- Author: Kathy Keatley Garvey
What a delight to see.
We strolled through milkweed patches in the UC Davis Arboretum Thursday noon and saw them.
Monarchs!
The monarch butterflies (Danaus plexippus) are returning from their coastal California overwintering sites. And we're getting new generations.
The UC Davis campus, including the 100-acre UC Davis Arboretum is home to much celebrated flora and fauna, including milkweed and monarchs.
After overwintering along the California coast and in central Mexico, the butterflies flutter north into the United States and Canada in the spring and summer.
However, scientists report that the monarch population in central Mexico declined from 100 million last year to 78 million this year, due to late winter storms, coupled with cold and wet weather, and deforestration.
It's a sure sign of spring, through, when the monarchs return. It's a cause for celebration. Welcome back!
Meanwhile, we're anticipating the arrival of Christine Merlin, assistant professor in Texas A&M's Department of Biology, who will discuss her research on "The Monarch Butterfly Circadian Clock: from Clockwork Mechanisms to Control of Seasonal Migration" when she presents a seminar on Wednesday afternoon, May 31 at the University of California, Davis. The seminar is set from 4:10 p.m. to 5 p.m. in Room 122 of Briggs Hall. Host is molecular geneticist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology.
- Author: Kathy Keatley Garvey
Yes, they do, says a Texas A&M researcher.
Christine Merlin, an assistant professor in Texas A&M's Department of Biology, will discuss her research on "The Monarch Butterfly Circadian Clock: from Clockwork Mechanisms to Control of Seasonal Migration" when she presents a seminar on Wednesday afternoon, May 31 at the University of California, Davis.
The seminar is set from 4:10 p.m. to 5 p.m. in Room 122 of Briggs Hall.
"The eastern North American monarch butterfly (Danaus plexippus) has emerged as a powerful model system to study animal circadian clocks and their role in an unconventional output, the photoperiod-induced long-distance migration," Merlin writes in her abstract. "Circadian clocks are endogenous 24-hour timekeepers that coordinate nearly all of the animal physiology and behavior to its environment to tune specific activities at the most advantageous time of the day. Monarchs use a circadian clock to navigate to their overwintering sites during their seasonal long-distance migration."
"The clock time-compensates for the movement of the sun across the sky over the course of the day and regulates the sun compass output in the brain. Circadian clocks could also be used to time the monarch seasonal departure from their breeding grounds, and consequently regulate the genetic/epigenetic program controlling migratory physiology and behavior. I will discuss progress that our lab has made in developing reverse-genetics in the monarch butterfly to unlock its potential as a genetic model system to study animal clockwork mechanisms and the involvement of the circadian clock in insect photoperiodic responses."
Merlin will be hosted by molecular geneticist Joanna Chiu, associate professor and vice chair, UC Davis Department of Entomology and Nematology, who is also involved in circadian-clock research. The weekly seminars, chaired by assistant professor Christian Nansen, are open to all interested persons. Plans call for recording the seminar for later posting on UCTV.
A native of France, Merlin received her bachelor's, master's and doctoral degrees majoring in animal biology, invertebrate physiology and insect physiology, respectively, at the University Paris 6 Pierre and Marie Curie in France. She accepted a postdoctoral fellowship at the University of Massachusetts in 2007.
From her post at Texas A&M University, located at College Station, 90 miles northwest of Houston, Merlin enjoys a front-row seat for the monarch butterfly migration.
She sees them heading to Mexico to overwinter, and she sees them returning.
But it's the science that drives her.
In a Texas A&M news story, Vimal Patel described her as trying to unravel "the mysteries of the migration and the role of internal clocks in the process."
"It's incredible how such a fragile insect can complete a long-range migration so demanding," Merlin told Patel. "Every piece of it fascinates me, from how it occurs to why they go precisely where they go."
An excerpt from Patel's piece:
"While she was a postdoctoral researcher at the University of Massachusetts Medical School in the laboratory of Prof. Steven Reppert, Merlin and colleagues showed that the clocks necessary for flight orientation lie in the creatures' antennae --a departure from the previous conventional wisdom that the brain controlled the mechanism, given that it controls behavioral rhythmicity in virtually every other animal, including humans.
