The Mating-Type Locus of Cryptococcus: Evolution of Gene Clusters Governing Sex Determination and Sexual Reproduction from the Phylogenomic Perspective

Cryptococcus ◽  
2014 ◽  
pp. 139-149 ◽  
Author(s):  
Yen-Ping Hsueh ◽  
Banu Metin ◽  
Keisha Findley ◽  
Marianela Rodriguez-Carres ◽  
Joseph Heitman
Keyword(s):  
Sex Determination ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Gene Clusters ◽  
Type Locus ◽  
Mating Type Locus

scholarly journals The iso1 gene of Chlamydomonas is involved in sex determination.

1995 ◽  
Vol 6 (1) ◽  
pp. 87-95 ◽  
Author(s):  
A M Campbell ◽  
H J Rayala ◽  
U W Goodenough
Keyword(s):  
Sex Determination ◽  
Chlamydomonas Reinhardtii ◽  
Mating Type ◽  
Dna Sequences ◽  
Sexual Differentiation ◽  
Type Locus ◽  
Mating Structure ◽  
Mating Type Locus

Sexual differentiation in the heterothallic alga Chlamydomonas reinhardtii is controlled by two mating-type loci, mt+ and mt-, which behave as a pair of alleles but contain different DNA sequences. A mutation in the mt minus-linked imp11 gene has been shown previously to convert a minus gamete into a pseudo-plus gamete that expresses all the plus gametic traits except the few encoded by the mt+ locus. Here we describe the iso1 mutation which is unlinked to the mt- locus but is expressed only in minus gametes (sex-limited expression). A population of minus gametes carrying the iso1 mutation behaves as a mixture of minus and pseudo-plus gametes: the gametes isoagglutinate but they do not fuse to form zygotes. Further analysis reveals that individual gametes express either plus or minus traits: a given cell displays one type of agglutinin (flagellar glycoprotein used for sexual adhesion) and one type of mating structure. The iso1 mutation identifies a gene unlinked to the mating-type locus that is involved in sex determination and the repression of plus-specific genes.

scholarly journals Correlation of Genetic and Physical Maps at the A Mating-Type Locus of Coprinus cinereus

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1471-1477 ◽  
Author(s):  
Lewis Lukens ◽  
Huang Yicun ◽  
Georgiana May
Keyword(s):  
Mating Type ◽  
Natural Populations ◽  
Gene Clusters ◽  
Coprinus Cinereus ◽  
Noncoding Dna ◽  
Type Locus ◽  
Coding Regions ◽  
Mating Type Locus ◽  
Physical Maps ◽  
Genetic And Physical Maps

The A mating type locus of Coprinus cinereus is remarkable for its extreme diversity, with over 100 different alleles in natural populations. Classical genetic studies have demonstrated that this hypervariability arises in part from recombination between two subloci of A, alpha and beta, although more recent population genetic data have indicated a third segregating sublocus. In this study, we characterized the molecular basis by which recombination generates nonparental A mating types. We mapped the frequency and location of all recombination events in two crosses and correlated the genetic and physical maps of A. We found that all recombination events were located in 6 kb of noncoding DNA between the alpha and beta subloci and that the rate of recombination in this noncoding region matched that generally observed for this genome. No recombination within gene clusters or within coding regions was observed, and the two alpha and beta subloci described in genetic analyses correlated with the previously characterized alpha and beta gene clusters. We propose that pairs of genes constitute both the sex determining and the hereditary unit of A.

scholarly journals Sex Determination Directs Uniparental Mitochondrial Inheritance in Phycomyces

2013 ◽  
Vol 13 (2) ◽  
pp. 186-189 ◽  
Author(s):  
Viplendra P. S. Shakya ◽  
Alexander Idnurm
Keyword(s):  
Sex Determination ◽  
Mating Type ◽  
Sex Chromosome ◽  
High Mobility ◽  
Uniparental Inheritance ◽  
Phycomyces Blakesleeanus ◽  
Type Locus ◽  
Content Type ◽  
Mating Type Locus ◽  
Major Factors

