It starts out slow.
Beginning in the spring (and sometimes year-around in some locales) Gulf Fritillaries (Agraulis vanillae) lay their eggs on their host plant, the passionflower vine (Passiflora).
They deposit their eggs on the tendrils, on the leaves, and sometimes on the fence, wall or door where the passionflower vine climbs.
When fall approaches and the Gulf Frits are still laying eggs, you won't recognize your vine. It is skeletonized. The caterpillars, incredible shredding machines, have devoured all the leaves, leaving nothing but scarred sticks. And the 'cats are now gobbling up the remaining fruit. Hungry, hungry caterpillars!
Your plant, now incognito, looks like it should be in the Federal Witness Protection Program--and you have to defend yourself for "being a bad gardener."
But that's why we plant the Passiflora: for the Gulf Frits.
"No plant wants to be eaten," wisely observes Bruce Hammock, a UC Davis distinguished professor with a joint appointment in the Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center. "They all have defenses. They do not like insects, fungi, cows or even vegetarians that eat them."
At the time, Professor Hammock was talking to a reporter about toxic plants, and how we have bred many poisons out of plants or learned to not eat the most toxic parts. "In some cases, we like the taste of the poisons: cinnamon, potato, parsley, and mustard," Hammock told him.
In the case of the passionflower vine, aka Scraped Skinny Stick, it probably wishes (if plants could wish) and wonders (if plants could wonder) "Why am I so attractive?" and "Where are all the birds, wasps and other predators of caterpillars when I need them?"
That's part of the creative title of a seminar that Arnaud Martin, assistant professor of biology, George Washington University, Washington, DC, will deliver next week to the UC Davis Department of Entomology and Nematology.
Martin, an evolutionary geneticist who studies butterfly wing patterns, will speak on "Do Butterflies Dream of Genetic Tattoos? Exploring the Genotype-Phenotype Map Using CRISPR" at the UC Davis Department of Entomology and Nematology seminar at noon, Friday, Oct. 19 in 122 Briggs Hall, announced seminar coordinator Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology.
CRISPR is an abbreviation for Clustered Regularly Interspaced Short Palindromic Repeats. Definition: Segments of DNA containing short, repetitive base sequences in a palindromic repeat (the sequence of nucleotides is the same in both directions).
"He is doing some really cool work investigating the mechanisms underlying wing patterning in butterflies using CRISPR to knock out genes that regulate those mechanisms," said Attardo, who noted that the seminar was initially scheduled for 4:10 p.m., Wednesday, Oct. 17 but was changed to noon, Friday, Oct. 19.
Martin, who researches the evolutionary and developmental genetics of butterflies and moths, was recently quoted in a Washington Post article (Sept. 19, 2017) titled "Mutant Butterflies Reveal the Genetic Roots of Colorful Wings." Reporter Ben Guarino wrote: "Engineered mutant butterflies give a glimpse deep into the genetic roots of wing patterns, an international team reported Monday in the Proceedings of the Natural Academy of Sciences. The authors of the new study rearranged colors on butterfly wings by deleting a single gene using a genome editing tool called CRISPR. The gene's absence had a dramatic effect in sever butterfly species, including some that aren't closely related."
"We use butterfly wing patterns as a proxy to understand fundamental rules about the function of genes," Martin told Guarino.
About his UC Davis talk: "Understanding the generative mechanisms of morphological diversification requires the routine manipulation of genomes in a comparative context," Martin says. "I will present how current work using CRISPR mutagenesis has allowed to decipher developmental mechanisms behind the diversification of a spectacular of morphological radiation: the color wing patterns of butterflies. These experiments illustrate how evo-devo can delve into the genome-to-phenome relationship at different taxonomic nodes, from population levels to more macro-evolutionary scales. I will discuss this principle in the broader context of GepheBase (www.gephebase.org), a database of known genotype-phenotype that compiles from the literature more than 1600 allele pairs across all Eukaryotes."
Martin received his doctorate in biological sciences in 2010 from UC Irvine (thesis: "The Developmental Genetics of Color Pattern Evolution in Butterflies.") He then did postdoctoral research at Cornell University and UC Berkeley before joining the Department of Biological Sciences at George Washington University in January 2016.
He's the principal investigator on a $414,266 National Science Foundation grant (2017-2020) on "Collaborative Research: cis-Regulatory Basis of Butterfly Wing Pattern Evolution," and co-author of a research article on "CRISPR/Cas9 as the Key to Unlocking the Secrets of Butterfly Wing Pattern Development and Its Evolution," published in December 2017 in Advances in Insect Physiology.
The abstract: "With the exception of a few moth and butterfly species, gene-editing tools in Lepidoptera have been lagging behind other well-studied insects. In order to elucidate gene function across the order, it is necessary to establish tools that enable such gene manipulation. CRISPR/Cas9 is a promising technique and here we review the recent progress made in implementing the technique in butterflies; from broad patterning of the wing, to the development of specific colours in particular wing sections, to eyespot formation. The often species-specific responses to the CRISPR/Cas9-induced mutations in candidate genes, underscore the significance of these genes in the wide evolutionary diversification of butterfly wing patterns. We further discuss potential caveats in the interpretation of the resulting mutant phenotypes obtained through CRISPR/Cas9 gene editing. Finally, we discuss the possibilities CRISPR/Cas9 offers beyond mere knockout of candidate genes, including the potential for the generation of transgenics that will further elucidate the developmental genetic basis for wing pattern evolution."
