Evidence for mitochondrial gene control of mating types in Phytophthora

2005 ◽  
Vol 51 (11) ◽  
pp. 934-940 ◽  
Author(s):  
Yu-Huan Gu ◽  
Wen-Hsiung Ko
Keyword(s):  
Mating Type ◽  
Mitochondrial Gene ◽  
Phytophthora Capsici ◽  
Nuclear Genes ◽  
Gene Control ◽  
Mating Types ◽  
Phytophthora Parasitica ◽  
Decisive Effect ◽  
Mating Type Genes ◽  
Fusion Products

When protoplasts carrying metalaxyl-resistant (Mr) nuclei from the A1 isolate of Phytophthora parasitica were fused with protoplasts carrying chloroneb-resistant (Cnr) nuclei from the A2 isolate of the same species, fusion products carrying Mr nuclei were either the A2 or A1A2 type, while those carrying Cnr nuclei were the A1, A2, or A1A2 type. Fusion products carrying Mr and Cnr nuclei also behaved as the A1, A2, or A1A2 type. The result refutes the hypothesis that mating types in Phytophthora are controlled by nuclear genes. When nuclei from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species and vice versa, all of the nuclear hybrids expressed the mating type characteristics of the protoplast parent. The same was true when the nuclei from the A1 isolate of P. parasitica were fused with the protoplasts from the A0 isolate of Phytophthora capsici and vice versa. These results confirm the observation that mating type genes are not located in the nuclei and suggest the presence of mating type genes in the cytoplasms of the recipient protoplasts. When mitochondria from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species, the mating type of three out of five regenerated protoplasts was changed to the A1 type. The result demonstrated the decisive effect of mitochondrial donor sexuality on mating type characteristics of mitochondrial hybrids and suggested the presence of mating type genes in mitochondria. All of the mitochondrial hybrids resulting from the transfer of mitochondria from the A0 isolate of P. capsici into protoplasts from the A1 isolate of P. parasitica were all of the A0 type. The result supports the hypothesis of the presence of mating type genes in mitochondria in Phytophthora.Key words: mating type, mitochondrial gene, Phytophthora parasitica, Phytophthora capsici.

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 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.

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.

Transplantation and subsequent behavior of mitochondria in cells of Phytophthora

2000 ◽  
Vol 46 (11) ◽  
pp. 992-997 ◽  
Author(s):  
Y H Gu ◽  
W H Ko
Keyword(s):  
Antibiotic Resistance ◽  
Asexual Reproduction ◽  
Second Generation ◽  
Random Distribution ◽  
Phytophthora Capsici ◽  
Selective Medium ◽  
Phytophthora Parasitica ◽  
Subsequent Behavior ◽  
Hybrid Antibiotic ◽  
Fusion Products

Mitochondria isolated from streptomycin-resistant (Sr) protoplasts of Phytophthora parasitica were transferred into chloramphenicol-resistant (Cpr) protoplasts of P. parasitica or Phytophthora capsici with an average successful rate of 1.7 × 10-4, using a selective medium containing streptomycin. No colonies appeared when self-fusion products of donor mitochondria or recipient protoplasts were exposed to the selective medium. Mitochondria isolated from Cpr protoplasts of P. capsici were also transferred into Sr protoplasts of P. parasitica with a similar success rate using a selective medium containing chloramphenicol. Zoospores produced by the Cpr+Sr intraspecific mitochondrial hybrid gave rise to Sr and Cpr+Sr cultures. The second generation zoospores produced by Sr and Cpr+Sr cultures also gave rise to Sr and Cpr+Sr cultures, suggesting the possible occurrence of fusion between some of the Cpr mitochondria and Sr mitochondria, and the displacement of non-fused Cpr mitochondria in the receptor protoplast by the donor Sr mitochondria. Zoospores produced by the interspecific mitochondrial hybrid gave rise to Cpr, Sr, Cpr+Sr, and Cps +Ss cultures. The second generation zoospores produced by Cpr+Sr or Sr cultures also gave rise to the same four types of cultures, suggesting the existence of residual antibiotic-sensitive mitochondria (Cps+Ss) in the parental isolates and the random distribution of Cpr, Sr, and Cps+Ss mitochondria during asexual reproduction. Results suggest that the phenotype of antibiotic resistance / sensitivity was the end result of the interactions among the three types of mitochondria.Key words: mitochondrial transplantation, mitochondrial hybrid, antibiotic resistance, Phytophthora parasitica, Phytophthora capsici.

scholarly journals Karakteristik morfologi dan sebaran tipe kawin Phytophthora capsici asal lada di Pulau Jawa

