Nutritional regulation of insulin-like growth factor-I receptor mRNA levels in growing chickens.
Insulin-like growth factor-I (IGF-I) exerts its effect through the IGF-I receptor. To investigate the effects of nutritional status on chicken IGF-I receptor gene expression, a solution hybridization/RNase protection assay for IGF-I receptor mRNA was developed. A cDNA clone corresponding to the carboxyl-terminal region of the IGF-I receptor was obtained by reverse transcription-PCR (RT-PCR). Sequence analysis of the clone showed that this region of the chicken IGF-I receptor is highly divergent from the human IGF-I receptor. IGF-I receptor mRNA was detected in all tissues examined from newly hatched chickens. The rank order of the IGF-I receptor mRNA levels was liver < thigh muscle < stomach < heart < lung < kidney < brain. In 1-week-old chickens, 5 days of starvation caused a 2.5- to 3-fold increase in the mRNA in muscle and kidney. Starvation of 4-week-old chickens for 5 days caused a 1.7 to 2.2-fold increase in IGF-I receptor mRNA levels in kidney, liver, and muscle. In contrast, IGF-I receptor mRNA levels in brain failed to change. The mRNA levels were reduced to the control level by refeeding of the starved chickens for 24h. These data suggest a tissue- and development-specific response of chicken IGF-I receptor gene expression to nutritional status.
Matsumura
Y
Y
Department of Animal Science, Faculty of Agriculture, Utsunomiya University, Japan.
Domeki
M
M
Sugahara
K
K
Kubo
T
T
Roberts
C T
CT
LeRoith
D
D
Kato
H
H
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D002645:Chickens / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009747:Nutritional Physiological Phenomena / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013217:Starvation; D014018:Tissue Distribution
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D017526:Receptor, IGF Type 1