The destiny of the neural crest cells where the homeobox gene was ectopically expressed.

点击翻译按钮获取中文摘要

I isolated the human homeobox gene HOXD3 on chromosome 2 from a human genomic library and determined its nucleotide sequence. To study the role of HOXD3 gene in erythropoiesis, expression vectors containing the HOXD3 gene in the sense or antisense orientation were introduced into HEL cells. The sense transfectants overexpressing the HOXD3 gene attached more efficiently to fibronectin and collagen than did the antisense transfectants and parental HEL cells. Northern blot analysis showed that integrin beta3 mRNA levels were significantly increased in the HEL cells overexpressing the HOXD3 gene, whereas the integrin beta1 and alphaIIb mRNA levels did not show a distinct correlation with HOXD3 mRNA levels. Fluorescense-activated cell sorting analysis showed that the sense transfectants overexpressing the HOXD3 gene expressed increased levels of integrin alphaIIbbeta3 (GP IIbIIIa) complex as compared with the parental HEL cells and antisense transfectants. In addition, reverse transcriptase-mediated polymerase chain reaction (RT-PCR) analysis revealed that R-cadherin mRNA Ievels were significantly increased in the antisense transfectants expressing very low levels of the HOXD3 mRNA as compared to the sense transfectants and parental HEL cells. These results implicate the homeobox gene HOXD3 in the regulation of cell adhesion process. To verify the regulation by the HOXD3 also in developing mouse embryos, I made transgenic mice where the human HOXD3 gene was specifically expressed in the neural crest cells and analyzed the differentiation and adhessiveness of the cells.