Sea Urchins, Life and the Moon
Since childhood, Abby Uehling ’18 has been fascinated by tide pools and the marine invertebrates who inhabit them. Although Hamilton is a bit far from the ocean, this summer, under the guidance of Visiting Assistant Professor of Biology Simon Coppard, she is studying sea urchins in the lab.
Uehling’s research will look at the role that light-sensitive genes called cryptochromes play in regulating the lunar spawning cycles of two sister-species of sea urchins that spawn on alternate lunar phases (full moon versus new moon). Currently, it is believed that these species primarily use temporal isolation of spawning time to avoid hybridization (cross-species reproduction).
Hometown: Glenside, Pa.
High School: Springfield Township High School
“I find it incredible that sea urchins have evolved the ability to synchronize their life processes with the lunar cycle and I want to understand the mechanisms behind this,” she said.
Uehling is building on Professor Coppard’s previous research, which observed the periodic lunar cycles of sea urchins in Fiji. The pair are working with two species that both reside in the Tropical Indo-West Pacific, Diadema savignyi and Diadema setosum, to begin to understand how varying level of moonlight are detected and control different spawning cycles to avoid hybridization.
The focus of Uehling’s summer research was narrowed down to looking at the expression of light sensitive genes that allow these species to synchronize their spawning with the lunar cycle.
She conducts her research using In Situ Hybridizations, which allows her to observe where a gene is being expressed on tissue by designing a probe (based on collected transcriptomic data) which will target this specific mRNA of the gene. After the probe is labeled with fluorescent dye, Uehling inserts it into tissue she has removed from the urchin and prepared on a slide. She then places the slide under a scanning electron microscope and the tissue will fluoresce brightly if the gene being targeted is expressed in that tissue.
By studying this phenomenon in congeneric species that spawn on alternate lunar phases, the pair will begin to understand the genetic basis of temporal reproductive isolation. This research will ultimately reveal more about the evolutionary mechanisms that have allowed the sister-species to remain separate, which is central to the study of specification.
This project has increased Uehling’s interest in studying reproduction in marine invertebrates and she will continue this research as part of her senior thesis. “I would like to continue to study reproduction and live stages, as a better understanding of these topics will hopefully contribute to new and much-needed marine conservation methods,” she said.