scholarly journals Mating types and mating-inducing factors (gamones) in the ciliate Euplotes patella syngen 2

1985 ◽  
Vol 46 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Rinji Akada
Keyword(s):  
Mating Type ◽  
Genetic Data ◽  
Pair Formation ◽  
Mating Types ◽  
Type Allele ◽  
Mating Type Genes ◽  
Inducing Factors ◽  
In Cells

SUMMARYRelationships between mating type genes and mating-inducing factors (gamones) were investigated in the ciliate Euplotes patella syngen 2. Ten mating types were distinguished, and genetic data indicated that the ten mating types were determined by four codominant alleles in possible combinations of two of them. There were six heterozygous types (mt1/mt2, mt3/mt4, etc.) and four homozygous types (mt1/mt1, mt2/mt2, etc.). Conjugation-conditioned fluid (CCF) obtained from a mixture of cells of homozygous types could induce homotypic pair formation in cells of all mating types except for a particular type. Genetic data of cell-CCF combination experiments suggest that each mating type allele controls the production of a specific gamone which induces pair formation in cells which do not produce the same gamone. Gamones and their hypothetical receptors are discussed.

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.

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.

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 Homotypic pair formation during conjugation in Tetrahymena thermophila

1986 ◽  
Vol 82 (1) ◽  
pp. 223-234
Author(s):  
A. Kitamura ◽  
T. Sugai ◽  
Y. Kitamura
Keyword(s):  
Phospholipase C ◽  
Mating Type ◽  
Tetrahymena Thermophila ◽  
Single Cells ◽  
Initial Step ◽  
Pair Formation ◽  
Mating Types ◽  
Morphological Markers ◽  
Mechanical Separation

In the ciliate Tetrahymena thermophila, conjugation has been believed to occur only between cells of different mating types. We found the formation of homotypic pairs during normal conjugation by using micronuclear morphological markers. Homotypic pairs formed preferentially during the first 10 min following the first pair formation and comprised about half of the pairs. These results suggest the involvement of mating-type non-specific adhesion of cells in the initial step of conjugation. Homotypic pairs apparently persist for at least 30 min and then separate into single cells. Homotypic pairs are also formed when conjugant pairs re-form after mechanical separation of heterotypic pairs. Five kinds of glycosidases, three kinds of proteases and phospholipase C showed no effect on either the formation of homotypic pairs of their separation. The relation between the mating-type substances and the molecules responsible for mating-type non-specific adhesion of cells is discussed.

scholarly journals GENES CONTROLLING MATING-TYPE SPECIFICITY IN PARAMECIUM CAUDATUM: THREE LOCI REVEALED BY INTERSYNGENIC CROSSES

Genetics ◽  
1983 ◽  
Vol 104 (1) ◽  
pp. 41-62
Author(s):  
Yuuji Tsukii ◽  
Koichi Hiwatashi
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Pair Formation ◽  
High Fertility ◽  
Mating Types ◽  
Paramecium Caudatum ◽  
Multiple Alleles ◽  
Behavioral Marker ◽  
Species Pairs ◽  
Recessive Homozygote

ABSTRACT In mating interactions in Paramecium caudatum, initial mating agglutination is strictly mating-type specific, but subsequent conjugating pair formation is not mating-type specific. Using this nonspecificity of pair formation, intersyngenic (intersibling species) pairs were induced by mixing four mating types of two different syngens. To distinguish intersyngenic pairs from intrasyngenic ones, the behavioral marker CNR (Takahashi 1979) was mainly used. Clones of intersyngenic hybrids showed high fertility and thus made feasible a genetic analysis of syngenic specificity of mating type. The syngenic specificities of E (even) mating types were found to be controlled by co-dominant multiple alleles at the Mt locus, and those of O (odd) mating types by interactions of co-dominant multiple alleles at two loci, MA and MB. Clones of heterozygotes express dual mating types. Mt is epistatic to MA and MB, and thus O mating types can be expressed only in the recessive homozygote (mt/mt) at the Mt locus. In addition, at least one allele each at the MA and MB loci must have a common syngen specificity for the expression of O types. Thus, when MA is homozygous for one syngen and MB is homozygous for another syngen, no mating type is expressed.

