- Author: Kathy Keatley Garvey
In less than 48 hours, nearly 500,000 people have seen them—but not in his restricted-access lab.
His research subjects are blood-sucking tsetse flies, and PBS featured them in its Deep Look video, “A Tsetse Fly Births One Enormous Milk-Fed Baby,” released Jan. 28, and its accompanying news story.
Infected tsetse flies transmit the parasite that causes human and animal trypanosomiasis, better known as sleeping sickness. “The parasite invades the central nervous system and disrupts the sleep cycle,” says Attardo, a global authority on tsetse flies and an assistant professor in the UC Davis Department of Entomology and Nematology. “If not treated, the disease can result in progressive mental deterioration, coma, systemic organ failure and death.”
“PBS sent out a film crew and we spent about two days filming,” he said. The video also includes footage from Africa that PBS purchased, and video of a tsetse trap that Attardo filmed in the Nguruman Escarpment, Kenya, on the border of Tanzania.
Attardo researches one of 35 tsetse fly species, Glossina morsitans morsitans, which prefers feeding on cattle to humans. Its strong mouthparts can easily puncture the tough cattle hide. In his lab, he feeds them warm cow blood.
Tsetse flies, which resemble house flies, are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young, Attardo says. Just like mammals, tsetse flies, deliver babies and feed them milk. A female produces more than her body weight in milk.
“We mammals like to think we're pretty special, right?” the video begins. “We don't lay eggs. We feed our babies milk. Well, this very pregnant fly is about to prove us wrong. Yep, this tsetse fly is in labor. And that emerging bundle of joy is her larva. While other insects can lay hundreds of eggs, she grows one baby at a time inside her, just like us. Congratulations!”
The accompanying news story, by Gabriela Quirós, explains that Attardo is “trying to understand in detail the unusual way in which these flies reproduce in order to find new ways to combat the disease, which has a crippling effect on a huge swath of Africa.”
The video shows tsetse flies feeding on cattle, at which point the script reader explains that
“Geoff Attardo…hopes to help. He's trying to stop tsetse flies from making babies in the first place. A female only mates once in her life, enough to make the 10 or so babies she'll have. The male makes sure she doesn't mate again by delivering a substance that makes her lose interest in sex. Scientists are trying to figure out what it is. If they could bottle it and spray it, female tsetse flies may never get busy at all. No more tsetse offspring to worry about.”
Attardo says that tsetse flies deliver only one offspring at a time, as compared to insects that lay hundreds or thousands of eggs at one time. Spraying insects and setting traps can reduce the number who develop the disease, but the insects may become resistant to the chemicals.
Once a female mates, storing the sperm she'll birth in a lifetime, the male delivers “a substance that makes her lose interest in sex,” Quirós wrote. It is that substance or what Attarado calls a “reproductive dead end,” that Attardo wants to replicate, to bottle and spray on the tsetse flies..
“The females definitely are making the decisions,” Attardo told Quirós. “She'll sort of tuck her abdomen underneath her body to prevent him from gaining access, and buzz her wings and knock him off.”
The news story also touched on a bacterium, Wigglesworthia glossinidia, found inside the females that apparently has a role in milk production. “When they kill the bacteria with antibiotics, female flies are no longer able to grow a larva, “Queros wrote. “Young larvae stop growing inside their mothers and are aborted. The results of an experiment by Attardo, which he hasn't published yet, suggest that this happens because flies without the bacteria have trouble making milk.”
Last fall, Attardo published landmark research that provides new insight into the genomics of the blood-sucking tsetse fly. The paper, published Sept. 2 in the journal Genome Biology, compares and analyzes the genomes of six species of tsetse flies and the research could lead to better insights into disease prevention and control.
“It was a behemoth project, spanning six to seven years,” said Attardo. “This project represents the combined efforts of a consortium of 56 researchers throughout the United States, Europe, Africa and China.”
Attardo joined the UC Davis Department of Entomology and Nematology in 2017 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.
A native of Poughkeepsie, N.Y., he 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.
