Qualitative and quantitative freeze-fracture studies on olfactory and respiratory epithelial surfaces of frog, ox, rat, and dog. IV. Ciliogenesis and ciliary necklaces (including high-voltage observations).
A comparison of the necklaces of sensory olfactory, and non-sensory nasal respiratory cilia of four vertebrate species (frog, ox, rat and dog) shows that the olfactory cilia have 7 +/- 1 (mean +/- standard deviation) strands in the three mammalian species and 6 +/- 1 strands in the frog; for the respiratory cilia these values are 5 +/- 1 and 4 +/- 1. This function- and species-dependency of ciliary necklace strand numbers is supported by a review of the literature. Necklaces show no other structural differences. Necklace strand densities range from 25--33 strand/micrometers. In both sensory and non-sensory cilia ciliogenesis is preceded by the formation of necklace strands. Sometimes cilia do not develop properly, as demonstrated by the presence of necklace-like structures in the membranes of olfactory dendritic endings and respiratory axonemal aggregates.
D000818:Animals; D002417:Cattle; D002923:Cilia / Q000648:ultrastructure*; D003712:Dendrites / Q000648:ultrastructure; D004285:Dogs; D005260:Female; D005614:Freeze Fracturing; D008297:Male; D009024:Morphogenesis; D009297:Nasal Mucosa / Q000648:ultrastructure*; D009831:Olfactory Mucosa / Q000648:ultrastructure*; D011893:Rana esculenta; D051381:Rats