scholarly journals Presence of both mating types of Ascochyta rabiei in Argentina suggests potential for sexual reproduction

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
C Crociara ◽  
L Valetti ◽  
S Pastor
Keyword(s):  
Sexual Reproduction ◽  
Ascochyta Rabiei ◽  
Mating Types

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.

scholarly journals Gamete signalling underlies the evolution of mating types and their number

2016 ◽  
Vol 371 (1706) ◽  
pp. 20150531 ◽  
Author(s):  
Zena Hadjivasiliou ◽  
Andrew Pomiankowski
Keyword(s):  
Mathematical Model ◽  
Sexual Reproduction ◽  
Mating Types ◽  
Simple Mathematical Model ◽  
Unicellular Eukaryotes ◽  
Evolutionarily Stable

The gametes of unicellular eukaryotes are morphologically identical, but are nonetheless divided into distinct mating types. The number of mating types varies enormously and can reach several thousand, yet most species have only two. Why do morphologically identical gametes need to be differentiated into self-incompatible mating types, and why is two the most common number of mating types? In this work, we explore a neglected hypothesis that there is a need for asymmetric signalling interactions between mating partners. Our review shows that isogamous gametes always interact asymmetrically throughout sex and argue that this asymmetry is favoured because it enhances the efficiency of the mating process. We further develop a simple mathematical model that allows us to study the evolution of the number of mating types based on the strength of signalling interactions between gametes. Novel mating types have an advantage as they are compatible with all others and rarely meet their own type. But if existing mating types coevolve to have strong mutual interactions, this restricts the spread of novel types. Similarly, coevolution is likely to drive out less attractive mating types. These countervailing forces specify the number of mating types that are evolutionarily stable. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’.

scholarly journals Genomic and Population Analyses of the Mating Type Loci in Coccidioides Species Reveal Evidence for Sexual Reproduction and Gene Acquisition

2007 ◽  
Vol 6 (7) ◽  
pp. 1189-1199 ◽  
Author(s):  
M. Alejandra Mandel ◽  
Bridget M. Barker ◽  
Scott Kroken ◽  
Steven D. Rounsley ◽  
Marc J. Orbach
Keyword(s):  
Sexual Reproduction ◽  
Mating Type ◽  
Mating Types ◽  
Coccidioides Immitis ◽  
Genome Sequences ◽  
Valley Fever ◽  
Population Analyses ◽  
Gene Acquisition ◽  
Close Proximity

ABSTRACT Coccidioides species, the fungi responsible for the valley fever disease, are known to reproduce asexually through the production of arthroconidia that are the infectious propagules. The possible role of sexual reproduction in the survival and dispersal of these pathogens is unexplored. To determine the potential for mating of Coccidioides, we analyzed genome sequences and identified mating type loci characteristic of heterothallic ascomycetes. Coccidioides strains contain either a MAT1-1 or a MAT1-2 idiomorph, which is 8.1 or 9 kb in length, respectively, the longest reported for any ascomycete species. These idiomorphs contain four or five genes, respectively, more than are present in the MAT loci of most ascomycetes. Along with their cDNA structures, we determined that all genes in the MAT loci are transcribed. Two genes frequently found in common sequences flanking MAT idiomorphs, APN2 and COX13, are within the MAT loci in Coccidioides, but the MAT1-1 and MAT1-2 copies have diverged dramatically from each other. Data indicate that the acquisition of these genes in the MAT loci occurred prior to the separation of Coccidioides from Uncinocarpus reesii. An analysis of 436 Coccidioides isolates from patients and the environment indicates that in both Coccidioides immitis and C. posadasii, there is a 1:1 distribution of MAT loci, as would be expected for sexually reproducing species. In addition, an analysis of isolates obtained from 11 soil samples demonstrated that at three sampling sites, strains of both mating types were present, indicating that compatible strains were in close proximity in the environment.

scholarly journals Invasion and extinction dynamics of mating types under facultative sexual reproduction

2019 ◽  
Author(s):  
Peter Czuppon ◽  
George W. A. Constable
Keyword(s):  
Sexual Reproduction ◽  
Mating Type ◽  
Average Rate ◽  
Natural Populations ◽  
Null Model ◽  
Mating Types ◽  
Stationary Probability Distribution ◽  
Time To Extinction ◽  
Establishment Probability ◽  
Mean Time

AbstractIn sexually reproducing isogamous species, syngamy between gametes is generally not indiscriminate, but rather restricted to occurring between complementary self-incompatible mating types. A longstanding question regards the evolutionary pressures that control the number of mating types observed in natural populations, which ranges from two to many thousands. Here, we describe a population genetic null model of this reproductive system and derive expressions for the stationary probability distribution of the number of mating types, the establishment probability of a newly arising mating type and the mean time to extinction of a resident type. Our results yield that the average rate of sexual reproduction in a population correlates positively with the expected number of mating types observed. We further show that the low number of mating types predicted in the rare-sex regime is primarily driven by low invasion probabilities of new mating type alleles, with established resident alleles being very stable over long evolutionary periods. Moreover, our model naturally exhibits varying selection strength dependent on the number of present mating types. This results in higher extinction and lower invasion rates for an increasing number of residents.

