title: Identification of differentially expressed genes related to intramuscular fat development in the early and late fattening stages of hanwoo steers.
abstract: Marbling of cattle meat is dependent on the coordinated expression of multiple genes. Cattle dramatically increase their intramuscular fat content in the longissimus dorsi muscle between 12 and 27 months of age. We used the annealing control primer (ACP)-differential display RT-PCR method to identify differentially expressed genes (DEGs) that may participate in the development of intramuscular fat between early (12 months old) and late fattening stages (27 months old). Using 20 arbitrary ACP primers, we identified and sequenced 14 DEGs. BLAST searches revealed that expression of the MDH, PI4-K, ferritin, ICER, NID-2, WDNMI, telethonin, filamin, and desmin (DES) genes increased while that of GAPD, COP VII, ACTA1, CamK II, and nebulin decreased during the late fattening stage. The results of functional categorization using the Gene Ontology database for 14 known genes indicated that MDH, GAPD, and COP VII are involved in metabolic pathways such as glycolysis and the TCA cycle, whereas telethonin, filamin, nebulin, desmin, and ACTA1 contribute to the muscle contractile apparatus, and PI4-K, CamK II, and ICER have roles in signal transduction pathways regulated by growth factor or hormones. The final three genes, NID-2, WDNMI, and ferritin, are involved in iron transport and extracellular protein inhibition. The expression patterns were confirmed for seven genes (MDH, PI4-K, ferritin, ICER, nebulin, WDNMI, and telethonin) using real-time PCR. We found that the novel transcription repressor ICER gene was highly expressed in the late fattening stage and during bovine preadipocyte differentiation. This information may be helpful in selecting candidate genes that participate in intramuscular fat development in cattle.
authors.affiliation: Animal Genomics & Bioinformatics Division, National Livestock Research Institute, RDA, Suwon 441-305, Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Eung-Woo
authors.initials: EW
authors.lastname: Park
authors.forename: Yong-Min
authors.initials: YM
authors.lastname: Cho
authors.forename: Sung-Kon
authors.initials: SK
authors.lastname: Kim
authors.forename: Jun-Heon
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin-Tae
authors.initials: JT
authors.lastname: Jeon
authors.forename: Chang-Soo
authors.initials: CS
authors.lastname: Lee
authors.forename: Seok-Ki
authors.initials: SK
authors.lastname: Im
authors.forename: Sung-Jong
authors.initials: SJ
authors.lastname: Oh
authors.forename: J M
authors.initials: JM
authors.lastname: Thompson
authors.forename: Duhak
authors.initials: D
authors.lastname: Yoon
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002454:Cell Differentiation / Q000235:genetics*; D002478:Cells, Cultured; D003285:Contractile Proteins / Q000235:genetics; D051786:Cyclic AMP Response Element Modulator / Q000235:genetics; D003893:Desmin / Q000235:genetics; D005223:Fats / Q000378:metabolism*; D005293:Ferritins / Q000235:genetics; D064448:Filamins; D020869:Gene Expression Profiling / Q000379:methods*; D018507:Gene Expression Regulation, Developmental; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D008840:Microfilament Proteins / Q000235:genetics; D009124:Muscle Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D003285:Contractile Proteins; D003893:Desmin; D005223:Fats; D064448:Filamins; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; C035620:nebulin; D051786:Cyclic AMP Response Element Modulator; D005293:Ferritins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases