Mating analyses of Trichophyton benhamiae offspring reveals linkage of genetic markers used in taxonomy

2019 ◽  
Vol 57 (7) ◽  
pp. 885-892 ◽  
Author(s):  
A Burmester ◽  
U-C Hipler ◽  
P Elsner ◽  
C Wiegand

AbstractMating experiments were conducted with four clinical Trichophyton benhamiae isolates, genetically similar to the Trichophyton benhamiae CBS 112371, featuring the plus mating type and with two minus type strains. One minus type strain belonged to the white subgroup, and the other minus type strain, DSM 6916, showed genetic kinship to the yellow subgroup. Only two plus type strains were able to form mature, pigmented gymnothecia with DSM 6916. These two plus type strains demonstrated dark pigmentation and powdery mycelium on Takashio agar, whereas the other three strains exhibited a low degree of pigmentation on the same medium. All five plus strains were able to mate with the minus type strain of their own white subgroup. Cultures from single ascospore isolates showed highly variable morphology and pigmentation. Three genetic markers (ITS, mating type, EF1 alpha) were analyzed in polymerase chain reaction (PCR) experiments with optimized primers and PCR conditions to discriminate between subgroups. Furthermore, RAPD-PCR was used to generate a DSM 6916-specific DNA-fragment which served as an additional genetic marker. Assessing the isolates with recombinant genotypes, it was found that three genetic markers behave like linked genes. The recombination of plus mating type went together with ITS, EF1 alpha and RAPD marker of the DSM 6916 parental strain and was most frequently isolated, whereas plus types recombinants in this case were completely missing. This shows a high imbalance in mating type distribution of recombinants.

2013 ◽  
Vol 12 (7) ◽  
pp. 1033-1038 ◽  
Author(s):  
Gabriela Rodríguez-Arellanes ◽  
Carolina Nascimento de Sousa ◽  
Mauro de Medeiros-Muniz ◽  
José A. Ramírez ◽  
Cláudia V. Pizzini ◽  
...  

ABSTRACTTheMAT1-1andMAT1-2idiomorphs associated with theMAT1locus ofHistoplasma capsulatumwere identified by PCR. A total of 28 fungal isolates, 6 isolates from human clinical samples and 22 isolates from environmental (infected bat and contaminated soil) samples, were studied. Among the 14 isolates from Mexico, 71.4% (95% confidence interval [95% CI], 48.3% to 94.5%) were of theMAT1-2genotype, whereas 100% of the isolates from Brazil were of theMAT1-1genotype. EachMAT1idiomorphic region was sequenced and aligned, using the sequences of the G-217B (+ mating type) and G-186AR (− mating type) strains as references. BLASTn analyses of theMAT1-1andMAT1-2sequences studied correlated with their respective + and − mating type genotypes. Trees were generated by the maximum likelihood (ML) method to search for similarity among isolates of eachMAT1idiomorph. AllMAT1-1isolates originated from Brazilian bats formed a well-defined group; three isolates from Mexico, the G-217B strain, and a subgroup encompassing all soil-derived isolates and two clinical isolates from Brazil formed a second group; last, one isolate (EH-696P) from a migratory bat captured in Mexico formed a third group of theMAT1-1genotype. TheMAT1-2idiomorph formed two groups, one of which included twoH. capsulatumisolates from infected bats that were closely related to the G-186AR strain. The other group was formed by two human isolates and six isolates from infected bats. Concatenated ML trees, with internal transcribed spacer 1 (ITS1) -5.8S-ITS2 andMAT1-1orMAT1-2sequences, support the relatedness ofMAT1-1orMAT1-2isolates.H. capsulatummating types were associated with the geographical origin of the isolates, and all isolates from Brazil correlated with their environmental sources.


