title: Expression profile of insulin-like growth factor system genes in muscle tissues during the postnatal development growth stage in ducks.
abstract: Insulin-like growth factors (IGFs) are regulators that modulate the proliferation and differentiation of muscle tissues. We quantified the messenger RNA (mRNA) expression of IGF-I, IGF-II, and type I and II IGF receptors (IGF-IR and IGF-IIR) in muscle tissues including the breast, leg, and myocardium during an early postnatal development growth stage (post-hatching weeks 1-8) in ducks. The results showed a significant age-related change in mRNA in these muscle tissues. In breast muscle, the developmental expression of IGF-I and IGF-II was highest during week 1 but decreased quickly and maintained a relatively lower level. Leg muscle had the highest mRNA expression of IGF-I and IGF-II genes at week 3. In myocardial tissues, the expression level of IGF-IR and IGF-IIR genes exhibited a "rise-decline" developmental trend. The expression patterns of IGF-I/IGF-IR and IGF-II/IGF-IIR were different between weeks 4 and 6. The same expression pattern was observed for IGF-I and IGF-IR; however, it was different from that observed for IGF-II and IGF-IIR. Our results showed a negative correlation between IGF-II mRNA expression and leg muscle weight at week 4 (P < 0.05). A negative correlation was also found between IGF-II mRNA expression and breast muscle weight (P < 0.01), and a positive correlation was found between IGF-IR expression and breast muscle weight. At week 6, a positive correlation was found between IGF-IR expression and breast muscle weight. However, at week 8, a negative correlation was found between IGF-IR expression and breast muscle weight. The results showed that the expression of IGF mRNA in duck tissues exhibits a specific developmental trend and an age-related pattern, suggesting that the regulation mechanism of these 4 genes in proliferation and differentiation of muscle tissues differed.
authors.affiliation: Institute of Animal Breeding and Genetics, Sichuan Agricultural University, Ya'an, Sichuan Province, China.
authors.forename: C-L
authors.initials: CL
authors.lastname: Song
authors.forename: H-H
authors.initials: HH
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Kou
authors.forename: L
authors.initials: L
authors.lastname: Lv
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: W-X
authors.initials: WX
authors.lastname: Wang
authors.forename: J-W
authors.initials: JW
authors.lastname: Wang
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D004372:Ducks / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018482:Muscle, Skeletal / Q000378:metabolism*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017451:Receptors, Somatomedin / Q000235:genetics / Q000378:metabolism; D013002:Somatomedins / Q000235:genetics* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D030161:Avian Proteins; D012333:RNA, Messenger; D017451:Receptors, Somatomedin; D013002:Somatomedins