[Effects of HCY-2 gene transfer on the development of chick neural tube]

In order to explore the relationship between novel gene HCY-2 and neural tube defects (NTDs) and to investigate whether HCY-2 gene was genotoxic, a mammalian expression vector containing HCY-2 cDNA (2014 bp) was transferred into chick fertilized ovum by using lipofectin reagent, then the biological effects of HCY-2 gene on embryos in culture for 3.5 days were observed. Western blotting and immunohistochemistry were used to analyse the expression and distribution of HCY-2 after gene being transferred. HCY-2 gene (5-20 micrograms/chick ovum) could induce NTDs in organogenesis period. Western blotting and immunohistochemical staining showed that HCY-2 protein could be greatly expressed by day 3.5, the time which NTDs developed, with stronger staining at the site of embryonic brain as compared with controls. Under electron microscope, it was observed that HCY-2 gene could damage embryonic cellular ultrastructures and cause excessive apoptosis of neurocytes. These findings suggested that HCY-2 gene with its product was dysmorphogenic to the neural tube, might be a genotoxic factor or teratogenic agent and should be responsible for chick NTDs and probably human NTDs as well.