Genetics ◽  
1983 ◽  
Vol 105 (4) ◽  
pp. 873-879
Author(s):  
M I Alvarez ◽  
A P Eslava

ABSTRACT The progeny of crosses between wild-type strains of Phycomyces usually do not exhibit all of the expected genotypes from meiosis. By backcrossing, we have isolated a new (+) mating-type strain, A56, which is nearly isogenic with the (-) wild-type NRRL1555 commonly used in Phycomyces research. Tetrad analysis of the backcrosses shows that meiosis becomes more regular as the parental (+) and (-) strains become more isogenic. In our two-factor crosses with unlinked markers, the regularity of meiosis is measured as the percent of reciprocal ditypes plus tetratypes in the progeny. We have shown that this percentage increases from about 15% for crosses between nonisogenic parents to 90% in the eighth backcross. The results indicate that routine, reliable recombination analyses are possible in P. blakesleeanus.


2005 ◽  
Vol 55 (1) ◽  
pp. 401-404 ◽  
Author(s):  
Franco Dellaglio ◽  
Giovanna E. Felis ◽  
Anna Castioni ◽  
Sandra Torriani ◽  
Jacques-Edouard Germond

Four strains isolated from Indian dairy products and initially identified as Lactobacillus delbrueckii could not be assigned to a definite subspecies because molecular identification and phenotypic traits did not agree with those of recognized subspecies of L. delbrueckii. Hybridization of total DNA (78–86 % against type strains of the other three subspecies), AFLP and RAPD-PCR fingerprints, phylogenetic analysis based on 16S rRNA gene sequences and sequence analysis of two coding genes (recA and hsp60), together with phenotypic profiles, indicated that the four strains form a coherent cluster and represent a novel subspecies, for which the name Lactobacillus delbrueckii subsp. indicus subsp. nov. is proposed. The type strain is NCC725T (=LMG 22083T=DSM 15996T).


1990 ◽  
Vol 36 (7) ◽  
pp. 484-489 ◽  
Author(s):  
G. C. Papavizas ◽  
D. P. Roberts ◽  
K. K. Kim

Aqueous suspensions of conidia of Gliocladium virens strains Gl-3 and Gl-21 were exposed to both ultraviolet radiation and ethyl methanesulfonate. Two mutants of Gl-3 and three of Gl-21 were selected for tolerance to benomyl at 10 μg∙mL−1, as indicated by growth and conidial germination on benomyl-amended potato dextrose agar. The mutants differed considerably from their respective wild-type strains in appearance, growth habit, sporulation, carbon-source utilization, and enzyme activity profiles. Of 10 carbon sources tested, cellobiose, xylose, and xylan were the best for growth, galactose and glucose were intermediate, and arabinose, ribose, and rhamnose were poor sources of carbon. The wild-type strains and the mutants did not utilize cellulose as the sole carbon source for growth. Two benomyl-tolerant mutants of Gl-3 produced less cellulase (β-1,4-glucosidase, carboxymethylcellulase, filter-paper cellulase) than Gl-3. In contrast, mutants of Gl-21 produced more cellulase than the wild-type strain. Only Gl-3 provided control of blight on snapbean caused by Sclerotium rolfsii. Wild-type strain Gl-21 and all mutants from both strains were ineffective biocontrol agents. Key words: Gliocladium, benomyl tolerance, Sclerotium, rhizosphere competence.


2006 ◽  
Vol 56 (9) ◽  
pp. 2025-2027 ◽  

The purpose of this announcement is to effect the valid publication of the following new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries (i.e. documents certifying deposition and availability of type strains). It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below, and these authors' names will be included in the author index of the present issue and in the volume author index. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in bacteriological nomenclature. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.


1989 ◽  
Vol 9 (11) ◽  
pp. 4621-4630
Author(s):  
D J Mahoney ◽  
J R Broach

Mating-type genes resident in the silent cassette HML at the left arm of chromosome III are repressed by the action of four SIR gene products, most likely mediated through two cis-acting sites located on opposite sides of the locus. We showed that deletion of either of these two cis-acting sites from the chromosome did not yield any detectable derepression of HML, while deletion of both sites yielded full expression of the locus. In addition, each of these sites was capable of exerting repression of heterologous genes inserted in their vicinity. Thus, HML expression is regulated by two independent silencers, each fully competent for maintaining repression. This situation was distinct from the organization of the other silent locus, HMR, at which a single silencer served as the predominant repressor of expression. Examination of identifiable domains and binding sites within the HML silencers suggested that silencing activity can be achieved by a variety of combinations of various functional domains.