Attardo says the seminar will be recorded and posted at a later date.
The UC Davis Honey and Pollination Center can change that!
Want to learn more about the product that honey bees make?
The UC Davis Honey and Pollination Center is offering a Sensory Evaluation of Honey Certificate Course, Oct. 26-28 in the Mondavi Institute's Sensory Building, located on Old Davis Road.
"This introductory course uses sensory evaluation tools and methods to educate participants in the nuances of varietal honey," according to Amina Harris, director of the Honey and Pollination Center, which is affiliated with the UC Davis Department of Entomology and Nematology. "Students will learn about methods of evaluation, stands and quality in this certificate program."
Who should take the course? Anyone interested in learning how to critically taste and assess honey. Attendees will receive a UC Davis Honey Flavor Wheel in addition to a jump drive with all presentations. (See agenda.)
- Taste more than 40 varietals from across the US, Europe and other locales.
- Learn the positive attributes and defects found in honey
- Learn about the science of tasting from UC Davis Sensory faculty
- Learn about labeling laws and their limitations
- Receive an update on the latest UC Davis Sensory research
- Listen to lectures from leading authorities in nutrition, medical science, and adulteration and even a live cooking demonstration on how to use honey in creative ways.
The cooking demonstration features Mani Niall, a former consultant and traveling chef-instructor for the National Honey Board, a sponsor of this year's Honey Sensory Evaluation Course. Niall will explain how to best enhance the flavor of food with different varietal honeys, from savory to sweet. "Mani understands the nuances of honey: when it is important to choose a specific varietal to enhance a recipe and when it is appropriate to use a great wildflower blend," Harris points out.
His recipes also will be served on Saturday and Sunday to the attendees during meals and breaks.
Tsetse flies, large biting flies that inhabit much of Africa, feed on the blood of humans and other vertebrates and transmit such parasitic diseases as African trypanosomiasis. In humans, this disease is better known as sleeping sickness.
In 2009, after continued control efforts, the number of cases reported dropped below 10,000 (9878) for the first time in 50 years. This decline in number of cases has continued with 2804 new cases reported in 2015, the lowest level since the start of systematic global data-collection 76 years ago. The estimated number of actual cases is below 20 000 and the estimated population at risk is 65 million people.--World Health Organization
"Tsetse flies are the sole vectors of human and animal trypanosmiasis throughout sub-Saharan Africa," says Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology.
He'll present a seminar on "Comparative Genomic Anaylsis of the Tsetse Fly: The Genetics of Lactation, Seminal Proteins and Other Unique Adaptations" at 4:10 p.m., Wednesday, Oct. 10 in 122 Briggs Hall. (He is also chairing the department's seminars for the 2018-2019 academic year.)
Attardo says that these "flies are distinguished from other Diptera by unique adaptations including male specific reproductive adaptations, lactation and the birthing of live young (obligate viviparity), exclusive blood feeding by to the sexes and visually based host seeking. To understand the genetic changes underlying these adaptations, we sequence the genomes of six species of tsetse flies representing three sub-genera. These sub-genera represent different habitats, host preferences and vectorial capacity."
In his talk, he will "describe some of our findings from these analyses and how the genetics of these flies compare with relatives such as Drosophila, with an emphasis on the genetic changes underlying tsetse's dramatic reproductive adaptations. In addition, we will discuss observations associated with visual, olfactory, and salivary biology, as well as the identification of features novel to Glossina and their respective sub-genera."
Attardo joined the department July 1, 2017 as an assistant professor after 13 years at the Yale University School of Public Health, New Haven, Conn., first as a postdoctoral fellow from 2004 to 2008, and then as associate research scientist and research scientist
“I got my start in science working as an undergraduate researcher” at the University of Massachusetts in the lab of John Edman, who moved to UC Davis in 1999. There Geoffrey reared and worked with various mosquito species and kissing bugs for four to five years. He also worked on aspects of mosquito ecology, reproduction and nutrition with Edman and Thomas Scott, now both UC Davis emeriti professors of entomology.
“I decided to develop my career in science and went to work in Dr. Alexander Raikhel's lab at Michigan State University as a graduate student. I was always drawn to understanding the molecular mechanisms underlying the extreme biology of insects and Dr. Raikhel's lab provided that opportunity. There I focused on the molecular biology of egg development in mosquitoes.”
