Expression of potential regulatory genes in abdominal adipose tissue during early developing broiler chickens.

摘要

Due to the potential economic impact, it is important that the poultry industry identify the genes and polymorphisms that cause population variation in chicken adipose tissue development. Previous studies in our laboratory have implicated Tenascin C (TNC), Collagen type III alpha 1 (COL3A1), Ephrin type-B receptor 2 (EPHB2), Fibroblast growth factor receptor 3 (FGFR3), Insulin-like growth factor binding protein 2 (IGFBP2), Stearoyl-CoA desaturase (SCD), Acyl-CoA binding domain containing 7 (ACBD7 ), and Gremlin 1(GREM1) as regulators of fat tissue in broiler chickens. Many scientific investigations have reported that Glucose transporter 8 (GLUT8), Adiponectin (ADIPOQ), Adiponectin receptor 1 (ADIPOR1), and Pyruvate dehydrogenase lipoamide kinase isozyme 4 (PDK4) show evidence that these genes contribute to mechanisms of fat deposition. To understand how these genes are regulated during early adipose tissue development and how they respond to dietary caloric manipulation, one-day-old broiler chicks were fed either a recommended or a high caloric diet from hatch to 8 weeks of age (WOA). The high caloric diet markedly affected the broiler birds' body weight. The mRNA levels of the TNC, COL3A1, EPHB2, FGFR3, IGFBP2, ACBD7, SCD, and GREM1 in the abdominal adipose tissue were assayed at 2, 4, 6, and 8 WOA using RT-qPCR from the male chicks. The results indicate that dietary manipulation significantly affected the expression of COL3A. Age and age-by-diet interaction were significant for TNC expression. EPHB2, SCD, and ACBD7 expressed significant differences in age only. A significant difference in the expression of FGFR3 was observed in age, diet, and age-by-diet interactions. The expression of GLUT8 was highly modulated by dietary caloric content; ADIPOQ mRNA level was significantly affected by age and diet; ADIPOR1 mRNA level had significant age difference; PDK4 showed significant differences among age groups, dietary groups, and age-by-diet interactions. Also, housekeeping genes Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and 18s ribosomal RNA (18s rRNA) were assayed to determine which one is more constant in abdominal fat tissue. The most constant gene was 18s rRNA. FGFR3, GREM1, CCL4, and IGFBP2 were searched for SNPs in the gene's promoter region. SNPs were identified from each gene, but FGFR3 contained extensive SNPs.