[A novel alternative splicing isoform of vascular endothelial growth factor gene in human beings]

To investigate a new alternative splicing isoform of vascular endothelial growth factor (VEGF) gene in human bejings.

The total RNA of the lung tissue of a legally aborted 4-month-old human fetus was isolated and then amplified by RT-PCR. The amplified product was cloned into the pMD18-T plasmid and pcDNA3.1(-). Then sequence analysis was conducted.

The electrophoresis of the RT-PCR product showed one short band of VEGF121 comprising of 487 bp and a long band with two fragments: one normal VEGF165 comprising of 619 bp and one fragment comprising of 639 bp which was the same VEGF165 nucleotide sequence with a 20 bp fragment inserted between exon 3 and exon 4. Sequence analysis showed that this 20 bp long nucleotide was inserted from the 3' end of the third intron that contained splicing signal, thus causing shift mutation in reading frame of VEGF gene and early appearance of the stop code UAG in the middle of exon 4.

A new alternative splicing isoform of VEGF has been identified in the lung tissue of a legally aborted human fetus. Its biological significance remains to be further investigated.