Принцип поливариантности матричных процессов

A feature which is common for all template processes in the cell is their ambiguity. We formulate some general "ambiguity principle" (princip polivariantnosti - in Russian): Ambiguity of every template process is result of and prerequisite for existence of living systems. Elementary expression of ambiguity is in accordence with elementary units of the corresponding process: in replication and transcription it is reading of single nucleotides, meanwhile in translation - both in reading of single nucleotides and trinucleotide codones. Besides that in all instances one may look for ambiguity in reading of single nucleotides, meanwhile in translation - both in reading of single nucleotides and trinucleotides codones. Besides that one may look'for ambiguity in reading of sygnals which separate replicons, scriptons and genes. Replication ambiguity is a source of spontaeneos mutations and of material for natural selection and evolutionary process. Some general considerations and the facts concerning the possibility of reading through the termination signals in bacteriophages permit one conclude that transcription is also ambiguios. Translational ambiguity expresses itself with frequency which is determined genetically and depends on environment. The elevation of ambiguity level in translation (and possibly in transcription) should couse variation of polipeptydes being synthesized under the control of all genes of the cell. This may serve for widening of norm of reaction of cell and consequently help latter to take chances for nonspecific adaptation in extraordinary environment. Accumulation of mutations in genes controling template processes may serve as a source of ambiguity. Sometimes being neutral in optimal environment these mutations may express themselves in amplification of ambiguity in extraordinary environment. It is possible to study the genetic determination of ambiguity level in nonsense translation in different conditions. In this connection experiments of S.Phillips and others with E.coli and our experiments with yeast are being discussed. It is possible to assume that all template processes and all correspooding multyenzyme complexes originated from the same common predecessor and so they are philogenetically relative. From this point one may suggest that some common proteins or peptides take part in different template processes. The structure of replicase of Qᵦ bacteriophage serves as an argument for such possibility. If some proteins are involved in different template processes than change in precision of one template process may lead to change in precision of another.Предпринята попытка рассмотреть с единых позиций три матричных процесса: репликацию, транскрипцию, трансляцию. Сформулирован принцип поливариантности, согласно которому неоднозначность матричных процессов имеет адаптивное значение. Высказано предположение о филогенетическом родстве всех матричных процессов в клетке. Рассмотрена возможность существования белков или пептидов, принимающих участие одновременно в нескольких матричных процессах. Приведены примеры, подтверждающие такую точку зрения. Отмечено, что существование "универсальных" компонентов матричных процессов позволяет рассматривать единые факторы наследственной и ненаследственной изменчивости

Генетическая школа Санкт-Петербургского государственного университета

В статье отражены основные моменты формирования традиции университетской генетической школы, перечислены основные этапы истории первой кафедры генетики в России

Предыстория молекулярной генетики в С.-Петербургском (ленинградском) университете

The article contains a detailed description of molecular genetics formation stages in St. Petersburg University, gives the analysis of problems, research methods of molecular genetics and topics investigated by group of scientists-enthusiasts, working In the field yeast genetics predominatingly.В статье подробно описаны этапы формирования молекулярной генетики в С.-Петербургском (Ленинградском) университете. Рассмотрены проблематика и методы исследований, конкретные задачи, стоящие перед группой ученых-энтузиастов

Некоторые исторические предпосылки и современные тенденции в работе кафедры генетики и селекции Ленинградского университета

Formation of scientific program and structure of department of Genetics and Breeding in Leningrad University is connected with the names of two outstanding Soviet geneticists: Y. A. Filipchenko, who founded the department at 1919 and M. E. Lobashev, reative efforts should be considered as one of desisive factors of restoration of Genetics in Leningrad University after the War. These two scientists contributed to the verv origin and to the formation of the physiological direction which is characteristic for the recent period in history of the Department. The main results of scientific work at the Department and at the Division of Genetics of Biological institute of Leningrad State University during recent 10 years have been obtained in the course of development of following directions: (1) physiology and biochemistry of mutational process; (2) genetic — biochemical study of generaction: (3) genetic study of homeostasis in higher plants: (4) comparative and particular genetic (5) ecological genetics.Кафедра генетики и экспериментальной зоологии Петроградского университета была основана в 1919 г. выдающимся генетиком проф. Ю. А. Филипченко. Большое влияние на формирование современной структуры н научной тематики кафедры оказал другой крупный советский ученый — проф. М. Е. Лобашев. Краткое рассмотрение биографий двух этих во многом различных исследователей обнаруживает, казалось бы, неожиданный параллелизм их творческих путей. Предсказанная Ю. А. Филипченко и воплощенная М. Е. Лобашевым концепция физиологической генетики стала основой проблематики кафедры и отдела генетики БиНИИ ЛГУ. В течение последних лет разрабатывались пять направлений: I) физиология и биохимия мутационного процесса; 2) генетико-биохимическое изучение действия гена; 3) генетическое изучение гомеостаза у высших растений; 4) сравнительная и частная генетика; 5) экологическая генетика. Представлены основные итоги педагогической и научно-исследовательской и организационно-научной работы кафедры за последние десять лет

Сравнение специфичности действия ультрафиолетовых и рентгеновых лучей на мутабильность дрожжей

