Polymorphism of genes encoding cytokines IL6 and TNF is associated with pig fatness

• Published in: Livestock science Vol. 136; no. 2; pp. 150 - 156
• Main Authors: Szydlowski, M., Buszka, A., Mackowski, M., Lechniak, D., Switonski, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2011; Amsterdam; New York: Elsevier
• Subjects: FABP3; Fatness; IL6; Pig; SNP; TNF; Fatness; IL6; FABP3; SNP; TNF; Pig
• ISSN: 1871-1413; 1878-0490
• DOI: 10.1016/j.livsci.2010.08.008

Porcine fatness is a polygenic trait, but there has been limited success in identifying genes underlying its variation. Three candidate genes for fatness were evaluated: two encoding cytokines, i.e. interleukin-6 (
IL6) and tumor necrosis factor-α (
TNF), and the gene encoding the heart fatty acid-binding protein (
FABP3). The animals were gilts of Polish Large White (
n
=
191), Polish Landrace (
n
=
239), and synthetic line 990 (
n
=
242). Four novel single-nucleotide polymorphisms (SNPs) were detected: g.61T
>
C (GenBank acc. no. EF450127), g.6464C
>
T (X54859), and g.701T
>
C (X98558) in the promoter regions of the
IL6, TNF and
FABP3 genes, respectively, and g.8653A
>
G (X54859) in exon 4 of
TNF. The gilts were dissected when they reached the weight of 100
kg, and 12 traits were analyzed: abdominal fat weight, backfat thickness (BFT) measured at 7 points, lean meat yield, intramuscular fat percentage (IMF), average daily gain, and feed conversion ratio. Multiple breed-specific associations were calculated between fatness traits and SNPs in the promoter regions of
IL6 (g.61T
>
C, 0.006
≤
P
≤
0.009) and
TNF (g.6464C
>
T, 0.002
≤
P
≤
0.005). Our results support the hypothesis that the polymorphisms of
IL6 and
TNF are associated with fatness variation within pig breeds.