DOCSLIB.ORG

Pisum Sativum) for Inheritance of Characters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pisum Sativum) for Inheritance of Characters • Gregor Johann Mendel was an Austrian priest in a monastery at Brunn. • He conducted experiments on garden pea (Pisum sativum) for inheritance of characters. • The conclusions were published in the annual proceedings of the Natural History Society of Brunn in 1865. • The results remained obscure till a rediscovery by three scientists, namely, Hugo de Vries (Holland), Karl Correns (Germany) and Kris Von Tschermark (Austria) in 1900 • On the basis of the results of the monohybrid cross and the dihybrid cross, Correns formulated four laws of inheritance, namely, 1. Law of Unit Character 2. Law of Dominance 3. Law of Segregation 4. Law of Independent Assortment • Due to many exceptions in Law of Unit Character, this law was immediately dropped. • Exceptions have also been reported in Law of Dominance and Law of Independent Assortment. Therefore, these laws are not perfect or universal laws. • Law of Segregation (also called 'Law of Purity of Gametes') has no exception till date. Therefore, this law is called perfect law or universal law. • Birth - 22 July 1822 • Became Priest - October 1843 • Became Gregor -1849 • Experimentation period - 1856 to 1864 • Publication of result -1865 • Death - 1884 • Father of Genetics - 1909 • Mendel selected Garden Pea (Pisum sativum) for his experiments because of the following reasons: (a) It is an annual plant (b) The flowers are bisexual (c) Self-pollination (d) Easy emasculation (e) Large number of seed formation (f) Large number of contrasting characters Mendel studied the inheritance of unit character at a time. Crosses were done between parents of pure breeding line having contrasting characters. This experiment was carried out on F1 and F2 generations. The crosses were of the following two types: • Monohybrid cross • Dihybrid cross 1. Monohybrid Cross • The cross between pure breeding line parents for a single pair of contrasting characters is called monohybrid cross. • When a pure tall (TT) pea plant was crossed with a pure dwarf (tt) pea plant, in F1 generation, all pea plants were tall (Tt). • The F1 plants are called hybrid and they were self- pollinated. • In the F2 generation, both tall and dwarf plants were found. • The cross is presented below. Results of the F 2 Generation • Phenotypic ratio = 3 tall: 1 dwarf (Phenotype ratio = 3: 1) • Genotypic ratio = 1 Homozygous tall : 2 Heterozygous tall : 1 Homozygous dwarf (Genotype ratio = 1 :2: 1) • Tallness and dwarfness are determined by a pair of contrasting factors or determiners. They are now called genes. • These factors occur in pairs and are received from either parent. • The factors are brought together by fertilisation and separate during gamete formation. • These factors never contaminate each other. • The cross between pure breeding line parents involving two pairs of contrasting characters is called dihybrid cross. • When pure axial and purple-flowered pea plant was crossed with pure terminal and white- flowered pea plant in the F1 generation, all pea plants were axial and purple flowered. • In the F2 generation, the self-cross of F1 plants gave the following four types of combinations: (a) Axial and purple flowered (b) Axial and white flowered (c) Terminal and purple flowered (d) Terminal and white flowered •Phenotypic ratio = 9 Axial and Purple: 3 Axial and White: 3 Terminal and Purple: I Terminal and White •Genotypic ratio = 1 :2:2:4: 1 :2: 1 :2: 1 • Axial, purple, terminal and white flower characters are determined by four different sets of factors. • These factors occur in pairs and are received from either parent. • These factors are brought together by fertilisation and separate during gametogenesis. • These factors never contaminate. • In the F1 generation, cross-fertilisation leads to formation of hybrids, all having heterozygous axial and purple flowers. • In the F2 generation, the process of independent assortment takes place among factors, so new combinations like axial white-flowered and terminal purple-flowered pea plants arise. • On the basis of monohybrid and dihybrid cross, the following four laws were formulated: 1. Law of Unit Character - An individual's body contains many characters. Each of these characters behaves as a unit and its expression is controlled by a particular gene. 2. Law of Dominance - For one or more sets of contrasting characters, when two individual are crossed, the characters which appear in F1 heterozygous are called dominant characters while those that do not appear are called recessive characters. 3. Law of Segregation - It is also called law of purity of gametes. 'Factors (genes) segregate at the time of gamete formation. 