Single Mating Type Research Articles

Population distribution characteristics of mating type genes and genetic stability in Morchella sextelata.

The reproductive mode of morels (Morchella spp.) is governed by mating type genes, specifically MAT1-1 and MAT1-2. This study investigated the presence of mating type genes at various growth stages and in different parts of cultivated Morchella sextelata. This study revealed significant fluctuations in the detection ratio of the two mating type genes during ascocarps growth. Single ascospore strains with MAT1-1, MAT1-2 and both mating types were selected for experimentations. Stress stimuli including H2O2, Congo red and NaCl were introduced into the medium. Differences in the cultural and physiological characteristics of single spore strains were analyzed, and mating type genes were identified after subculturing to assess their stability. The results indicated that a total of 297 samples with a single mating type gene were detected in 480 samples selected from the five stages of fruiting body growth, accounting for 61.9%. Stress exposure influenced colony morphology, mycelial growth rate, and biomass, leading to significant increases in malondialdehyde content and osmotic adjustment compounds, including soluble protein and proline. Physiological and biochemical parameters varied among the three mating type strains under different stress conditions. Principal component analysis was used to calculate the weight values, which showed that the MAT1-2 strain exhibited the highest tolerance to chemical stresses, particularly oxidative stress. Subculturing under stress revealed that single mating type strains ceased growth by the 8th generation, whereas both mating type strains could continue to the 15th generation without loss of mating type genes, indicating broader environmental adaptability and higher viability. These findings offer novel insights into mating type gene function and serve as a scientific foundation for the development of high-yield, stress-resistant morel varieties.

Effects of mating-type ratio imbalance on the degeneration of Cordyceps militaris subculture and preventative measures.

The rapid degeneration of Cordyceps militaris strains during subculture represents a bottleneck problem that affects production stability. This study explored the mechanism underlying this degeneration in three production and three wild-type strains of Cordyceps militaris, isolating single-conidium strains from each. The effects of subculturing on fructification in both original and single mating-type strains were compared. Changes in the ratio of the two mating types were analyzed in both original and degenerated strains. Based on these findings, the two mating strains were paired in different ratios to determine their effects on fruiting. The resulting five strains were heterokaryotic strains with both MAT1-1 and MAT1-2 mating-type genes. Strain jb-2 was a single mating type (MAT1-1) mutant strain that produced stable fruiting bodies but failed to produce ascospores. It was found that the loss of or imbalance in mating types was the main reason for the rapid degeneration of fruiting traits during subculture and that this occurred randomly in the MAT1-1 and MAT1-2 types. The strains differed significantly in their stability during subculture. Fruiting was stable in the single mating-type Jb-2 strain, and the eleventh-generation fruited normally. There were differences in yield between the production and wild strains after inoculation with spawn containing different proportions of mating types. The production strain was more stable when inoculated with strains with mating-type ratios of 1:9 to 9:1 without affecting the yield. However, the yield of the wild-type strain xf-1 was positively correlated with the proportion of the MAT1-2 type, while the other two strains showed no correlations. Subculturing single mating-type mycelia separately and mixing them before production effectively mitigated degeneration during subculture. For Cordyceps militaris breeding, selecting strains containing both mating types, which are insensitive to the proportion of mating-type genes, enhanced stability in subculture and reduced the risk of mating-type loss. Direct breeding of specific single-mating type strains to induce fruiting is thus an effective breeding strategy.

Mating type and microsatellite genotyping indicate that the Tunisian population of Phyllosticta citricarpa is clonal and thrives only asexually

Citrus black spot (CBS) caused by Phyllosticta citricarpa was reported for the first time in Tunisia in 2019. This was also the first reported occurrence of the disease in a Mediterranean climate. In Tunisia, CBS is mainly found in lemon (Citrus limon) orchards, and is seldom observed on sweet orange (Citrus × sinensis). This recent finding in North Africa raises questions about how the disease has been able to spread under Mediterranean climatic conditions. In this work, 216 Phyllosticta strains collected from lemon orchards in 2021, 2022 and 2023 throughout the country's main citrus-growing provinces were characterised by species morphological and molecular identification, mating type and Simple Sequence Repeats (SSR) microsatellite genotyping (MLG). P. citricarpa was the only species found to be associated with CBS in Tunisia. Although P. citricarpa is a heterothallic fungal species, potentially able to reproduce both sexually and asexually, a single mating type (MAT 1-1-1) idiomorph was found in the population. In addition, three MLGs were observed, across ten microsatellite loci, one of which was massively represented (93 %), indicating a clonal population. The clonality observed suggests a single recent introduction of the pathogen into the country. These findings support the idea that in Tunisia, P. citricarpa only reproduces asexually by pycniospores, with a relatively limited dispersal potential. This is consistent with the absence of pseudothecia on the leaf litter. These results show that CBS is able to thrive under Mediterranean conditions, even in the absence of sexual reproduction. This should be taken into consideration for CBS risk assessment and management.