After receiving his doctorate, Attardo joined the Yale lab of Serap Aksoy to work on tsetse flies. “In terms of fascinating physiological adaptations, the tsetse fly is one of the champions of the insect world!” Attardo says. “In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects. Some examples of this are their ability feed exclusively on blood, their obligate relationship with a bacterial symbiont, the fact that they lactate and that they give birth to fully developed larval offspring. The opportunity to study the adaptations these flies have made is like opening a toy chest for an insect physiologist. My work in tsetse has focused on the molecular biology underlying the adaptations associated with the development of lactation, symbiosis, male and female mating interactions/physiology and nutrient metabolism and mobilization.”
In research on mosquitoes, Attardo demonstrated that mosquitoes require nutritional cues to begin egg development. “Egg development had been known to be regulated by a steroid hormone called 20-hydroxyecdysone,” Attardo explained. “However, treatment of mosquitoes with this hormone along did not activate egg development. My research showed that when female mosquitoes take blood, the protein in the blood is broken down into amino acids which in combination with the hormone activate egg development. Either amino acids or the hormone along were not capable of activating this process, but when they are combined it unlocks a massive physiological change which causes the production of yolk proteins and activation of egg development.”
One of the highlights of his career: the publication of the tsetse fly genome in the journal Science. He served as the annotation coordinator, editor and illustrator for the publication. One of his tsetse fly images graced the cover. “The publication of the genome opened up new avenues of research in tsetse that were previously unavailable and facilitates more work to be done on this important disease vector by making all this data available to the community,” Attardo related. “I am working on following up this work with a paper comparing the genome sequences of six different species of tsetse flies that differ in their geographic, ecological, host preference and vectorial capacity characteristics. We hope to connect the underlying genetics of these flies with with these differing life traits to understand their biology, evolution and identify potential targets with which to control this vector.”
A native of Poughkeepsie, N.Y., Geoffrey received his bachelor's degree in entomology from the University of Massachusetts, Amherst, in 1994 and his doctorate in genetics from Michigan State University, East Lansing, in 2004.
A career in science came naturally. “My parents are both somewhat scientifically inclined, so I may have taken after them,” he says. “My father has a doctorate in metallurgy from Columbia University and led a long successful career at IBM. My mom was a full-time mom, but has a background in microbiology with a master's degree from Yale.”
(Editor's note: See list of seminars for the fall quarter.)
Ask away at the Science Café.
This is an informative scientific presentation held the second Wednesday of each month in the G St. Wunderbar, 228 G St., Davis. The scientist delivers a brief talk and then engages the public.
Next Wednesday, Oct. 10, biodemography expert James R. Carey, a UC Davis distinguished professor of entomology and an expert on human aging (as well as insects!) will speak at 5:30 p.m. on "Are There Upper Limits to Human Lifespan?"
How long can humans live? Well, supercentarian Jeanne Calment of France (1875-1997), lived to be 122. Born Feb. 21, 1875, she died Aug. 4, 1997. She enjoyed a healthy lifestyle, prayed and exercised daily, and lived a basically stress-free life. But yes, she drank a little wine and smoked a little. She outlived her husband, daughter and grandson.
“Why do we live as long as we do (evolutionary question), why do we age (mechanisms question) and why do we die (closure question)?” Carey asks.
Some of the topics to be discussed at the event, billed as “a conversation and dialogue with a scientist,” include:
- The trends in aging research on extending human lifespan.
- Theoretical arguments for upper limits and empirical evidence in humans
- The impact of disease elimination and organ replacement on longevity
- With the changes in human life expectancy, humans are now being given a second chance-- somewhat like the proverbial cat with nine lives--after an otherwise life-ending disease or incident
- Look to nature for perspectives on the limits of “life duration,” for example 40,000-year-old frozen nematodes; hibernation and dormancy) and limits to “active lifespan.”
An internationally recognized leader and distinguished scholar in insect demography and invasion biology, spanning three decades, Carey also researches health demography, biology of aging, and lifespan theory. He is the author of a landmark study published in the journal Science in 1992 that showed mortality of Mediterranean fruit flies (medflies) slows at older ages. Earlier this year scientists confirmed that this also occurs in humans, citing the study of 105-year-old Italian women.
Carey, who joined the UC Davis faculty in 1980, directed an 11-university, $10 million, 10-year study on biodemography of aging from 2003-2013. He is also known for discovering Carey's Equality or the death distribution in a life table population equals its age structure. He teaches a popular longevity course that draws 250 to 300 students year, and recently authored a book on biodemography, to be published by Princeton University next year.
And, if you want to ask Professor Carey about medflies, he can answer those, too. He was a recent recipient of a UC Davis Academic Senate Distinguished Scholarly Public Service Award for his “outstanding research, outreach and advocacy program involving invasion biology, specifically his significant contributions on two California insect pest invaders, the Mediterranean Fruit Fly (medfly) and the Light Brown Apple Moth (LBAM).”
Professor Jared Shaw, interim chair of the UC Davis Department of Chemistry and founder of the Science Café series, will host the Oct. 10th presentation. Launched in 2012 and initially supported by the National Science Foundation, the popular series now draws support from the Department of Chemistry and Division of Mathematical and Physical Sciences and is promoted by Capital Science Communicators.
See schedule on the UC Davis Department of Chemistry website.