title: Cholecystokinin mRNA in Atlantic herring, Clupea harengus--molecular cloning, characterization, and distribution in the digestive tract during the early life stages.
abstract: The mRNA of the peptide hormone cholecystokinin (CCK) was isolated from juvenile Atlantic herring, Clupea harengus, by RT-PCR. The open reading frame encodes a 137 amino acid-long precursor protein. The peptide sequence of herring CCK-8, DYMGWMDF, is identical to that of higher vertebrates and elasmobranchs, and contains methionine in the sixth position from the C-terminus, which has not been reported previously in teleosts. Expression analysis by in situ hybridization shows that positive endocrine-like cells were mainly located in the pyloric caeca and to a less extent in the rectum of the juvenile. A few positive cells were also found in the pyloric portion of the stomach and the intestine. CCK cells were present in all the larvae examined from the day of hatching onwards. Although the CCK cells were scattered throughout the whole midgut, no signals were detected in either the foregut or the hindgut. Since herring larvae have a straight gut, the distribution pattern of CCK cells seems to be reflected in the anatomy of the gut.
authors.affiliation: Department of Biology, University of Bergen, Allégt 41, N-5007 Bergen, Norway. yuko.kamisaka@sisyfos.zoo.uib.no
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kamisaka
authors.forename: Oyvind
authors.initials: O
authors.lastname: Drivenes
authors.forename: Tadahide
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Masatomo
authors.initials: M
authors.lastname: Tagawa
authors.forename: Ivar
authors.initials: I
authors.lastname: Rønnestad
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Jon Vidar
authors.initials: JV
authors.lastname: Helvik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002766:Cholecystokinin / Q000096:biosynthesis*; D003001:Cloning, Molecular; D005399:Fishes; D041981:Gastrointestinal Tract / Q000378:metabolism; D017403:In Situ Hybridization; D007413:Intestinal Mucosa / Q000378:metabolism; D008953:Models, Anatomic; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D011708:Pylorus / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012007:Rectum / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D012333:RNA, Messenger; D002766:Cholecystokinin