scholarly journals Genetic Change Within Populations of Phytophthora infestans in the United States and Canada During 1994 to 1996: Role of Migration and Recombination

1998 ◽  
Vol 88 (9) ◽  
pp. 939-949 ◽  
Author(s):  
Stephen B. Goodwin ◽  
Christine D. Smart ◽  
Robert W. Sandrock ◽  
Kenneth L. Deahl ◽  
Zamir K. Punja ◽  
...  
Keyword(s):  
United States ◽  
Sexual Reproduction ◽  
Phytophthora Infestans ◽  
High Sensitivity ◽  
The United States ◽  
Rapid Identification ◽  
Mating Types ◽  
Long Distance ◽  
New Genotype ◽  
The Us

Dramatic changes occurred within populations of Phytophthora infestans in the United States and Canada from 1994 through 1996. Occurrence of the US-8 genotype, detected rarely during 1992 and 1993, increased rapidly and predominated in most regions during 1994 through 1996. US-7, which infected both potato and tomato and made up almost 50% of the sample during 1993, was detected only rarely among 330 isolates from the United States analyzed during 1994. It was not detected at all in more limited samples from 1996. Thus, ability to infect both potato and tomato apparently did not increase the fitness of this genotype relative to US-8, as predicted previously. US-1, the previously dominant genotype throughout the United States and Canada, made up 8% or less of the samples analyzed during 1994 through 1996. A few additional genotypes were detected, which could indicate the beginnings of sexual reproduction of P. infestans within the United States and Canada. However, clonal reproduction still predominated in all locations sampled; opportunities for sexual reproduction probably were limited, because the A1 and A2 mating types usually were separated geographically. The high sensitivity of the US-1 genotype to the fungicide metalaxyl also could have reduced opportunities for contact between the mating types in fields where this compound was applied. The previous correlation between metalaxyl sensitivity and genotype was confirmed and extended to a new genotype, US-17: all US-1 isolates tested were sensitive; all isolates of the US-7, US-8, and US-17 genotypes tested to date have been resistant. Isolates of P. capsici and P. erythroseptica, two other species often found on tomato and potato, could be easily distinguished from each other and from P. infestans using a simple allozyme assay for the enzyme glucose-6-phosphate isomerase. This technique could be useful for rapid identification of species, in addition to genotype of P. infestans. It generally was not possible to predict which genotypes would be present in a location from 1 year to the next. Long-distance movement of US-8 in seed tubers was documented, and this was probably the primary means for the rapid spread of this genotype from 1993 through 1996.

Isozyme Variability in Field Populations of Phytophthora cinnamomi in Australia

1988 ◽  
Vol 36 (3) ◽  
pp. 355 ◽  
Author(s):  
KM Old ◽  
MJ Dudzinski ◽  
JC Bell
Keyword(s):  
Sexual Reproduction ◽  
Phytophthora Cinnamomi ◽  
Soil Samples ◽  
Mating Types ◽  
South Eastern ◽  
Enzyme Loci ◽  
Eastern Australia ◽  
Wide Range ◽  
Isozyme Variability ◽  
South Eastern Australia

Isozyme characteristics of 280 isolates from populations of Phytophthora cinnamomi in native veg- etation in six locations in south-eastern Australia were examined at 19 enzyme loci. No new enzyme genotypic arrays were identified as compared with earlier samplings. This work indicates that the low variability for P. cinnamomi in Australia obtained in earlier work, from separate isolates in a wide range of locations, is paralleled in detailed population samples in south-eastern Australia. At one location, A1 and A2 mating types coexisted in soil samples. The lack of recombinants in these population samples suggests an absence of sexual reproduction in the field.

scholarly journals Eighty Years after Its Discovery, Fleming's Penicillium Strain Discloses the Secret of Its Sex

2008 ◽  
Vol 7 (3) ◽  
pp. 465-470 ◽  
Author(s):  
Birgit Hoff ◽  
Stefanie Pöggeler ◽  
Ulrich Kück
Keyword(s):  
Antibacterial Activity ◽  
Sexual Reproduction ◽  
Strain Improvement ◽  
Mating Types ◽  
Penicillin Production ◽  
Industrial Strain ◽  
Pheromone Receptor ◽  
Improvement Programs ◽  
Alexander Fleming ◽  
Penicillium Strain

ABSTRACT Eighty years ago, Alexander Fleming discovered antibacterial activity in the asexual mold Penicillium, and the strain he studied later was replaced by an overproducing isolate still used for penicillin production today. Using a heterologous PCR approach, we show that these strains are of opposite mating types and that both have retained transcriptionally expressed pheromone and pheromone receptor genes required for sexual reproduction. This discovery extends options for industrial strain improvement programs using conventional genetical approaches.

scholarly journals Genetic Structure of the Phytophthora infestans Population in Morocco

