Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
Project description:Restriction site Associated DNA (RAD) tags are a genome-wide representation of every site of a particular restriction enzyme by short DNA tags. Most organisms segregate large numbers of DNA sequence polymorphisms that disrupt restriction sites, which allow RAD tags to serve as genetic markers spread at a high-density throughout the genome. Here, we demonstrate the applicability of RAD markers for both individual and bulk-segregant genotyping. First, we show that these markers can be identified and typed on pre-existing microarray formats. Second, we present a method that uses RAD marker DNA to rapidly produce a low-cost microarray genotyping resource that can be used to efficiently identify and type thousands of RAD markers. We demonstrate the utility of the former approach by using a tiling path array for the fruit fly to map a recombination breakpoint, and the latter approach by creating and utilizing an enriched RAD marker array for the threespine stickleback. The high number of RAD markers enabled localization of a previously identified region, as well as a second novel region also associated with the lateral plate phenotype. Taken together, our results demonstrate that RAD markers, and the method to develop a RAD marker microarray resource, allow high-throughput, high-resolution genotyping in both model and non-model systems. Keywords: microarray genotyping
Project description:IL-33 is constitutively expressed in many epithelial tissues at steady state and signals through the receptor, ST2. IL-33 is released upon tissue injury and functions as an endogenous danger signal to alert the immune system to tissue damage. Here we investigate the physiological role of the IL-33/ST2 axis in skin homeostasis and cancer development. We show that expression of IL-33 differentiates malignant from normal/benign human tissues and that in mouse models of cutaneous squamous cell carcinoma the IL-33/ST2 axis protects against carcinogenesis. Tissue Treg are the predominant cells expressing ST2 in the skin and localise around the hair follicle and IL-33+ epithelial cells (EC). Adoptive transfer experiments demonstrate that skin Treg regulate EC differentiation, minimizes mutational load and retrains cancer development following exposure to an environmental carcinogen. Our findings indicate an important role for direct EC-Treg cross-talk as an early checkpoint to contain tissue damage and carcinogenesis.
2024-08-15 | GSE241061 | GEO
Project description:RAD-seq of 4608 progeny from a cross of S. cerevisiae strains FY4 and Σ1278b as pilot for BEST genotyping and automated tetrad method.
| PRJEB1744 | ENA
Project description:RAD-seq of 384 progeny from a cross of S. cerevisiae strains S288c and YPS163 as pilot for BEST genotyping and automated tetrad method.
| PRJEB1581 | ENA
Project description:RAD-seq of 390 progeny from a cross of S. cerevisiae strains FY4 and Σ1278b as pilot for BEST genotyping and automated tetrad method.
Project description:Using microarrays to genotype the parental origin of progeny resulting from a cross between S96 and YJM789 yeast strains, we mapped the distribution of crossovers that occurred during meiosis. Knowledge of the crossover distribution allowed us to assess changes in crossover control in wild type and mutant strains. The S96 strain is a S288 derivative and thus its DNA sequence has high homology to the oligo sequences used to create the S98 Affymetrix Gene chip. The YJM789 strain is ~ 0.6% divergent from S288. Keywords: wild type and mutant analysis