NSF Postdoctoral Fellowship in Biology FY 2017: Parental programming via epigenetic modifications to female and male gametes

Hellmann Jennifer K, Urbana IL

Investigators

Abstract

This is an NSF Postdoctoral Research Fellowship in Biology, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Jennifer Hellman Johnson, is conducting research and receiving training that is increasing the participation of groups underrepresented in biology, at the University of Illinois at Urbana-Champaign, and is being mentored by Alison Bell (sponsoring scientist). The fellow's research explores how offspring development is altered by maternal and paternal exposure to the stress of predation, prior to fertilization. Recent advances in biology have demonstrated that parental experiences can be transmitted to future generations without changes in underlying DNA sequences. These parental effects may cause changes in the appearance of offspring, which allow individuals to cope with the change. Alternatively, the multigenerational nature of these parental effects may mean that damaging stressors encountered by one generation can persist for multiple generations, even after the stressor has passed. In either case, understanding the influence of parental transmission of experiences prior to fertilization, and the underlying mechanisms, will improve the ability to predict how organisms adapt to variable and stressful environments. This research is elucidating if maternal and paternal stress prior to fertilization alter offspring in similar ways, whether maternal and paternal influences are additive or synergistic, if parents' experiences reverberate through the generations, and what potential mechanisms underlie these parental effects. Using a well-studied fish species, the threespined stickleback (Gasterosteus aculeatus), the fellow is generating offspring with either no predator-exposed parents, predator-exposed mothers, predator-exposed fathers, or predator-exposed mothers and fathers. The fellow is measuring offspring and grandoffspring for differences in morphological and physiological traits and behavior. Further, because sperm and egg non-coding small RNAs have been increasingly recognized as an important epigenetic mechanism by which parents can influence offspring, the fellow is injecting embryos with maternal and/or paternal miRNAs that are differentially expressed due to predation experience. These injected embryos are being measured for the same phenotypic traits as the F1 and F2 generation above to determine if the effects of parents' experience on offspring and their grandchildren are mediated by miRNAs, and to what extent (if any) other mechanisms underlie these changes. This fellowship provides valuable training in behavioral genomics for the fellow and an opportunity to participate in existing diversity programs in the broader University of Illinois community, including participation in mentoring LGBTQ students in STEM and elementary school girls in local science clubs.