title: Tissue-specific expression of calbindin-D28K gene during ontogeny of the chicken.
abstract: The vitamin D3-dependent calcium binding protein, calbindin-D28K (CaBP-D28K), plays an important role in transepithelial calcium translocation. To evaluate its role in chick embryonic calcium metabolism, steady-state levels of CaBP-D28K mRNA in various tissues of the chick embryo were determined by Northern blot and slot blot analyses, and CaBP-D28K concentrations in the examined tissues and plasma were estimated by RIA. High levels of CaBP-D28K mRNA were found in the embryonic kidney (mesonephros) on embryonic day (E) 10 and E12 and thereafter gradually decreased until hatching. CaBP-D28K mRNA levels were low in the yolk sac until E16 but increased on E18 and reached a maximum on E20. A steady increase in CaBP-D28K mRNA levels was observed in the cerebellum during the development from E10 to post-hatching. CaBP-D28K mRNA levels in the intestine were very low during the incubation period but significantly increased on days 1 and 7 after hatching. By Northern blot analysis, CaBP-D28K mRNA was barely detectable in liver, heart, and chorioallantoic membrane of the embryonic chick. Changes in immunoreactive CaBP-D28K of each tissue paralleled observed changes in mRNA levels. In plasma, measurable levels of CaBP-D28K were found as early as E8 and were stable until E18, when 6.5-fold increase was observed compared to E16. The highest level of CaBP-D28K in plasma was found on E20 and decreased after hatching. These temporal profiles of CaBP-D28K suggest that it may play an important role in the regulation of chick embryonic calcium homeostasis.
authors.affiliation: Department of Animal Physiology, Faculty of Agriculture, Nagoya University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sechman
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: N
authors.initials: N
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Ieda
authors.forename: T
authors.initials: T
authors.lastname: Ono
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D015152:Blotting, Northern; D064026:Calbindins; D002642:Chick Embryo / Q000378:metabolism / Q000502:physiology*; D002645:Chickens / Q000254:growth & development / Q000378:metabolism*; D015342:DNA Probes; D005314:Embryonic and Fetal Development; D015870:Gene Expression; D009928:Organ Specificity; D012313:RNA / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis*
chemical_list: D064026:Calbindins; D015342:DNA Probes; D012333:RNA, Messenger; D064030:S100 Calcium Binding Protein G; D012313:RNA