BEHAVIOUR OF NEUROSPORA TETRASPERMA MATING-TYPE GENES INTROGRESSED INTO N. CRASSA

1973 ◽  
Vol 15 (3) ◽  
pp. 571-576 ◽  
Author(s):  
Robert L. Metzenberg ◽  
Sandra K. Ahlgren
Keyword(s):  
Mating Type ◽  
Genetic Background ◽  
Opposite Mating Type ◽  
Type Allele ◽  
Mating Type Gene ◽  
Mating Type Genes ◽  
Type Gene ◽  
Neurospora Tetrasperma ◽  
Do So

The two alleles of the mating-type gene of Neurospora tetrasperma have been introgressed into a largely N. crassa genetic background. Under these circumstances, they are no longer able to coexist without inhibition in heterocaryons, nor can they do so with their opposite mating-type allele from N. crassa. Neither are they compatible with the latter in partial diploids heterozygous for the mating-type alleles. The implications of this are briefly discussed.

scholarly journals GENETICS OF CHEMICAL INDUCTION OF CONJUGATION IN PARAMECIUM AURELIA

Genetics ◽  
1974 ◽  
Vol 76 (4) ◽  
pp. 703-714
Author(s):  
Donald L Cronkite
Keyword(s):  
Mating Type ◽  
Recessive Gene ◽  
Mating Types ◽  
Wild Type ◽  
Chemical Induction ◽  
Single Mating ◽  
In Cells

ABSTRACT Certain stocks of P. aurelia, syngen 8, could not be induced to conjugate in a solution (KCl + acriflavine + calcium-poor conditions) which was effective in inducing conjugation in other species of Paramecium as well as in other stocks of syngen 8. Both stocks could conjugate by interaction with cells of complementary mating type. Breeding analysis shows that each of the two stocks is homozygous for a recessive gene that blocks induction of conjugation by the KCl-acriflavine solution. These two genes are neither allelic nor linked. Analyses of the phenotypes of the two uninducibles and the wild type were carried out by attempting to induce mating in cells of a single mating type by exposing them to detached mating-reactive cilia from cells of complementary mating type and to the KCl-acriflavine solution, either sequentially or simultaneously. The results confirm the conclusions of others that there is at least one unique step in chemical induction not shared with induction by interaction of complementary mating types. But the results also indicate that there is more than one unique step in chemical induction and that the effects of the two genes described here operate during different periods of the hour required for chemical induction.

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 Mating Type Sequences in Asexually Reproducing Fusarium Species

2004 ◽  
Vol 70 (8) ◽  
pp. 4419-4423 ◽  
Author(s):  
Zoltán Kerényi ◽  
Antonio Moretti ◽  
Cees Waalwijk ◽  
Brigitta Oláh ◽  
László Hornok
Keyword(s):  
Mating Type ◽  
Dna Sequences ◽  
Fusarium Species ◽  
High Mobility ◽  
Inverse Pcr ◽  
Identification System ◽  
Mating Types ◽  
Hmg Box ◽  
Wide Range ◽  
Mating Type Genes

ABSTRACT To assess the potential for mating in several Fusarium species with no known sexual stage, we developed degenerate and semidegenerate oligonucleotide primers to identify conserved mating type (MAT) sequences in these fungi. The putative α and high-mobility-group (HMG) box sequences from Fusarium avenaceum, F. culmorum, F. poae, and F. semitectum were compared to similar sequences that were described previously for other members of the genus. The DNA sequences of the regions flanking the amplified MAT regions were obtained by inverse PCR. These data were used to develop diagnostic primers suitable for the clear amplification of conserved mating type sequences from any member of the genus Fusarium. By using these diagnostic primers, we identified mating types of 122 strains belonging to 22 species of Fusarium. The α box and the HMG box from the mating type genes are transcribed in F. avenaceum, F. culmorum, F. poae, and F. semitectum. The novelty of the PCR-based mating type identification system that we developed is that this method can be used on a wide range of Fusarium species, which have proven or expected teleomorphs in different ascomycetous genera, including Calonectria, Gibberella, and Nectria.

Sign in / Sign up

Export Citation Format

Share Document