Biology subjects

Ohtsuka, S.

Publications and source records attributed to Ohtsuka, S..

3 recordsLinked to original sources

bioRxiv2023

A Neanderthal/Denisovan GLI3 variant contributes to anatomical variations in mice

Changes in genomic structures underlie phenotypic diversification in organisms. Amino acid-changing mutations affect pleiotropic functions of proteins, although little is known about how mutated proteins are adapted in existing developmental programs. Here we investigate the biological effects of a variant of the GLI3 transcription factor (GLI3R1537C) carried in Neanderthals and Denisovans, which are extinct hominins close to modern humans. R1537C does not compromise protein stability or GLI3 activator-dependent transcriptional activities. In contrast, R1537C affects the regulation of downstream target genes associated with developmental processes. Furthermore, genome-edited mice carrying the Neanderthal/Denisovan GLI3 mutation exhibited various alterations in skeletal morphology. Our data suggest that an extinct hominin-type GLI3 contributes to species-specific anatomical variations, which were tolerated by relaxed constraint in developmental programs during human evolution.

evolutionary biology↗

bioRxiv2021

Inhibition of N-myristoyltransferase Promotes Naive Pluripotency in Mouse and Human Pluripotent Stem Cells

Naive and primed states are distinct states of pluripotency during early embryonic development that can be captured and converted to each other in vitro. To elucidate the regulatory mechanism of pluripotency, we performed a recessive genetic screen of homozygous mutant mouse embryonic stem cells (mESCs) and found that suppression of N-myristoyltransferase (Nmt) promotes naive pluripotency. Disruption of Nmt1 in mESCs conferred resistance to differentiation. Suppression of Nmt in mouse epiblast stem cells (mEpiSCs) promoted the conversion from the primed to the naive state. This effect was independent of Src, which is a major substrate of Nmt and is known to promote differentiation of mESCs. Suppression of Nmt in naive-state human induced pluripotent stem cells (hiPSCs) increased the expression of the naive-state marker. These results indicate that Nmt is a novel target for the regulation of naive pluripotency conserved between mice and humans.

developmental biology↗

bioRxiv2018

Implantation-Competent Blastocyst-Like Structures from Mouse Pluripotent Stem Cells

Soon after fertilization, the few totipotent cells of mammalian embryos diverge to form a structure called the blastocyst (BC). Although numerous types of cells, including germ cells and extended pluripotency stem cells, have been generated from pluripotent stem cells (PSCs) in-vitro, generating functional BCs only from PSCs has not yet been reported. Here we describe induced self-organizing 3D BC-like structures (iBCs) generated from mouse PSC culture in-vitro. Resembling natural BCs, iBCs have a blastocoel-like cavity and were formed with outer cells that are positive for trophectoderm lineage markers and with inner cells that are positive for pluripotency markers. iBCs transplanted to pseudopregnant mice uteruses implanted, induced decidualization, and exhibited growth and development before resorption, demonstrating that iBCs are implantation-competent. iBC production required the transcription factor Prdm14 and iBC precursor intermediates concomitantly activate the MERVL totipotency related cleavage stage reporter. Thus, our system may contribute to understanding molecular mechanisms underpinning totipotency, embryogenesis, and implantation.\n\nHIGHLIGHTS-Pluripotent cells self-organize blastocyst-like structures in defined conditions.\n-Structures have several extraembryonic and embryonic characteristics of blastocysts.\n-Structures can implant in the uterus and grow before resorption.\n-Totipotency is implicated concomitantly at loci that originate induced blastocysts.

developmental biology↗