(Editor's Note: By popular demand, Attardo plans to again show his virtual reality bugs this year at Briggs Hall during the campuswide UC Davis Picnic Day on Saturday, April 18. "We have some new 3D data showing the internal reproductive organs of the tsetse fly that we plan to adapt to virtual reality.")
Resources:
- Author: Kathy Keatley Garvey
Yes? Then you'll want to attend the Science Café presentation on Wednesday, June 7, when medical entomologist and tsetse expert Geoffrey Attardo of the UC Davis Department of Entomology and Nematology will discuss “Got Milk? The Evolution and Biology of the Lactation in the Tsetse Fly.”
The event, set for 5:30 p.m., in the G Street Wunderbar, 228 G St., Davis, Calif., is free and open to the public. Jared Shaw of the UC Davis College of Letters and Science will host the presentation.
“It is actually going to be a very basic talk aimed at lay audiences and kids,” Attardo says. “I'll be talking about my background, how I became an entomologist and how I ended up working on tsetse flies. Then I am going to discuss the life history of tsetse flies, where they can be found, why they are of medical importance and how their reproductive biology differs so dramatically from other flies that people are familiar with. My plan is to go over their reproductive cycle, how they develop intrauterine larvae, the reproductive adaptations that allow them to perform this feat and then go over what we know about tsetse milk secretions and how they compare to mammalian milk in terms of nutritional content.”
“The aim is for it to be very informal, with very little scientific jargon and to be discussion-oriented so that there is lots of questions and answers. I am also bringing some items from the lab that can be passed around the audience for show and tell (homemade tsetse cages, the blood feeding system we use to feed the flies and some tsetse flies preserved in alcohol).
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
Attardo considers the tsetse fly "one of the champions of the insect world."
"In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects," he says. "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."
If you'd like scientific information on tsetse fly lactation, see Adenotrophic Viviparity in Tsetse Flies: Potential for Population Control and as an Insect Model for Lactation, co-authored by Attardo and published in January 2015 in the Annual Review of Entomology.
The UC Davis scientist was featured in a New York Times' article on tsetse flies on Feb. 12. Pulitzer-Prize winning science writer Natalie Angier penned the article, "Everywhere in the Animal Kingdom, Followers of the Milky Way" (subhead: "As scientists learn more about milk's evolution and compositional variations, they are redefining what used to be a signature characteristic of mammals.")
"Most female flies take a low-rent approach to parenthood, depositing scores of seed-sized eggs in the trash or on pet scat to hatch, leaving the larvae to fend for themselves," Angier wrote. "Not so the female tsetse fly. She gestates her young internally, one at a time, and gives birth to them live. When each extravagantly pampered offspring pulls free of her uterus after nine days, fly mother and child are pretty much the same size."
Then she quoted Attardo: “It's the equivalent of giving birth to an 18-year-old."
Attardo is also a talented macro photographer. He won the 2010 Fogarty Grantee Photo Contest with an image of a tsetse fly. The Yale School of Public Health magazine featured his images on “An Eye for the Tsetse Fly.” The Los Angeles Times published his remarkable video (in 2014) of a tsetse fly giving birth. Also, see his portraits of the tsetse fly on Live Science, published in 2014.
- Author: Kathy Keatley Garvey
Totally fascinating.
Tsetse fly expert Geoffrey Attardo, a medical entomologist and assistant professor with the UC Davis Department of Entomology and Nematology, drew the attention of Pulitzer-Prize winning science writer Natalie Angier who penned the article, "Everywhere in the Animal Kingdom, Followers of the Milky Way" (subhead: "As scientists learn more about milk's evolution and compositional variations, they are redefining what used to be a signature characteristic of mammals.")
Her lede: "Most female flies take a low-rent approach to parenthood, depositing scores of seed-sized eggs in the trash or on pet scat to hatch, leaving the larvae to fend for themselves."
"Not so the female tsetse fly. She gestates her young internally, one at a time, and gives birth to them live. When each extravagantly pampered offspring pulls free of her uterus after nine days, fly mother and child are pretty much the same size."
Then she quoted the UC Davis medical entomologist:
“It's the equivalent of giving birth to an 18-year-old,” said Geoffrey Attardo, an entomologist who studies tsetse flies at the University of California, Davis.
