scholarly journals Nuclear interactions in a heterokaryon: insight from the model Neurospora tetrasperma

2014 ◽  
Vol 281 (1786) ◽  
pp. 20140084 ◽  
Author(s):  
Nicklas Samils ◽  
Jonàs Oliva ◽  
Hanna Johannesson
Keyword(s):  
Sexual Development ◽  
Mycelial Growth ◽  
Developmental Stages ◽  
Tissue Type ◽  
Mating Types ◽  
Sexual Stage ◽  
Expression Ratio ◽  
Filamentous Ascomycete ◽  
Expression Bias ◽  
Neurospora Tetrasperma

A heterokaryon is a tissue type composed of cells containing genetically different nuclei. Although heterokaryosis is commonly found in nature, an understanding of the evolutionary implications of this phenomenon is largely lacking. Here, we use the filamentous ascomycete Neurospora tetrasperma to study the interplay between nuclei in heterokaryons across vegetative and sexual developmental stages. This fungus harbours nuclei of two opposite mating types ( mat A and mat a ) in the same cell and is thereby self-fertile. We used pyrosequencing of mat -linked SNPs of three heterokaryons to demonstrate that the nuclear ratio is consistently biased for mat A -nuclei during mycelial growth (mean mat A / mat a ratio 87%), but evens out during sexual development (ratio ranging from 40 to 57%) . Furthermore, we investigated the association between nuclear ratio and expression of alleles of mat -linked genes and found that expression is coregulated to obtain a tissue-specific bias in expression ratio: during mycelial extension, we found a strong bias in expression for mat A -linked genes, that was independent of nuclear ratio, whereas at the sexual stage we found an expression bias for genes of the mat a nuclei. Taken together, our data indicate that nuclei cooperate to optimize the fitness of the heterokaryon, via both altering their nuclear ratios and coregulation genes expressed in the different nuclei.

scholarly journals Deletion of the Schizophyllum commune Aα Locus: The Roles of Aα Y and Z Mating-Type Genes

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1437-1444
Author(s):  
C Ian Robertson ◽  
Kirk A Bartholomew ◽  
Charles P Novotny ◽  
Robert C Ullrich
Keyword(s):  
Mating Type ◽  
Sexual Development ◽  
Schizophyllum Commune ◽  
Mating Types ◽  
Developmental Pathway ◽  
Mating Type Gene ◽  
Mating Type Genes ◽  
Regulatory Loci ◽  
Type Gene

The Aα locus is one of four master regulatory loci that determine mating type and regulate sexual development in Schizophyllum commune. We have made a plasmid containing a URA1 gene disruption of the Aα Y1 gene. Y1 is the sole Aα gene in Aα1 strains. We used the plasmid construction to produce an Aα null (i.e., AαΔ) strain by replacing the genomic Y1 gene with URA1 in an Aα1 strain. To characterize the role of the Aα genes in the regulation of sexual development, we transformed various Aα Y and Z alleles into AαΔ strains and examined the acquired mating types and mating abilities of the transformants. These experiments demonstrate that the Aα Y gene is not essential for fungal viability and growth, that a solitary Z Aα mating-type gene does not itself activate development, that Aβ proteins are sufficient to activate the A developmental pathway in the absence of Aα proteins and confirm that Y and Z genes are the sole determinants of Aα mating type. The data from these experiments support and refine our model of the regulation of A-pathway events by Y and Z proteins.

Mating types and sexual development in filamentous ascomycetes

1997 ◽  
Vol 61 (4) ◽  
pp. 411-428 ◽  
Author(s):  
E Coppin ◽  
R Debuchy ◽  
S Arnaise ◽  
M Picard
Keyword(s):  
Mating Type ◽  
Sexual Development ◽  
Single Species ◽  
Podospora Anserina ◽  
Type Model ◽  
Mating Types ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Hormonal Signal ◽  
Mat Genes

The progress made in the molecular characterization of the mating types in several filamentous ascomycetes has allowed us to better understand their role in sexual development and has brought to light interesting biological problems. The mating types of Neurospora crassa, Podospora anserina, and Cochliobolus heterostrophus consist of unrelated and unique sequences containing one or several genes with multiple functions, related to sexuality or not, such as vegetative incompatibility in N. crassa. The presence of putative DNA binding domains in the proteins encoded by the mating-type (mat) genes suggests that they may be transcriptional factors. The mat genes play a role in cell-cell recognition at fertilization, probably by activating the genes responsible for the hormonal signal whose occurrence was previously demonstrated by physiological experiments. They also control recognition between nuclei at a later stage, when reproductive nuclei of each mating type which have divided in the common cytoplasm pair within the ascogenous hyphae. How self is distinguished from nonself at the nuclear level is not known. The finding that homothallic species, able to mate in the absence of a partner, contain both mating types in the same haploid genome has raised more issues than it has resolved. The instability of the mating type, in particular in Sclerotinia trifolorium and Botrytinia fuckeliana, is also unexplained. This diversity of mating systems, still more apparent if the yeasts and the basidiomycetes are taken into account, clearly shows that no single species can serve as a universal mating-type model.

