Beetle Mitochondrial Sequence Variation

Determination of mitochondrial sequence variation among populations of montane leaf beetles

Presenter: Rocio Sosa Mercado

Presenter Status: Undergraduate student

Academic Year: 22-23

Semester: Spring

Faculty Mentor: Nathan Rank

Department: Biology

Funding Source/Sponsor: Other

Other Funding Source/Program: National Science Foundation, White Mountain Research Center

President's Strategic Plan Goal: Sustainability and Environmental Inquiry

Abstract:
The mitochondrion comprises a fundamental role in an organism’s metabolism and life cycle. The mitochondrial genome tends to evolve more rapidly than nuclear genes. This can lead to adaptation to local environments. The Sierra Nevada leaf beetle, Chrysomela aenecollis, lives at high elevations and spends the majority of its time dormant during the overwintering stage. It becomes active during the summer months. Leaf beetles experience oxygen limitation and temperature fluctuations throughout the day. Generations of evolutionary pressures allowed these beetles to withstand environmental changes, but little is known about how genetic differences contribute to their ability to thrive in stressful environments. In 2015, beetle larvae were collected from three drainages in the eastern Sierra Nevada (Rock Creek, Bishop Creek, and Big Pine Creek). The running speed of 205 larvae was quantified before and after heat exposure to evaluate recovery from heat stress. I analyzed next-generation sequencing data to determine whole-genome mitochondrial sequences for these 205 beetles and created a visual representation of the level of variation among subgroups. My results identified significant differences between northern and southern populations that might contribute to their ability to recover from exposure to stressful temperatures at high elevations.