"The conclusion stemmed from Merlin's and her co-workers' collective curiosity concerning a decades-old anecdote. Around 50 years ago, entomologist Fred Urquhart found that Monarchs became disoriented after he clipped off their antennae. Since then, it had remained just a suspicion until the Massachusetts team confirmed it with more rigorous research."
"The team's experiment exploited technology in a way Urquhart, who merely observed the Monarchs in flight, could not at the time. They used a plastic barrel-like device called a Mouritsen-Frost flight simulator in which a butterfly is connected by tungsten wire to an output system that indicates which direction it is flying. The results were clear: The antennae-less Monarchs flew in every which direction, while those with intact antennae flew southwesterly, the migratory direction."
Merlin points out that "Migration begins every year in the fall, when the day lengths change. The shortened day lengths might be a cue for the monarchs to start their migration. And if we can show this is the case and that the circadian clock is involved, we can now start to understand the genetic program that is allowing the migratory behavior."
- Author: Kathy Keatley Garvey
No, it's the mosquito.
Infected mosquitoes transmit diseases that account for some 750,000 deaths a year, according to a recent article in Science Alert.
The mosquito is a piece of work. Remember when several UC Davis scientists were featured in a KQED-produced science video on "How Mosquitoes Use Six Needles to Suck Your Blood?"
So when noted molecular neurobiologist Leslie Vosshall of the Rockefeller University, New York City, speaks on "Neurobiology of the World's Most Dangerous Animal" on Wednesday, May 24 at the University of California, Davis, her audience will not only learn just how dangerous the most dangerous animal is, but learn about her exciting research.
The hourlong seminar, free and open to the public, is set for 4:10 p.m. in the Student Community Center, UC Davis.
The Vosshall laboratory studies the molecular neurobiology of mosquitoes. Female mosquitoes require a blood meal to complete egg development, she explains. "In carrying out this innate behavior, mosquitoes spread dangerous infectious diseases such as malaria, dengue, Zika, Chikungunya and yellow fever."
"Some of the questions we are currently addressing are: Why are some people more attractive to mosquitoes than others? How do insect repellents work? How are multiple sensory cues integrated in the mosquito brain to elicit innate behaviors? How do female mosquitoes select a suitable body of water to lay their eggs? The long-term goal of all of our work is to understand how behaviors emerge from the integration of sensory input with internal physiological states."
The seminar is sponsored by the College of Biological Sciences and the Storer Life Sciences Endowment. Host is molecular geneticist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology.
At the Rockefeller University, Vosshall is the Robin Chemers Neustein Professor and head of the Laboratory of Neurogenetics and Behavior and director of the Kavli Neural Systems Institute. She is known for her work on the genetic basis of chemosensory behavior in both insects and humans.
Her notable contributions to science include the discovery of insect odorant receptors, and the clarification of general principles regarding their function, expression and the connectivity of the sensory neurons that express them to primary processing centers in the brain. She founded the Rockefeller University Smell Study in 2004 with the goal of understanding the mechanisms by which odor stimuli are converted to olfatory percepts.
Vosshall received her bachelor's degree in biochemistry from Columbia University, New York, in 1987 and her doctorate from Rockefeller University in 1993. Following postdoctoral work at Columbia University, she joined the Rockefeller faculty in 2000.
She is the recipient of the 2008 Lawrence C. Katz Prize from Duke University, the 2010 DART/NYU Biotechnology Award, and the 2011 Gill Young Investigator Award. She is an elected fellow of the American Association for the Advancement of Science and a member of the National Academy of Sciences.
For more information on the seminar, contact host Joanna Chiu at jcchiu@ucdavis.edu.
- Author: Kathy Keatley Garvey
Congratulations to the world's top 10 entomology departments, as listed today (April 3) in the long-awaited Times Higher Education's Center for World University Rankings.
The rankings show the University of Florida's Department of Entomology and Nematology as No. 1.
In California, the University of California, Riverside, is ranked No. 2, and UC Davis, No. 7. That's not a national statistic, but a global one. Kudos!