2019 ◽  
Vol 14 (5) ◽  
pp. 166
Author(s):  
Bahru Rohmah ◽  
Bambang Hadisutrisno ◽  
Dyah Manohara ◽  
Achmadi Priyatmojo
Keyword(s):  
Mating Type ◽  
Phytophthora Capsici ◽  
Morphological Characteristics ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Mating Types ◽  
Foot Rot ◽  
Distribution Map ◽  
Rot Disease ◽  
Special Region

Morphology characters and mating types distribution of Phytophthora capsici from black pepper in Java IslandPepper (Piper nigrum) is one of the most important spice crops in Indonesia.  Recently its production declining due to infection of foot rot disease caused by Phytophthora capsici. This pathogen has two different mating types, namely A1 and A2, in which the presence of opposite two mating types is important for sexual reproduction and formation of oospores. The movement of pepper seedling from one area to another is highly facilitated alteration of  mating type distribution map of P. capsici. The objectives of this research were to determine the morphological characteristics and the spread of mating types of P. capsici in Java. Morphology characters of P. capsici isolates were indicated by variation in sporangial size and shape, as well as types of colony appearance. The length (l) and width (w) of sporangium were in the range of 15.1–76.2 µm and 9.8–44.8 µm, respectively; while the l/w ratio was 1.12–2.27. Mating type assay showed that A2 type was more dominantly found than A1 type. This study found two different mating types present in the same area, i.e. Regency of Pacitan (East Java) and Regency of Sleman (Special Region of Yogyakarta). The findings of this research suggested that it is required more strict control strategy on the mobilization of black pepper seedling particularly in the area where the certain mating type is not found yet so that the emergence of new more virulent genotype of pathogen can be prevented.

Genetically Diverse Long-Lived Clonal Lineages of Phytophthora capsici from Pepper in Gansu, China

2013 ◽  
Vol 103 (9) ◽  
pp. 920-926 ◽  
Author(s):  
Jian Hu ◽  
Zhili Pang ◽  
Yang Bi ◽  
Jingpeng Shao ◽  
Yongzhao Diao ◽  
...  
Keyword(s):  
Mating Type ◽  
Recombinant Inbred Lines ◽  
Phytophthora Capsici ◽  
Significant Loss ◽  
Gansu Province ◽  
Mating Types ◽  
Metalaxyl Resistance ◽  
Important Variation ◽  
Physiological Race ◽  
Simple Sequence

Phytophthora capsici causes significant loss to pepper production in China, and our objective was to investigate the population structure in Gansu province. Between 2007 and 2011, 279 isolates were collected from pepper at 24 locations. Isolates (or subsets) were assessed for simple sequence repeat (SSR) genotype, metalaxyl resistance, mating type, and physiological race using cultivars from the World Vegetable Center (AVRDC) and New Mexico recombinant inbred lines (NMRILs). The A1 and A2 mating types were recovered from nine locations and metalaxyl-resistant isolates from three locations. A total of 104 isolates tested on the AVRDC panel resolved five physiological races. None of 42 isolates tested on the NMRIL panel caused visible infection. SSR genotyping of 127 isolates revealed 59 unique genotypes, with 42 present as singletons and 17 having 2 to 13 isolates. Isolates with identical genotypes were recovered from multiple sites across multiple years and, in many cases, had different race types or metalaxyl sensitivities. Isolates clustered into three groups with each group having almost exclusively the A1 or A2 mating type. Overall it appears long-lived genetically diverse clonal lineages are dispersed across Gansu, outcrossing is rare, and functionally important variation exists within a clonal framework.

Segregation following interspecific transfer of isolated nuclei between Phytophthora parasitica and P. capsici

2000 ◽  
Vol 46 (5) ◽  
pp. 410-416 ◽  
Author(s):  
Y H Gu ◽  
W H Ko
Keyword(s):  
Nuclear Transfer ◽  
Phytophthora Capsici ◽  
Selective Medium ◽  
Crossing Over ◽  
Phytophthora Parasitica ◽  
Parasexual Cycle ◽  
Different Types ◽  
Average Success Rate ◽  
Fusion Products ◽  
Interspecific Transfer

