Purpose: The purpose of the study was to investigate homeobox gene expression in human oocytes and preembryos and in postimplantation embryos with impaired embryonic development determined by chromosomal abnormalities.
Methods: Reverse transcriptase-polymerase chain reaction (RT-PCR) with intron spanning primer sets for Homeobox gene sequences was used.
Results: The homeobox genes HoxA4, HoxA7, HoxB4, and HoxB5 were present in human oocytes and cleaving normal and triploid embryos. The expression pattern was different between chromosomally abnormal and normal first-trimester embryos. Of four homeobox transcripts (HoxA7, HoxB4+ ++, HoxB5, and HoxC6) that are expressed in diploid embryos, only HoxA7, HoxB4 and HoxC6 were present in a trisomy 7 embryo, and only HoxB4 and HoxB 5 in triploid embryos and an embryo with trisomy 9. Cloning experiments revealed differences in the number of homeobox clones obtained from trisomy 7 and control embryos.
Conclusions: The transcripts of homeobox genes, HoxA4, HoxA7, HoxB4, and HoxB5, were present in oocytes and cleaving embryos. The pattern of expression of homeobox genes in cultured fibroblasts derived from spontaneously aborted embryos with aneuploidies was different from that in control diploid cells.