Hypoxia as a Chromosomal Mutagen

Abstract

Female hamsters breathing hypoxic atmospheres equivalent to 30,000 to 35,000 feat of altitude tor over three hours at three or 21 hours postcoitus were divided into two main groups for chromosomal examination at preimplantation and at organo-genetic stages of development Controls provided a basis for comparison. At preimplantation stages 4 of 166 embryos were found with triploidy and 14 with tetraploidy whereas only one with tetraploidy was found among 133 controls. At organogenetic six mosaics of diploid-tetraploid cells were founds three with 20% to 50% mixtures and three with 5% to 10% mosaicism. Higher concentrations of mosaic cells derived from mothers stressed on the first day of pregnancy; the lower proportions came from mothers treated later. Two triploid fetuses were found in the test group. No polyploid embryos were observed among controls.