In a typical expression vector, the polyhedrin (polh) gene, which codes for the major protein in the occluded form of the virus, is replaced by a transgene of interest. The transgene can then be expressed under the control of the polh promoter to achieve maximal protein expression in their natural hosts, insect cells.
Commercial rubber is a product that is important to the convenience of our everyday lives. We find it in our tires, our shoes, our flooring, adhesives, and in a plethora of small items that are all made from rubberâwhile the products themselves may be small in size, their significance is usually much larger. In any case, rubber is made from two main sources: naturally-produced latex and petroleum.
There are two main categories of man-made fibers: those that are made from natural products (cellulosic fibers) and those that are synthesized solely from chemical compounds (noncellulosic polymer fibers). Rayon is a natural-based material that is made from the cellulose of wood pulp or cotton. This natural base gives it many of the characteristicsâlow cost, diversity, and comfortâthat have led to its popularity and success.