A source of information about duplication is the immune system in which novel proteins, antibodies, arise very quickly

with but small local changes in a binding region but not in the backbone giving a great variety of proteins [37]. The case of this multiplication is considered to www.selleckchem.com/products/nutlin-3a.html be local modification of DNA, which arises from the more or less direct effect of the antigen. The direct changes include deamination of DNA of the cytosine and 5-methyl cytosine bases making uridine and thymidine [38]. Bert Vallee who knew that the deaminase was a zinc enzyme would have loved the fact that it is so important in gene modification and immune response. We have to consider how an environmental novelty can cause this DNA disruption to occur locally. One possible mechanism is that when a poison binds to a particular protein, the cell is forced to find PI3K activation a replacement so that the cell can function. An increase in protein production requires an increase in its RNA levels which demands in turn longer periods when DNA is single-stranded. Single-stranded DNA is more open to mutation by the above enzymes, such

as the deaminase, and then disruption of DNA copying. A way of connecting the DNA into a double-strand is to duplicate the offending section. This gives rise to local duplications. In the immune system it is known that duplication is relatively easy on the introduction of poisons but only in special cells and not in the germ cells so immunity is not reproducible from generation to generation. The system is only found in some modern animals. However it is known that components of the system such as the thymidine deaminase are inherited and occur in earlier organisms. A good example of the function of the protective system occurs in many species is the response to the drug, poison, methatrexate, which is inherited. There is an interesting observation in bacteria which have plasmids as well as a main DNA. The proteins of drug resistance are found in the plasmids where expansion of its DNA by duplication, must have occurred, Fig. 6. Now the plasmids also accumulate proteins for selleck chemicals llc resistance

to foreign metal ions in their environment. The suggestion is that protection arises generally by duplication giving not only protective proteins but some which are neutral, both of which can be mutated to give novel proteins. If a new poison similar to the earlier one enters the system the neutral proteins are available for protection. It is reasonable to say that protection from certain poisons preceded their use as is clearly the case in the oxidase family of P-450 enzymes. The conclusion is that duplication followed by mutation is the major route of evolution certainly before 0.54 Ga. Is this the way in which organism evolution followed metal ion availability? Bert Vallee was ill for many years before he died. He fought with all his strength against this. I was not in contact with him during this time.