scholarly journals Mating-Type and Sexual Differentiation of Phytophthora Colocasiae in Japan

2021 ◽  
Author(s):  
Wenzhuo Feng ◽  
Ayaka Hieno ◽  
Kayoko Otsubo ◽  
Haruhisa Suga ◽  
Koji Kageyama
Keyword(s):  
Mating Type ◽  
Sexual Differentiation ◽  
Culture Medium ◽  
Pathogenicity Test ◽  
Mating Types ◽  
Stable Property ◽  
Phytophthora Colocasiae ◽  
Causes Of Disease ◽  
The Stability ◽  
Disease Persistence

Abstract In Japan, Phytophthora colocasiae causes the leaf blight of taro, which has resulted in huge losses since 2015. To investigate the causes of disease persistence and expansion, it is important to clarify the basic properties of this pathogen. We collected in total 317 P. colocasiae isolates from 99 fields in 7 prefectures during 2014 to 2020. The mating-type of each isolate was examined, and two or more isolates which were collected in single fields or taro leaves were selected to analyze the mating-type complexity. We found five kinds of mating types were identified: heterothallic A1 and A2, self-fertile (SF) A1, A2 and A1/A2 types, and a complex and diverse distribution of mating-types was present in one field or leaf. In addition, the stability of each mating-type was analyzed by single hyphae, zoospore and zoosporangium. The results suggested that the SF isolates were shown to be genetically unstable, while heterothallic isolates had a stable property. In the pathogenicity test of different mating-type isolates, heterothallic A1 isolates were less pathogenic than heterothallic A2 and SF isolates. However, there was no relationship between the pathogenicity and the growth rate on culture medium.

scholarly journals Mating types of Phytophthora colocasiae on the island of Upolu, Samoa

2018 ◽  
Vol 71 ◽  
pp. 289-292 ◽  
Author(s):  
Kieran D. Mellow ◽  
Joy L. Tyson ◽  
Robert A. Fullerton ◽  
Angelika Tugaga ◽  
Fa'alelei Tunupopo ◽  
...  
Keyword(s):  
Sexual Reproduction ◽  
Mating Type ◽  
Genetic Recombination ◽  
Leaf Blight ◽  
Phytophthora Nicotianae ◽  
Mating Types ◽  
Comprehensive Understanding ◽  
Phytophthora Colocasiae ◽  
Oospore Formation ◽  
Taro Leaf Blight

Taro leaf blight (TLB) caused by Phytophthora colocasiae is a damaging disease that destroyed Samoa’s taro industry following its introduction in 1993. The aim of this study was to determine the occurrence of the A1 and A2 mating types of P. colocasiae for a more comprehensive understanding of the risk the pathogen poses for the future of the taro industry in Samoa. In September 2015, 54 isolates of P. colocasiae were collected from taro leaf blight lesions from 13 farms around the island of Upolu, Samoa. The mating types of each isolate was determined by observation of oospore formation when paired with tester isolates of Phytophthora nicotianae of known mating types (A1 or A2). Fifty isolates were found to be A2 mating type and four did not form oospores with either mating type. No A1 or self-fertile isolates were found. These results suggest that the A1 mating type has not been introduced to the island of Upolu, preventing the formation of oospores between compatible mating types of P. colocasiae and lessening the risk of new and potentially more threatening genotypes of the pathogen from emerging through genetic recombination. Keywords taro leaf blight, Colocasia esculenta, taro, sexual reproduction

scholarly journals Differential Gene Expression between Fungal Mating Types Is Associated with Sequence Degeneration

2020 ◽  
Vol 12 (4) ◽  
pp. 243-258 ◽  
Author(s):  
Wen-Juan Ma ◽  
Fantin Carpentier ◽  
Tatiana Giraud ◽  
Michael E Hood
Keyword(s):  
Differential Expression ◽  
Differentially Expressed Genes ◽  
Mating Type ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Gc Content ◽  
Differentially Expressed ◽  
Mating Types ◽  
Sexual Antagonism ◽  
Recombination Suppression

Abstract Degenerative mutations in non-recombining regions, such as in sex chromosomes, may lead to differential expression between alleles if mutations occur stochastically in one or the other allele. Reduced allelic expression due to degeneration has indeed been suggested to occur in various sex-chromosome systems. However, whether an association occurs between specific signatures of degeneration and differential expression between alleles has not been extensively tested, and sexual antagonism can also cause differential expression on sex chromosomes. The anther-smut fungus Microbotryum lychnidis-dioicae is ideal for testing associations between specific degenerative signatures and differential expression because 1) there are multiple evolutionary strata on the mating-type chromosomes, reflecting successive recombination suppression linked to mating-type loci; 2) separate haploid cultures of opposite mating types help identify differential expression between alleles; and 3) there is no sexual antagonism as a confounding factor accounting for differential expression. We found that differentially expressed genes were enriched in the four oldest evolutionary strata compared with other genomic compartments, and that, within compartments, several signatures of sequence degeneration were greater for differentially expressed than non-differentially expressed genes. Two particular degenerative signatures were significantly associated with lower expression levels within differentially expressed allele pairs: upstream insertion of transposable elements and mutations truncating the protein length. Other degenerative mutations associated with differential expression included nonsynonymous substitutions and altered intron or GC content. The association between differential expression and allele degeneration is relevant for a broad range of taxa where mating compatibility or sex is determined by genes located in large regions where recombination is suppressed.