ABSTRACTUniparental inheritance (UPI) of mitochondria is common among eukaryotes. The underlying molecular basis by which the sexes of the parents control this non-Mendelian pattern of inheritance is yet to be fully understood. Two major factors have complicated the understanding of the role of sex-specific genes in the UPI phenomenon: in many cases (i) fusion occurs between cells of unequal size or (ii) mating requires a large region of the genome or chromosome that includes genes unrelated to sex determination. The fungusPhycomyces blakesleeanusis a member of the Mucoromycotina and has a simple mating type locus encoding only one high-mobility group (HMG) domain protein, and mating occurs by fusion of isogamous cells, thus providing a model system without the limitations mentioned above. Analysis of more than 250 progeny from a series of genetic crosses between wild-type strains ofPhycomycesrevealed a correlation between the individual genes in the mating type locus and UPI of mitochondria. Inheritance is from the plus (+) sex type and is associated with degradation of the mtDNA from the minus (−) parent. These findings suggest that UPI can be directly controlled by genes that determine sex identity, independent of cell size or the complexity of the genetic composition of a sex chromosome.

Characterization of the mating-type locus (MAT) reveals a heterothallic mating system inKnightiella splachnirima

2017 ◽  
Vol 49 (4) ◽  
pp. 373-385 ◽  
Author(s):  
Lars R. LUDWIG ◽  
Tina C. SUMMERFIELD ◽  
Janice M. LORD ◽  
Garima SINGH
Keyword(s):  
Mating System ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Conservation Management ◽  
Inverse Pcr ◽  
Type Locus ◽  
Mating Type Locus ◽  
Screening Protocol ◽  
Pcr Techniques

AbstractIn the present study, we characterized the mating-type locus ofKnightiella splachnirima(Icmadophilaceae) using degenerate and inverse PCR techniques. We screened for the presence of both mating-type locus idiomorphs in DNA extracts of minuscule samples of haploid thalline tissue. We found that only one of the two idiomorphs was present in each sample, and the mating-type ratio (MAT1-1:MAT1-2) was very balanced, being 8:10 and 13:14 at local and global scales, respectively. This indicates that the species is probably self-incompatible and requires the presence of compatible mating partners for sexual reproduction (heterothallic mating system). Furthermore, we provide a mating-type screening protocol withK. splachnirimaspecific mating-type locus primers, which could serve as an essential tool for the conservation management of this rare Australasian endemic.

scholarly journals Mating-type locus rearrangement leads to shift from homothallism to heterothallism in Citrus-associated Phyllosticta species

2020 ◽  
Author(s):  
Desirrê Alexia Lourenço Petters-Vandresen ◽  
Bruno Janoski Rossi ◽  
Johannes Z. Groenewald ◽  
Pedro W. Crous ◽  
Marcos Antonio Machado ◽  
...  
Keyword(s):  
Disease Management ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Management Practices ◽  
Black Spot ◽  
Tan Spot ◽  
Ancestral State ◽  
Type Locus ◽  
Mating Type Locus ◽  
Host Interaction

AbstractCurrently, eight Phyllosticta species are known to be associated with Citrus hosts, incorporating endophytic and pathogenic lifestyles. As sexual reproduction is a key factor involved in host-interaction, it could be related to the differences in lifestyle. To evaluate this hypothesis, we characterized the mating-type loci of six Citrus-associated Phyllosticta species from whole genome assemblies. Mating-type genes are highly variable in their sequence content, but the genomic locations and organization of the mating-type loci are conserved. Phyllosticta citriasiana, P. citribraziliensis and P. paracitricarpa are heterothallic, and P. citrichinaensis was confirmed to be homothallic. In addition, the P. citrichinaensis MAT1-2 idiomorph occurs in a separate location from the mating-type locus. Ancestral state reconstruction suggests that homothallism is the ancestral thallism state in Phyllosticta, with a shift to heterothallism in Phyllosticta species that are pathogenic to Citrus. Moreover, the homothallic strategies of P. capitalensis and P. citrichinaensis result from independent evolutionary events. As the pathogenic species P. citriasiana, P. citricarpa and P. paracitricarpa are heterothallic and incapable of selfing, disease management practices focused in preventing the occurrence of sexual reproduction could assist in the control of Citrus Black Spot and Citrus Tan Spot diseases. This study emphasizes the importance of studying Citrus-Phyllosticta interactions under evolutionary and genomic perspectives, as these approaches can provide valuable information about the association between Phyllosticta species and their hosts, and also serve as guidance for the improvement of disease management practices.

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