scholarly journals First description of the sexual stage ofVenturia effusa, causal agent of pecan scab

2019 ◽  
Author(s):  
Nikki D. Charlton ◽  
Mihwa Yi ◽  
Clive H. Bock ◽  
Minling Zhang ◽  
Carolyn A. Young
Keyword(s):  
Mating Type ◽  
Culture Media ◽  
Spatial Scales ◽  
Sexual Cycle ◽  
Economic Losses ◽  
Mating Types ◽  
Sexual Stage ◽  
Pecan Scab ◽  
Prevalent Disease ◽  
The Impact

ABSTRACTVenturia effusa, cause of pecan scab, is the most prevalent disease of pecan in the southeastern USA; epidemics of the disease regularly result in economic losses to the pecan industry. Recent characterization of the mating type distribution revealed the frequency of theMATidiomorphs are in equilibrium at various spatial scales, indicative of regular sexual recombination. However, the occurrence of the sexual stage ofV. effusahas never been observed, and the pathogen was previously believed to rely entirely on asexual reproduction. To explore the existence of a sexual cycle, we paired opposite mating types on oatmeal culture media. In initial experiments, cultures were incubated at 24 C for 2 mo for hyphal interactions to occur between mating types and then maintained at 4 C for 4 mo. Immature pseudothecia were initially observed but following exposure to a 12 h photoperiod for 2 weeks at 24 C, asci and ascospores developed. Further experiments explored the effect of time on pseudothecial development with 4 mo at 4 C as the optimal requirement. The results of this study demonstrate the heterothallic nature ofV. effusa.Following experiments investigated progeny from a sexual cross of an albino and a wild-type isolate. Evaluation of isolate pigmentation, mating type, and multilocus genotyping of single ascospore progeny provided evidence that recombination occurred within the sexual crosses. The impact of determining the source of the overwintering ascostroma will aid in management decisions to reduce the primary inoculum in the disease cycle.

scholarly journals Dynamic Spatial-Temporal Expression Ratio of X Chromosome to Autosomes but Stable Dosage Compensation in Mammals

2021 ◽  
Author(s):  
Sheng Hu Qian ◽  
Yu-Li Xiong ◽  
Lu Chen ◽  
Ying-Jie Geng ◽  
Xiao-Man Tang ◽  
...  
Keyword(s):  
X Chromosome ◽  
Dosage Compensation ◽  
Developmental Stages ◽  
Evolutionary Model ◽  
Orthologous Gene ◽  
Temporal Expression ◽  
Gene Expressions ◽  
Expression Ratio ◽  
Allele Expression ◽  
Comprehensive Evaluations

In the evolutionary model of dosage compensation, per-allele expression level of the X chromosome was proposed to have two-fold upregulation, compensating for its dose reduction in males (XY) compared to females (XX). However, the upregulation of X chromosome is still in dispute, and comprehensive evaluations are still lacking. By integrating multi-omics datasets in mammals, we investigated the expression ratios and underlying pattern of X to autosomes (X:AA ratio) and X to orthologs (X:XX ratio) at the transcriptome, translatome, and proteome layers. The results indicated a dynamic spatial-temporal X:AA ratio during development in human and mouse. Meanwhile, by tracing the evolution of orthologous gene expressions in chicken, platypus, and opossum, we found a constant expression ratio between X-linked genes in human and their autosomal orthologs in other species (X:XX ~1) across tissues and developmental stages, demonstrating stable dosage compensation in mammals. We also revealed that different epigenetic regulations could shape the higher tissue- and stage-specificity of X-linked gene expression, and affect X:AA ratios. We conclude that the dynamics of X:AA ratios are attributed to the different gene contents and expression preferences of the X chromosome, instead of the stable dosage compensation.