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.

scholarly journals A PCR-based Assay for Distinguishing between A1 and A2 Mating Types of Phytophthora capsici

2017 ◽  
Vol 142 (4) ◽  
pp. 260-264
Author(s):  
Ping Li ◽  
Dong Liu ◽  
Min Guo ◽  
Yuemin Pan ◽  
Fangxin Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Phytophthora Capsici ◽  
Mating Types ◽  
Sequence Repeat ◽  
Chain Reaction ◽  
Plant Parasite ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Microsatellite Diversity

Sexual reproduction in the plant parasite Phytophthora capsici Leonian requires the interaction of two distinct mating types, A1 and A2. Co-occurrence of these mating types can enhance the genetic diversity of P. capsici and alter its virulence or resistance characteristics. Using an intersimple sequence repeat (ISSR) screen of microsatellite diversity, we identified, cloned, and sequenced a novel 1121-base pair (bp) fragment specific to the A1 mating type of P. capsici. Primers Pcap-1 and Pcap-2 were designed from this DNA fragment to specifically detect the A1 mating type. Polymerase chain reaction (PCR) using these primers amplified an expected 997-bp fragment from known A1 mating types, but yielded a 508-bp fragment from known A2 mating types. This PCR-based assay could be adapted to accurately and rapidly detect the co-occurrence of A1 and A2 P. capsici mating types from field material.

The alpha-mating type locus of Cryptococcus neoformans contains a peptide pheromone gene

1993 ◽  
Vol 13 (3) ◽  
pp. 1962-1970
Author(s):  
T D Moore ◽  
J C Edman
Keyword(s):  
Cryptococcus Neoformans ◽  
Mating Type ◽  
Cell Types ◽  
Yeast Cells ◽  
Mating Types ◽  
Type Locus ◽  
Reading Frame ◽  
Cloning Method ◽  
Opportunistic Fungal Pathogen ◽  
Specific Fragment

The opportunistic fungal pathogen Cryptococcus neoformans has two mating types, MATa and MAT alpha. The MAT alpha strains are more virulent. Mating of opposite mating type haploid yeast cells results in the production of a filamentous hyphal phase. The MAT alpha locus has been isolated in this study in order to identify the genetic differences between mating types and their contribution to virulence. A 138-bp fragment of MAT alpha-specific DNA which cosegregates with alpha-mating type was isolated by using a difference cloning method. Overlapping phage and cosmid clones spanning the entire MAT alpha locus were isolated by using this MAT alpha-specific fragment as a probe. Mapping of these clones physically defined the MAT alpha locus to a 35- to 45-kb region which is present only in MAT alpha strains. Transformation studies with fragments of the MAT alpha locus identified a 2.1-kb XbaI-HindIII fragment that directs starvation-induced filament formation in MATa cells but not in MAT alpha cells. This 2.1-kb fragment contains a gene, MF alpha, with a small open reading frame encoding a pheromone precursor similar to the lipoprotein mating factors found in Saccharomyces cerevisiae, Ustilago maydis, and Schizosaccharomyces pombe. The ability of the MATa cells to express, process, and secrete the MAT alpha pheromone in response to starvation suggests similar mechanisms for these processes in both cell types. These results also suggest that the production of pheromone is under a type of nutritional control shared by the two cell types.

The origin of multiple mating types in mushrooms

1993 ◽  
Vol 104 (2) ◽  
pp. 227-230
Author(s):  
U. Kues ◽  
L.A. Casselton
Keyword(s):  
Mating Type ◽  
Multiple Mating ◽  
Mating Types ◽  
Mating Partner ◽  
Binucleate Cells ◽  
Large Numbers ◽  
Mating Type Genes ◽  
And Function ◽  
Developmental Switch ◽  
Sterile Mycelium

Having multiple mating types greatly improves the chances of meeting a compatible mating partner, particularly in an organism like the mushroom that has no sexual differentiation and no mechanism for signalling to a likely mate. Having several thousands of mating types, as some mushrooms do, is, however, remarkable - and even more remarkable is the fact that individuals only recognise that they have met a compatible mate after their cells have fused. How are such large numbers of mating types generated and what is the nature of the intracellular interaction that distinguishes self from non- self? Answers to these fascinating questions come from cloning some of the mating type genes of the ink cap mushroom Coprinus cinereus. A successful mating in Coprinus triggers a major switch in cell type, the conversion of a sterile mycelium with uninucleate cells (monokaryon) to a fertile mycelium with binucleate cells (dikaryon) which differentiates the characteristic fruit bodies. The mating type genes that regulate this developmental switch map to two multiallelic loci designated A and B and these must both carry different alleles for full mating compatibility. A and B independently regulate different steps in the developmental switch, making it possible to study just one component of the system and work in our laboratory has concentrated on understanding the structure and function of the A genes. It is estimated that some 160 different A mating types exist in nature, any two of which can together trigger the A-regulated part of sexual development. The first clue to how such large numbers are generated came from classical genetic analysis, which identified two functionally redundant A loci, (alpha) and beta. Functional redundancy is, indeed, the key to multiple A mating types and, as seen in Fig.1, molecular cloning has identified many more genes than was possible by recombination analysis.

