Sunday, July 20, 2014

Bacterial CRISPRs: Not Just For Targeting Foreign Nucleic Acids

The CRISPR-Cas system has been found to play roles
in the antibiotic resistance of some bacteria. <Source>
In recent years, CRISPRs (Clustered, regularly interspaced, short palindromic repeats) have been gaining popularity in the microbiology field.  Briefly, CRISPRs serve as an adaptive immune system for bacteria, meaning that they are able to remember what viruses (bacteriophages) or other entities have infected them and mount a targeted defensive response the next time they are infected with the same entity (think of it as an analog to our adaptive immune response which uses antibodies and other agents to target invading microbes).  More specifically, the CRISPR-Cas (Cas are the CRISPR associated genes) system facilitates the integration of a small section of the foreign genomic DNA into the CRISPR array within the bacterial genome (see left side of the detailed diagram below).  While in the array, this section of foreign DNA will serve as a template for recognizing the invading genome again if another infection occurs, and the template will be used for targeting that invading genome for rapid destruction.  As can be seen in the figure below, this system is similar to the Eukaryotic RNA-interference system found in organisms including humans.  I've already gotten pretty technical here, and anything more in-depth would be beyond the scope of this post, so please check out reference [1] for further reading.

Sunday, July 13, 2014

Gene Therapy for Hemophilia, Blindness, and Cancer, and the Tools That Make it Possible at the HMGS 2014 Symposium

Every blogger has those times when life gets busy and their blog takes a back seat.  For me, this summer has been one of those times.  Between meetings, research, our family trip back home, and the general effort involved in being a scientist, I have been behind in updating this blog.  Despite my blog slacking, I'm sure it will be worth it when I have more cool stuff to write about in the next couple of months (especially when I have cool new research findings to talk about!).  So let's get started with some awesome catchup!

Dr. Maus presenting her research to the students attending
the symposium.
A month ago, we here at Penn hosted the annual Howard Hughes Medical Institute (HHMI) Med Into Grad Scholars (HMGS) symposium for the participating northeast schools.  This program was made to promote translational research in PhD training by integrating more medically relevant training into the PhD candidate curriculum (including coursework and clinical clerkships).  For more information about the program, and to read about the symposium last year, check out my post here.