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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Cloning and Sequence Analyses of Vasotocin and Isotocin Precursor cDNAs in the Masu Salmon, Oncorhynchus masou : Evolution of Neurohypophysial Hormone Precursors
| Title: | Cloning and Sequence Analyses of Vasotocin and Isotocin Precursor cDNAs in the Masu Salmon, Oncorhynchus masou : Evolution of Neurohypophysial Hormone Precursors |
| Authors: | Suzuki, Masakazu Browse this author | | Hyodo, Susumu Browse this author | | Urano, Akihisa Browse this author |
| Issue Date: | 1992 |
| Publisher: | Zoological Society of Japan |
| Journal Title: | Zoological Science |
| Volume: | 9 |
| Start Page: | 157 |
| End Page: | 167 |
| Abstract: | We have cloned and determined the nucleotide sequences of cDNAs encoding precursors of neurohypophysial hormones, vasotocin (VT) and isotocin (IT), from the hypothalamus of masu salmon, Oncorhynchus masou. The deduced amino acid sequences of masu salmon VT and IT precursors (proVT-I and proIT-I) are highly homologous to those of chum salmon proVT-I and proIT-I, respectively. The VT and IT precursors are composed of a signal peptide, hormone and neurophysin (NP), the middle portion of which is highly conserved among vertebrates. Both the NPs extend about 30 amino acids at the C-terminal. The extended C-terminals have a leucin-rich segment in the carboxyl-terminal, as copeptin of vasopressin precursor. Southern bot analysis showed the presence of two types of proVT genes (proVT-I and proVT-II) and proIT genes (proIT-I and proIT-II) in an individual masu salmon, as in a chum salmon. Southern blot analysis with proVT probes further suggested that at least two different types of proVT-I genes exist in a single masu salmon. Norhtern blot analysis indicated that proVT-I and proIT-I genes are expressed in the hypothalamus, whereas proVT-II and proIT-II genes are not expressed. Evolutionary distance between proVT-I and proIT-I genes was statistically estimated based on synonymous nucleotide substitution in the coding region of the cDNAs. The magnitude of distance between masu salmon proVT-I and proIT-I genes suggested that the highly conserved central portion of NPs resulted from a gene conversion event. Between masu salmon and chum salmon, evolutionary distance for proVT-I genes is about 6-fold larger than that for proIT-I genes. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/43962 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 浦野 明央
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