The things that change our DNA

The possible factors that can change the human DNA are being discovered all the time. These changes mostly affect the Germline DNA.

Germline cells are immortal, in the sense that they can reproduce indefinitely. This is largely due to the activity of the enzyme known as telomerase. This enzyme extends the telomeres of the chromosome, preventing chromosome fusions and other negative effects of shortened telomeres. Somatic cells, by comparison, can only divide around 30-50 times due to the Hayflick limit.

That little tid-bit I found rather interesting for several other reasons...

Changes in the DNA due to Diabetes

That article is an example of a change occuring through 'natural causes', however, by using retro-viral vectors that infect a wide range of cells in a wide range of tissue types, changes are theoretically possible as well. Problem is, most such vectors target fairly specific cell types.

Retrovirus vectors are the agent most commonly used to insert, or change, genes in multi-cellular organisms. They are the agent used for the retroviral based flu vaccine. Also, there have been some other gene therapies developed on retroviral vectors. The problem with them, as disease treatment agents, is that they are finite; that is, the immune system eventually clears them, and any cells with altered DNA are eventually lost due to normal tissue turn over. So, the "cure" is not permanent.

And, of course, mutagens can impact and alter DNA on a cell by cell basis. And, several environmental toxicants are now known to exert an "epigenetic" effect on DNA. Exposure to these after birth leads, especially during early development, to a change in DNA structure in many or all cells. The change is not a mutation. Rather, it is a change in DNA methylation or histone phosphorylation, that alters gene expression. This epigenetic mechanism is now recognized as one of the primary ways that environmental substances may cause disease later in life.

The field of molecular biology and genetic engineering began in the 1970's with the discovery of restriction enzymes. The structure of DNA was understood. From the 1970's, our ability to manipulate DNA has exploded as we have developed an ever increasing repertoire of tools with which to manipulate DNA, and as we have elucidated the sequence of the human genome.

Seldom a week goes by without the discovery of a gene for yet another disease. Genetic explanations are touted for everything from cancer and heart disease to more diffuse conditions like alcoholism, homosexuality, and crime. It's been suggested that there may even be a gene for shyness! Biologists believe that new gene technology will revolutionize our understanding of disease and will have a greater impact on us than nuclear power or the computer.

What will make an even greater impact, however is the discovery of being able to alter these markers and genes which create traits such as shyness. What will we be when we can alter our base personality? What happens when the effect wears off?

Alterations in the ID of a DNA Fingerprint

Of course the panacea of DNA Fingerprinting for criminals, is to be able to alter the existing DNA finger print, either for the duration of the crime, or for the investigation afterward.

Just the idea of mucking about with your core DNA areas, sounds like an invitation for primate mutation (and an ape appetite for vegetation), the thought of actually doing it is, well ... fairly creepy. But then, some criminals are fairly creepy...

A study titled: Changes in DNA induced by toxic agents
(Forensic Sci Int. 1996 Apr 23;78(3):169-78, Sawaguchi T, Wang X, Sawaguchi A. Department of Legal Medicine, Tokyo Women's Medical College, Japan.)

Seems to suggest that it is possible, although from this publication, most of the methods would be fatal.

This is a preliminary report on significant alterations in the DNA profile caused by toxic substances which potentially has profound implications for the use of DNA techniques in identification. Acute DNA changes in the globus pallidus of the brain in man caused by carbon monoxide poisoning were detected by DNA profiling with probe 33.15. Chronic DNA changes in rabbits caused by methamphetamine were detected by DNA profiling with probe 33.15, AmpFLP on D1S80, TH01, CSF1PO and TPOX loci. Pre-intoxication bands appeared, disappeared or were discoloured after intoxication. With PCR-dot blot hybridization testing for HLADQ alpha, pre-intoxication positive spots became negative after intoxication and pre-intoxication negative spots became positive after intoxication. Intravenous injection of 10 mg/kg of methamphetamine every 2 days for 2 weeks was a large enough dose for inducement of genetic changes. In this investigation, clear changes in DNA due to intoxication were confirmed.