4. Law of Independent Assortment - For more than one set of contrasting characters, the alleles segregate and assort independently. • The significance of Mendel's laws is stated below. • The outcome of Mendel's laws is useful in Eugenics, which deals with the betterment of the human race. • The laws are useful in improvement of crops, cattle, fowl, etc. • Mendel's laws help in pedigree analysis for many diseases • Backcross • The cross between the FI hybrid and any of the parent (back generation) is called backcross. • Test Cross • The cross between the FI hybrid and the recessive individual (parent) is called test cross. It is utilised to find out the heterozygosity in FI individuals. • It is a post-Mendelian cross. It is also known as blending inheritance. It is an exception to Mendel's findings. • Reference: When two contrasting alleles come together in the FI hybrid, the character expressed is neither of the parents' type, but a mixture of both. (i) Incomplete dominance is seen in the four o'clock plant (Mirabilis jaLapa). (ii) When a red-flowered (RR) plant is crossed with a white-flowered (rr) plant. (iii) In the FI generation, all plants bear pink (Rr) flowers. (iv) The self-cross in FI hybrids yields red, pink and white-flowered plants. • Result • Phenotypic ratio = Genotypic ratio (1 :2:1) = 1 Red: 2 Pink: 1 White • Explanation - The allele R is incompletely dominant over allele 'r', so that all heterozygous (Rr) individuals produce pink flowers. • It is a post-Mendelian cross and an exception to Mendel's findings. It is also known as Bateson factor hypothesis. • Definition - When two contrasting alleles come together in a heterozygous individual, both alleles express themselves side by side. • Co-dominance is seen in the inheritance of coat colour in cattle and blood group inheritance in humans. When red-hair cattle is crossed with white hair cattle. In F1 hybrids, the roan colour is expressed. The cross (inbreeding) between such male and female hybrids give red-, roan- and white-hair-coloured cattle in the F2 generation • The allele for red hair colour (R) is equally expressed as the allele for white hair colour (r), so all heterozygous individuals have roan (Rr) colours. • Epistasis is the interaction of two non-allelic genes, in which, one gene masks the expression of another gene. The gene, which masks the activity of another gene, is called an epistatic gene. The gene, whose activity is suppressed, is called a hypostatic gene. The genes are located on different loci. 1 . Dominant epistasis 2. Recessive epistasis • In this case, a dominant gene suppresses the expression of another allele either dominant or recessive. • Example (i) In poultry, there are two kinds of white breed, viz., the white leghorn and the white Plymouth rock. (ii) When such homozygous poultry are left to interbreed, in the F1 generation, all poultry become heterozygous white leghorn. (iii) Interbreeding between the F1 hybrid male and female produces 13 white and 3 coloured individuals. • When a set of more than two alleles, occupying the same locus in the homologous chromosomes, affects the expression of phenotypic character, they are called multiple alleles and the phenomenon is called multiple allelism. • The varied alleles in a set have arisen as a result of mutation in genes They are found on the same locus in the homologous chromosomes. (ii) Only two genes of multiple alleles are found in an individual in diploid condition. (iii) The gamete contains anyone of the genes. (iv) Crossing over is absent in multiple alleles. (v) Multiple alleles influence only one character. (vi) Their interaction shows dominant, recessive and co-dominance phenomena. • The inheritance of ABO blood groups in humans is a very good example of multiple alleles. The four blood groups, viz., A, B, AB and 0 are due to the presence of three alleles occupying the same locus on the homologues chromosome. These alleles IA, IB and IO, IO is recessive to both lA and IB alleles. IA and IB show co-dominance. Individual heterozygous for these two alleles have AB blood group. • When an individual with blood group A in heterozygous condition is married to a woman with heterozygous B blood group: • The offspring may have any of the four types of possible blood groups in ABO system. • Blood group A and B in the offspring is due to expression of allele lA over IO and allele over IO. • Blood group AB in the offspring is due to co-dominance of allele lA and IB. • Blood group 0 in the offspring is due to the combination of two recessive alleles IOIO. • There are certain characters in human population, which show phenotypic variations (eg., height, weight, skin colour, etc.). • These characters are expected due to cumulative effect of genes. • These genes are called polygenes and their inheritance is called polygenic inheritance, while the characters are called polygenic traits. (i) The effect of polygenes is cumulative. (ii) All the alleles of polygenes have equal effect. (iii) The inheritance is free from dominance, epistasis and linkage. (iv) The environment has little role in the expression of characters. (v) It was first found in humans by F.C Galton in 1883. (vi) It was first found in wheat by H.
