title: IGF-I and IGF-II mRNA expression in slow and fast growing families of USDA103 channel catfish (Ictalurus punctatus).
abstract: The objective of this study was to examine insulin-like growth factor (IGF)-I and IGF-II mRNA levels in fast and slow growing families of catfish. Relative levels of IGF-I and IGF-II mRNA were determined by real-time PCR. Family A exhibited a specific growth rate (SGR) of 3.6 and was designated as fast growing, while family H exhibited a SGR of 3.1 and was designated as slow growing (P=0.017). Levels of IGF-II mRNA were 3.3-fold greater (P=0.006) in muscle for the fast growing family compared to the slow growing family. Levels of IGF-II mRNA were 1.8-fold greater (P=0.049) in liver for the fast growing family compared to the slow growing family. Levels of IGF-II mRNA from both fast and slow families were 12.2-fold greater (P<0.001) in muscle and 5.8-fold greater (P=0.021) in liver, respectively, compared to levels of IGF-I mRNA. Muscle and liver levels of IGF-I mRNA were similar between families. Elevated levels of IGF-II mRNA in muscle and liver compared to IGF-I mRNA, as well as differences in levels of IGF-II mRNA between fast and slow growing families of fish suggests a role of IGF-II in growth of channel catfish.
authors.affiliation: USDA/ARS Catfish Genetics Research Unit, Thad Cochran National Warmwater Aquaculture Center, PO Box 38, Stoneville, MS 38776, USA. bpeterson@ars.usda.gov
authors.forename: Brian C
authors.initials: BC
authors.lastname: Peterson
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Waldbieser
authors.forename: Lelania
authors.initials: L
authors.lastname: Bilodeau
mesh_terms: D000821:Animal Feed; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D007059:Ictaluridae / Q000235:genetics* / Q000254:growth & development; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II