Plant Disease ◽  
2000 ◽  
Vol 84 (2) ◽  
pp. 173-176 ◽  
Author(s):  
M. Sedegui ◽  
R. B. Carroll ◽  
A. L. Morehart ◽  
T. A. Evans ◽  
S. H. Kim ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Late Blight ◽  
Sexual Reproduction ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Potato Seed ◽  
Mating Types ◽  
Potato Field ◽  
New Genotype

ABSRACT In 1996 to 1998, a late-blight survey was conducted in potato- and tomato-growing regions of Morocco. A total of 149 isolates of Phytophthora infestans were collected and analyzed for the glucose-6-phosphate isomerase (Gpi) and peptidase (Pep) alleles, mating types, and metalaxyl sensitivities. Four genotypes were identified: MO-1 (mating type A1, Gpi 100/100, Pep 92/100), MO-2 (mating type A1, Gpi 86/100, Pep 92/100), MO-3 (mating type A2 Gpi 100/100, Pep 100/100), and MO-4 (mating type A1, Gpi 100/100, Pep 100/100). The potato isolates were MO-1 (1996 & 97), MO-3 (1998), and MO-4 (1998). The frequencies of A1 (MO-4) and A2 (MO-3) mating types in potato fields in 1998 were 26 and 74%, respectively. Potato isolates were pathogenic to both potatoes and tomatoes. The isolates collected from tomatoes in 1997 and 1998 were MO-2. Potato and tomato isolates were insensitive and sensitive to metalaxyl, respectively. The change of genotype population in 1998 was probably caused by migration of a new genotype from Europe associated with importation of potato seed. The detection of A1 and A2 mating types in the same potato field indicates the potential for sexual reproduction of P. infestans in Morocco.

scholarly journals First Report of Ascochyta Blight of Cicer montbretii, a Wild Perennial Chickpea in Bulgaria

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 830-830 ◽  
Author(s):  
W. J. Kaiser ◽  
R. M. Hannan ◽  
F. J. Muehlbauer ◽  
M. Mihov
Keyword(s):  
Ascochyta Blight ◽  
Potato Dextrose Agar ◽  
Ascochyta Rabiei ◽  
Mating Types ◽  
Perennial Species ◽  
First Report ◽  
Native Populations ◽  
Plant Pathol ◽  
The Village ◽  
Time Of Collection

In the Stranja Mountains of southeastern Bulgaria, native populations of Cicer montbretii Jaub. & Spach were found on the edge of a road in an oak forest near the village of Gramatikova (42°1′38″N; 27°36′49″E) at an elevation of about 125 m. C. montbretii, a perennial species, is the only wild Cicer sp. native to Bulgaria. At the time of collection, necrotic lesions were observed on the stems, leaflets, and pods of several plants, and these lesions were reminiscent of those induced by Ascochyta rabiei (Pass.) Labrousse. The teleomorph (sexual stage) of A. rabiei, Didymella rabiei (Kovachevski) v. Arx (syn. Mycosphaerella rabiei Kovachevski), was discovered in 1936 on overwintered chickpea residue in southern Bulgaria. The fungus is heterothallic and requires the pairing of two compatible mating types for development of fertile pseudothecia. Both mating types of A. rabiei were isolated previously from naturally infected, cultivated chickpeas (C. arietinum L.) from northeastern and southern Bulgaria (1), and the teleomorph, Didymella rabiei (Kovachevski) v. Arx, developed on naturally infested chickpea debris from both regions when it was incubated at appropriate environmental conditions. Isolations were made from lesions on the leaflets, stems, pods, and seeds of C. montbretii by surface disinfecting tissue in 0.25% NaOCl for 5 min, drying on paper hand towels, and placing small pieces of tissue on 2% water agar and Difco potato dextrose agar. Plates were incubated at 22 to 24°C under fluorescent lights with a 12-h photoperiod. A. rabiei was isolated from all foliar tissues of the plant, including seeds. Koch's postulates were fulfilled by inoculating the foliage of chickpea PI 458870 and reisolating the fungus from lesions that developed on the leaflets and stems. Six Bulgarian isolates of A. rabiei from C. montbretii were paired with compatible mating type tester isolates of A. rabiei, MAT1-1 (ATCC 76501) and MAT 1-2 (ATCC 76502), following the procedure of Kaiser and Kusmenoglu (2). Both mating types were found among the six isolates. Two were MAT 1-1 and four MAT 1-2. The teleomorph did not develop on the small amount of naturally infested chickpea residue tested. Therefore, in Bulgaria, both cultivated and wild chickpeas are infected naturally by A. rabiei and both mating types have been isolated from these hosts. D. rabiei will likely be found in native stands of C. montbretii in Bulgaria as more samples of overwintered infested debris are examined for the teleomorph. This is the first report of A. rabiei causing blight of a wild Cicer sp. References: (1) W. J. Kaiser. Can. J. Plant Pathol. 19:215, 1997. (2) W. J. Kaiser and I. Kusmenoglu. Plant Dis. 81:1284, 1997.

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