Load more

Recommended publications
  • Segregation and Recombination of Non-Mendelian Genes in Chlamydomonas
    Symposium on Non-chromosomal Inheritance: XIII International Congress of Genetics SEGREGATION AND RECOMBINATION OF NON-MENDELIAN GENES IN CHLAMYDOMONAS NICHOLAS W. GILLHAM, JOHN E. BOYNTON AND ROBERT W. LEE2 Departments of Botany and Zoology, Duke University, Durham, North Carolina 27706 ABSTRACT Non-Mendelian genes in Chamydomonas reinhardfii axe inherited in a uniparental (UP) fashion. Most zygotes and their progeny receive UP genes only from the mt+ or maternal parent. Homwever, a few exceptional zygotes are also found in which tlie mt ur paternal UP genome is transmitted. Most of the exceptional zygotes are biparental in that their progeny segregate UP genes transmitted by bath parents. As a result, biparental zygotes have been extensively used to study the rules governing UP inheritance. The frequency of biparental zygotes can be greatly increased if the maternal parent is irradiated with ultraviolet light priosr to mating. Based principally on studies with ultraviolet-induced biparental zygotes, SAGERhas argued that a vegetative cell contains two copies of the UP genome and that the progeny of a biparental zygote receive a copy derived from each parent. Results reported in this paper with spontaneous and ultraviolet-induced biparental zygotes do not support the two copy mcdel, but argue for a mulitple copy model with most of the copies normally being transmitted by the maternal parent. A multiple copy model which accolunts for both SAGER’Sresults and ours is presented. ON-MENDELIAN mutations exhibiting uniparental (UP) inheritance in Chla- “zydomonas reinhardtii were first reported by SAGERin 1954. Since that time the UP genetic system has been subject to extensive investigation at both the molecular and genetical levels (see reviews by GILLHAM1969; SAGER1972).
    [Show full text]
  • Bzyct-137 Genetics and Evolutionary Biology
    BZYCT-137 GENETICS AND Indira Gandhi EVOLUTIONARY BIOLOGY National Open University School of Sciences VOL 1 GENETICS BLOCK 1 HEREDITY AND PHENOTYPE 7 BLOCK 2 THE PHYSICAL BASIS OF HEREDITY 127 GENETICS AND EVOLUTIONARY BIOLOGY Genetics goes hand in hand with evolution. All traits are inherited whenever we bring up a trait, we should ask when that trait evolved and place in on the appropriate phylogenetic tree. This tree not only shows when certain traits evolved, but can also be used to infer who has them. This tree can be used to show how our genetic traits go back to the universal ancestor that lived 3-5 billion years ago and that all of today’s genomes are product of duplication and divergence. The evidence for the evolution can be read from our genomes. Understanding the connection between Mendel’s principles of heredity and DNA is of paramount importance. There are concrete examples of mutations in DNA that change proteins which in turn, change phenotype is one of the best ways to make these connections we now understand same of the Mendel’s traits at molecular level. Genes code for proteins and proteins determine phenotype. The more vividly you can make this connection, the richer will be their understanding of both genetics and evolution. Looking at the functioning of DNA, RNA and protein in determining phenotype, students can begin to understand that they are guardians of 3.5 billion years of evolution and this provides motivation for taking care of our fragile planet that makes life possible. We welcome you to the study of the first volume of this course which tells you about Genetics.
