Sleep and memory are connected by a pair of neurons in Drosophila

In a recent post on the Fly on the Wall blog, Neuroscience grad student Bethany Christmann talks about recently published research from Leslie Griffith’s lab:

 … [How are sleep and behavior] connected in the brain? Does sleep simply permit memory storage to take place, such that the part of the brain involved in memory just takes advantage of sleep whenever it can? Or are sleep and memory physically connected, and the same mechanism in the brain is involved in both? In a recent study published in eLife, researchers in the Griffith lab may have [uncovered the answer]. They found that a single pair of neurons, known as the DPM neurons, are actively involved in both sleep and memory storage in fruit flies.

Haynes PR, Christmann BL, Griffith LC. A single pair of neurons links sleep to memory consolidation in Drosophila melanogaster. eLife. 2015;4.

The “Fly on the Wall” Blog

fruit_fly_drawingBethany Christmann, a Neuroscience Ph.D. student in Leslie Griffith’s lab at Brandeis University has created a blog titled Fly on the Wall. The blog’s purpose is to introduce fly science to a broader audience of non-fly scientists. Check it out if you want to learn more about fly life, current research and how fruit fly research has already made huge contributions to understanding human biology and will continue to do so in the future.

Learn more about research in the Griffith Lab.


How regulatory sequences evolve in fruit flies

An IMP-Brandeis collaboration reveals the evolution of regulatory sequences in Drosophilids

By Yuliya Sytnikova and Nelson Lau

Enhancers are cis-regulatory DNA sequences that influence the promoters of genes, but identifying enhancers is not a straightforward process. Previously, the Stark lab developed a method for genome-wide enhancer detection called STARR-seq, (Arnold, Gerlach et al. 2013), that allowed them to identify thousands of enhancer sequences around the Drosophila melanogaster genome. In the most recent issue of Nature Genetics, a collaboration between the Stark lab of the IMP (Institute of Molecular Pathology) in Vienna, Austria, and the Lau lab at Brandeis University examines this hypothesis by studying the conservation of enhancer regulatory regions during Drosophilid fly evolution.

To ask if enhancers from D. melanogaster enhancers are also conserved in other Drosophila species in their sequences and locations, the Stark lab extended the STARR-Seq approach to D.yakuba and D.ananassae, which are separated from D.melanogaster by 11 and 40 million years ago, respectively (Arnold, Gerlach et al. 2014). Interestingly, this study also revealed hundreds of new sequences that gained enhancer function differentially between D.yakuba, D.ananassae, and D.melanogaster.

However, to test if these new sequences meaningfully direct different gene expression changes, the Lau lab conducted a targeted mRNA profiling experiment in purified endogenous follicle cells from D.yakuba and D.ananassae. The Stark lab had initiated the STARR-Seq analysis in an Ovarian Somatic Cell (OSC) line, which originated from the follicle cells of D.melanogaster, therefore the profiling of endogenous follicle cells from D.yakuba and D.ananassae was critical. The Lau lab achieved this using a methodology they developed for profiling Piwi-interacting RNAs from these cells (Matts, Synikova et al. 2013).

Figure 6: Evolution of enhancer activity in OSCs and gene expression in follicle cells in vivo.


Arnold CD, Gerlach D, Spies D, Matts JA, Sytnikova YA, Pagani M, Lau NC, Stark A. Nat Genet. 2014 Jun 8. doi: 10.1038/ng.3009. [Epub ahead of print] Quantitative genome-wide enhancer activity maps for five Drosophila species show functional enhancer conservation and turnover during cis-regulatory evolution.

Matts JA, Sytnikova Y, Chirn GW, Igloi GL, Lau NC. Methods Mol Biol. 2014;1093:123-36. doi: 10.1007/978-1-62703-694-8_10. Small RNA library construction from minute biological samples.


Another way that flies sense temperature

If you remember your (bio-)physical chemistry, you’ll remember that most proteins are temperature sensitive. But which ones acts as the sensors that drive behavior in higher organisms? The Garrity Lab at Brandeis has been working on thermosensation in Drosophila, and previous work has implicated the channel protein TRPA1 as a key mediator of temperature preference and thermotaxis,  In a new paper in Nature, members of the Garrity lab working in collaboration with the Griffith and Theobald have have identified another protein, GR28B(D), a member of the family of gustatory receptor proteins, as another behaviorally important temperature sensor, involved in rapid avoidance of high temperatures. Authors on the paper include postdocs Lina Ni (lead author) and Peter Bronk, grad students April Lowell (Mol. Cell Biology) and Vincent Panzano (PhD ’13, Neuroscience), undergraduate Juliette Flam ’12, and technician Elaine Chang ’08.

