3rd Week of Research

Good Afternoon Readers,

In my third week of research in the Shakes’ lab, I worked with a fellow student researcher in the Kerscher lab to utilize their UTAG protocol on my nematode gonads. The kmUTAG protocol is developed from one of the SUMO proteases, Ulp-1; further, kmUTAG is a useful tool of evaluation because it has less affinity to bind to free, unconjugated SUMO. A quick note about the SUMOylation pathway, three enzymes are required for a protein to be SUMOylated. The three enzymes are known as the activating enzyme – E1, the conjugating enzyme – E2, and the ligase E3 – in nematodes, the enzymes frequently studied for their localization throughout nematode gonads, especially during the meiotic divisions are the conjugating enzyme (E2) UBC-9 and the ligase (E3) GEI-17. I have included a pathway depiction developed by Dr. Shakes at the bottom of this post.

A stage in spermatogenesis of C. elegans known as karyosome – where the DNA is very compacted and undergoes a global down-regulation of transcription before entering pro-metaphase – has always fluoresced intensely with the anti-SUMO antibody we have utilized in previous preps; however, in the slides from the UTAG prep Rui Yin and I conducted, karyosome did not fluoresce at all in multiple worms. I have included the image of those cells at the bottom of this post. The karyosome not fluorescing with the UTAG is interesting because this indicates the SUMO that is localizing to the chromatin is an unconjugated form of SUMO. We will do further studies to ensure this is a supported characterization of SUMO during spermatogenesis with the kmUTAG protocol.

Thank you for taking the time to read about my summer research!

Katie McDonald


SUMOylation Pathway                   Karyosome in C. elegans

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