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.
The rubber made this way is pressed into slabs or sheets and then dried, ready for the next stages of production. By itself, unprocessed rubber is not all that useful. It tends to be brittle when cold and smelly and sticky when it warms up. Further processes are used to turn it into a much more versatile material.The first one is known as mastication (a word we typically use to describe how animals chew food).hoto: Left: Rubber bands are a very familiar everyday use of latex rubber. Right: Guayule: one of many plants from which rubber can be made. Photo by Peggy Greb courtesy of US Department of Agriculture/Agricultural Research Service (USDA/ARS).