The list:
- University of Florida, 100 score
- University of California, Riverside, 95.23
- Cornell University, 91.95
- Kansas State University, 91.29
- North Carolina State University, 90.88
- Michigan State University, 90.74
- University of California, Davis, 89.88
- University of Georgia, 88.98
- Nanjing Agricultural University, China, 86.74
- University of São Paulo in Brazil, 86.74
The departments were scored in five peformance areas: Teaching (the learning environment); research (volume, income and reputation); citations (research influence); international outlook (staff students and research) and industry outcome (knowledge transfer). View the World University Rankings methodology here.
The UC Davis Department of Entomology and Nematology, based in Briggs Hall, is led by chair Steve Nadler and vice chair Joanna Chiu.
Interested in insect science? Be sure to visit the UC Davis Department of Entomology and Nematology's displays at the 103rd annual campuswide Picnic Day on Saturday, April 22. Last year thousands of visitors flocked to Briggs Hall; Bohart Museum of Entomology, home of nearly eight million insect specimens; and the Sciences Laboratory Building (nematology display). Here's what the department did last year. More information pending!
- Author: Kathy Keatley Garvey
If you want to know more about circadian timing and why "circadian timing is everything"--from human beings to fruit flies--don't miss the Science Café session on Wednesday night, March 8 at Davis.
Molecular geneticist Joanna Chiu, vice chair of the UC Davis Department of Entomology and Nematology, will speak on "Circadian Timing Is Everything: From a Good Night's Sleep to Minimizing Insecticide Use" at the Science Café session at 5:30 p.m., Wednesday, March 8 in the G St. Wunderbar, 28 G St., Davis.
Professor Jared Shaw of the UC Davis Division of Math and Physical Science is hosting the informal session. Free and open to all interested persons, it is sponsored by the Capital Science Communicators and the UC Davis Department of Chemistry. Science Café events take place in casual settings and aim to feature an engaging conversation with a scientist about a particular topic.
Chiu, an associate professor who specializes in molecular genetics of animal behavior, joined the UC Davis Department of Entomology faculty in June 2010. She received her doctorate in molecular genetics from the Department of Biology at New York University.
"All living things on our planet, from bacteria to humans, organize their daily activities around the perpetuating 24-hour day-night cycles, the result of earth rotating on its own axis and orbiting around the sun," Chiu says. "In order for organisms to anticipate predictable variations in their environment that naturally occurs over the 24-hour cycle and coordinate their physiology and behavior to perform at their best, they rely on an internal biological clock. At the science cafe presentation, I will discuss how this internal clock, termed the circadian clock, affects many important aspects of our lives, including the timing of when we feel tired and want to go to bed, the time-of-day our immune systems are most susceptible to pathogen attack, and even when medicines should be taken to give you 'the most bang for your buck.'" In addition, I will discuss the consequences of when the circadian clock is 'broken' or 'off-kilter' because of diseases, work-schedule, jetlag, and light pollution."
Back in 2011, Chiu and colleagues from Rutgers University, the State University of New Jersey, published their work on the fruit fly, Drosophila melanogaster, describing how they identified a new mechanism that slows down or speeds up the internal clock of fruit flies. That research, published in the journal Cell, has important implications: it could lead to discoveries on alleviating human sleep disorders.
By mutating one amino acid in a single protein, “we changed the speed of the internal clock and flies now ‘think' it is 16 hours a day instead of 24 hours a day,” Chiu explained in a 2011 interview. “Our goal, of course, is not to trick flies into thinking the day is shorter or longer, but to dissect this complex phospho-circuit (phosphorylation sites) that controls clock speed in metazoans.”
“Living organisms—plants, animals and even bacteria—have an internal clock or timer that helps them to determine the time of day," she said in that 2011 interview. "This internal clock is vital to their survival since it allows them to synchronize their activity to the natural environment, so that they can perform necessary tasks at biologically advantageous times of day.”
“A functional clock is required to generate proper circadian rhythms of physiology and behavior including the sleep-wake cycle, daily hormonal variations and mating rhythms,” Chiu said. “Based on genetics, molecular biology and biochemical experiments performed in many different model organisms, we know that the speed of the internal clock is controlled by a core set of circadian proteins."
So if you aren't getting that good night's sleep and you're wondering about that internal clock, be sure to head over to the G St. Wunderbar on March 8. You'll learn the connection between circadian timings and minimizing insecticide use, too.