[Sequencing analysis of the control region and intron1 region and characterization of two novel microsatellites in obese gene of pig]

For the first time, a 16 kb fragment of the porcine Ob gene, namely intron1, exon1, 5' region of Ob gene, was restrictively analyzed and sequenced by the primers designed in the portion of the swine Ob sequence. The first small 38 bp untranslated exon1 is located 11.1 kb upstream of the initiator ATG codon, and two novel microsatellites SW200 and SW160 are found in intron1. Promoter analysis of several putative binding sites revealed that this 300 bp promoter located at -1 to -300, including C/EBP and two Sp1, may be as effective as the longer promoter in directing leptin transcription. To examine microsatellites association with important economic traits, we statistically analyzed genotypes and alleles of the two microsatellites. Statistical analysis carried out by SAS 8.2 revealed significant positive correlation between the two microsatellites genotypes and the litter size in first parity of Erhualian.