Molecular analyses of carbonic anhydrase‐II expression and regulation in the developing chicken lens

Abstract

The expression of carbonic anhydrase-I1 (CA-11) in the developing chicken lens was examined and compared with that in the retina of the chicken embryo. CA-I1 expression was measured by immunohistochemistry and radioimmunoassay during development, and CA-I1 mRNA was quantified by Northern blot and densitometric scanning and localized by in situ hybridization. A functional promoter of the chicken CA-I1 gene was identified by transfection of primary embryonic chicken lens epithelial cells and analyzed in deletion mutants. The results establish that CA-I1 makes u p about 0.1% of the total soluble protein of the embryonic chicken lens, an amount insufficient to make it a candidate for an enzyme crystallin in this species. Lens fiber differentiation coincided with a loss of CA-I1 mRNA and protein; by contrast, CA-I1 persisted in the epithelial cells of the embryonic and mature lens. This and previous studies showed that CA-I1 amounts to as much as 3% of the protein of the embryonic chicken retina and follows a different developmental time course of expression; like the lens, CA-I1 decreases until day 10 in the embryonic retina, but, unlike the lens, it increases thereafter and plateaus at hatching. Progressive deletions of the 5' flanking regions (from position -1314 to +32) of the CA-I1 gene fused to the bacterial chloramphenicol acetyltransferase (CAT) reporter gene resulted in a gradual loss of promoter activity, consistent with an additive effect of putative cis-regulatory elements found in many crystallin genes. These experiments provide the foundation for a molecular analysis of the developmental and differential regulation of the CA-I1 gene in lens and retina. o 1992 Wiley-Liss, Inc.

Rat Adrenal Chromaffin Cells Are Neonatal CO2Sensors

“…CAs, although ubiquitously expressed, are highly regulated enzymes, and, in some tissues, CAII expression changes during development, differentiation, or in the presence of hormones and growth factors (Disela et al, 1991;Buono et al, 1992;Quelo and Jurdic, 2000). The variables that determine the spatiotemporal changes in CAI and/or CAII expression and CO 2 chemosensitivity in the AM remain to be determined.…”

Glutamine synthetase is a glial-specific marker in the olfactory regions of the lobster (Panulirus argus) nervous system

“…Denaturing formaldehyde gels were run according to standard methods as described (Buono et al, 1992). After electrophoresis, RNA was transferred to nitrocellulose by capillary blotting and UV cross-linked as described (Buono et al, 1992;Sambrook et al, 1989).…”

“…Denaturing formaldehyde gels were run according to standard methods as described (Buono et al, 1992). After electrophoresis, RNA was transferred to nitrocellulose by capillary blotting and UV cross-linked as described (Buono et al, 1992;Sambrook et al, 1989). Positions of molecular weight markers (run in parallel lanes) and ribosomal RNA bands were located either with ethidium bromide or methylene blue staining (Sambrook et al, 1989).…”

“…To probe Northern blots, a 150 nucleotide segment of the GS coding region was liberated from the cDNA with EcoR-I plus Rsa-I endonucleases and then gel purified. The fragment was then labelled with dCTP-P 32 by the random-prime-labelling method according to Boehringer Mannheim (Buono et al, 1992). Labelled probe was separated from free label with Nuc-trap ''push columns'' from Stratagene according to the manufacturer's specifications.…”

Carbonic anhydrase II expression pattern in mouse embryonic and fetal heart

“…In rodent development, CA II expression was reported in rat hepatocytes (Laurila et al 1989). By immunocytochemistry, CA II appeared in the developing bovine parotid gland (Asari et al 1994) and in chicken lens (Buono et al 1992). In the human, CA II was identified in human villous syncytiotrophoblast (Aliakbar et al 1990;Mühlhauser et al 1994), amniotic epithelium, chorionic plate and umbilical cord, as well as in endothelial cells of full-term villi vessels (Mülhauser et al 1994).…”