Red adenineless mutants have been induced in haploid of Saccharomyces cerevisiae by UV- and X-rays. 180 such mutants have proved to be distributed between two loci designed as adᵢ and adz. The adz locus have proved to be more sensitive to mutagenic action of both kinds of radiation than the adᵢ locus. Leaky and nonleaky mutants have been scored in both loci. In adᵢ locus we have considered alleles suppressible and nonsuppressible by the external dominant suppressor. Gene specificity of UV- and X-rays was determined by the ratio (adz mutations / adᵢ mutations). The gene specificity of these two agents appeared to be the same. Intragenic specificity of the mutagens used proved to be the same too. The latter kind of specificity was determined by the ratio (leaky mutations / nonleaky mutations ) both in adᵢ and the adz locus and by ratio ( suppressible mutations / nonsuppressible mutations) in the adᵢ locus. The cause of the different sensitivity to radiation of the loci under consideration is discussed. Two alternative hypotheses have been proposed to explain the impossibility to distinguish UV- and X-rays effects by means of observation of their mutagenic specificity: 1) indirect action of the mutagens used; 2) only one class of mutations, common for both mutagens, was scored. These are the point mutations. Chromosome aberrations by which the effect of UV- and X-rays distinguishable are supposed to be inviable

Связь суперсупрессии и межаллельной комплементации в локусе AD, у Saccharomyces cerevisiae

Relationship of the supersuppression and the interallelic complementation at ad2 locus of Saccharomyces cerevisia

Выделение аскоспор дрожжей для генетического анализа без использования микроманипулятора

A new method of isolation of yeast spore population for genetic analysis has been developed. The method is based on digestion of ascus wall with the snail crop juice and on selective elimination of vegetative cells by treatment with 33.6% ethyl alcohol. Use of the visible selector genes for detection of the monospore clones makes the method more suitable. Application of the new method to genetic analysis of ''roughness"' in colony morphology proved the monogenic inheritance of this character

Межаллельная комплементация в локусе ad2 у дрожжей Saccharomyces cerevisiae

Interallelic complementation at ad2 locus of yeast Saccharomyces cerevisia

Изучение мутантов по экзогенной фосфатазе дрожжей Saccharomyces cerevisiae

Acid phosphatase activity was found in the cultural medium after growing of veast S. serevisiae on the peptone plus glucose (PEP), peptone plus glucose plus inorganic phosphate (PEPPho) and yeast extract plus peptone plus glucose (YEPD) medium. 1 4 mutants were isolated on PEPPho medium: 7 after UV irradiation of strain IG-P188 (a hisx lys A2) and 7 after irradiation of strain P4-2I9 (aad1-14 hisx lys A12). Allelism test show that all mutants studied are in one gene. Analysis of an isoenzyme composition of exogenious acid phosphatase of yeast S. cerevisiae show that on the PEP medium there are two isoenzymes (I and II). After growing of yeast cells on the PEPPho medium there is only I in the cultural medium. Regulation of synthesis of these two enzymes is discussed.Начата работа по изучению кислой фосфатазы дрожжей Sacch. cerevisiae с целью создания новой мутационной системы. Обнаружено, что кислая фосфатаза выбрасывается в среду в процессе выращивания клеток, что значительно облегчает задачу очистки этого фермента. В работе использовали два типа сред: YEPД и ПЕПФо. При выращивании клеток дикого типа на среде УЕРД обнаружены два изофермента кислой фосфатазы при электрофорезе в полиакриламидном геле — фосфатаза I и фосфатаза II. Синтез фосфатазы II прекращается при добавлении в среду неорганического фосфата. В то же время фосфатаза I не чувствительна к 20-кратному величению содержания неорганического фосфора в среде. На среде ПЕПФо получено 14 мутантов по фосфатазе I. Все 14 мутаций локализуются в одном гене, сцепленном с геном lys A12 и находящимся предположительно в правом плече IX хромосомы. В настоящее время в лаборатории разрабатывается метод очистки фосфатазы I из среды ПЕПФо

Неоднозначность действия гена

Realization of information from gene (DNA) up to the specific enzyme activity is being considered The process consists of the following general steps: transcription, translation, polypeptide chain folding and in particular cases assembly of protein subunits. Genetic control of the steps is evident now. It makes possible to consider consequences of mutational alterations for different stages of gene realization. Furthermore it is possible to apply methods of genetic analysis for studying the very gene action. One of the promising genetical approaches to the problem is the study of suppression on the level of translation (and possibly transcription). Consideration of suppression mechanisms known so far points on the possibility of ambiguity in translation of genetic message. Experimental data presented in the paper and in several other publications show the existence of suppressors, namely weak suppressors (known as modifier genes) in strains of microorganisms used in experimental work. So the situation conforms possibility of ambiguous translation within the living cell. Besides that a few available direct evidences of translational ambiguity in vivo are presented. It is necessary to distinguish between the ambiguity of translation and ambiguity of gene action in general. So the latter one means hot only the possibility of translational mistakes but simultaneously a considerable stability of the phenotype. Nonexpressivity of some amino acid substitution in proteins is one of the possible mechanisms for maintaining the phenotypic stability. Another mechanism of this type is "correction" of some mutational defects in proteins on the level of the multimeric structure. On the other hand these mechanisms can considerably amplify the ambiguity in relation between gene and phenotypic character. The possible role of the ambiguity of gene action in living things is being discussed