Collection, characterization, and utilization of germ plasm of Lentinula edodes

1995 ◽  
Vol 73 (S1) ◽  
pp. 955-961 ◽  
Author(s):  
S. T. Chang ◽  
H. S. Kwan ◽  
Y. N. Kang
Keyword(s):  
Molecular Markers ◽  
Mycelial Growth ◽  
Germ Plasm ◽  
Lentinula Edodes ◽  
Molecular Genetic ◽  
Genetic Maps ◽  
Mating Types ◽  
Genomic Fingerprinting ◽  
Polymerase Chain ◽  
Selection Of

Wild and cultivated strains of Lentinula edodes have been collected to form a germ-plasm bank of the mushroom. In addition to the ecological, morphological, and physical properties, the strains were characterized to determine their mating types (alleles of A and B incompatibility factors), substrate degradation abilities, mycelial growth rates, and fruiting abilities. The strains were used to establish molecular genetic methods of strain authentification. The genomic fingerprinting method of arbitrarily primed polymerase chain reaction was found to be a better method than the rDNA internal transcribed spacer regions sequence comparison for L. edodes strain typing. The utilization of the characterized germ-plasm bank for the selection of desirable germ plasm for breeding and cultivation is described. The value and use of molecular markers and genetic maps is also discussed. Key words: mating types, mycelial growth rate, molecular markers.

Molecular characterisation of oestrogen receptor ERα and the effects of bisphenol A on its expression during sexual development in the Chinese giant salamander (Andrias davidianus)

2019 ◽  
Vol 31 (2) ◽  
pp. 261
Author(s):  
Yao Gao ◽  
Chenhao Yang ◽  
Huihui Gao ◽  
Liqing Wang ◽  
Changming Yang ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Sexual Development ◽  
Oestrogen Receptor ◽  
Developmental Stages ◽  
Ovary Development ◽  
Testicular Development ◽  
Interstitial Tissue ◽  
Andrias Davidianus ◽  
Reading Frame ◽  
Chinese Giant Salamander

The aim of this study was to characterise the molecular structure of the oestrogen receptor ERα and to evaluate the effect of bisphenol A (BPA) on ERα expression during sexual development of the Chinese giant salamander (Andrias davidianus). The ERα cDNA of A. davidianus includes an open reading frame of 1755bp (encoding 584 amino acids), a 219-bp 5′ untranslated region (UTR) and a 611-bp 3′UTR. A polyadenylation signal was not found in the 3′UTR. Amino acid sequence analysis showed high homology between ERα of A. davidianus and that of other amphibians, such as Andrias japonicas (99.66% identity) and Rana rugose (81.06% identity). In 3-year-old A. davidianus, highest ERα expression was observed in the liver and gonads. During different developmental stages in A. davidianus (from 1 to 3 years of age), ERα expression in the testes increased gradually. ERα was localised in the epithelial cells of seminiferous lobules and in interstitial cells. ERα-positive cells were more abundant in the interstitial tissue during testicular development. ERα was located in the nucleus of oocytes during ovary development. We found that the sex of 6-month-old A. davidianus larvae could not be distinguished anatomically. The sex ratio did not change after larvae were treated with 10μM BPA for 1 month. However, BPA treatment reduced bodyweight and ERα expression in the gonads in male larvae.

THE MIGRATION OF FUNGAL NUCLEI IN AN ELECTRIC FIELD

1942 ◽  
Vol 20c (2) ◽  
pp. 92-100 ◽  
Author(s):  
E. S. Dowding ◽  
E. H. Gowan
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Mycelial Growth ◽  
Nuclear Migration ◽  
Normal Direction ◽  
The Other ◽  
Electric Currents ◽  
Pass Through ◽  
Neurospora Tetrasperma

The mycelium of Neurospora tetrasperma readily conducts an electric current. During the time an electric current of about 5 μa. is allowed to pass through cultures of N. tetrasperma or Gelasinospora tetrasperma, mycelial growth ceases almost entirely, but afterwards the fungi grow normally again and show no ill effects. Electric currents of the order of 1 or 10 μa. running in either direction through two fused strains of N. tetrasperma do not alter the normal direction of nuclear migration from one strain to the other.

scholarly journals Contribution of Hydrogen Cyanide to the Antagonistic Activity of Pseudomonas Strains Against Phytophthora infestans

2020 ◽  
Vol 8 (8) ◽  
pp. 1144
Author(s):  
Abhishek Anand ◽  
Delphine Chinchilla ◽  
Christopher Tan ◽  
Laurent Mène-Saffrané ◽  
Floriane L’Haridon ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Phytophthora Infestans ◽  
Hydrogen Cyanide ◽  
Mycelial Growth ◽  
Developmental Stages ◽  
Antagonistic Activity ◽  
Potato Leaf ◽  
Relative Contribution ◽  
Production Of Hydrogen

