Jadwiga Giebultowicz
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Associate Professor, Zoology |
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Education
Ph.D. 1981 University of WarsawResearch
Chronobiology is an interdisciplinary, rapidly expanding field aimed to understand the mechanisms and functional significance of biological timing. All living organisms, from bacteria to humans, display circadian rhythms which synchronize life functions with environmental day/night cycles. These rhythms persist in constant conditions with near 24-h (circadian) period. The powerful nature of daily rhythms, such as wake and sleep cycle, is revealed to any student who tries to study late into the night without falling asleep! Circadian rhythms are controlled by molecular oscillators (clocks) formed by a network of clock genes, which are conserved from insects to humans. We use Drosophila and other insects as models to investigate clock genes, and their functional significance.Clock genes are expressed in the brain and in many peripheral organs. Our research demonstrated that many peripheral clocks operate in Drosophila and other insects. We found that clock genes in the male reproductive system regulate rhythms associated with fertility. Our goal is to investigate molecular cascades leading from clock genes via effector genes to cellular and physiological rhythms. To do this, we study reproductive phenotypes in Drosophila with mutated clock genes and use microarray technology to identify clock-effector genes. We also investigate daily cycles of sperm release and maturation in the moth reproductive systems cultured in vitro, and use RNAi gene silencing techniques to determine functions of clock genes in these systems.
We recently discovered a novel functions for clock genes in Drosophila females; they are involved in adjusting the level of fecundity to nutritional state of the female. To understand the molecular basis of this phenotype, we manipulate spatial and temporal patterns of gene expression in fly organs using the Gal4/UAS system. In addition to our interest in reproduction, we are also investigating the possibility that clock genes may be involved in protecting the organism from stress and premature aging. Our research will provide new insights into the bio-timing mechanism and may have a broader impact related to human reproduction, nutrition, and longevity. We have many fascinating projects for graduates and undergraduates: interested students are encouraged to contact the PI.