TIDAL-Fly: a new database resource of Transposon Landscapes for understanding animal genome dynamics.

We tend to think of our genomes as nicely-ordered encyclopedias,  curated with only useful information that makes up our genes.  In actuality, nature and evolution is extremely sloppy.  All animal genomes, from us humans to the simple fruit fly, are littered with genetic baggage.  This baggage is sizeable, making up at least 11% of the fly genome and more than 45% of our genome.  The scientific term for this baggage is transposable elements (TEs) or transposons, which are mobile entities that must copy themselves to other places of the genome to ensure their survival during animal evolution.

Because there are so many copies of transposons, they can be difficult to analyze by most standard genetic methods. Brandeis postdoctoral fellow Reazur Rahman and a team in Nelson Lau’s lab have formulated a new tool called the Transposon Insertion and Depletion AnaLyzer (TIDAL). TIDAL aims to provide an accurate and user-friendly program to reveal how frequently transposons can move around in animal genomes.  Currently, the TIDAL tool has been applied to over 360 fruit fly genomes that have been sequenced and deposited in the NIH NCBI Sequencing Read Archive.  The outputs from this program are available to the whole genetics community through the TIDAL-FLY database.

tidal fly banner

The TIDAL-Fly database will allow geneticists to pick their favorite fly strain and see if a transposon has landed near to their gene and perhaps affect gene expression. Fruit flies are key model organisms utilized by many researchers, including here at Brandeis, to study human diseases, from infertility to insulin signaling to aging to sleep disorders.  Since these new transposon insertions are not available in the standard genome databases, this tool and website may provide answers to previously puzzling genetic effects not revealed by typical DNA sequencing studies.  It is Reazur’s and the Lau lab’s goal to continue updating the TIDAL-Fly database with more genomes as fly genome re-sequencing becomes easier and easier to perform.

see also: Rahman R, Chirn GW, Kanodia A, Sytnikova YA, Brembs B, Bergman CM, Lau NC. Unique transposon landscapes are pervasive across Drosophila melanogaster genomes. Nucleic Acids Res. 2015.

Summer 2015: “Introduction to Microfluidics Technology”

Students are in the cleanroom during training.

Students in the clean room during training

The annual one-week course offered during the summer of 2015 is “Introduction to Microfluidics Technology” (June 22 – 26). It will be held at Brandeis University and sponsored by the National Science Foundation’s Bioinspired Soft Materials Research Science and Engineering Center (MRSEC) at Brandeis. It is intended for graduate students, post docs, faculty and industrial scientists and engineers interested in utilizing microfluidic technology in their work, in both physical sciences and life sciences, and does not assume any specific prerequisites.

SUMMER COURSE ANNOUNCEMENT 2015

Microfluidic Xmas Tree

“Scientist of small things”

IMAGE: BMXIMAGE (from Forbes India)

IMAGE: BMXIMAGE (from Forbes India)

Forbes India recently named Brandeis post-doc alumna Prerna Sharma as one of India’s “30 under 30”. Sharma, who worked in Prof. Zvonimir Dogic’s group in Physics, is currently an Assistant Professor at the Indian Institute of Science (IISc), Bangalore.

Read the original at Prerna Sharma: The scientist of small things, or perhaps her 2014 Nature paper on Hierarchical organization of chiral rafts in colloidal membranes

 

Fast-spiking interneurons and the critical period

How do children learn to play instruments and speak languages so much easier than adults, and why does brain damage result in worse outcomes in the mature brain vs. the young brain?  These questions are central to the study of how “critical periods” are regulated in the brain.

fs-interneuron

Electron micrograph from a single 70 nm cross-section through a fast-spiking parvalbumin-containing (gold labeling = white dots) presynaptic terminal forming a synapse (red dots) with a pyramidal soma. Original colors are inverted, contours have been raised and membranous structures are highlighted in aqua for ease of visualization. Presynaptic vesicles (colored ovals) within perisomatic fast spiking terminals mostly cluster within ∼200 nm of the synapse, with a few close enough (≤2 nm) to be deemed docked.

Critical periods in brain development define temporal windows when neuronal physiology and anatomy are most sensitive to changes in sensory input or experience (e.g. sound, touch, light, etc.).  The maturation of inhibitory cells that release the neurotransmitter GABA, especially a subset called fast-spiking (FS) interneurons, is thought to gate this period of neuronal ‘plasticity’ in the mammalian primary visual cortex.  However, it has remained unclear what aspects of FS cell development are important for permitting this period of neuronal malleability in the visual cortex. A new paper in Journal of Neuroscience from the Turrigiano lab addresses the question.

To explore how FS cell development might be linked to critical period plasticity, Brandeis postdoc Marc Nahmani and Professor Gina Turrigiano employed a well-established assay for cortical plasticity in visual cortex called monocular deprivation (MD), and measured FS cell connections using confocal and electron microscopy, as well as optogenetic stimulation of the FS cell population (i.e. shining light onto FS cells possessing light-gated channels to make them fire action potentials).

Following up on previous work from the Turrigiano lab (Maffei et al., 2006), they found that MD induces a coordinated increase in FS interneuron to pyramidal cell (the major excitatory output cells of the cortex) pre- and postsynaptic strength.  These changes occur if MD is performed during, but not before the critical period in visual cortex, suggesting they may play a role in gating this period of heightened neuronal plasticity.  Future studies are aimed at determining the timeline for these changes across the extent of the critical period in visual cortex.

see: Nahmani M, Turrigiano GG (2014) Deprivation-Induced Strengthening of Presynaptic and Postsynaptic Inhibitory Transmission in Layer 4 of Visual Cortex during the Critical Period. Journal of Neuroscience 34:2571-2582.

4th Annual Sprout Grants – Call for applications

Bring your research and entrepreneurial ambitions to life!

The Brandeis University Virtual Incubator invites member of the Brandeis Community (undergrads, grad students, postdoctoral fellows, faculty, staff) to submit an application for a “Sprout Grant”. These grants are intended to stimulate entrepreneurship on campus and help researchers launch their ideas and inventions from Brandeis to the marketplace.

This spring we will be awarding $50,000 to be shared amongst the most promising proposals.

Come get your questions about the Sprout grant answered at one of our upcoming information sessions.

Info sessions:

Tuesday      February 18th    1pm – 2pm

Tuesday      February 25th    10am – 11am

Thursday     February 27th    11am – noon

Tuesday      March 4th          11am – noon

All information sessions will be held in the Shapiro science center 1st floor library, room 1-03 (the glass walled room near the elevators).

Deadlines: Preliminary applications are due on Friday, March 7th

Benefits of participation:

  • Teams that are selected to submit full applications will be given assistance in further developing their ideas into an effective business pitch.
  • Sprout grant winners will be connected with an experienced mentor, and given further assistance in getting their ideas to market by the Office of Technology Licensing.
  • Previous winners have come from many departments: Neuroscience, Biology, Biochemistry, Physics and Computer Science. Some of the funded technologies have resulted in patent applications and are moving towards commercial development. Read more about previous winners from your department here: Sprout winners 2011, Sprout winners 2012, Sprout winners 2013.

For more information go to our website (http://www.brandeis.edu/otl/grants/index.html) or contact Melissa Blackman at melblack@brandeis.edu.

Can Self-Referencing Contribute to Memory Errors?

A recent paper in the Journal of Gerontology by Brandeis Ph.D. program alumnus Dr. Nicole Rosa and Professor Angela Gutchess attempts to answer this question. During an interview with ElderBranch, Dr. Nicole Rosa discusses the relationship between self-referencing and false memory. For more information, please read the article on ElderBranch.

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