St Petersburg University biologists discuss prospects in genetics
The Russian Society ‘Znanie’ is a public non-commercial organisation that is aimed to ensure that research and education benefit wider publics.
Rostov-on-Don has held the educational and research forum ‘Transfer of Knowledge. Technologies of the Future’ as part of the project by the Russian Society ‘Znanie’.
St Petersburg University biologists took part in the lecture course in Genetics and Quality of Life. Oleg Tikhodeev, Candidate of Biology and Associate Professor at St Petersburg University, delivered a report ‘Molecular mechanisms and applied aspects of inheritance of acquired characters’.
'All basic genetic concepts were developed in the middle of the last century, when it was assumed that DNA acted as the carrier of the genetic information, while acquired characters (modification in structure or function acquired by an organism during its life, caused by environmental factors) could not be inherited. Today, we have accumulated extensive evidence based on scientific data that goes beyond these concepts. In particular, the inheritance of acquired characters has been described in detail in a wide range of living organisms, including animals, fungi, plants, and bacteria. In some cases, we have evidence of its molecular mechanisms. Most of them are epigenetic, i.e. inheritance that does not involve alterations in the DNA sequence. However, they result from environmental factors or the molecules it encodes: RNA or proteins. Thus, we should approach basic genetic concepts from different perspectives. Today, the most neglected area in genetics is theory,' said Oleg Tikhodeev.
The inheritance of acquired characters was first introduced by Jean-Baptiste Lamarck in the early 19th century, but the theory of acquired traits was not supported by science, said Oleg Tikhodeev. Today, we have to admit that neglecting this theory was a mistake, he assumed. In this regard, the Lamarck’s Second Law ‘All that nature has caused individuals to gain or lose by the influence of the circumstances to which their race has been exposed for a long time, is conserved through generation in the new individuals’ should be reformulated as following: ‘Some of the alterations caused by the influence of a predominant use or constant disuse can persist in several generations’.
The modern theory of evolution should incorporate Lamarck’s and Darwin’s theories.
Oleg Tikhodeev, Candidate of Biology and Associate Professor at St Petersburg University
The second report was delivered by Anton Nizhnikov, Associate Professor at St Petersburg University, Doctor of Biology and Head of the Laboratory of Proteomics of Supra-Organismal Systems at the Federal State Budgetary Scientific Institution ‘All-Russia Research Institute for Agricultural Microbiology’. His report ‘Amyloids, prions and quality of life’ focused on research of aggregating proteins and their relationship with the quality of life of human beings.
'Amyloids are aggregates of proteins characterised by a fibrillar morphology of a special spatial structure that makes them one of the most stable biogenic particles. For over 150 years, amyloidosis, i.e. diseases associated with the formation of pathological amyloid aggregates in various tissues and organs of humans and animals, has been arousing curiosity and interest of scientists. Today, there are over 40 proteins, the pathological aggregation of which causes amyloidosis,' said Anton Nizhnikov.
Amyloidosis is an incurable condition that is difficult to treat. Today, we are developing approaches based on chemotherapy or transplantation of the affected organs, which can significantly extend the duration and quality of life of patients. Nevertheless, these approaches do not solve the key problem of effective 'disassembly’ of pathological amyloid inclusions.
Anton Nizhnikov, Doctor of Biology, Associate Professor at St Petersburg University
According to Anton Nizhnikov, neurodegenerative amyloidosis is a special group. They are associated with prion diseases caused by the infectious amyloid protein PrPSc. Unlike in humans and a number of other mammals, in which the PrPSc prion causes incurable diseases, in other organisms, for example, yeast, prions can be functional and even mediate a special type of transmission of hereditary information called protein inheritance. Non-infectious amyloids can also be involved in a variety of vital functions. Similar functional amyloids have been found in bacteria, archaea, fungi, and animals.
'In our recent works, we have shown that functional amyloids can be found in plants. We asserted that functional amyloids form storage proteins in seeds that are a key source of amino acids for the plant embryo and an essential component of the human diet. Plant seeds are associated with long-term natural dehydration and unfavourable conditions. Preserving the structure and properties of storage proteins is a critical factor for the survival of the embryo. The number of amyloid aggregates in plant seeds increases as they mature, which can account for stabilising the supply of nutrients, and rapidly decreases during seed germination,' said Anton Nizhnikov.
This effect is especially interesting as it shows that in plant cells, unlike the human organism, there are molecular machines that are able to quickly and efficiently disassemble large accumulations of amyloid aggregates, said Anton Nizhnikov.
‘In general, we can conclude that protein amyloidogenesis is a mechanism that determines the performance of key biological functions in a wide variety of organisms, from bacteria to humans. However, abnormal aggregation of proteins can lead to the formation of pathological amyloids and the development of a number of incurable diseases. How to cure these diseases is not known yet,' concluded Anton Nizhnikov.
The work of Anton Nizhnikov and his colleagues was supported by a grant from the Russian Science Foundation' (project No 17-16-01100).