  • Ni L, Bronk P, Chang EC, Lowell AM, Flam JO, Panzano VC, Theobald DL, Griffith LC, Garrity PA. A gustatory receptor paralogue controls rapid warmth avoidance in Drosophila. Nature. 2013.
  • story at BrandeisNOW


Hall, Rosbash, and Young share Wiley Prize

menetfig1The 12th annual Wiley Prize in Biomedical Sciences has been awarded jointly to Michael Rosbash and Jeffrey Hall of Brandeis and Michael Young of Rockefeller University. The trio are once again being honored for their work on the molecular mechanisms governing circadian rhythms (see more on this site)

Pieter Wensink (1941-2012)

Professor Jim Haber presented the following memorial tribute at Faculty Meeting on Nov 8, 2012:

Professor Emeritus Pieter Croissant Wensink passed away on October 2, 2012 in Wellesley, MA. Pieter was born in Washington, DC, in 1941, and grew up in Bethesda and Chevy Chase, MD. He attended Lawrence College in Appleton, WI, but like many young people in the 60s, dropped out. He ended up working in a laboratory at Johns Hopkins, where he discovered a passion for science. He never got his BA, but by taking night courses Pieter got himself accepted as a graduate student at Johns Hopkins, where he received his PhD in Biology in 1971, working with Don Brown, a pioneer in studying the regulation of gene expression in frogs. Pieter then went to Stanford, where he did post-doctoral work with David Hogness. At Stanford, Pieter got in on the ground floor of the new recombinant DNA technology. He published, with Hogness, a landmark paper entitled “A system for mapping DNA sequences in the chromosomes of Drosophila melanogaster” – the fruit fly.

In 1975 Pieter came to Brandeis as an Assistant Professor in the Rosenstiel Center and in the Department of Biochemistry, bringing to Boston the then-rare and prized knowledge of how to clone genes. I remember clearly in 1976 when an MIT professor, David Botstein, and his postdoc, Tom Petes, camped out at Brandeis for several weeks learning from Pieter how to clone yeast genes. Their collaboration resulted in another major paper “Isolation and analysis of recombinant DNA molecules containing yeast DNA.” Soon thereafter Matthew Mesleson arrived from Harvard, to collaborate with Pieter on the “Sequence organization and transcription at two heat-shock loci in Drosophila.” All of these papers were pioneering works.

Pieter also taught these “dark arts” to the people in my lab and launched us and others at Brandeis on the way to understanding the mysteries of chromosome architecture and gene regulation. In 1981 Pieter also wrote a book in collaboration with his Biochemistry colleague Bob Schleif: Practical Methods in Molecular Biology.

Pieter’s own work, carried out with a series of superb graduate students, focused on genes that encode the proteins that make up the yolk of Drosophila eggs. The study of these genes revealed the complicated way that yolk protein genes are turned on only in females and only in their ovaries. Many of Pieter’s students are now Professors in their own right at major universities around the country.

In the early 1990s Pieter was diagnosed with a benign brain tumor – a meningioma – that required two surgeries to extirpate. Probably his tumor was the result of the now-impossible-to-believe treatment of a ringworm infection with X-rays when he was about 2 years old. The second operation left him unable to concentrate as he had, and Pieter, sadly, decided that he could no longer run his lab or give the clear lectures had had been offering. So he left Brandeis as an emeritus Professor with a medical disability. Pieter was remarkably calm and accepting about his situation. He decided to pursue a long-deferred passion to paint, and some years ago he earned his BFA with distinction in painting from the Massachuetts College of Art. Altogether, Pieter had 5 operations on the cancers that led to his death.

Pieter’s greatest joy in life was his family. He was married to Dorothy E. (Perry) for 43 years and was the devoted father of Tom, Alan and Joe (who recently earned his PhD in English from Brandeis).

Most of you never met Pieter, so I thought it would be good to see Pieter and some of his colleagues as we looked in the late1970s (Pieter, Michael Rosbash, Marion Nestle (now oft-interviewed nutritionist at NYU), myself, and David DeRosier). And to see two of his paintings. He was a fine man.


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