scholarly journals Triparental inheritance in Dictyostelium

2018 ◽  
Author(s):  
Gareth Bloomfield ◽  
Peggy Paschke ◽  
Marina Okamoto ◽  
Tim J. Stevens ◽  
Hideko Urushihara
Keyword(s):  
Mitochondrial Genome ◽  
Dictyostelium Discoideum ◽  
High Frequency ◽  
Genetic Material ◽  
Lateral Transfer ◽  
Mating Types ◽  
Zygote Nucleus ◽  
Social Amoebae

AbstractSex promotes the recombination and reassortment of genetic material and is prevalent across eukaryotes. In social amoebae sex involves a promiscuous mixing of cytoplasm before zygotes consume the majority of cells. We report here the first genomewide characterisation of meiotic progeny in Dictyostelium discoideum. We find that recombination occurs at high frequency in pairwise crosses between all three mating types, despite the absence of the SPO11 enzyme that is normally required to initiate crossover formation. In crosses involving three strains, transient fusions involving more than two gametes frequently lead to triparental inheritance, with recombined nuclear haplotypes inherited from two parents and the mitochondrial genome from a third. Cells that do not contribute genetically to the Dictyostelium zygote nucleus thereby have a stake in the next haploid generation. We suggest that this lateral transfer helps to enforce cooperation in this confictual system.

scholarly journals Triparental inheritance inDictyostelium

2019 ◽  
Vol 116 (6) ◽  
pp. 2187-2192 ◽  
Author(s):  
Gareth Bloomfield ◽  
Peggy Paschke ◽  
Marina Okamoto ◽  
Tim J. Stevens ◽  
Hideko Urushihara
Keyword(s):  
High Frequency ◽  
Genetic Material ◽  
Mitochondrial Genomes ◽  
Genome Wide ◽  
Organelle Genomes ◽  
Initial Evolution ◽  
Sexual Progeny ◽  
Sexual Inheritance ◽  
Social Amoebae

Sex promotes the recombination and reassortment of genetic material and is prevalent across eukaryotes, although our knowledge of the molecular details of sexual inheritance is scant in several major lineages. In social amoebae, sex involves a promiscuous mixing of cytoplasm before zygotes consume the majority of cells, but for technical reasons, sexual progeny have been difficult to obtain and study. We report here genome-wide characterization of meiotic progeny inDictyostelium discoideum. We find that recombination occurs at high frequency in pairwise crosses between all three mating types, despite the absence of the Spo11 enzyme that is normally required to initiate crossover formation. Fusions of more than two gametes to form transient syncytia lead to frequent triparental inheritance, with haploid meiotic progeny bearing recombined nuclear haplotypes from two parents and the mitochondrial genome from a third. Cells that do not contribute genetically to theDictyosteliumzygote nucleus thereby have a stake in the next haploid generation.D. discoideummitochondrial genomes are polymorphic, and our findings raise the possibility that some of this variation might be a result of sexual selection on genes that can promote the spread of individual organelle genomes during sex. This kind of self-interested mitochondrial behavior may have had important consequences during eukaryogenesis and the initial evolution of sex.

scholarly journals Sex Determination in the Social Amoeba Dictyostelium discoideum

Science ◽  
2010 ◽  
Vol 330 (6010) ◽  
pp. 1533-1536 ◽  
Author(s):  
Gareth Bloomfield ◽  
Jason Skelton ◽  
Alasdair Ivens ◽  
Yoshimasa Tanaka ◽  
Robert R. Kay
Keyword(s):  
Sex Determination ◽  
Dictyostelium Discoideum ◽  
Genetic Locus ◽  
Model Organism ◽  
Mating Types ◽  
Type Locus ◽  
Social Amoeba ◽  
The Third ◽  
The Social ◽  
Social Amoebae

The genetics of sex determination remain mysterious in many organisms, including some that are otherwise well studied. Here we report the discovery and analysis of the mating-type locus of the model organism Dictyostelium discoideum. Three forms of a single genetic locus specify this species' three mating types: two versions of the locus are entirely different in sequence, and the third resembles a composite of the other two. Single, unrelated genes are sufficient to determine two of the mating types, whereas homologs of both these genes are required in the composite type. The key genes encode polypeptides that possess no recognizable similarity to established protein families. Sex determination in the social amoebae thus appears to use regulators that are unrelated to any others currently known.

