Medically Important Human Proteins Made in E Coli

Human proteins manufactured in E. coli cells include, among others, insulin, erythropoietin, blood-clotting factors, somatotropin, os-teogenic protein, and tPA, or tissue plasminogen activator. Insulin is used to assist individuals who cannot make their own insulin, people suffering from type I diabetes. Erythropoietin is a protein factor that plays a key role in the production of red blood cells. It is used to treat anemia, in particular anemia that may follow cancer chemotherapy. It is also a...

Another Sex Influenced Trait Male Pattern Baldness

A more dramatic example of a sex-influenced trait is male pattern baldness. Because mostly men are affected, one might guess that it is a sex-linked trait. A classic case of male pattern baldness appears in President Adams's family. The second U.S. president, John Adams, and his son John Quincy Adams, the sixth president, as well as the latter's son and grandson, all had male pattern baldness. If this trait was on the X chromosome, as figure 3.2 shows, a father could not pass the trait onto his...

Mutagens

Since mutations occur in the natural process of DNA replication, how shall we define mutagens It would be strange to define the natural replication of DNA as mutagenic. Thus we will define mutagens as factors that increase the rate of mutation over and above that of the spontaneous mutation rate. Two categories of mutagens will be discussed. One is electromagnetic radiation and the other comprises various chemicals. First, let us look at electromagnetic radiation. Electromagnetic radiation...

Natural Selection Determined Skin Color in Humans

Selection can occur on Mendelian, or single-gene, traits, but also on traits determined by many genes, since selection acts on the pheno-type, as we have seen in the case of goats, lions, and four-o'clock plants. An example of a trait determined by many genes is skin color in humans. Natural selection for or against skin pigmentation is well understood and took place tens of thousands of years ago as modern humans left Africa to colonize the rest of the planet. People from tropical areas with...