    [Show full text]
  • Uniparental Inheritance of Mitochondrial Genes in Yeast: Dependence on Input Bias of Mitochondrial Dna and Preliminary Investigations of the Mechanism
    UNIPARENTAL INHERITANCE OF MITOCHONDRIAL GENES IN YEAST: DEPENDENCE ON INPUT BIAS OF MITOCHONDRIAL DNA AND PRELIMINARY INVESTIGATIONS OF THE MECHANISM C. WILLIAM BIRICY, JR.*t, CATHERINE A. DEMKO*, PHILIP S. PERLMAN*t, AND ROBERT STRAUSBERwt The Ohio Stale University, Columbus, Ohio 43210 Manuscript received September 26, 1977 Revised copy received March 17, 1978 ABSTRACT In Saccharomyces cerevisiae, previous studies on the inheritance of mito- chondrial genes controlling antibiotic resistance have shown that some crosses produce a substantial number of uniparental zygotes, which transmit to their diploid progeny mitochondrial alleles from only one parent. In this paper, we show that uniparental zygotes are formed especially when one parent (major- ity parent) contributes substantially more mitochondrial DNA molecules to the zygote than does the other (minority) parent. Cellular contents of mito- chondrial DNA (mtDNA) are increased in these experiments by treatment with cycloheximide, alpha-factor, or the uvsp5 nuclear mutation. In such a biased cross, some zygotes are uniparental for mitochondrial alleles from the majority parent, and the frequency of such zygotes increases with increasing bias. In two- and three-factor crosses, the cupl, ery1, and oli1 loci behave coordinately, rather than independently; minority markers tend to be trans- mitted or lost as a unit, suggesting that the uniparental mechanism acts on entire mtDNA molecules rather than on individual loci. This rules out the possibility that uniparental inheritance can be explained by the conversion of minority markers to the majority alleles during recombination. Exceptions to the coordinate behavior of different loci can be explained by marker rescue via recombination. Uniparental inheritance is largely independent of the posi- tion of buds on the zygote.
    [Show full text]
  • Genome Imprinting -R-ES-ONANCE
    GENERAL I ARTICLE Genome Imprinting The Silencing of Genes and Genomes H A Ranganath and M T Tanuja Gregor Mendel, the Father of Genetics was, fortunately for us, very lucky in that the characters studied by him presented a very neat pattern of inheritance. This enabled him to generalize from his observations and to give us the basic tenets of inheritance. Genetic investigations in the 20th century have, however, re­ H A Ranganath is a vealed many contradictions to the principles enunciated by Professor of Zoology at Mendel. One of the important challenges facing geneticists is to the University of Mysore. explain the mode of inheritance of traits and conditions that do His interests centre not appear to follow Mendel's laws. One of the principles of around cytogenetics and other aspects of the Mendel is 'The Principle of Equivalence in Reciprocal Crosses': process of race formation no matter which parent contributes a gene to its offspring, the and speciation in gene will behave in the same way in producing the phenotype. Drosophila. Even though this principle holds true most of the time, there are a few exceptions. They are (1) traits linked to genes on the sex chromosomes - X and Y, (2) traits controlled by genes outside the cell nucleus (mitochondrial and chloroplast genomes), and (3) traits governed by a phenomenon called genome imprinting. The term 'imprinting' was probably first used in biology in the M T Tanuja is a CSIR late 1930's in connection with animal behaviour. Helen Crouse Senior Research Fellow, presently working on first used it in cytogenetic context in her study of chromosome hybridization and elimination in Sciara in 1960.
