Salmonella sp. is a zoonotic infection that infects the intestinal tract of domestic animals and humans and causes food poisoning. It grows mainly on macrophages that have differentiated from monocytes. In this study, we examined the changes in gene expression of three receptor genes in swine monocytes induced by lipopolysaccharide (LPS) from S. enterica serovar Typhimurium. The relative expression level of the LILRB3 gene in both the LPS-stimulated and control groups increased after 6 h of culture, and after 24 and 48 h the relative expression level decreased to the same extent as that at the start of the culture. The relative expression level of the LAIR1 gene significantly increased 24 and 48 h after culture in the LPS-stimulated group. In the LXRα-1 variant of the LXRα gene, the relative expression level increased with time in the LPS stimulation group. In the LXRα-2 variant, the gene expression level significantly increased in the LPS-stimulated group after 6 and 48 h of culture, whereas in the control group, the expression level increased with time.
STRA6 is a cell membrane receptor for a complex of retinol, a type of vitamin A (VA), and RBP4, and promotes VA uptake into a cell. It is known that VA has many physiological functions. In Japanese black cattle, to improve marbling, a fattening is performed by VA restriction. Therefore, polymorphisms in STRA6 gene can affect marbling and other carcass traits. We searched for polymorphisms of STRA6 gene in Japanese black cattle, and 7 SNPs were detected. Of these SNPs, only c.866A>G（p. Q289R） was a non-synonymous SNP. Genotyping of the c.866A>G was performed with 1,235 fattened Japanese black steers, and an association between the SNP and major carcass traits were analyzed. The analysis indicated that the mean BMS of G/G cattle was significantly higher than other genotypes, A/A and A/G (p<0.05). Furthermore, to make equal the genetic background among individuals, A/A cattle and their half-sibs, a total of 150, were selected from the 1,235 cattle. Even in the selected cattle, the mean BMS of G/G cattle was significantly higher than other genotypes (p=0.05). STRA6 p.Q289R was located around the VA transport pore. Moreover, amino acid residues, which the p.Q289R was adjacent, had been reported that substitution of these amino acids impedes vitamin A transport. Therefore, it was suggested that c.866A>G affects the marbling formation by reducing the function of STRA6 and promoting adipocyte differentiation without significantly impairing physiology.