Stem Cells

As noted earlier in the week, our featured article focus in August’s Cold Spring Harbor Protocols is on gene transfer into stem cells. The first featured protocol presented a method for using lentiviral vectors as the means for getting your gene of interest expressed. Alhough viral vectors are highly efficient, their use can raise concerns about recombination, immune responses and other safety issues. In contrast, DNA transposons offer an effective, alternative method for nonviral gene transfer that avoids the safety concerns associated with viral vectors. Use of the Sleeping Beauty Transposon System for Stable Gene Expression in Mouse Embryonic Stem Cells from Catherine Krull and colleagues at the University of Michigan provides a method for stable integration and reliable long-term expression of a transgene. Sleeping Beauty transposon-based transfection is a two-component system consisting of a transposase and a transposon containing inverted repeat/direct repeat sequences that result in precise integration into a TA dinucleotide. Like all of our featured articles, this protocol is freely accessible to subscribers and non-subscribers alike.

Our featured articles in the August issue of Cold Spring Harbor Protocols focus on methods for gene transfer in stem cells. Vectors derived from retroviruses are useful tools for long term gene transfer, because they allow stable integration of transgenes and propagation into daughter cells. Lentiviral vectors are preferred because they can transduce non-proliferating cellular targets. These vectors can be engineered to target specific tissues, and an overview of approaches to modify lentivirus vectors for use in gene transfer can be found in Engineering the Surface Glycoproteins of Lentiviral Vectors for Targeted Gene Transfer. Along with this overview, François-Loïc Cosset and colleagues from Ecole Normale Superieure de Lyon present a method for targeting hematopoietic stem cells using engineered viral vectors. The article, Hematopoietic Stem Cell Targeting with Surface-Engineered Lentiviral Vectors is one of our featured articles for August, and like all our featured articles, is freely available to subscribers and non-subscribers alike.

Cold Spring Harbor Laboratory’s courses have long been tremendous community resources, training generation after generation of scientists in the latest cutting-edge techniques. The highly competitive nature of the courses means that not everyone who wants to attend can do so, and one of our missions at CSH Protocols is to help disseminate course material to the scientific community at large. The course instructors have been generously providing CSH Protocols with articles based on their lectures and laboratories, some of which you can see collected here.

November’s issue of CSH Protocols features several methods from the renowned Molecular Embryology of the Mouse course. This long-running course (25-plus years) has long been the absolute standard for training mouse biologists and has resulted in three editions of the well-known manual, Manipulating the Mouse Embryo. What’s interesting about the course as of late, is that the focus has shifted away from just the generation of transgenic and knock-out animals, and more towards the analysis of phenotypes in those animals. November’s featured articles present methods for analyzing specific tissues in the mouse.
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The September issue of CSH Protocols is now available online, and this month brings a set of nine protocols from Renee Reijo Pera’s laboratory at Stanford describing methods for the generation, maintenance and analysis of human embryonic stem cells (hESC). With the upcoming presidential elections, and both candidates favoring expanding federal funding for stem cell research (and one vice presidential candidate agrees, the other, not so much), the near future should see increased usage of these valuable research techniques. Two of these hESC protocols are featured in this month’s issue (our featured protocols each month are available to subscribers and non-subscribers alike).

Noninvasive Human Nuclear Transfer with Embryonic Stem Cells describes the transfer of a nucleus from a somatic cell to an enucleated oocyte for reprogramming to an embryonic cell state. Older methods commonly use Hoechst and UV light, which can lead to DNA damage. Here, a polarized microscopic imaging system is used to visualize the meiotic spindle without DNA staining and UV illumination.

Culturing Human Embryonic Stem Cells in Feeder-Free Conditions describes the culture of hESCs in feeder-free conditions on Matrigel with MEF-conditioned medium. This protocol can be used for applications such as genetic modification of hESCs without feeder cell contamination.

This year’s CSHL Annual Symposium is nearly upon us. The subject for 2008 is Control & Regulation of Stem Cells and the meeting begins on Wednesday, May 28. Sadly I’ll be out of town speaking at the Society for Scholarly Publishing meeting in Boston. If, like me, you can’t attend, be sure to visit the website put together for the Symposium by CSHL’s Meetings & Courses office, which will feature video interviews of the key players in the field of Stem Cells. Also, the volume of collected papers from last year’s Symposium, on Clocks and Rhythms is now available (also online for subscribing institutions).

Scientists and Engineers for America (SEA) is a nonprofit, nonpartisan, educational organization dedicated to, “educating the public about science policy issues, educating members of the scientific community about the political process and ways in which they can effectively participate in elections, influencing elected officials, and ultimately holding politicians accountable through the dissemination of accurate and timely information about the positions they take on science issues.” They’ve just launched a great new tool for tracking your representatives’ record on scientific issues, called the Science, Health And Related Policies (SHARP) Network. SHARP is a wiki based resource, allowing you to edit and update any information on a given politician. It covers important issues such as stem cell funding, global warming, energy policies and funding for education among others.

This is a tremendously useful website. I’ve read a few articles that attempt to detail the current presidential candidates’ science positions but have found them incomplete and often contradictory. Here we’ve got one resource that puts it all together in an easily read, easily searched manner. If you’re a working scientist, or just have an interest in science policy, I urge you to check it out and participate. With the deplorable state of science funding in this country, we need to hold our leaders responsible for investing in our future, not to mention making sound decisions based on real science, rather than pandering to public opinion or the whims of corporate donors.