Structure and function of alleles in the 3 ' end region of human apoB gene

Objective To study the structure of alleles in the 3' end of the apoB gene in Han, Mongolian and Tibetan populations in China as well as the roles in the regulation of gene expression. Methods DNA were obtained from human leukocytes by phenol-chloroform extrac tion and ethanol precipitation. PCR were carried out in a 50 mu l volume co ntaining 50 ng genomic DNA as template. The Ssp1-digested products were loa ded on a gradient acrylamide gel and run for 3 hours. The constructs contai ning alleles were tested in cultured HepG2 and Hela cells using transient a ssays. Results Sixteen alleles with different repeat number were characterized. Al l of the alleles varying from HVE22 to HVE52, allele HVE34 was the most com mon (58.4%), followed by allele HVE36 (13.8%) and HVE32 (10.5%). 258 PCR pr oducts were digested with Ssp1 and run in 4-12% PAGE. We detected the fragm ents of 266bp, 91bp, 61bp and 39bp in almost all samples. The small alleles (including HVE22, HVE24, HVE26 and HVE36) decreased the expressive activit y of the luciferase reporter, in contrary, the large alleles (including HVE 44, HVE46 and HVE48) elevated obviously the expressive activity of the luci ferase reporter. Conclusions More alleles with different number of tandem repeats in 3' end of apoB gene exist in the Chinese populations. The alleles in 3' end minisa tellite of human apoB gene could control the expression of the gene itself.