Functional analyses of in vitro fertilized, preimplanation human embryos reveal that the first lineage segregation depends on cell polarization signaling that is regulated by Phospholipase C (PLC) activity.
Irreversible differentiation into somatic cells is evolutionarily optimal if changing cell phenotype is costly, a few somatic cells already improve the organism's performance, and the organism is large enough.
Preimplantation screening of embryos using polygenic risk scores may substantially reduce risk for a given complex disease, but this effect depends on several quantifiable factors and raises significant ethical issues.
Human herpesvirus 6B can transition between telomere-integrated and free viral forms, and frequent telomere-loop-driven partial or complete viral genome excision events create mosaicism in germline carriers of inherited chromosomally integrated HHV-6B.
The relationship between APOE genotype and disease risks may be environmentally moderated, with APOE4 being less harmful and unlikely to increase cardiometabolic risk in a physically active, energy-limited population.
Gamete-derived three-amino-acid-loop-extension homeodomain proteins activate zygote development in a strikingly similar manner between basal land plants and green algae, indicating an ancestral role of these transcription factors in green plants.
The ancestral mechanism to activate diploid gene expression via homeodomain transcription factors was retained in liverworts, an early diverging land plant lineage, and subsequently co-opted during evolution of the diploid sporophyte body.