Scientists find two forms of genetic material chromatin

Biologists have discovered what appear to be fundamental differences in the physical properties of the genetic material known as chromatin. Chromatin packages DNA into cells, and the scientists found the differences between chromatin that packages genes and the chromatin that packages DNA with regulatory or unknown functions. The variation represents a previously unrecognized level of genomic organization and complexity, the scientists report, one that may exist in all cells with nuclei.

Researchers silence genes with new approach

Researchers have developed a way to exploit RNA interference for the first time to silence genes in a wide variety of mammalian cells, including embryonic cells. The study will appear in the Feb. 17 edition of Nature Genetics. This new approach allows genes to be switched off by inserting short pieces of ribonucleic acid (RNA) into developing cells. It is currently being used to help researchers uncover the function of the more than 30,000 genes found in humans, as well as in animal models of important diseases.

Tailor-made proteins manufactured in novel E. coli system

The prospect of using bacteria to manufacture complex human proteins for use in therapeutic drugs is a step closer thanks to new research published today in Science. Researchers from Switzerland and the UK report they have engineered the bacterium Escherichia coli to carry a vital piece of cell machinery that adds sugar molecules to newly synthesized proteins by a process known as glycosylation. The finding opens up the possibility of producing complex human proteins such as Factor VIII and the hormone erythropoietin, which stimulates the production of red blood cells by stem cells in bone marrow. Both these proteins, which require the addition of sugar molecules to function properly, are currently produced by culturing mammalian cells, which can be a costly and technically difficult process.