Study on the copy number variations of neural tube defect animal model with folate dysmetabolism

Abstract

Objective To detect the genomic copy number variations(CNVs) of mice embryonic neural tissue with neural tube defects(NTDs) induced by methotrexate(MTX), and investigate the molecular genetic mechanisms between folic acid metabolism disorders and NTDs pathogenesis. Methods C57BL/6J NTD mice model was induced by MTX on gestational day 7.5, and the maternal serum and NTD embryonic neural tissues were collected; the array-comparative genomic hybridization(array-CGH) assay was utilized to analyze the whole genomic CNVs in NTD embryonic neural tissues; reverse transcription polymerase chain reaction(RT-PCR) was used to confirm the positive results; the maternal serum concentrations of folic acid and related metabolites and dihydrofolate reductase(DHFR) activity were detected by liquid chromatography-tandem mass spectrometry and enzymatic methods, respectively. Results Array-CGH and RT-PCR results showed the 3 high confidence CNVs on XqE3, XqA1.1-qA2 and XqA1.1 in the NTD embryonic neural tissues.The NTD maternal serum concentrations of 5-methyltetrahydrofolate, 5-formyltetrahydrofolic acid, S-adenosyl methionine and DHFR activity were reduced significantly compared with the control group, and there were statistical differences(all P<0.05). Conclusions There are obvious CNVs in embryonic neural tissue of NTD mice induced by MTX and folic acid dysmetabolism might cause mice embryonic neural tube developmental disorders through CNVs. Key words: Neural tube defects; Folic acid; Copy number variations