    [Show full text]
  • Uniparental Inheritance Promotes Adaptive Evolution in Cytoplasmic
    bioRxiv preprint doi: https://doi.org/10.1101/059089; this version posted November 17, 2016. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Uniparental inheritance promotes adaptive evolution in 2 cytoplasmic genomes 1,2 1 3 Joshua R. Christie and Madeleine Beekman 1 4 School of Life and Environmental Sciences, The University of Sydney, Sydney, 2006, NSW, 5 Australia 2 6 Corresponding author: [email protected] 7 1 Abstract 8 Eukaryotes carry numerous asexual cytoplasmic genomes (mitochondria and plastids). 9 Lacking recombination, asexual genomes should theoretically suffer from impaired adap- 10 tive evolution. Yet, empirical evidence indicates that cytoplasmic genomes experience 11 higher levels of adaptive evolution than predicted by theory. In this study, we use a com- 12 putational model to show that the unique biology of cytoplasmic genomes—specifically 13 their organization into host cells and their uniparental (maternal) inheritance—enable 14 them to undergo effective adaptive evolution. Uniparental inheritance of cytoplasmic 15 genomes decreases competition between different beneficial substitutions (clonal interfer- 16 ence), promoting the accumulation of beneficial substitutions. Uniparental inheritance 17 also facilitates selection against deleterious cytoplasmic substitutions, slowing Muller’s 18 ratchet. In addition, uniparental inheritance generally reduces genetic hitchhiking of 19 deleterious substitutions during selective sweeps. Overall, uniparental inheritance pro- 20 motes adaptive evolution by increasing the level of beneficial substitutions relative to 1 bioRxiv preprint doi: https://doi.org/10.1101/059089; this version posted November 17, 2016. The copyright holder for this preprint (which was not certified by peer review) is the author/funder.
    [Show full text]
  • The Faculty of Medicine, Harvard University
    Ruth Sager Ruth Sager should be remembered above all as a gifted, original, and imaginative scientist who loved her life of exploring nature, and in her later years, brought her gifts and passion to investigating the scourge of breast cancer. Her discovery of science came through an epiphany. She enrolled at the University of Chicago with the intention to study music or literature. The University’s insistence on a broad liberal arts education brought Ruth to courses in biology, where she is said to have encountered the physiologist, Professor Anton Carlson, and was so taken by his course in physiology that she switched her major to biology and her concentration to physiology. She found all her science courses stimulating and at first thought medicine would be her career choice. Having received her B.S. (Phi Beta Kappa) from the University in 1938, Ruth spent the war years first as a secretary, and later in a graduate program at Rutgers University, where she participated in a wartime research project. She obtained her master’s degree in Plant Physiology in 1944. The title of her master’s thesis was “Nutritional Status of the Tomato Seedling in Relation to Successful Transplanting.” The taste of research and her duties as a teaching assistant at Rutgers convinced her that a life of laboratory research and teaching was her true calling, so she enrolled in 1945 for a Ph.D. at Columbia University, and wisely selected genetics as her field. Professor Marcus M. Rhoades was her thesis advisor, and the genetics of corn her special area.
    [Show full text]
  • Proquest Dissertations
    Evolution of Uniparental Genetic Systems in Dermanyssine Mites (Acari: Mesostigmata) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY OF THE UNIVERSITY OF LONDON by Robert Hamish Cruickshank Molecular Biology Unit, Department of Zoology, The Natural History Museum, Cromwell Road, South Kensington, LONDON SW7 5BD, England, UK Department of Biology, The Galton Laboratory, University College London, 4 Stephenson Way, LONDON NW l 2HE, England, UK September 1997 ProQuest Number: 10045787 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10045787 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 DEDICATION This thesis is dedicated, with love, to my wife Alice who I met and married whilst working on this project and who has put up with so much to help me get it finished. "The meaning of this degree is that the recipient of instruction is examined for the last time in his life, and is pronounced completely full. After this, no new ideas can be imparted to him. " Stephen Leacock "Sunshine Sketches of a Little Town” ACKNOWLEDGEMENTS This thesis could not have been completed without the guidence, enthusiasm and patience of my supervisor Dr.
