Cellular senescence protects multicellular organisms from tissue overgrowth including @entity5 , and contributes to tissue ageing. With stable cell cycle arrests and particular molecular features, cellular senescence has been mostly studied in the adult tissues of animals including mammals. In the present study, we report a widespread of cellular senescence in certain time windows of late phase normal development of @entity19 embryos. Using in situ senescence-associated b-galactosidase (SA-b-gal) staining, we demonstrate SA-b-gal activity in selected cell populations of brain, stomach, interdigital webs, tail, ear, limbs, and @entity2133 area in the gestation day 14.5 of the @entity19 embryos. In the 18.5 day of gestation, selected cells in the intestines and bone developmental areas showed SA-b-gal activity. The chondrocytes in ossification zones were significantly marked by the activities of SA-b-gal, @entity5207 , @entity3722 and Hp1r, suggesting activation of the cell cycle checkpoint by the @entity899 and Rb pathways and development of @entity7905 ( @entity7905 ). Throughout the 14.5-18.5 gestation days, the trophoblast cells in the labyrinth layer of placenta also displayed strong activities of SA-b-gal, @entity899 and @entity5207 . Increased expressions of of @entity14293 , @entity5795 , Rb of the @entity5795 /Rb pathway, and reduced expressions of @entity14160 were also observed in the placentas. Taken together, our findings suggest that cellular senescence represents an essential mechanism in multiple sites including the fetal bone forming zone and placenta during @entity1 embryonic development, playing potential roles in the full embryonic development of tissue growth and organ formation. This article is protected by copyright. All rights reserved.

Cellular senescence occurred widespread to multiple selective sites in the fetal tissues and organs of XXXX .

@entity1 :: ('9606', 'Species') :: ['mammalian'] @entity14293 :: ('83430(Tax:10090)', 'Gene') :: ['p19'] @entity14160 :: ('17345(Tax:10090)', 'Gene') :: ['Ki67'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cancer'] @entity2133 :: ('MESH:D014987', 'Disease') :: ['nasal mouth'] @entity19 :: ('10090', 'Species') :: ['mouse'] @entity899 :: ('22060(Tax:10090)', 'Gene') :: ['p53'] @entity7905 :: ('MESH:C565785', 'Disease') :: ['SAHF', 'senescence-associated heterochromatic foci'] @entity5207 :: ('12575(Tax:10090)', 'Gene') :: ['p21'] @entity5795 :: ('13088(Tax:10090)', 'Gene') :: ['p16'] @entity3722 :: ('12579(Tax:10090)', 'Gene') :: ['p15']
@entity19 :: (10090,Species) :: ['mice']
