Tag Archives: RNA

Dr. C’s Journal: ‘Mutation’

Mutation is engrained in the very nature of life. Even if there were no X-rays, free radicals or toxic chemicals, mutation still would take place because of errors in the replication of DNA that occasionally escapes the proofreading mechanisms of meiosis and mitosis.

The majority of germline mutations produce LOSS OF FUNCTION, and are weeded out by evolution. In vertebrates, mutation is vital in producing the random changes in the DNA of germ cells of the ovaries and testes. If the mutation is beneficial, involving a GAIN OF FUNCTION, environmental selection acts to preserve the change, producing the diversity of organisms in the world, each exploiting a different environmental niche.

It is the rare species so versatile, like the shark, that can remain almost the same over eons without dying out. In the teeming unicellular world, mutation in the genome is similarly useful in allowing for variations which often prove useful for survival. The mutations thrive if the proper environment presents itself. For instance, antibiotic resistance may be encoded in a few members of a bacterial species, which become the dominant members in an infected patient on antibiotic treatment, and crowd out family members without the mutation.

In Viruses, RNA is often the Memory nucleotide. RNA is less stable than DNA. The resulting instability allows more mutations, and sometimes greater success. An example is the English Covid variant in the spike protein which leads to greater contagion. Hopefully, the spike protein change will not be so successful as to interfere with the effectiveness of vaccine-produced protective antibodies.

The Mutations we have been discussing refer to GERMLINE mutations, which occur in the gonads. In higher animals, germline mutations affect the offspring, which then carry the mutation. A GAIN OF FUNCTION mutation may confer greater adaptability and survivability, and perhaps may lead even to a different species, if the troop number is small and the environment demanding. Non-germ SOMATIC cell mutation may lead to undesirable effects like cancer, which is another discussion.

–Dr. C

‘INFECTIONS’: HOW WE EXPERIENCE INTERACTIONS WITH MICROORGANISMS

The RNA molecule is central to life. It is the information molecule of the Pandemic SARS CoV 2 virus, whose Messenger RNA specifying Spike proteins is the basis of 2 recently-released vaccines.

“RNA Life” is the leading theory for the Origin of Life itself, more than 3 Billion years ago. DNA evolved as the blueprint information molecule in cellular life, but the ubiquitous RNA may well have become the first viruses.

The stage was set for the ongoing battle of life: Parasite vs. Host, Pathogen vs. Target, but recent research reveals a much more nuanced picture. Viruses and bacteria can be BENEFICIAL as well as deleterious. We now speak of the MICROBIOME, usually referring to our host of resident BACTERIA, and the VIROME referring to all of our indwelling VIRUSES.

INFECTION is how we experience our interaction with microorganisms, their benefits unseen. Bacteria, viruses and parasites have always been with us, increasing in impact as Paleolithic man crowded into agricultural settlements.

Enlarging cities became more dense, favoring spread of infection and PLAGUES. The Bacterium, Yersinia Pestis,emerged in Roman times,
causing the Justinian plague, and resurfaced in the 14th C. as the Black Death. Viral Plagues, including Smallpox, were devastating during European adventures into the New World.

Malaria, a one-cell Eukaryotic Parasite, may be the greatest killer of all time. Modern Sanitation and improving medication have lately pushed bacterial infections into the background.

Viral infections such as Influenza and most recently Covid have become the Modern face of infection. Many Viruses reduce Immunity, however, paving the way for bacteria to invade: Haemophilus influenzae, a bacterium, may have caused much of the mortality of the 1817-1918
Flu epidemic.

IV drug usage has facilitated the spreading of the viruses causing Hepatitis and AIDS. The immune-compromising nature of the latter has reinvigorated TB and Syphilis, both bacterial infections. Only a few years ago, bacterial infection was thought to be conquered by antibiotics, and viral infection contained by Vaccines.

Microorganisms are constantly evolving, however, and often share their resistance factors. Infection is no more a thing of the past than War. The Battle continues.

–Dr. C.