Biological characteristics of Cordyceps militaris single mating-type strains.

Cordyceps militaris has been extensively cultivated as a model cordyceps species for commercial purposes. Nevertheless, the problems related to strain degeneration and breeding technologies remain unresolved. This study assessed the physiology and fertility traits of six C. militaris strains with distinct origins and characteristics, focusing on single mating-type strains. The results demonstrated that the three identified strains (CMDB01, CMSY01, and CMJB02) were single mating-type possessing only one mating-type gene (MAT1-1). In contrast, the other three strains (CMXF07, CMXF09, and CMMS05) were the dual mating type. The MAT1-1 strains sourced from CMDB01, CMSY01, and CMJB02 consistently produced sporocarps but failed to generate ascospores. However, when paired with MAT1-2 strains, the MAT1-1 strains with slender fruiting bodies and normal morphology were fertile. The hyphal growth rate of single mating-type strains (CMDB01, CMSY01, and CMJB02) typically surpassed that of dual mating-type strains (CMXF07, CMXF09, and CMMS05). The growth rates of MAT1-2 and MAT1-1 strains were proportional to their ratios, such that a single mating-type strain with a higher ratio exhibited an increased growth rate. As C. militaris matured, the adenosine content decreased. In summary, the C. militaris strains that consistently produce sporocarps and have a single mating type are highly promising for production and breeding.

Invasive Californian death caps develop mushrooms unisexually and bisexually

Canonical sexual reproduction among basidiomycete fungi involves the fusion of two haploid individuals of different mating types, resulting in a heterokaryotic mycelial body made up of genetically different nuclei. Using population genomics data and experiments, we discover mushrooms of the invasive and deadly Amanita phalloides can also be homokaryotic; evidence of sexual reproduction by single, unmated individuals. In California, genotypes of homokaryotic mushrooms are also found in heterokaryotic mushrooms, implying nuclei of homokaryotic mycelia are also involved in outcrossing. We find death cap mating is controlled by a single mating type locus, but the development of homokaryotic mushrooms appears to bypass mating type gene control. Ultimately, sporulation is enabled by nuclei able to reproduce alone as well as with others, and nuclei competent for both unisexuality and bisexuality have persisted in invaded habitats for at least 17 but potentially as long as 30 years. The diverse reproductive strategies of invasive death caps are likely facilitating its rapid spread, suggesting a profound similarity between plant, animal and fungal invasions.

MIL-CELL: a tool for multi-scale simulation of yeast replication and prion transmission

The single-celled baker’s yeast, Saccharomyces cerevisiae, can sustain a number of amyloid-based prions, the three most prominent examples being [URE3], [PSI+], and [PIN+]. In the laboratory, haploid S. cerevisiae cells of a single mating type can acquire an amyloid prion in one of two ways (i) spontaneous nucleation of the prion within the yeast cell, and (ii) receipt via mother-to-daughter transmission during the cell division cycle. Similarly, prions can be lost due to (i) dissolution of the prion amyloid by its breakage into non-amyloid monomeric units, or (ii) preferential donation/retention of prions between the mother and daughter during cell division. Here we present a computational tool (Monitoring Induction and Loss of prions in Cells; MIL-CELL) for modelling these four general processes using a multiscale approach describing both spatial and kinetic aspects of the yeast life cycle and the amyloid-prion behavior. We describe the workings of the model, assumptions upon which it is based and some interesting simulation results pertaining to the wave-like spread of the epigenetic prion elements through the yeast population. MIL-CELL is provided as a stand-alone GUI executable program for free download with the paper. MIL-CELL is equipped with a relational database allowing all simulated properties to be searched, collated and graphed. Its ability to incorporate variation in heritable properties means MIL-CELL is also capable of simulating loss of the isogenic nature of a cell population over time. The capability to monitor both chronological and reproductive age also makes MIL-CELL potentially useful in studies of cell aging.

