- Author: Kathy Keatley Garvey
Her seminar begins at 4:10 p.m. The Zoom link is https://ucdavis.zoom.us/j/99515291076. The host is doctoral candidate Xavier Zahnle of the Jason Bond lab, UC Davis Department of Entomology and Nematology.
"I use arthropod appendages as a model to understand how ancient structures like gills and legs evolve and innovate over hundreds of millions of years," Bruce writes in her abstract. "My work suggests that many unexpected structures, such as the insect wing and the crustacean carapace, are derived from a shared ancestral structure. This has deep implications for how we assume genetic networks evolve over vast phylogenetic distances: rather than repeated co-option events, my work suggests that genetic networks are more ancient, more evolvable, and more predictable than currently thought."
A native of the San Francisco Bay area, Heather moved with her family to Cornville, Ariz., at age 12. She holds an associate of arts degree in biological sciences (2006) from Yavapai College, Prescott, Ariz., and a bachelor's degree in cell/cellular and molecular biology (2010) from the University of Arizona. She received her doctorate in cell/cellular and molecular biology from UC Berkeley in 2017.
Bruce authored Insect Wings and Body Wall Evolved from Ancient Leg Segments, published in bioRxiv in January 2018. She wrote: "Researchers have long debated the origin of insect wings. One theory proposes that the proximal portion of the ancestral crustacean leg became incorporated into the body, which moved the leg's epipod (multi-functional lobe, e.g. gill) dorsally, up onto the back to form insect wings. Another theory proposes that the dorsal insect body wall co-opted crustacean epipod genes to form wings. Alternatively, wings may be derived from both leg and body wall (dual origin). To determine whether wings can be traced to ancestral, pre-insect structures, or arose by co-option, comparisons are necessary between insects and arthropods more representative of the ancestral state, where the hypothesized proximal leg region is not fused to the body wall."
"To do so," she continued, "we examined the function of five leg gap genes in the crustacean Parhyale hawaiensis and compared this to previous functional data from insects. Here we show, using CRISPR-Cas9 mutagenesis, that leg segment deletion phenotypes of all five leg gap genes in Parhyale align to those of insects only by including the hypothesized fused ancestral proximal leg region. We also argue that possession of eight leg segments is the ancestral state for crustaceans. Thus, Parhyale incorporated one leg segment into the body, which now bears the tergal plate, while insects incorporated two leg segments into the body, the most proximal one bearing the wing. We propose a model wherein much of the body wall of insects, including the entire wing, is derived from these two ancestral proximal leg segments, giving the appearance of a dual origin. This model explains many observations in favor of either the body wall, epipod, or dual origin of insect wings."
As a research scientist, Bruce led an independent research project from 2018-2018 in the San Francisco Bay Area where "I integrated CRISPR-Cas9 data with previous research spanning 130 years and several disciplines to demonstrate that all arthropods use the same leg patterning system, and that insect wings evolved from crustacean gills."
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, is coordinating the spring seminars. For Zoom technical issues, contact him at ssiddique@ucdavis.edu.
- Author: Kathy Keatley Garvey
Born Jan. 30, 1951 in Hong Kong and fondly known as “Amazing Grace,” she received her doctorate at UC Davis in 1983 with major professor Hammock, now a UC Davis distinguished professor who holds a joint appointment with the Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center.
Her husband of 41 years, Davy Jones, a longtime professor in the UK Department of Toxicology and Cancer Biology, received his doctorate from UC Davis, studying with major professor Jeffrey Granett of the then Department of Entomology.
Hammock described Grace Jones as a hard-working scientist with “amazing skill and creative insight.”
“Following her research at Texas A&M University, Grace joined my lab in the 1970s at UC Riverside and then finished her PhD at Davis in 1983,” recalled Hammock, a member of the UC Riverside faculty from 1975 to 1980, when he accepted a joint-faculty appointment in toxicology and entomology at UC Davis.
“She asked how juvenile hormone regulated the development of moth larvae that are serious agricultural pests,” Hammock said. “She also found two parasites, one of which sped up host larval development and the other of which slowed host larval development. She found that both parasitoids were manipulating the host insect endocrine system to their benefit. Endocrine regulation of insect development was a theme of Grace's whole career which she pursued with amazing skill, hard work and creative insight.”