High Frequency Recombination During the Sexual Cycle of Dictyostelium discoideum

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1829-1832 ◽  
Author(s):  
David Francis
Keyword(s):  
Dictyostelium Discoideum ◽  
Genetic Map ◽  
High Frequency ◽  
Cell Biology ◽  
Physical Map ◽  
Genetic System ◽  
Sexual Cycle ◽  
Chromosome 2 ◽  
New Combinations ◽  
Restriction Sites

Abstract Analysis of Dictyostelium development and cell biology has suffered from the lack of an ordinary genetic system whereby genes can be arranged in new combinations. Genetic exchange between two long ignored strains, A2Cycr and WS205 is here reexamined. Alleles which differ in size or restriction sites between these two strains were found for seven genes. Six of these are in two clusters on chromosome 2. Frequencies of recombinant progeny indicate that the genetic map of the two mating strains is colinear with the physical map recently worked out for the standard nonsexual strain, NC4. The rate of recombination is high, about 0.1% per kilobase in three different regions of chromosome 2. This value is comparable to rates found in yeast, and will permit fine dissection of the genome.

scholarly journals Transduction mechanisms of bacteriophage ε15I. General properties of the system

1971 ◽  
Vol 18 (1) ◽  
pp. 9-19 ◽  
Author(s):  
R. W. Hedges
Keyword(s):  
High Frequency ◽  
Genetic Material ◽  
Recipient Strain ◽  
The Other ◽  
Donor Strain ◽  
General Properties ◽  
Show Evidence ◽  
Transduction Mechanisms ◽  
Defective Prophage

SUMMARYBacteriophageεγis capable of transduction both by replacement of a genetic segment of the recipient by the homologous genetic material from the donor strain and by the formation of defective transducing particles capable of lysogenizing the recipient strain ofS. anatum.The isolation of strains carrying such prophages, which have incorporated the lactose or arabinose operons, is reported. Lysogenic strains, carrying both normal and defective transducing prophage, form high-frequency transducing lysates. Other strains, carrying only defective prophage, show evidence that the association of prophage genes and transduced materials is stable since the loss of one frequently entails loss of the other.

scholarly journals Mitochondrial genome of the nonphotosynthetic mycoheterotrophic plant Hypopitys monotropa, its structure, gene expression and RNA editing

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9309
Author(s):  
Viktoria Yu Shtratnikova ◽  
Mikhail I. Schelkunov ◽  
Aleksey A. Penin ◽  
Maria D. Logacheva
Keyword(s):  
Mitochondrial Genome ◽  
Rna Editing ◽  
Transcriptome Sequencing ◽  
Unique Feature ◽  
Genetic Material ◽  
Mitochondrial Genes ◽  
Vaccinium Macrocarpon ◽  
Mitochondrial Genomes ◽  
Plastid Genomes ◽  
Trans Splicing

Heterotrophic plants—plants that have lost the ability to photosynthesize—are characterized by a number of changes at all levels of organization. Heterotrophic plants are divided into two large categories—parasitic and mycoheterotrophic (MHT). The question of to what extent such changes are similar in these two categories is still open. The plastid genomes of nonphotosynthetic plants are well characterized, and they exhibit similar patterns of reduction in the two groups. In contrast, little is known about the mitochondrial genomes of MHT plants. We report the structure of the mitochondrial genome of Hypopitys monotropa, a MHT member of Ericaceae, and the expression of its genes. In contrast to its highly reduced plastid genome, the mitochondrial genome of H. monotropa is larger than that of its photosynthetic relative Vaccinium macrocarpon, and its complete size is ~810 Kb. We observed an unusually long repeat-rich structure of the genome that suggests the existence of linear fragments. Despite this unique feature, the gene content of the H. monotropa mitogenome is typical of flowering plants. No acceleration of substitution rates is observed in mitochondrial genes, in contrast to previous observations in parasitic non-photosynthetic plants. Transcriptome sequencing revealed the trans-splicing of several genes and RNA editing in 33 of 38 genes. Notably, we did not find any traces of horizontal gene transfer from fungi, in contrast to plant parasites, which extensively integrate genetic material from their hosts.

