Developmental patterns of serum leptin levels, leptin gene expression in adipose tissue and Ob-Rb gene expression in hypothalamus of Erhualian and Large White pigs.
The present study was aimed to investigate the developmental patterns of leptin mRNA expression in dorsal subcutaneous adipose tissue and Ob-Rb mRNA expression in hypothalamus in pigs of different breeds and sexes. Erhualian gilts and boars and Large White boars were sampled at birth, 3, 20, 30, 45, 90, 120 and 180 days of age, respectively. Serum concentration of leptin was measured with RIA and single tube semi-quantitative RT-PCR was applied to determine the relative abundances of mRNA expression using 18S rRNA as an internal standard. The results showed that leptin mRNA expression in adipose tissue increased with age and displayed both sex and breed differences. In Erhualian pigs, females expressed higher leptin mRNA compared with males, and Erhualian boars showed higher abundance of leptin mRNA than Large White boars (P < 0.01). Serum leptin levels were in good agreement with adipose leptin mRNA, displaying similar sex and line differences. In contrast, expression of Ob-Rb mRNA in hypothalamus exhibited a distinctive pattern, decreased gradually after birth, and then increased till weaning. After weaning, Ob-Rb gene expression decreased gradually with age but rose gradually again from 120 to 180 days of age in Erhualian pigs. The expression of Ob-Rb mRNA was higher in Large White pigs than that in Erhualian pigs (P< 0.01). The results suggest that the serum leptin level and leptin gene expression in adipose tissue highly correlate with adiposity.
Zhou
Jie
J
Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
Zhao
Ruqian
R
Wei
Xihui
X
Xia
Dong
D
Xu
Qingfu
Q
Chen
Jie
J
D000273:Adipose Tissue / Q000502:physiology*; D000375:Aging; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D007031:Hypothalamus / Q000502:physiology; D020738:Leptin / Q000097:blood* / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012727:Sex Characteristics; D013045:Species Specificity; D013552:Swine / Q000145:classification / Q000235:genetics
D017931:DNA Primers; D020738:Leptin; D012333:RNA, Messenger