Identifying Genes Involved in the Variability of Genetic Fatness in the Growing Chicken

Abstract

A precise knowledge of the genome involved in the expression of a quantitative trait could provide a useful tool in breeding programs; molecular genetic methods are capable of yielding this kind of information. An experimental procedure is presented here for identifying genes whose expression is related to weight variability of abdominal adipose tissue in the growing chicken. Quantitative traits are the result of metabolic pathways exhibiting some major regulation stages that are controlled genetically. These steps involve genes that may act as "major genes". With regard to chicken fat metabolism, most fatty acids are synthesized in the liver and incorporated into very low density lipoprotein (VLDL) particles before their secretion into the plasma. Accordingly, the present study focused on the expression of liver genes. The mRNA of lipogenic enzymes (acetyl-coenzyme-A carboxylase, fatty acid synthase, malic enzyme, and delta 9-desaturase) were analyzed. Also studied were apoprotein (apo)A1, apoVLDL-II, and apoB mRNA from 9-wk-old male chickens from two lines selected for high and low abdominal fat pads. Significant differences for apoA1 mRNA levels occurred between fat and lean birds. Moreover, the total quantity of mRNA provided an accurate estimation of the abdominal fat pad (r = .74 with P < .05).

Detection of differentially expressed genes in the longissimus dorsi of Northeastern Indigenous and Large White pigs

“…The present study found that FASN regulates fatty acid biosynthesis, lipid biosynthesis and fatty acid synthase activity. The association of FASN gene polymorphisms with production traits had been studied in pigs, chickens (Douaire et al, 1992;Sourdioux et al, 1999;Roy et al, 2006) and sheep (Morris et al, 2007). These studies suggest that FASN is a candidate gene influencing fat traits, a conclusion which is consistent with the results of our research.…”

The regulation of stearoyl-CoA desaturase gene expression is tissue specific in chickens

“…However, previous studies have shown that hepatic SCD activity was significantly higher in FL than in LL chickens (Legrand et al 1987, Legrand & Hermier 1992. Furthermore, the proportion of palmitoleic acid which results from hepatic D 9 desaturation was higher in FL compared with LL chickens (Legrand & Hermier 1992) and a positive correlation has been found between SCD mRNA levels and fatness in vivo (Douaire et al 1992). We have recently shown that circulating leptin levels and hepatic leptin gene expression were significantly higher in FL compared with LL chickens (Dridi et al 2005b).…”

Hepatic lipogenesis gene expression in two experimental egg-laying lines divergently selected on residual food consumption

“…The similarity includes the part of apolipoprotein E which mediates the interaction with lipoprotein cellular receptors, suggesting that chicken APOA1 could have the same functions as apolipoprotein E in mammals [33] and be implied in the catabolism of VLDL and triglyceride storage in adipose tissue as already suggested [21]. Other studies, carried on divergently selected lean and fat broiler lines, and on goose strains differing in hepatic steatosis ability, have also shown significantly higher amounts of hepatic APOA1 mRNA levels in the fatter lines, compared to the lean ones [8,11,12,13]. These results increased the interest in this gene whose product seems to play a role in triglyceride transport and storage, and further fatness, in birds.…”

“…Electrophoresis and northern blots were performed with 10 μg of liver total RNA from each bird, as previously described [13]. Each northern blot carrying all the samples, i.e.…”