Immunocytochemistry of carbonic anhydrase and non-radioactive detection of its RNA by in situ hydridization in the chick embryo membranous labyrinth.
An immunocytochemical study was carried out with the aim to localize carbonic anhydrase isozymes (CA I and CA II) in the chick membranous labyrinth. CA I and CA II were localized in the same cells and, during the early developmental stages, were diffusely present in the labyrinthine epithelium. At later stages, the sensorial epithelium of the maculae acusticae, crista ampullaris and papilla basilaris, as well as labyrinthine dark cells and the epithelium of the endolymphatic sac strongly stained by the immunocytochemical procedure. In 1-day and 1-week old chicks, CA was present in the same sites as at advanced embryonal stages. In order to detect mRNA for carbonic anhydrase II, in situ hybridization was also used. Strong hybridization signals were observed in the sensorial epithelium of the saccule, utricle and crista ampullaris, in the tegmentum vasculosum, the endolymphatic sac, the erythrocytes and the choroid plexus in embryos older than 10 days. This positivity persisted until the day after hatching. The authors discuss the significance of labyrinthine CA and, based on in situ hybridization results, suggest that melanocytes do not provide labyrinthine dark cells with enzyme protein.
Balsamo
G
G
Department of Genetics, General and Molecular Biology, University of Naples, Napoli, Italy.
Avallone
B
B
Rocco
L
L
Marmo
F
F
D000818:Animals; D002256:Carbonic Anhydrases / Q000032:analysis*; D002462:Cell Membrane / Q000201:enzymology; D002642:Chick Embryo; D007758:Ear, Inner / Q000196:embryology / Q000201:enzymology*; D004848:Epithelium / Q000201:enzymology; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000032:analysis*
D012333:RNA, Messenger; D002256:Carbonic Anhydrases