Longtime friend and colleague Lynn Riddiford, emerita professor of biology at the University of Washington, Seattle, who worked with Grace Jones on a National Science Foundation grant, praised her as “a creative and imaginative scientist.”
“Her research focused on the action of juvenile hormone (JH), a key hormone regulating metamorphosis in insects,” Riddiford said. “Early on Grace studied the molecular mechanisms involved in the regulation by JH of several proteins in the cabbage looper, Trichoplusia ni—the JH-inducible JH esterase that breaks down JH and several JH-suppressible hemolymph storage proteins. Her work was always careful and thorough and contributed significantly to the field.”
Riddiford said that “Grace became intrigued by the idea that Ultraspiracle (USP), the heterodimeric partner of the ecdysone receptor (EcR), might be the long-sought JH receptor. She pursued this line of research with rigor, and later found that USP bound methyl farnesoate, the immediate precursor of JH, with the high affinity typical for hormone receptors. Furthermore, she showed that the methyl farnesoate-USP complex was critical for the larval-pupal transformation in Drosophila. Even though her initial idea that USP was the JH receptor proved wrong, her work stimulated the field and resulted in a deeper understanding of the factors controlling metamorphosis in Drosophila.”
Riddiford added: “Grace will be especially remembered for her amazing drive and determination to forge ahead with her science and to continue to make significant contributions despite the disabilities engendered by her stroke.” (See research publications)
Keith Wing, Hammock's second doctoral student who went on to become a senior research associate at Rohm and Haas and DuPont, and is now a consultant, remembered her as “a cheerful, hard-working colleague and friend, and wife of Dr. Davy Jones, University of Kentucky. A few of us spent many a late night studying juvenile hormone esterase and binding proteins at UC Riverside and Davis in lepidopteran larvae, trying to help the lab piece together the story of how JH metabolism and transport helped to regulate insect metamorphosis.”
“We shared everything and always helped each other out,” Wing said. “Grace went on to focus on this in much greater detail, including exploration into insect hormone receptors and regulation. She was an incredibly dedicated researcher who contributed a lot to the field."
Grace Jones received her bachelor's degree in biology in 1973 from Belmont (N.C.) Abbey College, and her master's degree in biology in 1974 from Jacksonville (Ala.) State University. She did post graduate research at Texas A&M in insect physiology and endocrinology before joining the Hammock lab in UC Riverside (1979-80). After receiving her doctorate in 1983 from UC Davis, she headed to Harvard University's Medical School as a visiting scholar in the Department of Cell Biology and Department of Pathology, working there from 1989 to 2000. Her career then included visiting scientist at Massachusetts Institute of Technology's Department of Biology and a visiting professor at Baylor College of Medicine, where she specialized in stem cell research.
The UC Davis alumnus joined the UK Department of Entomology in 1984 as an assistant research professor, studying insect biochemistry and molecular biology. She was promoted to associate research professor in 1990, and then switched to UK's School of Biological Sciences, becoming an assistant professor of molecular and cellular biology in 1991; an associate professor in 1993; and a full professor in 1999.
"Dr. Jones was a superb, internationally recognized scientist, even as her health declined over the past 18 years, but she continued to work on teaching and research throughout," wrote UK Department of Biology chair Vincent Cassone on a web page memoralizing her. "Over the course of her research career, Dr. Jones had received millions of grant dollars for her important studies from the National Institutes of Health and National Science Foundation, and published more than 100 research articles in prestigious journals such as the Proceedings of the National Academy of Sciences, USA, Journal of Biological Chemistry, and Molecular and Cellular Endocrinology. She and Davy also received a patent in 2007 for a method to identify drugs that interact with insect nuclear receptors, which could be used for biological control of pest species."
"Over the years, students have expressed great admiration and love for Professor Jones in letters and emails, and eminent scientists have expressed their high regard for her work," Cassone wrote. "A Grace Jones Memorial Fund for Family Support has been set up. Donations can be sent to the UK College of Health Science c/o Loralyn Cecil, 900 South Limestone 124E, Lexington, KY 40508 or online at https://karrn.org/. Her infectious smile will be missed in the halls of Biology, as she had her daily walks, arm in arm, color-coordinated with her husband, Davy, a testament to devotion and love."
