Axonemal dynein expression in human fetal tracheal epithelium.
Ciliogenesis in human fetal airway epithelium occurs from 11 to 24 gestational weeks. Using genetic and antigenic markers specific for human axonemal dynein heavy chain 9, we characterized temporal aspects of axonemal dynein expression associated with large airway epithelial ciliogenesis during human fetal development. Late in the first trimester, an undifferentiated columnar epithelium is characteristic of the large airways, and immunocytochemical studies exhibited focal localization of axonemal dynein antigen on luminal epithelial cell borders at sites consistent with emergent ciliary beds. From 12 to 22 wk, immunocytochemical labeling of new ciliary beds was prominent, and localization within the cytoplasm of epithelial cells suggested avid synthesis of axonemal dynein in advance of ciliogenic events. Quantitative RT-PCR of tracheal RNA and in situ hybridization studies compared favorably with immunocytochemical findings with the earliest expression of axonemal dynein at 9-10 wk gestation. These studies have documented that axonemal dynein is expressed early in human fetal life during airway epithelial maturation and well before histological or ultrastructural evidence of ciliogenesis is apparent.
Carson
Johnny L
JL
Department of Pediatrics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. jcarson@med.unc.edu
Reed
William
W
Lucier
Thomas
T
Brighton
Luisa
L
Gambling
Todd M
TM
Huang
Chien-Hui
CH
Collier
Albert M
AM
D056444:Axonemal Dyneins; D002923:Cilia / Q000502:physiology / Q000648:ultrastructure; D004398:Dyneins / Q000235:genetics* / Q000378:metabolism; D005314:Embryonic and Fetal Development; D004848:Epithelium / Q000196:embryology; D005260:Female; D005333:Fetus / Q000166:cytology / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014132:Trachea / Q000196:embryology*
D012333:RNA, Messenger; D056444:Axonemal Dyneins; C430745:DNAH9 protein, human; D004398:Dyneins