The results of the study, do suggest the possibility of a market for criminal re-sequencing for the purpose of acquittal. The repercussions of such an action, I can't imagine, are going to be better than going to prison, since all we are able to confirm through this study is that the DNA changes. There is no mention of a Predictable change... just A Change... so place your bets... monkey time!

Bicycle Protesters hit San Diego

Just after 8:00pm a group of bicycle protesters emerged downtown, numbering well over 500. I wasn't able to count them as they went by, but considering my first estimate was 1000(based on the amount of times the traffic lights cycled as they road through the intersection of 4th and Broadway), I'm betting "over 500" is at the very least, accurate.

Three groups of bicycle cops were in the garden area of Horton Plaza (is the front of Horton Plaza an eye-sore these days or what?) when the protesters emerged. The bike-cops where ineffectual, as were the squad cars which were attempting to stem the tide as the cycles poured on through.

After the first group, a second group emerged which continued on down 4th street, turning left on Fst and into the Gas-lamp main area, disrupting traffic, to the cheers of hundreds as they passed by.

Most of the drivers who were paused in their travel to find parking and start their Friday night revelry cheered the bicyclists on, I noticed a few drivers who boiled into a state of road rage, but not many.

Most of the cyclists were in the college student age bracket, but there were more than a few 30 and 40-somethings out there in that pack, shouting "Go, go go!" when the police hit the sirens, attempting to disperse the pack -- It is good to have silver-backs around at times like those, to keep the youngsters from panicking themselves into a ticket.

In a city where the greater portion of people bitch and do nothing, it was great to see that many people out doing "something" because they felt change was required.

And for you City Council Members, recall that these were all voters, the riders and those cheering them on.

A Introduction look at DNA Finger Printing

I've posted a few "overview" looks at DNA Finger Printing so far on this blog, this time the link is to an article on JSTOR, An Introduction to DNA Finger Printing

Personally, getting the same information from different authors helps my writing on the subject. While the information is basically the same, the choice of words, vocabulary and the focus of importance is often different between two different authors, which not only provides me with a larger vocabulary, but often a new set of search criteria for further information.

This is one of the methods I developed working as a Google Researcher, to speed up the absorption of a new topic, and develop answers, and a technique that is invaluable as a freelance writer.

Passing the Buck - Homeless in San Diego

The Museum of San Diego History, for its NOW! program starting Feb 25th is showing the Passing the Buck: Homeless in San Diego exhibit.

"Although there is great concern for assisting the homeless, where to house them in San Diego is a political hot button."

Time for the show is 6:00pm - 7:30pm Admission is Free, and promises to be an informative look at what is really being done for the homeless in San Diego.

The Chimera

In Greek mythology, "chimera," derived from the Greek word for "billy goat," referred to a fire-breathing she-demon that was part lion, part goat, and part dragon or snake. Getting rid of this killer was quite an achievement, and Bellerophon was heaped with praise and riches for his courageous and clever dispatch of the beast. The term "chimera" has come down to us through the ages with 3 definitions: the original monster, an impossible and fanciful creation of the imagination (eg, Woody Allen's malefactor with the body of a crab and the head of social worker), and an organism containing tissues from at least 2 genetically distinct parents. It is this last definition that is of compelling medical interest, based largely on the work of Ray Owen.

The Chimera and the Crime

There is a fantastic paper on the subject of the Chimera as directly related to Crime Scene investigation.

CHIMERAS: DOUBLE THE DNA-DOUBLE THE FUN FOR
CRIME SCENE INVESTIGATORS, PROSECUTORS, AND
DEFENSE ATTORNEYS?
(This Link is to a PDF File)

One thing she doesn't address, which does come up in the Winter's Harvest novel, is the idea of triplets or ... more... in the make up of the Chimera.

Despite this, Catherine Arcabascio has written one of the best papers I've read on the subject so far, and just about all of the information presented is current science.