Author(s):  
Suguru Ariyoshi ◽  
Yusuke Imazu ◽  
Ryuji Ohguri ◽  
Ryo Katsuta ◽  
Arata Yajima ◽  
...  

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.


2007 ◽  
Vol 57 (5) ◽  
pp. 893-897 ◽  

The purpose of this announcement is to effect the valid publication of the following new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper, to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries (i.e. documents certifying deposition and availability of type strains). It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below, and these authors' names will be included in the author index of the present issue and in the volume author index. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in bacteriological nomenclature. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.


2007 ◽  
Vol 136 (5) ◽  
pp. 644-652 ◽  
Author(s):  
M. FLOROU ◽  
L. LEONTIDES ◽  
P. KOSTOULAS ◽  
C. BILLINIS ◽  
M. SOFIA ◽  
...  

SUMMARYThis study aimed to: (1) investigate whether non-ruminant wildlife interfacing with dairy sheep and goats of four Greek flocks endemically infected withMycobacterium aviumsubspeciesparatuberculosis(MAP) harboured MAP and (2) genetically compare the strains isolated from the wildlife to those isolated from the small ruminants of these flocks. We cultured and screened, by polymerase chain reaction (PCR), pooled-tissue samples from 327 wild animals of 11 species for the MAP-specific IS900insertion sequence. We also cultured faecal samples from 100 sheep or goats from each of the four flocks. MAP was detected in samples from 11 sheep, 12 goats, two mice, two rats, a hare and a fox. Only one rat had histopathological findings. Genetic typing categorized 21 isolates as cattle-type strains and two, from a house mouse and a goat respectively, as sheep-type strains; this is the first report of a rodent harbouring a sheep-type strain. The MAP types that were most frequently isolated amongst the sheep and goats of each flock were also the ones isolated from sympatric rodents; those isolated from the fox and hare also belonged to the predominant ruminant strains.


Genetics ◽  
1977 ◽  
Vol 87 (3) ◽  
pp. 401-420
Author(s):  
Paul N Adler ◽  
Charles E Holt

ABSTRACT Rare plasmodia formed in clones of heterothallic amoebae were analyzed in a search for mutations affecting plasmodium formation. The results show that the proportion of mutants varies with both temperature (18°, 26° or 30°) and mating-type allele (mt1, mt2, mt3, mt4). At one extreme, only one of 33 plasmoida formed by mt2 amoebae at 18° is mutant. At the other extreme, three of three plasmodia formed by mt1 amoebae at 30° are mutant. The mutant plasmodia fall into two groups, the GAD (greater asexual differentiation) mutants and the ALC (amoebaless life cycle) mutants. The spores of GAD mutants give rise to amoebae that differentiate into plasmodia asexually at much higher frequencies than normal heterothallic amoebae. Seven of eight gad mutations analyzed genetically are linked to mt and one (gad-12) is not. The gad-12 mutation is expressed in strains with different alleles of mt. The frequency of asexual plasmodium formation is heat sensitive in some (e.g., mt3 gad-11), heat-insensitive in two (mt2 gad-8 and mt2 gad-9) and cold-sensitive in one (mt1 gad-12) of twelve GAD mutants analyzed phenotypically. The spores of ALC mutants give rise to plasmodia directly, thereby circumventing the amoebal phase of the life cycle. Spores from five of the seven ALC mutants give rise to occasional amoebae, as well as plasmodia. The amoebae from one of the mutants carry a mutation (alc-1) that is unlinked to mt and is responsible for the ALC phenotype in this mutant. Like gad-12, alc-1 is expressed with different mt alleles. Preliminary observations with amoebae from the other four ALC mutants suggest that two are similar to the one containing alc-1; one gives rise to revertant amoebae, and one gives rise to amoebae carrying an alc mutation and a suppressor of the mutation.


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