Identification of biosynthetic intermediates for the mating hormone α2 of the plant pathogen Phytophthora

2021 ◽  
Author(s):  
Suguru Ariyoshi ◽  
Yusuke Imazu ◽  
Ryuji Ohguri ◽  
Ryo Katsuta ◽  
Arata Yajima ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Plant Pathogen ◽  
Type Strain ◽  
Mating Types ◽  
Synthetic Intermediates ◽  
The Cross

Abstract The heterothallic group of the plant pathogen Phytophthora can sexually reproduce between the cross-compatible mating types A1 and A2. The mating hormone α2, produced by A2 mating type and utilized to promote the sexual reproduction of the partner A1 type, is known to be biosynthesized from phytol. In this study, we identified two biosynthetic intermediates, 11- and 16-hydroxyphytols (1 and 2), for α2 by administering the synthetic intermediates to an A2 type strain to produce α2 and by administering phytol to A2 strains to detect the intermediates in the mycelia. The results suggest that α2 is biosynthesized by possibly two cytochrome P450 oxygenases via two hydroxyphytol intermediates (1 and 2) in A2 hyphae and secreted outside.

INTERCONVERSION OF YEAST MATING TYPES II. RESTORATION OF MATING ABILITY TO STERILE MUTANTS IN HOMOTHALLIC AND HETEROTHALLIC STRAINS

Genetics ◽  
1977 ◽  
Vol 85 (3) ◽  
pp. 373A-393
Author(s):  
James B Hicks ◽  
Ira Herskowitz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Mating Types ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Ability ◽  
Mating Type Locus ◽  
Regulatory Information ◽  
Ho Gene

ABSTRACT The two mating types of the yeast Saccharomyces cerevisiae can be interconverted in both homothallic and heterothallic strains. Previous work indicates that all yeast cells contain the information to be both a and α and that the HO gene (in homothallic strains) promotes a change in mating type by causing a change at the mating type locus itself. In both heterothallic and homothallic strains, a defective α mating type locus can be converted to a functional a locus and subsequently to a functional α locus. In contrast, action of the HO gene does not restore mating ability to a strain defective in another gene for mating which is not at the mating type locus. These observations indicate that a yeast cell contains an additional copy (or copies) of α information, and lead to the "cassette" model for mating type interconversion. In this model, HM  a and hmα loci are blocs of unexpressed α regulatory information, and HMα and hm  a loci are blocs of unexpressed a regulatory information. These blocs are silent because they lack an essential site for expression, and become active upon insertion of this information (or a copy of the information) into the mating type locus by action of the HO gene.

scholarly journals Evolutionary strata on young mating-type chromosomes despite the lack of sexual antagonism

2017 ◽  
Vol 114 (27) ◽  
pp. 7067-7072 ◽  
Author(s):  
Sara Branco ◽  
Hélène Badouin ◽  
Ricardo C. Rodríguez de la Vega ◽  
Jérôme Gouzy ◽  
Fantin Carpentier ◽  
...  
Keyword(s):  
Mating Type ◽  
Balancing Selection ◽  
Smut Fungi ◽  
Mating Types ◽  
Sexual Antagonism ◽  
Recombination Suppression ◽  
Ancestral Gene ◽  
Anther Smut ◽  
Mating Type Genes ◽  
Suppressed Recombination

Sex chromosomes can display successive steps of recombination suppression known as “evolutionary strata,” which are thought to result from the successive linkage of sexually antagonistic genes to sex-determining genes. However, there is little evidence to support this explanation. Here we investigate whether evolutionary strata can evolve without sexual antagonism using fungi that display suppressed recombination extending beyond loci determining mating compatibility despite lack of male/female roles associated with their mating types. By comparing full-length chromosome assemblies from five anther-smut fungi with or without recombination suppression in their mating-type chromosomes, we inferred the ancestral gene order and derived chromosomal arrangements in this group. This approach shed light on the chromosomal fusion underlying the linkage of mating-type loci in fungi and provided evidence for multiple clearly resolved evolutionary strata over a range of ages (0.9–2.1 million years) in mating-type chromosomes. Several evolutionary strata did not include genes involved in mating-type determination. The existence of strata devoid of mating-type genes, despite the lack of sexual antagonism, calls for a unified theory of sex-related chromosome evolution, incorporating, for example, the influence of partially linked deleterious mutations and the maintenance of neutral rearrangement polymorphism due to balancing selection on sexes and mating types.

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