Diversity Profiling and the Distribution of Pathotypes and Mating Types in Indian Isolates of Ascochyta rabiei Causing Ascochyta Blight of Chickpea

The prevalence and distribution of pathotypes and mating types of Ascochyta rabiei (Pass.) Labr. were evaluated during the winter (October to March) seasons of 2017-18 and 2018-19. Forty-five A. rabiei isolates were obtained from six different states. From the survey results, the state of Punjab recorded the highest disease rating (Rating 9) compared with other chickpea-growing areas. The β-tubulin gene was amplified (330 bp) from all the isolates, and sequence analysis was performed. The phylogenetic tree produced by cluster analysis of β-tubulin gene sequences differentiated the 44 A. rabiei isolates . Using multiplex PCR, mating types were identified. From the mating type (MAT) study of all the A. rabiei isolates, amplification was observed at the 490-bp size, which corresponds to mating type 2 (MAT1-2). The four pathotypes (I, II, III, IV) and six physiological races were delineated based on the differential reaction of the disease. The most widely distributed pathotype was pathotype III (52.27%) among the surveyed regions of North Indian states, except Uttarakhand (where only pathotype II was recorded), followed by the least aggressive pathotype I (22.7%), highly aggressive pathotype IV (15.9%), and aggressive pathotype II (9.1%). Among the six physiological races identified, the most common races were race 5 (25%), followed by race 1 (22.73%), race 6 (18.18%), race 4 (18.18%), race 3 (9.09%), and race 2 (6.82%). Because of the prevalence of a single mating type among the surveyed locations in India, we opine that there may be less diversity in A. rabiei compared with isolates reported from other countries. However, to substantiate this conclusion, evaluation of more isolates of A. rabiei is required. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

The relationship between the preference of mating type (MAT) and source in the opportunistic pathogen Talaromyces marneffei.

Genome-wide comparisons have shown Talaromyces marneffei possessed a stable mating type locus in its meiosis genes. But the function of mating type locus in Talaromyces marneffei is not clear. The potential sex recombination might lead to problems in clinical, such as the evolution of increased resistance to antifungal drugs and virulence. To determine the mating type in a sample of 107 Talaromyces marneffei isolates and to explore the possible relationship between fungus virulence and mating type or source. We used PCR analysis to determine the distribution of mating type genes and also analyzed the relationship between mating type and isolated sources (including HIV-positive patients, HIV-negative patients, bamboo rats and environment). Further, Drosophila melanogaster model of infection was used to compare the different of virulence in mating type and sources. Our results showed entire sample population of Talaromyces marneffei with an overabundance of MAT1-2 alleles, but with higher ratio of MAT1-1 in the isolates from HIV-negative patients. However, no significant differences in the survival of the Drosophila melanogaster infected neither with MAT1-1 (6.5 days) nor MAT1-2 (4 days) isolates. Similar results were also observed in virulence analysis tested with different sources of isolates. So, we found that all isolates bearing single mating type idiomorphs and unequal distribution. The distribution of the MAT genes seems related to different sources. And the virulence differences are independent of mating type genotype and source.

Temporal and Spatial Variation in the Population Structure of Spanish Fusarium circinatum Infecting Pine Stands

Fusarium circinatum is an introduced fungal pathogen extended to the northern regions of Spain that causes Pine Pitch Canker (PPC) disease. In this work, we analyzed the pathogen's genetic diversity to study changes over time and space since the first outbreak occurred in Spain. Using six polymorphic SSR markers, 15 MLGs were identified in 66 isolates, and only three haplotypes were found with frequencies higher than one. In general, genotypic diversity was low and decreased shortly over time in the northwestern regions while maintained at País Vasco, where only one haplotype (MLG32) was detected 10 years. This population also included isolates of a single mating type (MAT-2) and VCGs identified in only two groups, while isolates from NW regions were of both mating types and VCGs represented in 11 groups. The existence of haplotype MLG32 maintained on time and widely distributed suggests its good adaptation to the environment and the host. Results showed that the pathogen in País Vasco remains clearly differentiated from other northwestern populations. This fact was supported with no evidence of migration among regions. Results are explained by the asexual reproduction, but also selfing at least to a lesser extent that leads to identification of two new haplotypes.

