via blastocyst complementation with PSCs. Implications of this study may extend to development of transgenic rat gametes in sterile mice and could further assist efforts to generate germ cells from endangered animal species.
Project description:Pluripotent stem cells (PSCs) provide a powerful tool to produce transgenic animals for biomedical research. However, impaired PSC contribution to chimerism and most notably the germline oftentimes impedes production of genetically modified animals, rendering techniques that expediate PSC contribution to the germline highly desirable. Blastocyst complementation denotes a technique which purposes to generate organs, tissues or cells in animal chimeras via microinjection of PSCs into genetically compromised blastocyst-stage embryos. Here we report on successful blastocyst complementation of the male germline in adult chimeras following microinjection of mouse or rat PSCs into mouse blastocysts mutated for Tsc22d3, an essential gene for spermatozoa production. Microinjection of mouse embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) into Tsc22d3-KnockOut (KO) blastocyst-stage embryos gave rise to intraspecies chimeras embodying functional spermatozoa, which were solely derived from microinjected PSCs. Furthermore, microinjection of rat ESCs into Tsc22d3-KO mouse embryos gave rise to viable mouse-rat chimeras that exhibited extensive contribution of rat cells to various organs. Notably, multiple mouse-rat chimeras showed contribution of rat ESCs to the male germline, solely harboring rat spermatids and spermatozoa that were rat ESC-derived and could fertilize rat oocytes. Collectively, this study reports a method for exclusive production of functional germ cells of one species in another via blastocyst complementation with PSCs. Implications of this study extend to development of transgenic rats via sterile mice, and may further assist efforts to generate xenogeneic gametes from endangered animal species.
Project description:Pluripotent stem cells (PSCs) provide a powerful tool to produce transgenic animals for biomedical research. However, impaired PSC contribution to chimerism and most notably the germline oftentimes impedes production of genetically modified animals, rendering techniques that expediate PSC contribution to the germline highly desirable. Blastocyst complementation denotes a technique which purposes to generate organs, tissues or cells in animal chimeras via microinjection of PSCs into genetically compromised blastocyst-stage embryos. Here we report on successful blastocyst complementation of the male germline in adult chimeras following microinjection of mouse or rat PSCs into mouse blastocysts mutated for Tsc22d3, an essential gene for spermatozoa production. Microinjection of mouse embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) into Tsc22d3-KnockOut (KO) blastocyst-stage embryos gave rise to intraspecies chimeras embodying functional spermatozoa, which were solely derived from microinjected PSCs. Furthermore, microinjection of rat ESCs into Tsc22d3-KO mouse embryos gave rise to viable mouse-rat chimeras that exhibited extensive contribution of rat cells to various organs. Notably, multiple mouse-rat chimeras showed contribution of rat ESCs to the male germline, solely harboring rat spermatids and spermatozoa that were rat ESC-derived and could fertilize rat oocytes. Collectively, this study reports a method for exclusive production of functional germ cells of one species in another via blastocyst complementation with PSCs. Implications of this study extend to development of transgenic rats via sterile mice, and may further assist efforts to generate xenogeneic gametes from endangered animal species.
Project description:Pluripotent stem cells (PSCs) provide a powerful tool to produce transgenic animals for biomedical research. However, impaired PSC contribution to chimerism and most notably the germline oftentimes impedes production of genetically modified animals, rendering techniques that expediate PSC contribution to the germline highly desirable. Blastocyst complementation denotes a technique which purposes to generate organs, tissues or cells in animal chimeras via microinjection of PSCs into genetically compromised blastocyst-stage embryos. Here we report on successful blastocyst complementation of the male germline in adult chimeras following microinjection of mouse or rat PSCs into mouse blastocysts mutated for Tsc22d3, an essential gene for spermatozoa production. Microinjection of mouse embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) into Tsc22d3-KnockOut (KO) blastocyst-stage embryos gave rise to intraspecies chimeras embodying functional spermatozoa, which were solely derived from microinjected PSCs. Furthermore, microinjection of rat ESCs into Tsc22d3-KO mouse embryos gave rise to viable mouse-rat chimeras that exhibited extensive contribution of rat cells to various organs. Notably, multiple mouse-rat chimeras showed contribution of rat ESCs to the male germline, solely harboring rat spermatids and spermatozoa that were rat ESC-derived and could fertilize rat oocytes. Collectively, this study reports a method for exclusive production of functional germ cells of one species in another via blastocyst complementation with PSCs. Implications of this study extend to development of transgenic rats via sterile mice, and may further assist efforts to generate xenogeneic gametes from endangered animal species.
Project description:Transcriptomes of mouse E12.5 primordial germ cells (PGCs), primordial germ cell-like cells (PGCLCs) isolated from 6-day culture embryoid bodies, and the precursor pluripotent stem cells [embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)] and epiblast-like cells (EpiLCs) Total RNA was isolated from FACS-enriched, SSEA1+/CD61+ double-positive PGCs and PGCLCs. RNA was also isolated from ESC, iPSC, and EpiLC cultured without enrichment. Transcriptomes were determined using Affymetrix microarray.