    [Show full text]
  • Unit III Chapter 7 Genetic Principles Basic Processes and Molecular Chapter 8 Genetic Disorders Processes
    Chapter 6 Basic Principles of Inheritance Unit III Chapter 7 Genetic Principles Basic Processes and Molecular Chapter 8 Genetic Disorders Processes The idea of inheritance patterns emerged from the work of Mendel and other scientists who followed him. What was not clear was the nature of the ‘factors’ which are responsible for determining a particular phenotype. It became crucial to have an understanding of the structure of genetic material and the patterns of inheritance. The foundation of molecular biology and genetics was laid down by many eminent scientists of that time, such as Watson, Crick, Nirenberg, Khorana, Monod, Benzer, etc. The contributions of these scientists and the concepts explained by them have been discussed in three chapters of this unit. 2021-22 Chapter 6.indd 145 11/14/2019 10:12:55 AM Gregor Johann Mendel (1822-1884) Gregor Johann Mendel was born on July 22, 1822 in Austria. His pioneering work laid the foundation of science of genetics and therefore, he is known as ‘father of genetics’. In 1843, Mendel began studying even while being a monk at St. Thomas Monastery in Brno. There he was exposed to the lab facilities and got interested in research and teaching. His experiments focussed on cross-breeding of pea plants and gathering data on the variations for several generations. Based on his experiments on a total of seven characteristics in garden pea, he established Law of segregation and Law of independent assortment. Decades after his death in 1884, his work got recognition by other researchers. His research is now considered to be the basis of modern genetics.
    [Show full text]
  • Do Progeny Inherit Traits from Their Parents in Predictable Ways?
    Do progeny inherit traits from their parents in predictable ways? MCB 142/ICB 163, Fall 2008 © Abby Dernburg Gregor Mendel (1822-1884) sought to answer this question through careful breeding experiments. Gregor Mendel and his garden in Brno, Czech Republic (formerly Brunn, Moravia) MCB 142/ICB 163, Fall 2008 © Abby Dernburg Prevalent views of inheritance before Mendel “Preformation” / uniparental inheritance Inherited characteristics were determined by information from just one parent (the female if you were an “ovist,” the male if you were a “spermist”). However, various qualities could be modulated by their environment, just as plants grown in different soils will appear different and produce different yields. Blended inheritance Offspring somehow merge information from both parents, resulting in a unique version of information and a change of the original information. MCB 142/ICB 163, Fall 2008 © Abby Dernburg A “spermist” view of inheritance Michael Phelps - In the beginning Nicolas Hartsoeker - 1695 Patrick Moberg - 2008 Microscopic observation of rapidly-moving Are there still spermists among us? “spermatozoa” (seed animals) seemed to validate the spermists’ view that sperm were alive, while the egg seemed relatively passive. MCB 142/ICB 163, Fall 2008 © Abby Dernburg Problems with existing theories... • Lacked explanatory or predictive power Why do offspring sometimes look like a blend of their parents, and sometimes “favor” one or the other? How do some traits “skip” generations, but then reappear later? Why does the putative “blending” of traits result in such obvious differences among the offspring of the same parents? Why are some traits - for example, gender - essentially binary? MCB 142/ICB 163, Fall 2008 © Abby Dernburg Why peas? Due to favorable anatomical properties, pea plants can easily be mated to others (outcrossed) in a controlled fashion, in either direction (♀ x ♂).
    [Show full text]
  • 3 Third Variability, the Inheritance Types and Seed
    Sel’skokhozyaistvennaya Biologiya [Agricultural Biology], 2013, № 5, p. 3-29. UDK 631.522/.524:[575+575.22/.23+575.16/.162 THIRD VARIABILITY, THE INHERITANCE TYPES AND SEED REPRODUCTION IN PLANTS S.I. Maletsky1, N.V. Roik2, V.A. Dragavtsev3 1Institute of Cytology and Genetics of Siberian Branch, Russian Academy of Sciences, 10, prosp. Lavrentieva, Novosibirsk, 630090 Russia, e-mail: [email protected]; 2Isitute of Bioenergetic Crops and Sugar Beet, Ukrainian Academy of Agricultural Sciences, 25, Klinicheskaya ul., Kiev, 03321 Ukraine, e-mail: [email protected]; 3Agrophysical Research Institute, Russian Academy of Agricultural Sciences, 14, Grazhdanskiy prosp., St. Petersburg, 195220 Russia, e-mail: [email protected] Received April 25, 2013 The G. Mendel’s model for hereditary factors (genes) and appeared on its base the genecentric paradigm, which postulates that genes control not only inheritance of simple traits of plants and animals, but determine ontogenesis, morphogenesis and all cardinal tendencies of life evolution, are examined. In the article, it is indicated, that along with the discovery of discrete heredity forPisum sativum L., G. Mendel by fact described, in addition to well-known genotypic and paratypic variability, a one more variability for plants of generaHieracium L., which now is denominated as an epigenetic variability. Analysis of literature permits to evolve the idea, that the real distribution of genotypes is determined not only by the G. Mendel’s lows for inheritance, but by structure of genomes (a ploidy) and by a manner of plant seeds reproduction (uniparental or biparental). In particular, the facts about the manner of reproduction of seeds of different species and genera demonstrate, that very often the reproductive characters are difficultly dedicated as mendelian, and their inheritance usually has an epigenetic nature.
