The image above is not a paid advertisement. It represents my (Joel Huberman's) hope that, if you the reader are a US citizen, you'll click on the image to discover ways in which you can help bring national health insurance to the United States. In addition, please write to your congressional representative and ask her/him to support HR676 ("Medicare for All").
|The images on the left (click on them) are also not paid advertisements. Instead, they are an attempt on my (Joel Huberman's) part to call your attention to some of the efforts being made to make the results of research freely available on the World Wide Web. I have had excellent experience with BioMed Central, whose outstanding editorial staff offers superb peer review, rapid publication, nearly immediate post-publication listing in MedLine and post-publication archiving in PubMed Central, unrestricted free access to the published article at both the BMC Central and PubMed Central web sites, and copyright retention by the authors of the article. BioMed Central now offers publication in a "prestige" journal, the Journal of Biology, that intends to be as selective in its content as Science, Nature or Cell. I do not yet have personal publishing experience with the Public Library of Science, but they offer similar advantages to those who publish in their new prestige journals, PLOS Biology and PLOS Medicine. I strongly recommend that you try publishing your research with one or the other of these organizations.|
Creating pretty 2D gel pictures is just one of the many things we do in our laboratory. Most of our activities don't produce such pleasing graphics as those at the top of this page but are equally or more informative scientifically. This particular experiment is one of several published in Brun et al., 1995, which demonstrate that replication intermediates (RIs) from budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) have similar structures, and that their structures also resemble those of mammalian RIs. We conclude they have similar structures because they comigrate during neutral-neutral two-dimensional (2D) agarose gel electrophoresis, as shown here. Restriction fragments from the two yeasts were mixed and subjected to 2D gel electrophoresis in a single gel, which was subsequently blotted to a membrane and then sequentially hybridized with probes specific for an S. cerevisiae origin-containing restriction fragment of 4.3 kb (left; red) and an S. pombe origin-containing restriction fragment of approximately the same size (right; green). Image superposition (middle frame) demonstrates that, despite the differences in strengths of Y and bubble arcs, the RIs responsible for generating these arc signals migrate along nearly identical paths. The slight differences in migration paths are probably a consequence of the slight differences in size of the two restriction fragments. Thus the structures of these RIs must be very similar if not identical. The similarities in structure argue that S. pombe and S. cerevisiae initiate DNA replication by similar mechanisms.
By the way, "Y arcs" are the paths followed during 2D gel electrophoresis by the Y-like RIs generated by restriction fragments that are passively replicated, while "bubble arcs" are the paths followed by RIs that contain internal bubble-like structures due to initiation of replication within the fragment. Mixed Y and bubble arcs, as shown here, are a consequence of inefficient origin usage: within some cells in the population, the origin fires, but in other cells, it does not.
This page was slightly updated on March 9, 2009. However, the page and site need major updating. I'm postponing such updating until I have more free time. You'd think I would already have more free time, now that I'm officially retired.
To contact Joel Huberman by E-mail:
Additional links of possible interest:
Roswell Park Cancer Institute Home Page