In this Research Opportunities for Women Planning Grant Dr. Piroska Huvos, working at Southern Illinois University, will carry out preliminary genetic experiments to determine the functional and evolutionary significance of DNA elimination during the cell cycle of ciliate protozoans. These protozoans have an unusual genetic and developmental system in which genes are transmitted from sexual-generation to sexual-generation by a structure termed the micronucleus. A second nucleus, the macronucleus, derives from the micronucleus and functions as a special organelle for transcribing and translating genetic information into cellular development. The full gene complement is transmitted by the micronuclei, but DNA is systematically eliminated from macronuclei during cell development. Dr. Huvos will determine the function of DNA elimination through a comparative study of the chromosomal sites where breakage and rejoining occurs during DNA elimination and by determination of whether the same DNA sequences are eliminated in different species. The comparative study will be made on several species of the well known protozoan genus Tetrahymena. The conservation of breakage sites and the DNA sequences eliminated in many species would support the theory that these sites and sequences are integral parts of the genetic system for sexual reproduction. This study will lead to a better understanding of the phenomenon of genetic recombination, which is nearly universal among higher organisms.