    [Show full text]
  • Uniparental Mitochondrial Inheritance in Cryptococcus Is Controlled by The
    bioRxiv preprint doi: https://doi.org/10.1101/813998; this version posted October 21, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Uniparental mitochondrial inheritance in Cryptococcus is controlled by the pheromone and pheromone receptor mating-type locus Sheng Sun, Ci Fu, Giuseppe Ianiri, and Joseph Heitman* Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA 27710 * Corresponding author: Joseph Heitman Department of Molecular Genetics and Microbiology Duke University Medical Center Phone: 919-684-2824 Fax: 919-684-5458 Email: [email protected] bioRxiv preprint doi: https://doi.org/10.1101/813998; this version posted October 21, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. ABSTRACT Mitochondria are inherited uniparentally during sexual reproduction in the majority of eukaryotic species studied, including humans, mice, nematodes, as well as many fungal species. Mitochondrial uniparental inheritance (mito-UPI) could be beneficial in that it avoids possible genetic conflicts between organelles with different genetic backgrounds, as recently shown in mice; and it could prevent the spread of selfish genetic elements in the mitochondrial genome. Despite the prevalence of observed mito-UPI, the underlying mechanisms and the genes involved in controlling this non-mendelian inheritance are poorly understood in many species. In Cryptococcus neoformans, a human pathogenic basidiomyceteous fungus, mating types (MATα and MATa) are defined by alternate alleles at the single MAT locus that evolved from fusion of the two MAT loci (P/R encoding pheromones and pheromone receptors, HD encoding homeodomain transcription factors) that are the ancestral state in the basidiomycota.
    [Show full text]
  • Unusual Patterns of Mitochondrial Inheritance in the Brown Alga Ectocarpus
    Unusual Patterns of Mitochondrial Inheritance in the Brown Alga Ectocarpus Laure Mignerot, Chikako Nagasato, Akira Peters, Marie-Mathilde Perrineau, Delphine Scornet, Florian Pontheaux, Walid Djema, Yacine Badis, Taizo Motomura, Coelho Susana M., et al. To cite this version: Laure Mignerot, Chikako Nagasato, Akira Peters, Marie-Mathilde Perrineau, Delphine Scornet, et al.. Unusual Patterns of Mitochondrial Inheritance in the Brown Alga Ectocarpus. Molecular Biology and Evolution, Oxford University Press (OUP), 2019, 10.1093/molbev/msz186. hal-02269449 HAL Id: hal-02269449 https://hal.archives-ouvertes.fr/hal-02269449 Submitted on 22 Aug 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Unusual Patterns of Mitochondrial Inheritance in the Brown Alga Ectocarpus 2 Laure Mignerot1, Chikako Nagasato2, Akira F. Peters3, Marie-Mathilde Perrineau1,4, Delphine 3 Scornet1, Florian Pontheaux1, Walid Djema5, Yacine Badis1,4, Taizo Motomura2, Susana M. 4 Coelho1 and J. Mark Cock*,1 5 1Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models 6 (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France. 7 2Muroran Marine Station, Hokkaido University, Japan. 8 3Bezhin Rosko, 29250, Santec, France. 9 4The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland.
    [Show full text]