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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #298861

Title: Linking cellular zinc status to body weight and fat mass: mapping quantitative trait loci in Znt7 knockout mice

Author
item Tepaamorndech, Surapun - University Of California
item Kirschke, Catherine
item Huang, Liping

Submitted to: Mammalian Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary: Zinc transporters (Znt) are responsive for storing or providing zinc ions in organelles (specialized subunits within a cell that perform specific functions). Znt7 knockout mice completely lack the expression of ZnT7 protein. Lack of ZnT7 function results in abnormalities in body weight gain and body fat accumulation in mice. Regulation of body weight and fatness is complex, involving multiple genetic and environmental factors. To understand how zinc homeostasis influences body weight gain and fat deposit and to identify quantitative trait loci (QTL, a genetic component in a given genome) that links zinc metabolism to growth, we conducted a genome-wide scan using male F2 Znt7 KO and wild type (WT) mice with a mixed 129P1 and C57Bl/6J genetic background. The mice were fed a semi-purified diet containing 30 mg Zn/kg diet at weaning. Body weights and fat pad weights including epididymal (near the epididymis in males), retroperitoneal (near the kidney), and femoral subcutaneous fat (under the skin near the thigh muscle) were measured at 16 weeks of age. We detected two significant QTLs for body weight gain and fat deposit. The two candidate QTLs were specific to the Znt7 genotype. In Znt7 KO mice, the body weight gain and fat deposit was significantly linked to a locus on chromosome 7 ranging from 64.3 to 81.3 Mb. In WT mice, a significant linkage of retroperitoneal fat mass was found on chromosome 8 between 14.5 and 63.5 Mb. The candidate QTLs identified in this study may provide new hints to uncover the genes linking cellular zinc status to growth and body fat accumulation.

Technical Abstract: Zinc transporter 7 (Znt7, Slc30a7) knockout (KO) mice display abnormalities in body weight gain and body adiposity. Regulation of body weight and fatness is complex, involving multiple genetic and environmental factors. To understand how zinc homeostasis influences body weight gain and fat deposit and to identify quantitative trait loci (QTL) that links zinc metabolism to growth, we conducted a genome-wide scan using male F2 Znt7 KO and wild type (WT) mice with a mixed 129P1 and C57Bl/6J genetic background. The mice were fed a semi-purified diet containing 30 mg Zn/kg diet at weaning. Body weights and fat pad weights including epididymal, retroperitoneal, and femoral subcutaneous fat were measured at 16 weeks of age. We detected two significant QTLs for body weight gain and fat deposit. The two candidate QTLs were specific to the Znt7 genotype. In Znt7 KO mice, the body weight gain and fat deposit was significantly linked to a locus on chromosome 7 ranging from 64.3 to 81.3 Mb. In WT mice, a significant linkage of retroperitoneal fat mass was found on chromosome 8 between 14.5 and 63.5 Mb. The candidate QTLs identified in this study may provide new hints to uncover the genes linking cellular zinc status to growth and body fat accumulation.