Tissue and Development Specific Regulation of a Complex Family of Rat Insulin-Like Growth Factor I Messenger Ribonucleic Acids
Autor: | Judson J. Van Wyk, P. Kay Lund, Eileen C. Hoyt |
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Rok vydání: | 1988 |
Předmět: |
Male
Polyadenylation medicine.medical_treatment Molecular Sequence Data Biology Insulin-like growth factor Endocrinology Somatomedins medicine Animals RNA Messenger Northern blot Insulin-Like Growth Factor I Molecular Biology Messenger RNA Fetus Base Sequence Growth factor Nucleic Acid Hybridization RNA Rats Inbred Strains DNA General Medicine Blotting Northern Molecular biology Rats Gene Expression Regulation Liver Functional significance |
Zdroj: | Molecular Endocrinology. 2:1077-1086 |
ISSN: | 1944-9917 0888-8809 |
Popis: | To obtain information about the functional significance of the structural heterogeneity that has been described for rat insulin-like growth factor I (IGF-I) cDNAs, we hybridized polyadenylated RNAs from rat tissues at different developmental stages with probes specific for two variant 5'-sequences (designated here as type 1 and type 2), with a probe specific for IB type E domain coding sequences and with a probe for E domain sequences common to IA and IB type IGF-I cDNAs. Northern blot analyses revealed that previously reported rat liver IGF-I mRNAs of estimated size 7.5-7.0, 1.9-1.5, and 1.2-0.9 kilobases each are comprised of multiple closely migrating IGF-I mRNA species containing either of two 5'-sequences and either IA or IB type E domain coding sequences. In liver, each of these detected IGF-I mRNA species showed postnatal increases in abundance. The mRNAs detected with the probe for type 2 5'-sequences were detected exclusively in postnatal liver and also showed a different pattern of postnatal increase in abundance than other IGF-I mRNA types. IGF-I mRNAs detected with the probe for IB type E domain coding sequences likewise were highly liver specific and were undetectable or barely detectable in other fetal or adult rat tissues. In contrast, IGF-I mRNAs that hybridized with probes for type 1 5'-sequences or for E domain coding sequences common to IA and IB type IGF-I mRNAs were detected in all fetal and adult rat tissues tested. These findings suggest development and tissue specific regulation of the expression of different rat IGF-I mRNA types, and also suggest a possible role of different precursor sequences encoded by the various mRNAs in targeting of IGF-I to a local site of action. |
Databáze: | OpenAIRE |
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