Newswise — The Genetics Society of America (GSA) is pleased to announce that Anne Villeneuve, PhD, of Stanford University is the recipient of the 2019 Genetics Society of America Medal. Villeneuve is recognized for her research on the mechanisms governing chromosome inheritance during sexual reproduction. Her research focuses on meiosis, the specialized cell division program involved in generating egg and sperm cells. Meiosis enables diploid organisms (which have two copies of each chromosome) to generate haploid gametes (which have only a single set of chromosomes). This halving of chromosome number is crucial for sexual reproduction, as it allows restoration of the diploid chromosome number in the offspring formed once the egg and sperm fuse.
As an independent fellow at Stanford, Villeneuve recognized the considerable untapped potential of the nematode Caenorhabditis elegans as an experimental system for studying chromosomes during meiosis. Trained as a geneticist, she set out to exploit this opportunity by conducting screens to identify genes important for meiosis, most famously an elegant approach nicknamed “Green eggs and Him,” which was published in GENETICS and continues to be used as an exemplar in many university genetics courses.
Research from Villeneuve’s lab and those of her former trainees has played a key role in establishing C. elegans as one of the premier experimental systems for investigating chromosome organization, genetic recombination, and genome maintenance in the context of meiosis. Villeneuve’s research integrates sophisticated genetic strategies with high-resolution and super-resolution cytological imaging of chromosomes in the context of an optically transparent gonad in which germ cells progressing through meiosis are arranged in a temporal/spatial “time course.” This approach has enabled them to identify numerous components of the machinery responsible for the key chromosomal and DNA events of meiosis and to elucidate the mechanisms underlying these events and how they are coordinated. A substantial fraction of the genetic mutants, assays, and cytological reagents used to investigate genome maintenance, recombination, and meiosis inC. elegans was developed in her laboratory.
Papers published by the Villeneuve lab during the past 15 years have had a significant impact on our understanding of most major aspects of the meiotic program, including pairing between homologous chromosomes; structure, function, assembly and dynamics of the synaptonemal complex (SC), a meiosis-specific structure located at the interface between aligned homologs; formation and repair of DNA double-strand breaks; spatial patterning and maturation of meiotic crossovers; remodeling of chromosome structure in response to recombination; regulated release of sister chromatid cohesion; organization of chromosomes on the oocyte meiotic spindle; and quality control mechanisms that ensure a robust outcome of meiosis.
“Literally every major event in meiosis has been dissected in Anne's lab and generated beautiful, high-profile papers,” says Barbara Meyer, a Professor at the University of California, Berkeley and one of the scientists who nominated Villeneuve for the Medal. “It is extremely rare to be able to cite a single lab with such a huge impact on a field of biology.”
A hallmark of research from the Villeneuve lab is the generation of microscopic images of meiotic chromosomes that provide a stunning visual readout of the inner workings of meiosis. This is beautifully illustrated in a recent paper from postdoctoral researcher Alex Woglar, which revealed the distinct spatial architecture of recombination proteins localized at meiotic crossover sites and showed that recombination site architecture undergoes dynamic changes during meiotic progression.
Villeneuve’s group has also provided insight into the process of crossover interference, which was originally described by Muller over 100 years ago, yet has remained largely mysterious during the intervening century. Crossover interference refers to the non-random placement of crossovers, such that a (nascent) crossover reduces the likelihood that another crossover will be formed nearby. A series of papers from the Villeneuve lab exploited genetic and cell biological tools available in the worm to implicate the SC as an important conduit of communication along the chromosomes. Their findings support a model of meiotic crossover regulation as a self-limiting system in which SC components initially promote the formation of crossover intermediates, which in turn trigger a change in the state of the SC that inhibits further crossover formation.
“Anne is a true scholar and has made a number of significant and impactful contributions to the field of genetics over the last 15 years,” says JoAnne Engebrecht, a Professor at the University of California, Davis and one of the scientists who nominated Villeneuve for the GSA Medal. “She embodies the ingenuity of the GSA membership in using genetics to investigate a fundamental biological process.”
Villeneuve’s influence on the fields of meiosis and recombination in particular, and genetics in general, extends well beyond the research conducted in her own lab. She has an outstanding record for mentoring younger scientists, and many of her trainees have gone on to establish their own productive independent research groups. Moreover, she has fostered a collegial community among meiosis researchers and has provided mentorship for numerous scientists outside her own group. Villeneuve also has a long-standing involvement with the GSA. She first joined the GSA as a graduate student, served as its Secretary from 2013 to 2015, and was an Associate Editor for the GSA journal GENETICSfrom 2004 to 2010. Villeneuve’s scientific contributions and leadership in the Meiosis and Recombination fields have been recognized in recent years by a Research Professor Award from the American Cancer Society and by her election to the American Academy of Arts and Sciences in 2016 and the National Academy of Sciences of the USA in 2017.
The GSA Medal was established in 1981 to recognize members who have made outstanding contributions to the field of genetics during the past 15 years. The award will be presented to Villeneuve at the 22nd International C. elegans Conference, which will be held June 20–24, 2019 in Los Angeles, CA.