Nuclei isolated from metalaxyl-resistant (MR) protoplasts of Phytophthora parasitica were transferred into chloroneb-resistant (CnR) protoplasts of Phytophthora capsici and vice versa, with an average success rate of 2.6 × 10-4 (protoplasts with donor nuclei/regenerated protoplasts), using a selective medium containing only the fungicide tolerated by the nuclear donor. No colonies appeared when self-fusion products of donor nuclei or recipient protoplasts were exposed to the selective medium. Colonies produced by the nuclear transfer formed sectors commonly, and differed from the parental types in appearance. All the zoospores produced by the nuclear hybrids were of normal size, and one-fifth of them contained both MR and CnR genes. Since zoospores are mostly uninucleate, these results indicated the occurrence of chromosome re-assortment or mitotic crossing-over following the production of transitory tetraploids, followed by diploidization during zoosporogenesis, thus suggesting the completion of events leading to a parasexual cycle. Hyphal fragment cultures from a nuclear hybrid tested showed considerable variation in growth rate, mycelial morphology, and level of resistance to metalaxyl, indicating uneven distribution and continuous segregation of different types of nuclei in mycelia during vegetative growth.Key words: interspecific nuclear transfer, parasexual cycle, karyogamy, Phytophthora parasitica,Phytophthora capsici.

scholarly journals The Specificity Determinant of the Y Mating-Type Proteins of Schizophyllum commune Is Also Essential for Y-Z Protein Binding

Genetics ◽  
1997 ◽  
Vol 145 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Changli Yue ◽  
Michael Osier ◽  
Charles P Novotny ◽  
Robert C Ullrich
Keyword(s):  
Amino Acids ◽  
Protein Binding ◽  
Mating Type ◽  
Schizophyllum Commune ◽  
Mating Types ◽  
Mating Activity ◽  
Critical Residues ◽  
Mating Type Genes ◽  
Z Protein ◽  
Mating Tests

This paper concerns the manner in which combinatorial mating proteins of the fungus, Schizophyllum commune, recognize one another to form complexes that regulate target gene expression. In Schizophyllum, tightly linked Y and Z mating-type genes do not promote development in the combinations present in haploid strains (i.e., self combinations). When the Y and Z genes from two different mating types are brought together by the fusion of two haploid cells, the Y and Z proteins from different mating types recognize one another as nonself; form a complex and activate development. Several Y and Z alleles are present in the population and all nonself combinations of Y and Z alleles are equally functional. We have made chimeric genes among Y1, Y3, Y4 and Y5 and examined their mating-type specificities by transformation and mating tests. These studies show that the specificity of Y protein recognized by Z protein is encoded within a short region of N-terminal amino acids. The critical region is not precisely the same in each Y protein and in each Y-Z protein interaction. For Y3 protein compared with Y4 protein, the critical residues are in an N-terminal region of 56 amino acids (residues 17–72), with 40% identity and 65% similarity. Two-hybrid studies show that: the first 144 amino acids of Y4 protein are sufficient to bind Z3 and Z5 proteins, but not Z4 protein, and proteins deleted of the Y4 specificity region do not bind Z3, Z4 or Z5 protein. Thus the specificity determinant of the Y protein is essential for protein-protein recognition, Y-Z protein binding and mating activity.

scholarly journals Presence of α and a Mating Types in Environmental and Clinical Collections of Cryptococcus neoformans var. gattii Strains from Australia

1999 ◽  
Vol 37 (9) ◽  
pp. 2920-2926 ◽  
Author(s):  
C. L. Halliday ◽  
T. Bui ◽  
M. Krockenberger ◽  
R. Malik ◽  
D. H. Ellis ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Mating Type ◽  
Causative Agent ◽  
Pcr Primers ◽  
Mating Types ◽  
Limited Data ◽  
Environmental Isolates ◽  
Specific Pcr ◽  
Sexual Recombination ◽  
Mating Type Genes

Cryptococcus neoformans var. gattii lives in association with certain species of eucalyptus trees and is a causative agent of cryptococcosis. It exists as two mating types, MATα and MATa, which is determined by a single-locus, two-allele system. In the closely related C. neoformansvar. neoformans, the α mating type has been found to outnumber its a counterpart by at least 30:1, but there have been very limited data on the proportions of each mating type in C. neoformans var. gattii. In the present study, specific PCR primers were designed to amplify two separate α-mating-type genes from C. neoformans var.gattii strains. These were used to survey for the presence of the two mating types in clinical and environmental collections ofC. neoformans var. gattii strains from Australia. Sixty-eight of 69 clinical isolates produced both α mating type-specific bands and were assumed to be of the α mating type. The majority of environmental isolates were also of the α mating type, but the a mating type was located in two separate areas. In one area, the a mating type outnumbered the α mating type by 27:2, but in the second area, the ratio of the two mating types was close to the 50:50 ratio expected for sexual recombination.

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