Plants face many biotic and abiotic challenges in nature; one of them is attack by disease-causing microbes. Phytophthora infestans, the causal agent of late blight is one of the most prominent pathogens of the potato responsible for multi-billion-dollar losses every year. We have previously reported that potato-associated Pseudomonas strains inhibited P. infestans at various developmental stages. A comparative genomics approach identified several factors putatively involved in this anti-oomycete activity, among which was the production of hydrogen cyanide (HCN). Here, we report the relative contribution of HCN emission to the overall anti-Phytophthora activity of two cyanogenic Pseudomonas strains, P. putida R32 and P. chlororaphis R47. To quantify this contribution, we generated HCN-negative mutants (Δhcn) and compared their activities to those of their respective wild types in different experiments assessing P. infestans mycelial growth, zoospore germination, and infection of potato leaf disks. Using in vitro experiments allowing only volatile-mediated interactions, we observed that HCN accounted for most of the mycelial growth inhibition (57% in R47 and 80% in R32). However, when allowing both volatile and diffusible compound-mediated interactions, HCN only accounted for 1% (R47) and 18% (R32) of mycelial growth inhibition. Likewise, both mutants inhibited zoospore germination in a similar way as their respective wild types. More importantly, leaf disk experiments showed that both wild-type and Δhcn strains of R47 and R32 were able to limit P. infestans infection to a similar extent. Our results suggest that while HCN is a major contributor to the in vitro volatile-mediated restriction of P. infestans mycelial growth, it does not play a major role in the inhibition of other disease-related features such as zoospore germination or infection of plant tissues.

scholarly journals Sex-linked transcriptional divergence in the hermaphrodite fungus Neurospora tetrasperma

2013 ◽  
Vol 280 (1764) ◽  
pp. 20130862 ◽  
Author(s):  
Nicklas Samils ◽  
Anastasia Gioti ◽  
Magnus Karlsson ◽  
Yu Sun ◽  
Takao Kasuga ◽  
...  
Keyword(s):  
Mating Type ◽  
Sequence Divergence ◽  
Differentially Expressed ◽  
Female Development ◽  
Molecular Phenotype ◽  
Filamentous Ascomycete ◽  
Agar Media ◽  
Suppressed Recombination ◽  
Neurospora Tetrasperma ◽  
Male Tissue

In the filamentous ascomycete Neurospora tetrasperma , a large (approx. 7 Mbp) region of suppressed recombination surrounds the mating-type ( mat ) locus. While the remainder of the genome is largely homoallelic, this region of recombinational suppression, extending over 1500 genes, is associated with sequence divergence. Here, we used microarrays to examine how the molecular phenotype of gene expression level is linked to this divergent region, and thus to the mating type. Culturing N. tetrasperma on agar media that induce sexual/female or vegetative/male tissue, we found 196 genes significantly differentially expressed between mat A and mat a mating types. Our data show that the genes exhibiting mat -linked expression are enriched in the region genetically linked to mating type, and sequence and expression divergence are positively correlated. Our results indicate that the phenotype of mat A strains is optimized for traits promoting sexual/female development and the phenotype of mat a strains for vegetative/male development. This discovery of differentially expressed genes associated with mating type provides a link between genotypic and phenotypic divergence in this taxon and illustrates a fungal analogue to sexual dimorphism found among animals and plants.

scholarly journals MAT Loci Play Crucial Roles in Sexual Development but Are Dispensable for Asexual Reproduction and Pathogenicity in Rice Blast Fungus Magnaporthe oryzae

2021 ◽  
Vol 7 (10) ◽  
pp. 858
Author(s):  
Jiao-yu Wang ◽  
Shi-zhen Wang ◽  
Zhen Zhang ◽  
Zhong-na Hao ◽  
Xiao-xiao Shi ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Magnaporthe Oryzae ◽  
Sexual Development ◽  
Fungal Pathogen ◽  
Rice Blast ◽  
Molecular Mechanisms ◽  
Mating Types ◽  
Mat Genes

Magnaporthe oryzae, a fungal pathogen that causes rice blast, which is the most destructive disease of rice worldwide, has the potential to perform both asexual and sexual reproduction. MAT loci, consisting of MAT genes, were deemed to determine the mating types of M. oryzae strains. However, investigation was rarely performed on the development and molecular mechanisms of the sexual reproduction of the fungus. In the present work, we analyzed the roles of two MAT loci and five individual MAT genes in the sex determination, sexual development and pathogenicity of M. oryzae. Both of the MAT1-1 and MAT1-2 loci are required for sex determination and the development of sexual structures. MAT1-1-1, MAT1-1-3 and MAT1-2-1 genes are crucial for the formation of perithecium. MAT1-1-2 impacts the generation of asci and ascospores, while MAT1-2-2 is dispensable for sexual development. A GFP fusion experiment indicated that the protein of MAT1-1-3 is distributed in the nucleus. However, all of the MAT loci or MAT genes are dispensable for vegetative growth, asexual reproduction, pathogenicity and pathogenicity-related developments of the fungus, suggesting that sexual reproduction is regulated relatively independently in the development of the fungus. The data and methods of this work may be helpful to further understand the life cycle and the variation of the fungus.

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