P371 The relation of mating type (MAT) preference and source in the opportunistic pathogen Talaromyces marneffei

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM BackgroundGenome-wide comparisons have shown Talaromyces marneffei possessed a stable mating type locus in its meiosis genes. But the function of the mating-type locus in T. marneffei is not clear. The potential sex recombination might lead to problems in clinical, such as the evolution of increased resistance to antifungal drugs and virulence.ObjectivesTo determine mating type in a sample of 107 strains and to explore the possible relationship between mating-type and fungus virulence.MethodsWe used PCR analysis to determine the distribution of mating-type genes in 107 T. marneffei strains. We also analyzed the relationship between mating-type and isolated sources (including HIV-positive patients, HIV-negative patients, bamboo rats, and environment). Further, Drosophila melanogaster model of infection was used to compare the virulence difference between different mating-type and source strains.ResultsThe results showed an entire sample population of T. marneffei with an overabundance of MAT1-2 alleles, but with a higher ratio of MAT1-1 in the isolates from HIV-negative patients. However, no significant differences in the survival of the Drosophila melanogaster infected neither with MAT1-1 (6.5 days) nor MAT1-2 (4 days) isolates. Similar results were also observed in virulence analysis tested with different sources of isolates.ConclusionsAll isolates bearing single mating type idiomorphs and unequal distribution. The distribution of the MAT genes seems related to different sources. And the pathogenicity differences are independent of mating type genotype and source.

Efficient breeding of industrial brewing yeast strains using CRISPR/Cas9-aided mating-type switching

Yeast breeding is a powerful tool for developing and improving brewing yeast in a number of industry-relevant respects. However, breeding of industrial brewing yeast can be challenging, as strains are typically sterile and have large complex genomes. To facilitate breeding, we used the CRISPR/Cas9 system to generate double-stranded breaks in the MAT locus, generating transformants with a single specified mating type. The single mating type remained stable even after loss of the Cas9 plasmid, despite the strains being homothallic, and these strains could be readily mated with other brewing yeast transformants of opposite mating type. As a proof of concept, we applied this technology to generate yeast hybrids with an aim to increase β-lyase activity for fermentation of beer with enhanced hop flavour. First, a genetic and phenotypic pre-screening of 38 strains was carried out in order to identify potential parent strains with high β-lyase activity. Mating-competent transformants of eight parent strains were generated, and these were used to generate over 60 hybrids that were screened for β-lyase activity. Selected phenolic off-flavour positive (POF +) hybrids were further sporulated to generate meiotic segregants with high β-lyase activity, efficient wort fermentation, and lack of POF, all traits that are desirable in strains for the fermentation of modern hop-forward beers. Our study demonstrates the power of combining the CRISPR/Cas9 system with classic yeast breeding to facilitate development and diversification of brewing yeast.Key points• CRISPR/Cas9-based mating-type switching was applied to industrial yeast strains.• Transformed strains could be readily mated to form intraspecific hybrids.• Hybrids exhibited heterosis for a number of brewing-relevant traits.

Host range, genetic variability, and mating types of Lecanosticta acicola in Slovakia

ABSTRACT In recent years, there has been an apparent Europe-wide emerging presence of brown spot needle blight, a disease of pine species caused by the fungus Lecanosticta acicola. In this study, we report the first well-documented occurrences of the pathogen in Slovakia, identified molecularly using species-specific primers and based on sequencing of the ITS region and TEF1 gene. Among the material collected from 84 locations within the country, L. acicola was present in 17 samples from 13 different locations, mainly distributed in urban environments. Four pine species were identified as hosts, among which, Pinus nigra and P. mugo were found to be the most frequently infected. Analysis of the mating type genes of 24 isolates obtained from two localities revealed the presence of a single mating type in Slovakia. All analyzed ITS sequences of the Slovak isolates were found to be uniform. However, although analysis of the TEF1 gene indicated that all Slovak isolates could be grouped into a single lineage, we detected nucleotide polymorphisms suggestive of a certain degree of genetic diversification within central European populations of the fungus.

The Destructive Tree Pathogen Phytophthora ramorum Originates from the Laurosilva Forests of East Asia.

As global plant trade expands, tree disease epidemics caused by pathogen introductions are increasing. Since ca 2000, the introduced oomycete Phytophthora ramorum has caused devastating epidemics in Europe and North America, spreading as four ancient clonal lineages, each of a single mating type, suggesting different geographical origins. We surveyed laurosilva forests for P. ramorum around Fansipan mountain on the Vietnam-China border and on Shikoku and Kyushu islands, southwest Japan. The surveys yielded 71 P. ramorum isolates which we assigned to eight new lineages, IC1 to IC5 from Vietnam and NP1 to NP3 from Japan, based on differences in colony characteristics, gene x environment responses and multigene phylogeny. Molecular phylogenetic trees and networks revealed the eight Asian lineages were dispersed across the topology of the introduced European and North American lineages. The deepest node within P. ramorum, the divergence of lineages NP1 and NP2, was estimated at 0.5 to 1.6 Myr. The Asian lineages were each of a single mating type, and at some locations, lineages of “opposite” mating type were present, suggesting opportunities for inter-lineage recombination. Based on the high level of phenotypic and phylogenetic diversity in the sample populations, the coalescence results and the absence of overt host symptoms, we conclude that P. ramorum comprises many anciently divergent lineages native to the laurosilva forests between eastern Indochina and Japan.

