Lipid metabolism and adipocyte differentiation are reglulated by networking of transcription factors. It is generally known that three factors, peroxisome proliferator-activated receptor y （PPARγ）, CCAAT/element-binding protein a （C/EBPa） and sterol regulatory element binding protein-1 （SREBP1）, play fundamental roles in metabolic pathways. And they are also important in adipocyte differentiation. Expressions of these factors are regulated by some compounds such as fatty acids or some steroid hormones （insulin） which is stimulated by the nutritional level. Furthermore, these factors are related to some metabolic diseases including type II diabetes and obesity, Lots of researches have focused on relationships between the factors and the genetic diseases. Different functions of factors on inducing the adipocyte differentiation are other hot spots according to previous studies. This paper summarized these studies and gave a limpid description of structures and functions of these genes.
Peroxisome proliferator-activated receptor g（PPARg） is an important regulator of chicken preadipocyte proliferation and differentiation.In this study,polymorphisms were detected by DNA sequencing,PCR-RFLP and some other methods and three polymorphisms（g.-1784_-1768del17,c.-1241GA and c.-75GA） were found in the 5＇ flanking region of PPARg gene.Growth and body composition traits were measured in the 8th-10th generation populations of the Northeast Agricultural University broiler lines were divergently selected for abdominal fat content.Polymorphisms among individuals were screened in the above populations.The haplotype-based association analysis on growth and body composition traits was carried out.The association analysis showed that haplotypes based on three polymorphisms at 5＇ flanking region of PPARg gene were significantly associated with abdominal fat weight（AFW）,abdominal fat percentage（AFP,AFW/BW7）,liver weight（LW）,liver weight percentage（LFP,LW/BW7）,shank length（ShL）,femur weight（FeW）,keel length（KeL）,and metatarsus circle（MeC）（P0.05） and suggestive significantly associated with pectoralis major weight（PMaW）,pectoralis minor weight（PMiW）,pectoralis minor weight percentage（PMiWP,PMiW/BW7）,and metatarsus length（MeL）（P0.2）.The least square analysis showed that the birds with BGA haplotype had significantly higher AFW and AFP than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher LW and LW/BW than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher PMiW and PMiW/BW than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher ShL,FeW,MeL,MeC and KeL than the birds with AGG haplotypes（P0.05）.The results in this study revealed that QTL affecting fatness traits may exist in 5＇ flanking region of PPARg gene in chickens and PPARg gene might be one of the genes having important influences on the growth and bone tr
The nuclear receptor peroxisome proliferator-activated receptor γ（PPAR-γ） is a key transcriptional regulator of adipocyte differentiation.It also modulates the synthesis of adipocytokines in the adipose tissue.Its polymorphisms are associated with the risk of type Ⅱ diabetes,obesity,cardiovascular diseases and cancer.In the present study,to investigate the regulatory mechanism of PPAR-γ gene on lipid metabolism,the computational prediction of peroxisome proliferator response elements（PPREs） was pursued with a genome-wide scale by using MEME/MAST method based on the information of TRANSFAC database,then GO and KEGG analyses were carried out.The results showed that a huge number of predicted target genes of PPAR-γ were significantly enriched in 36 GO terms（P〈0.05） and 10 KEGG pathways（P〈0.05） which were related closely to the lipid metabolism.The results should be a valuable resource for elucidation of the regulatory mechanism of PPAR-γ influence on lipid metabolism,also of the major importance to the diagnosis,prevention and treatment of the complex diseases such as obesity and diabete.
