Nasal pit formation in the hamster: A transmission and scanning electron microscopic study☆
[摘要] Thesurfacemorphologyofcellscomprisingthenasalplacodeandadjacentbodysurfacewasexaminedbytransmissionandscanningelectronmicroscopyduringnasalpitformationinhamsterembryosranginginagefrom814to912dayspostcoitum.Asharpdistinctionbetweentheapicalsurfaceappearanceofcellsofthenasalepitheliumandcellsofthesurroundingperidermdevelopsattheperipheryofthenasalplacode.Peridermcellsincreaseinsurfacearea,exhibitachangeinthedistributionofsurfacemicrovilli,andmanyacquireasingleciliumpercell.Cellsofthenasalplacoderetainadensesurfacecoatofmicrovilliandexhibitrelativelysmallerapicalsurfaceareas.Olfactoryrodscanbepositivelyidentifiedonthebasisoftheirultrastructureatthenasalgroovestage.Theventralmarginofthenasalgroovedoesnotinitiallydependonthemaxillaryprocess,butisboundedbythelateralandmedialnasalprocesses.Fromtheirearliestdevelopmenttheoralandnasalcavitiesappeartobeseparatedinthisspecies.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
