Mosquitoes' genes alter thinking about resilience in the face of climate change

EUGENE, Ore. — (Oct 10, 2012) — A comprehensive study at the University of Oregon, using cutting-edge genetic tools, shows that temperate and polar species of animals may be much more resilient to rapid climate change than previously expected.

Thousands of species in temperate zones read the length of day — or photoperiodism — to cue irrevocable life and death behaviors, including the timing of development in the spring, when to enter dormancy in the fall, when to reproduce and when to migrate.

In the new study, a team of biologists in the lab of William E. Bradshaw and Christina Holzapfel studied ancient and derived populations of the pitcher-plant mosquito, Wyeomyia smithii. Researchers created three forms of genetic maps of mosquitoes from New Jersey, northern Maine and southern Alabama. This species of mosquito completes its pre-adult development in the water-filled leaves of the purple pitcher plant.

The research team found that the underlying genetic architecture of photoperiodism is highly variable, not only through evolutionary time but also within populations. Species have a high level of built-in genetic flexibility with which to respond to the seasonal demands of a changing world, a fact that co-author Holzapfel said "will provide more challenges than previously expected in efforts to control unwanted pests and invasive species in temperate climates."

Bradshaw and Holzapfel had shown earlier that an interpretation of length of day by animals is coded in the genes and can be shifted in as few as five years in response to climate change.

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View a video produced about their earlier findings by the National Science Foundation and NBC Learn

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Their ongoing project seeks the basis for the evolution of seasonal timing at the level of genes and an understanding of how the integration of genes has changed over geographical ranges and over different evolutionary time scales.

Bradshaw, the lead author in the new study, said that "gaining such genetic knowledge is key to predicting and mitigating the movement of vector-borne diseases from tropical to temperate zones of Earth as vectors and their hosts migrate into increasingly milder northern climates."

"This research by Drs. Bradshaw and Holzapfel and their group is furthering our understanding of how different species are responding to climate change," said Kimberly Andrews Espy, UO vice president for research and innovation, and dean of the graduate school. "The modern genetic analysis tools being used by these researchers, some of which were developed here at the University of Oregon, are helping to yield solutions to tomorrow's problems today."

The new paper was placed online ahead of regular publication by the Proceedings of the Royal Society B.

The National Science Foundation, under the American Recovery and Reinvestment Act (grants IOS-0839998, DEB-0917827 and DEB-0919090) and a subsequent grant (IOS-1048276), provided the major support for the project. The National Institutes of Health (grants R24GM079486 and 1F32GM095213-01), W.M. Keck Foundation and the M.J. Murdock Charitable Trust provided additional funding.

Co-authors with Bradshaw and Holzapfel, were Kevin J. Emerson, Julian M. Catchen and William A. Cresko, all members of the UO Institute of Ecology and Evolution. Emerson is now at St. Mary's College of Maryland. The paper is titled "Footprints in time: comparative quantitative trait loci mapping of the pitcher-plant mosquito, Wyeomyia smithii."

About the University of Oregon
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.

Media Contact: Jim Barlow, director of science and research communications, 541-346-3481, jebarlow@uoregon.edu

Source: William Bradshaw, professor of biology, 541-346-4542, bradshaw@uoregon.edu

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Gallery

Pitcher plant mosquito on a pitcher plant