title: Senescence-associated β-galactosidase activity marks the visceral endoderm of mouse embryos but is not indicative of senescence.
abstract: Senescence-associated β-galactosidase (SA-β-gal) activity is widely used as a marker of cellular senescence and as an indicator of organismal aging. Here, we report that SA-β-gal activity is present in the visceral endoderm layer of early postimplantation mouse embryos in predictable patterns that vary as the embryo progresses in development. However, determination of the mitotic index and analysis of the expression of Cdkn1a (p21), a marker of senescent cells, do not indicate cellular senescence. Instead, analysis of embryos in culture revealed the presence of SA-β-gal activity in apical vacuoles of visceral endoderm cells likely a reflection of acidic β-galactosidase function in these organelles. SA-β-gal serves as a practical marker of the dynamics of the visceral endoderm that can be applied to developmental as well as functional studies of early mammalian embryos.
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, 01655.
authors.forename: Tingting
authors.initials: T
authors.lastname: Huang
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Rivera-Pérez
mesh_terms: D000818:Animals; D016922:Cellular Senescence; D004622:Embryo, Mammalian / Q000166:cytology / Q000201:enzymology; D004707:Endoderm / Q000166:cytology / Q000201:enzymology*; D051379:Mice; D008938:Mitosis; D008940:Mitotic Index; D014617:Vacuoles / Q000201:enzymology; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D001616:beta-Galactosidase
keywords: SA-β-gal; apical vacuoles; embryo; mouse; yolk sac