Skip to main content
ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #93735
Title: STEAROYL COENZYME A DESATURASE GENE EXPRESSION DURING GROWTH IN ADIPOSE TISSUE FROM OBESE AND CROSSBRED PIGS

Author
item SMITH, STEPHEN - TEXAS A&M UNIVERSITY
item Mersmann, Harry
item SMITH, E - BAYLOR COLLEGE OF MED
item BRITAIN, KIMBERLY - TEXAS A&M UNIVERSITY

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Adipose tissue, or fat, grows rapidly after birth in pigs and many other mammals. The growth of fat at this time is not associated with high rates of synthesis of the building blocks, fatty acids. The nursing pig obtains fatty acids from the high fat content of the milk. An indicator of growth of fat cells in rats and mice is stearoyl coenzyme A desaturase. The gene for this indicator was measured in fat from pigs that were nursing and those that were weaned for a short time. The indicator was strongly related to the size of fat cells. Obese pigs with larger fat cells had more of the indicator than lean pigs at the earliest ages suggesting the earlier and more rapid growth of fat in obese pigs. This indicator may be useful to indicate the stage of growth of fat cells.

Technical Abstract: This investigation addressed the hypothesis that, as a market of adipocyte differentiation, stearoyl-coenzyme A desaturase (SCD) gene expression would be greater during growth in obese pigs than in crossbred, contemporary pigs. Suckled pigs from a single litter were removed from the sow for sampling at 0, 3, 10, and 17 d. The number of litters at 0, 3, 10 and 17 d of age was 0, 2, 3, and 3 (obese sows) and 4, 2, 3, and 3 (crossbred sows) respectively. Postweaning pigs were removed from the sow at 14 d of age. One set of postweaning pigs was fed a high-fat, milk-based diet from d 28 to 49; pigs were killed at each time of sampling. The grain-fed pigs were switched to a pelleted, grain-based grower diet for d 28, and samples were obtained at 31, 35, or 49 d of age. Adipose tissue from all pigs in a litter for preweaning and postweaning pigs was pooled for the measurement of cellularity and SCD and mRNA. There were significant genetic and age effects for adipocyte diameter and volume; overall, adipocytes from obese pigs were larger than those from crossbred pigs. Stearoyl-coenzyme A desaturase mRNA was barely detectable for 0 d of age and increased (P<.01 by 20-fold by 49 d of age. There was a significant gene x age interaction (P=.026); there was more SCD mRNA in adipose tissue from obese pigs than in crossbred pigs during the suckling period, whereas crossbred pigs exhibited greater SCD gene expression than obese pigs during the postweaning period. The latter effect was caused a strong depression in SCD gene expression in the grain-fed obese pigs. The data suggest that SCD gene expression provides a market for terminal differentiation, especially in preweaning pigs. Furthermore, these results provide additional evidence that SCD gene expression is upregulated by diets high in saturated fatty acids.