Emergence and diversification of a highly invasive chestnut pathogen lineage across southeastern Europe.

Invasive microbial species constitute a major threat to biodiversity, agricultural production and human health. Invasions are often dominated by one or a small number of genotypes, yet the underlying factors driving invasions are poorly understood. The chestnut blight fungus Cryphonectria parasitica first decimated the North American chestnut, and a more recent outbreak threatens European chestnut stands. To unravel the chestnut blight invasion of southeastern Europe, we sequenced 230 genomes of predominantly European strains. Genotypes outside of the invasion zone showed high levels of diversity with evidence for frequent and ongoing recombination. The invasive lineage emerged from the highly diverse European genotype pool rather than a secondary introduction from Asia or North America. The expansion across southeastern Europe was mostly clonal and is dominated by a single mating type, suggesting a fitness advantage of asexual reproduction. Our findings show how an intermediary, highly diverse bridgehead population gave rise to an invasive, largely clonally expanding pathogen.

Kan Kültürlerinden İzole Edilen Candida parapsilosis Kompleks Türlerinin Eşey Tipi (MTL) Genotiplerinin Belirlenmesi

Objective: Candida parapsilosis is one of the most common species after Candida albicans among the causative factors of systemic candidosis. In Candida species, determination of the cell identity and the sexual reproduction process take place under the control of the mating type (MTLα) locus. This region has completely different sequences in two different mating types (a and α) and is called an idiomorph. While the MTLa idiomorph encodes the transcription factors a1 and a2, MTLα encodes α1 and α2 proteins. Apart from these genes, both idiomorphs have a or α versions of PAB, OBP, and PIK genes, whose functions in sexual reproduction are unknown. On the other hand, up to now neither Candida parapsilosis nor the closely related species Candida orthopsilosis or Candida metapsilosis has been reported to have sexual cycles. While C. orthopsilosis was found to have a mixed population structure harboring MTLa and MTLα homozygous and MTLa/MTLα heterozygous genotypes in realized studies, the majority of C. metapsilosis isolates were MTLa/MTLα heterozygotes. Nevertheless, all C. parapsilosis isolates analyzed were found to be of a single mating type (MTLa). Method: This study was aimed to determine the MTL genotypes of C. parapsilosis isolates of Turkey origin, and 167 blood isolates were used for this purpose. The isolates identified as C. parapsilosis by PCR-amplifying and sequencing the ITS region were screened for MTLa1, MTLa2, MTLα1 and MTLα2 genes. Results: Only MTLa1 and MTLa2 genes were detected in PCR; therefore, all isolates were determined to have the MTLa genotype. Conclusion: When the results are assessed with previous findings, it could be inferred that the MTLα mating type of C. parapsilosis has been lost or extremely rare in yet unanalyzed geographical regions.

Evolution of the mating type gene pair and multiple sexes in Tetrahymena.

SummaryThe multiple mating type system of the Ciliate Tetrahymena thermophila is a self/non-self recognition system, whose specificity resides in a head-to-head, functionally distinct pair of genes, MTA and MTB. We have now sequenced and analyzed these mating type genes in nine additional Tetrahymena species. We conclude that MTA and MTB are derived from a common ancestral gene and have co-evolved for at least ∼150 Myr. We show that T. shanghaiensis, a perpetual selfer (unisexual) species, has a single mating type gene pair, whose MTA and MTB genes likely have different mating type specificity. We document the recent replacement of a complete different set of mating type specificities for another, illustrating how quickly this can happen. We discuss how varying conditions of reproductive stress could result in evolutionary co-adaptations of MTA and MTB genes and changes in mating type determination mechanisms.

Drivers of Mating Type Composition in Tetrahymena thermophila.

