Tissue culture growth medium derives a substantial fraction of its growth-stimulating activity from the fetal bovine serum (FBS) commonly used as a supplement. In addition to the source of serum, non-essential additives such as colorized pH indicator dyes may also affect the growth stimulating properties of complete media. We show here that both of these culture medium components can dramatically affect gene expression in vitro. Using a custom gene expression chip for herpes simplex virus 1, we demonstrated significant changes of expression levels in several categories of viral genes including the immediate early viral transcription factors ICP0 (p < 0.05), ICP4 and ICP27 (both p < 0.001). This dependence of virus growth on serum source and other medium components have implications for not only in vitro virus studies, but also viral vector design and vaccine efficacy. This is especially true when examining a large DNA pathogen that potentially contains response elements that are common in the mammalian genome...
Tag: <span>gene expression</span>
Beginning with the production of the very first recombinant deoxyribonucleic acid (DNA) molecule in 1972 and continuing through the following decade, DNA-focused molecular biology researchers firmly positioned themselves on the cutting edge of scientific inquiry. With each passing day, month and year, these researchers made significant leaps forward in understanding, modifying and manipulating the key roles that DNA plays in all living organisms. Some of the key milestones…
The non-viral introduction of genes into mammalian cells (transfection) is of growing interest for tissue engineering and as an alternative to the use of viral transfer of recombinant genes. The introduction of a foreign gene into cells in vivo is often limited to the use of viral vectors such as adeno or retroviruses. Viral vector may present several disadvantages or side effects that can be disastrous, and the selection of cells that are transduced by the virus is very poor. A number of non-viral vectors have been explored and used to date: lipid-based carriers, hydrogel polymers, polycationic lipids, polylysine, polyornithine, histones, and other chromosomal proteins, such as hydrogen polymers and precipitated calcium phosphate. Most of these vectors are usable in vitro but are difficult to apply in vivo, especially when local transfection to a specific cell line must be obtained…