Davy Jones notified his wife's friends and colleagues, including Hammock, of her death with an email, “Butterfly has flown on.” He attached a photo of Grace and a blue morpho butterfly.
She died in his arms, as this song, “Amazing Grace,” played softly in the room, he wrote.
“UC Riverside, UC Davis and the field lost a wonderful colleague and we have all lost a dear friend,” Hammock told him.
- Author: Kathy Keatley Garvey
“This is a wonderful surprise,” said Luckhart, professor with the Department of Medical Microbiology and Immunology and adjunct professor in the Department of Entomology and Nematology.
She will receive the award on April 8 at the annual Interdisciplinary Graduate and Professional Student Award Banquet.
Luckhart, whose expertise includes molecular cell biology and biochemistry of malaria parasite transmission, was singled out for creating a thriving lab environment and her drive to help her students succeed.
Lab member Elizabeth “Lizzy” Glennon, a doctoral candidate in entomology, said that Luckhart is “unique in her creation of a cohesive lab environment, the quality of training that her students receive, and the strength of her dedication to education and wellbeing of students.”
“The most effective way of studying disease transmission is a multi-disciplinary approach,” Glennon wrote. “This is precisely the environment Shirley has created in her lab and all of her students benefit from it. Members of her lab are from several different departments and are encouraged to use their background to broaden the scope of their research. Shirley expects students to work collaboratively both within and beyond the lab and has put an enormous amount of effort towards forming and maintaining the community of vector-borne disease researchers at UC Davis.”
“Shirley served as interim co-director of the Center for Vectorborne Disease, served as an advisor to all students who are part of the designated emphasis in vector-borne disease, and sought to expand the community by involving new faculty members and their students,” Glennon said. “She organized and promoted events to allow students to meet and interact with each other, UC Davis faculty, and distinguished visiting scholars in the field. All of this work builds a legacy of excellent research and collaboration in the field that is a service to all current and future students at UC Davis.”
Luckhart “expects a great deal from her students and pushes them to work and think independently but also supports them unflaggingly in their efforts to do original research and form themselves as professionals,” Glennon said. “She ensures funding for all students joining the lab but encourages us to apply for external funding, both by forwarding scholarships she comes across and reading our applications.”
“All students are expected to take part in writing grants, updates, and portions of collaborative papers and are always given credit for the work they do,” Glennon wrote. “Students in her lab receive an education in the nitty-gritty of conducting research, from forming collaborations to acquiring funding to overcoming administrative hurdles. This is invaluable, particularly for students such as myself who are considering a career in academia.”
“Perhaps her greatest strength as a mentor is the sense of cohesiveness that she has created within the lab,” Glennon pointed out. “There are currently 10 members in her lab, including undergraduates and technicians, and the projects of every individual are overlapping. Through lab lunches, weekly meetings, and practice presentations we receive not only feedback from our principal investigator, but also from our peers.”
Lab member Lattha Souvannaseng, a doctoral candidate in genetics, praised Luckhart for instilling skills for quality research and placing great importance on communicating effectively. “These are qualities that include writing and presenting information clearly, concisely, and intelligently, all competencies that can be applied in any field and for any audience.”
“She will make time to help anyone, from an inexperienced undergraduate student presenting for the first time at the Undergraduate Research Conference, linking a master's student to a connection in a biomedical company, to the seasoned senior scientist interviewing for a tenured faculty position,” wrote Souvannaseng, who plans a career in science education outreach. “I have now mentored four undergraduate students and looked to Shirley as an example of what a great mentor should be. She is always available to me when I need advice on how to guide my students, and as a result, the students are gaining valuable experiences in the lab.”
Maribel “Mimi” Portilla, a doctoral candidate in the Sharon Lawler lab, praised Luckhart's support and guidance. “Due to this positive and supportive experience, her name immediately came to mind as an academic adviser to the women in STEM support group I created, Sisters in Science. Her involvement in this group speaks to her ability to show support in a way that goes beyond her mentorship as a principal investigator.”
Luckhart earlier received the 2012 Outstanding Mentor Award from the UC Davis Consortium for Women and Research.
Luckhart, who joined the UC Davis faculty in 2004 from Virginia Tech, received her master's degree in entomology from Auburn University, and her doctorate in entomology from Rutgers, the State University of New Jersey.