Skin microbes discussed and their associated skin diseases.

<p>Skin microbes discussed and their associated skin diseases.</p

Summary of mating abilities and genotypes at the <i>MAT</i> genes of F1 set 2 and F2 progeny.

<p>Bold: fertile with parents;</p><p>Bold and Italics: fertile with siblings from F1 set 1 and F2 progeny;</p><p>Underlined genotypes indicate intra-<i>MAT</i> (A or B locus) recombinant progeny;</p>1<p>: “a” represents allele from A1B1 parent CBS6039; “b” represents allele from A2B2 parent CBS6273.</p

Sexual reproduction of <i>C. amylolentus</i>.

<p>Microscopic examination of mating structures produced during sex between the two <i>C. amylolentus</i> strains, CBS6039 and CBS6273, on V8 (pH = 5) medium incubated in the dark at room temperature for 2 weeks. (A) SEM of basidiospores attached to basidia. Scale bar represents 10 µm. (B) SEM of fused and unfused clamp connections. (C and D) Light microscopy at a magnification of 20X of hyphal filaments, basidia, and basidiospores, scale bar = 10 µm. (E) Basidium with youngest spores attached and associated detached spore chains, scale bar = 1 µm. (F) A cluster of basidiospores and basidia. Scale bar = 10 µm.</p

<i>C. amylolentus</i> has a tetrapolar mating system.

<p>(A) In a bipolar mating system, haploid <b>a</b> and α cells fuse to form a diploid <b>a</b>/α cell. Sex culminates in meiosis, which gives rise to four meiotic progeny, 2 <b>a</b> and 2 α. The <b>a</b> progeny can mate with the α parent (50%) while the α progeny can mate with the <b>a</b> parent (50%). In a tetrapolar mating system, haploid A1B1 and A2B2 cells fuse to form a dikaryon/diploid A1B1/A2B2. Meiosis then results in the production of four haploid meiotic progeny: A1B1 can mate with the A2B2 parent and progeny (25%), A2B2 can mate with the A1B1 parent and progeny (25%), and A1B2 and A2B1 are recombinants (50%) that are sterile with either parent but interfertile with one another. (B) An example of a RAPD and genotyping marker analysis on four progeny and the two parental strains that represent the different gentoypes in a tetrapolar mating system (1 = F1S2 #3 (A1B1), 2 = F1S2 #13 (A2B2), 3 = F2 #1 (A2B1), 4 = F1S2 #10 (A1B2), 5 = CBS6039 (A1B1), and 6 = CBS6273 (A2B2)). (C) Results of mating assays of all possible combinations among the four mating types. Mating was performed by mixing strains on V8 plate (pH = 5). (“−” indicates lack of sexual reproduction and “+” indicates sexual reproduction occurs). (D) Microscopic images of hyphae and spore chains generated during <i>C. amylolentus</i> mating assays described in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002528#pgen-1002528-g009" target="_blank">Figure 9C</a> (the mating-type of each strain is indicated in parenthesis). Dikaryotic hyphae and spore chains were produced in matings between CBS6039 (A1B1) and CBS6273 (A2B2) and between F1 set2 #10 (A1B2) and F2 #1 (A2B1). Monokaryotic hyphae were produced in all of the other mating combinations, including individual strains grown in the absence of a mating partner.</p

Model for the evolution of the mating-type locus in the pathogenic <i>Cryptococcus</i> species.

<p>The physically unlinked ancestral tetrapolar HD and P/R loci contained both homeodomain genes and the pheromone/receptor genes respectively. Additional genes were acquired into both loci, expanding the <i>MAT</i>-specific region. A translocation event occurred, likely between chromosomes 4 and 5 of <i>Cryptococcus</i>, resulting in the formation of a transient tripolar intermediate and one of the HD genes was lost. The hypothetical genes (grey arrows) relocated, likely through a translocation event, to the telomeric ends of chromosome 4. The unstable tripolar intermediate later collapsed to a bipolar state. The fused loci were subjected to further gene rearrangement and gene conversion events, which led to the formation of the bipolar alleles of the pathogenic <i>Cryptococcus</i> species. White arrows indicate the five genes most recently acquired into <i>Cryptococcus MAT</i> locus and black arrows are <i>MAT</i>-specific genes present in the pathogenic <i>Cryptococcus</i> species.</p

Phylogenetic patterns of four <i>C. amylolentus MAT</i> genes.

<p>The phylogenetic relationships of <i>C. amylolentus</i> to the pathogenic <i>Cryptococcus</i> species and neighboring taxa based on four genes, <i>GEF1</i>, <i>CID1</i>, <i>SXI1</i>, and <i>SXI2</i>, are shown. <i>GEF1</i> and <i>CID1</i> display a species-specific phylogeny and the <i>SXI1</i> and <i>SXI2</i> alleles are very diverged from the pathogenic <i>Cryptococcus</i> species. The trees were constructed using the Neighbor-Joining method implemented in the software MEGA4. Bootstrap values on tree branches were calculated from 500 replicates. (α) indicates strains with the <i>MAT</i>α locus, and (<b>a</b>) indicates strains with the <i>MAT</i><b>a</b> locus.</p

<i>T. wingfieldii MAT</i> loci and chromosomal locations.

<p>(A) Six fosmids were analyzed to generate the assembly for <i>T. wingfieldii</i>. The <i>MAT</i> gene probes used to probe the <i>T. wingfieldii</i> library are indicated in blue. The HD (<i>B</i>) and P/R (<i>A</i>) loci are embedded within assemblies that span 40 and 70 kb respectively. Grey arrows indicate genes that either flank <i>MAT</i> or are hypothetical genes, black arrows are <i>Cryptococcus MAT</i>-specific genes, and yellow indicates the genes most recently acquired into the <i>Cryptococcus MAT</i> locus. Scale bar = 10 kb. (B) Chromosomes from <i>T. wingfieldii</i> were separated using PFGE, followed by Southern hybridization using three <i>MAT</i>-specific probes, two from the HD locus and one from the P/R locus. Arrows depict hybridization of HD genes to an ∼1 Mb chromosome distinct from hybridization of the P/R genes to an ∼1.1 Mb chromosome.</p

Supplementary Electronic Files

Supplementary Electronic File