Todd, R.B., Davis, M.A. & Hynes, M.J. Genetic manipulation of Aspergillus nidulans: meiotic progeny for genetic analysis and strain construction. Nat. Protocols 2, 811-821

Department of Genetics, The University of Melbourne, Parkville, Victoria 3010, Australia.
Nature Protocol (Impact Factor: 9.67). 02/2007; 2(4):811-21. DOI: 10.1038/nprot.2007.112
Source: PubMed

ABSTRACT The multicellular microbial eukaryote Aspergillus nidulans is an excellent model for the study of a wide array of biological processes. Studies in this system contribute significantly to understanding fundamental biological principles and are relevant for biotechnology and industrial applications, as well as human, animal and plant fungal pathogenesis. A. nidulans is easily manipulated using classical and molecular genetics. Here, we describe the storage and handling of A. nidulans and procedures for genetic crossing, progeny analysis and growth testing. These procedures are used for Mendelian analysis of segregation of alleles to show whether a mutant phenotype segregates as a single gene and independent assortment of genes to determine the linkage relationship between genes. Meiotic crossing is used for construction of multiple mutant strains for genetic analysis. Genetic crossing and analysis of progeny can be undertaken in 2-3 weeks and growth testing takes 2-3 days.

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Available from: Michael J Hynes, Sep 25, 2015
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    • "Moreover, Aspergillus nidulans provides a genetically tractable model system, in particular to study telomere length in a number of different cell types such as asexual conidia and sexual ascospores. A. nidulans has ascospores that are uniquely housed in a separate structure called the cleistothecium. One cleistothecium holds 10,000 or more ascospores [17], but unfortunately the external surfaces of cleistothecia are covered by conidia and other cell types. These cells are extremely labor intensive to remove, and thus pure ascospore DNA can be obtained only in small quantities. "
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    ABSTRACT: Telomere length varies between germline and somatic cells of the same organism, leading to the hypothesis that telomeres are lengthened during meiosis. However, little is known about the meiotic telomere length in many organisms. In the filamentous fungus Aspergillus nidulans, the telomere lengths in hyphae and asexual spores are invariant. No study using existing techniques has determined the telomere length of the sexual ascospores due to the relatively low abundance of pure meiotic cells in A. nidulans and the small quantity of DNA present. To address this, we developed a simple and sensitive PCR strategy to measure the telomere length of A. nidulans meiotic cells. This novel technique, termed "telomere-anchored PCR," measures the length of the telomere on chromosome II-L using a small fraction of the DNA required for the traditional terminal restriction fragment (TRF) Southern analysis. Using this approach, we determined that the A. nidulans ascospore telomere length is virtually identical to telomeres of other cell types from this organism, approximately 110 bp, indicating that a surprisingly strict telomere length regulation exists in the major cell types of A. nidulans. When the hyphal telomeres were measured in a telomerase reverse transcriptase (TERT) knockout strain, small decreases in length were readily detected. Thus, this technique can detect telomeres in relatively rare cell types and is particularly sensitive in measuring exceptionally short telomeres. This rapid and inexpensive telomere-anchored PCR method potentially can be utilized in other filamentous fungi and types of organisms.
    PLoS ONE 06/2014; 9(6):e99491. DOI:10.1371/journal.pone.0099491 · 3.23 Impact Factor
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    • "Comparative analysis of eisosomes in S. cerevisiae and A. nidulans reveals striking differences in their assembly and developmental fate (Scazzocchio et al., 2011). The homothallic fungus Aspergillus (Emericella) nidulans is arguably , among the Pezizomycotina, the organism where membrane proteins have been better studied and is a genetic model system having the ability to reproduce through two different types of spores, conidiospores and ascospores, the products of the asexual and the sexual cycle respectively (Pontecorvo et al., 1953b; Han et al., 2001; Todd et al., 2007). Conidiospores and ascospores are very different cells, which have a radically different morphology and are formed through completely different developmental pathways . "
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    ABSTRACT: In the model filamentous fungus Aspergillus nidulans, PilA and PilB, two homologues of the Saccharomyces cerevisiae eisosome proteins Pil1/Lsp1, and SurG, a strict orthologue of Sur7, are assembled and form tightly packed structures in conidiospores. As A. nidulans differs in its reproduction pattern from the Saccharomycotina in that it has the ability to reproduce through two different types of spores, conidiospores and ascospores, the products of the asexual and the sexual cycle respectively, we investigated the eisosome distribution and localization during the sexual cycle. Our results show that core eisosome proteins PilA, PilB and SurG are not expressed in hülle cells or early ascospores, but are expressed in mature ascospores. All eisosomal proteins form punctate structures at the membrane of late ascospores. In mature but quiescent ascospores, PilA forms static punctate structures at the plasma membrane. PilB also was observed at the ascospore membrane as well, with higher concentration at the areas where the two halves of ascospores are joined together. Finally, SurG was localized both at the membrane of ascospores and perinuclearly. In germlings originating from ascospores the punctate structures were shown to be composed only of PilA. PilB is diffused in the cytoplasm and SurG was located in vacuoles and endosomes. This altered localization is identical to that found in germlings originated from conidiospores. In germinated ascospores PilA foci did not colocalise with the highly mobile and transient peripheral punctate structures of AbpA, a marker for sites of clathrin-mediated endocytosis. Deletions of each one or all the three core eisosomal genes do not affect viability or germination of ascospores. In the presence of myriocin -a specific inhibitor of sphingolipid biosynthesis- PilA-GFP foci of ascospore germlings were less numerous and their distribution was significantly altered, suggesting a correlation between PilA foci and sphingolipid biosynthesis.
    Fungal Genetics and Biology 02/2013; 53. DOI:10.1016/j.fgb.2013.01.002 · 2.59 Impact Factor
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    • "This genus contains species with tremendous impact on public health: both positively and negatively [22]. Aspergillus nidulans (A.nidulans) is considered a premier model fungus for filamentous fungi especially for other Aspergilli due to its well-established genetic system [23], [24]. Similar to the pathogenic Aspergilli, A. nidulans produces small, hydrophobic conidia that disperse easily into the air and can survive a broad range of environmental conditions [23], [25]. "
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    ABSTRACT: Although the high affinity Ca(2+) channel, Cch1, and its subunit Mid1 have been investigated and evaluated in yeast and some of filamentous fungi, little is known about the function of their homologs in the Aspergilli. Here, we have functionally characterized the yeast homologs, CchA and MidA, in Aspergillus nidulans using conditional and null deletion mutants. CchA and MidA not only have functional benefits of fast growth, which is consistent with Cch1 and Mid1 in yeast, but also have unique and complex roles in regulating conidiation, hyphal polarity and cell wall components in low-calcium environments. The defect of CchA or MidA resulted in a sharp reduction in the number of conidiospores, accompanied by abnormal metulae, and undeveloped-phialides at a higher density of inoculum. Most interestingly, these conidiation defects in mutants can, remarkably, be rescued either by extra-cellular Ca(2+) in a calcineurin-dependent way or by osmotic stress in a calcineurin-independent way. Moreover, the fact that the phenotypic defects are not exacerbated by the presence of the double deletion, together with the Y2H assay, indicates that CchA and MidA may form a complex to function together. Our findings suggest that the high-affinity Ca(2+) channel may represent a viable and completely unexplored avenue to reduce conidiation in the Aspergilli.
    PLoS ONE 10/2012; 7(10):e46564. DOI:10.1371/journal.pone.0046564 · 3.23 Impact Factor
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