Project description:Four hybrid yeast strains isolated from a variety of industrial substrates were hybridized to an array-CGH platform containing probes to query the whole genomes of seven different Saccharomyces species. For most of the strains we found evidence of multiple interspecific hybridization events and multiple introgressed regions. The strains queried were GSY205 (isolated from a cider fermentation), GSY505 (a contaminant from a lager beer fermentation), GSY2232 (a commercial wine yeast strain), and GSY312 (a commercial lager beer strain). Additionally, 3 different rare viable spores derived from laboratory-created interspecific S. cerevisiae-S. bayanus (aka S. uvarum) hybrids were queried, before and after evolution in chemostats, via S. cerevisiae-S. bayanus microarrays.
Project description:The influence of the extracellular matrix (ECM) within the stem cell niche remains poorly understood. We found that Syndecan-4 (Sdc4) and Frizzled-7 (Fzd7) form a coreceptor complex in satellite cells and that binding of the ECM glycoprotein Fibronectin (FN) to Sdc4 stimulates the ability of Wnt7a to induce the symmetric expansion of satellite stem cells. Newly activated satellite cells dynamically remodel their niche via transient high-level expression of FN. Knockdown of FN in prospectively isolated satellite cells severely impaired their ability to repopulate the satellite cell niche. Conversely, in vivo overexpression of FN with Wnt7a dramatically stimulated the expansion of satellite stem cells in regenerating muscle. Therefore, activating satellite cells remodel their niche through autologous expression of FN that provides feedback to stimulate Wnt7a signaling through the Fzd7/Sdc4 coreceptor complex. Thus, FN and Wnt7a together regulate the homeostatic levels of satellite stem cells and satellite myogenic cells during regenerative myogenesis. The data set contains one microarray of pooled quiescent skeletal muscle satellite cells
Project description:Here we show that alveolar macrophages maintain their core AM transcriptomic identity through culture expansion but show adaptations during culture expansion that are transient, reversible and fully restored upon transplantation into the alveolar niche.
2022-01-23 | GSE194142 | GEO
Project description:Lionfish Range Expansion RAD-seq
Project description:The small intestinal crypt exhibits a defined spatial organisation involving multiple cell types that undergo continuous proliferation and differentiation while migrating towards the villus. We have built a multi-scale agent-based model (ABM), with individual cells interacting in the crypt geometry, which reproduces the self-organizing stable behaviour reported for the crypt. In our ABM, spatial organization emerges from the dynamic interaction of multiple signalling pathways, which include the Wnt, Notch, BMP and RNF43/ZNRF3 pathways that orchestrate cellular fate and mechanisms of contact inhibition of proliferation as well as feedback loops that regulate the expansion of the niche and size of the crypt. Moreover, this dynamic signalling network interacts with the main cell cycle proteins, governing the progression of each cell across the division stages.
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.