Unraveling the mystery of life: House fly edition

Richard Meisel, assistant professor of biology and biochemistry, has received a Faculty Early Career Development (CAREER) Award from the National Science Foundation. The CAREER award will provide $1.2 million over five years to study sex determination of house flies.

“We understand a fair bit about sex determination in humans. A gene on the Y chromosome initiates the male developmental process, and that’s how nearly all mammals develop,” said Meisel. “But outside the class of mammals, sex determination operates differently in other animals. In addition, it is not well understood why genetic variation in male female-determination exists within other species. We want to understand why something so essential and important as sex determination is not done the same way across all animals,” said Meisel, an evolutionary biologist.

Meisel chose to study the house fly because it has substantial variation in how the male/female decision is made. There are two common ways that male development can be initiated, and they differ in their geographical distributions. One male-determining variant predominates at northern latitudes, and the other is more common in the south.

“We can look at the variation within the species and develop a snapshot in time that we cannot capture if we look at a species without the variation,” said Meisel. He is investigating if the two different variants are both maintained because they are beneficial at different temperatures. The environment-dependent effects of very young Y chromosomes will be assessed using laboratory experiments and gene-expression profiling.

In addition, female development can be initiated independently from the male-determining variants in house flies. Meisel will also investigate if the variants that initiate male development have harmful effects in females.

“These antagonistic effects could further explain why variation in male/female-determination is maintained in house fly populations,” said Meisel. He will also explore genome sequences to understand if a pattern is present that will help him understand what is occurring at a genetic level.

The results of Meisel’s project, “Maintenance of Variation in a Developmental Pathway as a Result of Environmental Heterogeneity” have potential applications for use in understanding how to reduce the burden of houseflies as pests. Housefly larvae live in manure and are involved in the decomposition of manure, but since manure is full of bacteria, concerns arise about them carrying the bacteria to crops or infecting livestock.

Undergraduate students training to be high school teachers will contribute to the research, and Meisel will provide continuing education training to current teachers. They will also lead middle and high school classrooms in exercises that use house flies to illustrate core concepts in genetics and evolution.

NSF CAREER awards are granted to highly promising junior faculty members who exemplify the role of teacher-scholars through “outstanding research, excellent education and the integration of education and research.”

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