Sex offers advantages even in primarily asexual species. Some ciliates appear to utilize such reproductive strategy with many mating types. However, the factors determining the composition of mating types in the unicellular ciliate Tetrahymena thermophila are poorly understood, and this is further complicated by non-Mendelian determination of mating type in the offspring. We therefore developed a novel population genetics model to predict how various factors influence the dynamics of mating type composition, including natural selection. The model predicted either the coexistence of all seven mating types or fixation of a single mating type in a population, depending on parameter combinations, irrespective of natural selection. To understand what factor(s) may be more influential and to test the validity of theoretical prediction, five replicate populations were maintained in laboratory such that several factors could be controlled or measured. Whole-genome sequencing was used to identify newly arising mutations and determine mating type composition. Strikingly, all populations were found to be driven by strong selection on newly arising beneficial mutations to fixation of their carrying mating types, and the trajectories of speed to fixation agreed well with our theoretical predictions. This study illustrates the evolutionary strategies that T. thermophila can utilize to optimize population fitness.

Mating strategy and mating type distribution in six global populations of the Eucalyptus foliar pathogen Teratosphaeria destructans

Teratosphaeria destructans is an aggressive fungal pathogen causing leaf and shoot blight on young Eucalyptus trees in plantations. The disease occurs across tropical and subtropical regions of South East Asia and has recently been found in South Africa. Asexual structures of the pathogen are produced on infected tissues, but sexual structures have never been observed. The aim of this study was to investigate the reproductive biology of T. destructans by characterising its mating type (MAT1) locus and investigating its potential for sexual recombination. We found that T. destructans has a heterothallic mating system, with either the MAT1-1-1 and MAT1-1-10 genes (MAT1-1 idiomorph) or the MAT1-2-1 and MAT1-2-12 genes (MAT1-2 idiomorph) present in a single individual. With a multiplex PCR assay, it was possible to distinguish the two MAT idiomorphs in several Teratosphaeria species and this approach was applied to six global populations of T. destructans. Although both mating types occurred in the South East Asian populations, a single mating type dominated each population. Isolates from the recent disease outbreak in South Africa comprised only a single mating type. Attempts to induce a sexual cycle in vitro using strains of opposite mating type were not successful. The uneven distribution of mating types in populations of T. destructans and the presence of only an asexual state on infected tissues suggests the absence of or at least a minor role for sexual reproduction where the pathogen occurs on non-native Eucalyptus in plantations.

Genomic characterization of mating type loci and mating type distribution in two apparently asexual plantation tree pathogens

The Eucalyptus stem canker pathogens Teratosphaeria gauchensis and T. zuluensis (Capnodiales, Teratosphaeriaceae) are found in many tropical regions of the world where their hosts are cultivated for plantation forestry. Population genetic analyses have suggested that some populations undergo recombination, even though their sexual states have never been observed. Against this background, the aim of this study was to characterize the mating type (MAT) locus of these species and thus to better understand the basis of their diversity. Known Mycosphaerellaceae MAT genes were used to identify and investigate the MAT locus in the T. gauchensis and T. zuluensis genomes. Both species were found to be heterothallic and primers were designed to amplify the opposite MAT idiomorphs as well as conserved regions within the MAT1‐1‐1 and MAT1‐2‐1 genes. Each Teratosphaeria MAT idiomorph was defined by either the MAT1‐1‐1 or the MAT1‐2‐1 gene, and an idiomorph‐specific hypothetical protein (MAT1‐1‐10 and MAT1‐2‐12). Populations of T. zuluensis from Asia and southern Africa were dominated by a single mating type, whereas the proportions of the different idiomorphs for T. gauchensis in South America and southern Africa were similar. There was no physical evidence of sexual reproduction for either species and it is argued that although recombination may be possible, it is unlikely to form an important part of their life cycles in diseased Eucalyptus plantations. Instead, continuous human‐mediated multiple introductions of these species have probably resulted in the current genetic structure of their populations, which holds risk for future disease outbreaks and interspecific hybridization.

She Loves Me, She Loves Me Not: On the Dualistic Asexual/Sexual Nature of Dermatophyte Fungi.

Dermatophytes are ascomycetous fungi whose sexuality is greatly influenced by their ecology. Sexual reproduction is ubiquitous among soil-related geophiles and some animal-associated zoophiles. In contrast, anthropophiles are generally present as a single mating type in the population and appear to reproduce asexually. In this article, the current knowledge on the sexuality of dermatophytes including reproduction modes, mating conditions, mating type distributions and the mating type (MAT) locus is presented in the context of revised taxonomy and discussed from an evolutionary perspective.