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from tje Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
In terms of "fascinating physiological adaptations," Attardo considers the tsetse fly "one of the champions of the insect world!" As he explained to us in a 2017 news story: "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.”
Attardo's published research is drawing national and international attention, as are his incredible images of tsetse flies. He won the 2010 Fogarty Grantee Photo Contest with an image of a tsetse fly. The Yale School of Public Health magazine featured his images on “An Eye for the Tsetse Fly.” The Los Angeles Times published his remarkable video (in 2014) of a tsetse fly giving birth. Also, see his portraits of the tsetse fly on Live Science, published in 2014.
In her New York Times article, Angier points out that "Only in the class Mammalia do all member species nurse their young, yet evolutionary biologists now believe that the roots of mammalian lactation date back more than 300 million years, a good 100 million years before the first mammals appeared."
Who knew?
And while on the subject of tsetse flies, be sure to read the September 2016 article, "Tsetse Flies Are Strange and Dangerous," by Kevin Fitzgerald in Entomology Today, a publication of the Entomological Society of America. Fitzgerald featured the work of Attardo and posted one of his photos.
- Author: Kathy Keatley Garvey
He targets the tsetse fly.
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.)
- Author: Kathy Keatley Garvey
The tsetse fly (Glossina genus), found in sub-Saharan Africa, transmits Trypanosomiasis, a parasitic disease that we commonly refer to as "sleeping sickness."
Sleeping sickness occurs in 36 sub-Saharan Africa countries, but due to sustained control efforts, the number of new cases is decreasing, according to the World Health Organization (WHO): "In 2009 the number reported dropped below 10,000 for the first time in 50 years, and in 2015 there were 2804 cases recorded."
Enter Alvaro Acosta-Serrano of Liverpool School of Tropical Medicine, England, who researches tsetse flies.
Acosta-Serrano speaks on "A Hunger Game: Exploiting Tyrosine Degradation for Tsetse Control" at the next UC Davis Department of Entomology and Nematology seminar, set for 4:10 p.m., Wednesday, March 14 in 122 Briggs.
His research focuses on fundamental aspects of the biology of kinetoplastid parasites and their vectors, and on developing molecular tools to control and prevent parasite transmission in disease-endemic areas.
In his abstract, Acosta-Serrano writes: "My lab uses a combination of biochemistry, molecular genetics and cell biology to study the interactions between African trypanosomes and tsetse flies. These parasites undergo a complex life cycle in the tsetse that involves migration and colonization of different fly tissues. Establishment of a trypanosome infection occurs after the parasites reach the ectoperitrophic space (ES), which is in direct contact with the gut epithelium and is separated from the lumen by the peritrophic matric (PM). The tsetse PM works a barrier for oral pathogens and harmful molecules present in the blood meal. Although unproven, the most accepted hypothesis of how T. brucei reaches the ES is by direct crossing of the tsetse PM."
"My lab studies the reproductive biology and genetics of tsetse flies and other disease vectoring insects," Attardo related. "Tsetse flies are very unique in that they lactate and give birth to live young. We are exploring the fascinating physiological processes underlying the strange reproductive biology of this important vector insect. This work covers multiple areas of reproduction in tsetse including nutrition; analysis of genes associated with milk production; the molecular and biochemical interactions between male and female flies and the role symbiotic bacteria play in tsetse reproduction. We hope to eventually use what we learn to enhance current tsetse control efforts by exploiting their reproductive biology."
Attardo, who joined the faculty last year, holds a doctorate in genetics from Michigan State University and worked for 13 years at the Yale School of Public Health in the Department of Epidemiology of Microbial diseases, first as a postdoctoral associate and then as a research scientist. (See feature story)
The UC Davis Department of Entomology and Nematology hosts weekly research seminars at 4:10 p.m. on Wednesdays in 122 Briggs Hall, off Kleiber Hall Drive. The seminar on tsetse flies is the last of the winter quarter series. Coordinators are assistant professor Rachel Vannette; Extension apiculturist Elina Lastro Niño and Ph.D student Brendon Boudinot.
