Toward the ‘new century’ of handedness in biology: In commemoration of the 100th anniversary of the birth of Francis Crick.

June 8th of this year marks the 100th birthday of one of the 20th century’s most influential scientists, Francis Crick (1916–2004). Together with James Watson, he discovered the double-helix structure of DNA (Watson and Crick 1953) and led the way for cracking the genetic code, laying the foundation formolecular biology. For the last 28 years of his life, he focused on human consciousness. Life and consciousness were the main themes of Francis Crick’s impressive body of work. The energy and brilliance he exuded throughout his life has been likened to the ‘incandescence of an intellectual nuclear reactor’ (Sacks 2005). The groundbreaking discovery of the ‘right-handed’ double-helix structure of DNA byWatson and Crick might also have been the dawn of the age of ‘Molecular Handedness’. The DNA of every organism on Earth forms a right-handed double helix, but the reason for this preference remains a mystery to date. Life is composed asymmetrically. Natural proteins comprise left-handed amino acids, whereas nucleic acids possess right-handed sugars. The ribosome has been shown to be a ribozyme and, therefore, the evolutionary transition from the putative ‘RNA world’ to ‘RNA/protein world’ would be a key step in the establishment of life. tRNA aminoacylation exists as a bridge between both worlds and chiral-selective nonenzymatic aminoacylation has been shown to occur depending on RNA chirality (Tamura and Schimmel 2004). Crick’s final paper with Christof Koch proposed that the claustrum may be involved in consciousness (Crick and Koch 2005). (The first draft of this manuscript was completed by Crick on July 19th, 2004, and he was still refining it in the hospital on the day he died, July 28th. It is said that he ended the first handwritten draft with the urgent words, ‘What could be more important? So why wait?’ (Ridley 2006)) The claustrum is a thin sheet of grey matter on each side of the head, located concealed between the inner surfaces of the neocortex. The functions of the brain are also asymmetrical. As generally accepted, leftbrain thinking is verbal and analytical, whereas right-brain thinking is non-verbal, intuitive, and visual. Although the claustrum is present on both sides of the brain, is the origin of the human consciousness based on ‘Brain-Handedness’? Crick maintained that the only unsolved problem is the one on consciousness and free will, which might be related to brain-handedness (Crick 1994). He tried to break the shell of scientists and paved the way for thorough investigations on consciousness. In the future, the detailed local circuit diagram of the claustrum would be elucidated, which might contribute to understanding its actual function in terms of ‘Molecular Handedness’. Francis Crick remained indomitable until his last moment. He had no interest in being famous and wealthy. His passion for science will continue to inspire scientists now and forever. Crick offers that, ‘Nature isn’t conspiring against us to make important problems difficult, so given a finite life span, aim high – go after fundamental problems.’ Let us celebrate the 100th anniversary of his birth. The ‘new century’ has the potential for profound discoveries in ‘Handedness’.

On the centenary of the birth of Francis H. C. Crick – from physics to genetics and neuroscience / O centenário de nascimento de Francis H.C. Crick – da física para a genética e a neurociência

ABSTRACT The year 2016 marks the centenary of the birth of Francis Crick (1916–2004), who made outstanding contributions to genetics and neuroscience. In 1953, in a collaborative study, Francis Crick and James Watson discovered the DNA double helix, and in 1962 they and Maurice Wilkins were awarded the Noble Prize in Physiology or Medicine. Crick subsequently became very interested in neuroscience, particularly consciousness and its relationship to the claustrum, a small gray matter structure between the insula and putamen.

RESUMO O ano de 2016 é o centenário de nascimento de Francis Crick (1916–2004), físico, biólogo e neurocientista, cujas contribuições para a genética e a neurociência foram magníficas. Crick, em um estudo colaborativo com Watson, descobriu a estrutura molecular do DNA (dupla hélice) em 1953, e em 1962 ambos receberam o prêmio Nobel de Fisiologia ou Medicina, junto com Wilkins. Após Crick tornou-se muito interessado na área de neurociência, particularmente no estudo da consciência, e a sua relação com o claustrum, uma pequena estrutura de substância cinzenta localizada entre a ínsula e o putame.

Mutagenic role of Watson–Crick protons in alkylated DNA bases: A theoretical study.

Loss of Watson–Crick protons following DNA base alkylation has been proposed as a key event which confers mutation-inducing properties on to alkylated DNA bases. In this theoretical study, the promutagenic O6-guanine and O4-thymine sites are clearly distinguished from the nonmutagenic N7-guanine site on the basis of calculated values of mechanistic indicators for Watson–Crick proton acidity following alkylation at these respective sites. The degree of acidity predicted for these protons for each type of alkylated base accords well with the presence or absence of mutagenicity observed experimentally in each case.