scholarly journals Wild Dictyostelium discoideum social amoebae show plastic responses to the presence of nonrelatives during multicellular development

2020 ◽  
Vol 10 (3) ◽  
pp. 1119-1134
Author(s):  
Suegene Noh ◽  
Lauren Christopher ◽  
Joan E. Strassmann ◽  
David C. Queller
Keyword(s):  
Dictyostelium Discoideum ◽  
Multicellular Development ◽  
Plastic Responses ◽  
Social Amoebae

scholarly journals Comparative genomics of the social amoebae Dictyostelium discoideum and Dictyostelium purpureum

2011 ◽  
Vol 12 (2) ◽  
pp. R20 ◽  
Author(s):  
Richard Sucgang ◽  
Alan Kuo ◽  
Xiangjun Tian ◽  
William Salerno ◽  
Anup Parikh ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Dictyostelium Discoideum ◽  
The Social ◽  
Dictyostelium Purpureum ◽  
Social Amoebae

scholarly journals Exposure to dense bacteria lawns does not cause the social amoeba Dictyostelium discoideum to carry bacteria through the social stage

2017 ◽  
Author(s):  
Debra A Brock ◽  
Alicia Canas ◽  
Kai Jones ◽  
David C Queller ◽  
Joan E Strassmann
Keyword(s):  
Dictyostelium Discoideum ◽  
Associated Bacteria ◽  
Social Amoeba ◽  
Future Studies ◽  
Bacterial Cultures ◽  
Large Numbers ◽  
The Social ◽  
External Forces ◽  
Social Amoebae ◽  
Food Bacteria

Background. Interactions between eukaryotic amoebae and bacteria are understudied and important. Bacteria inside of amoebae are protected from external forces including antibiotics. An excellent model for bacteria-amoeba interactions is the social amoeba Dictyostelium discoideum and its associated bacteria. A third of wild-collected clones of the soil-dwelling amoeba Dictyostelium discoideum exhibit a suite of characteristics that make them simple farmers of bacteria. They carry bacteria internally through the social spore-making stage. They then release these bacteria to grow and subsequently eat them, prudently stopping before they are entirely consumed so some bacteria can be carried to the next generation. D. discoideum defend their food bacteria with other inedible bacteria that produce compounds toxic to non-farmers. Both carried bacteria and social amoeba hosts have demonstrated co-evolved characteristics. Most farmer clones discovered to date carry inedible Burkholderia in addition to food bacteria, but it is not clear whether or not a preponderance of naïve bacteria might induce the farming state by overwhelming the phagocytic actions of the host amoebae. In this study we address this question with D. discoideum clones that naturally carry bacteria and those that do not. Will naïve bacteria in large numbers succeed in colonizing the amoebae? Methods. We grew five non-farmer clones and five farmer clones of wild-collected Dictyostelium discoideum on three different concentrations of a highly palatable bacterial food source, Klebsiella pneumoniae. We then tested them to see if they carried bacteria through the social stage. Results. We found that bacterial density did not have a significant effect on whether or not the clones carried bacteria through the social stage. Even those grown in very dense bacterial cultures were able to shed them successfully unless they were also carrying Burkholderia. Discussion. Our results indicate that even a preponderance of food bacteria cannot overwhelm the ability of social amoebae to digest and not carry bacteria. Apparently, only the inedible Burkholderia have that effect. This points to the importance of understanding co-infection with multiple bacteria because those that cannot induce carriage can nevertheless become carried, foiling digestive processes, but only in the presence of another bacterium. Future studies of host bacteria interactions should consider using multiple bacteria simultaneously.

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