Persistent meiotic arrest in basidia of Agaricus bisporus
نویسندگان
چکیده
The pattern of distribution of genetic markers among progeny of Agaricw bisporus, whether conventional mutants, electrophoretic isozyme variants or restriction fragment length polymorphisms, implies a combination of reduced recombination rates and preferential segregation of centromeres during meiosis. We have considered an alternative explanation, namely that meiosis may be an infrequent event, the majority of basidiospores being produced by mitosis. By examining the dynamic population structure of nuclear division in the A. bisporus hymenium over the whole of the development of the mushroom fruit body, we find that meiosis is common. Fusion nuclei were readily observable and were in a large majority. However, basidioles with single fusion nuclei remained the majority class throughout the life of the fruit body, right through to senescence. This suggests that release from meiotic arrest is a rare event and some of the observed peculiarities in segregation patterns might be a consequence.
منابع مشابه
Study on development of Agaricus bisporus by fluorescent microscopy and scanning electron microscopy.
Two strains of Agaricus bisporus have been investigated by fluorescent microscopy and scanning electron microscopy. Somatic nuclei, stained with auramin O and examined by fluorescent microscopy, appear to be randomly distributed, divide asynchronously, and assume a nonclassical or "two-track" configuration during mitotic metaphase. A similar configuration has been observed for nuclei during mei...
متن کاملA meiotic DNA polymerase from a mushroom, Agaricus bisporus.
A meiotic DNA polymerase [DNA nucleotidyltransferase (DNA-directed), EC 2.7.7.7], which likely has a role in meiotic DNA repair, was isolated from a mushroom, Agaricus bisporus. The purified fraction displays three bands in SDS/PAGE, at molecular masses of 72 kDa, 65 kDa and 36 kDa. Optimal activity is at pH 7.0-8.0 in the presence of 5 mM Mg2+ and 50 mM KCl and at 28-30 degrees C, which is the...
متن کاملInheritance of restriction fragment length polymorphisms in Agaricus brunnescens.
The cultivated mushroom, Agaricus brunnescens, is secondarily homothallic; most basidia produce only two basidiospores, each of which receives two of the four post meiotic nuclei. The segregation of restriction fragment length polymorphisms (RFLPs) detected by four plasmid probes carrying single-copy nuclear DNA of Agaricus was followed in seven parental strains including commercial, wild-colle...
متن کاملStudies on Chemical Composition and Nutritive Evaluation of Wild Edible Mushrooms
Agaricus bisporus and Agaricus bitorquis are among most favorite mushrooms of the world. Mineral contents, proximate composition and fatty acid profile of these mushrooms were determined for evaluation of their dietary value. Na, K and Li contents were high, while Cr, Cu, Pb, Co, Zn, Mn and Ni concentrations were low in both Agaricus bisporus and Agaricus bitorquis. Proximate analysis showe...
متن کاملAgrobacterium tumefaciens mediated transformation of Agaricus bisporus
Agrobacterium tumefaciens is known to transfer parts of its tumor-inducing plasmid to filamentous fungi including Agaricus bisporus. We have used this transformation system to transform germinating basidiospores of A. bisporus. Analysis of hygromycin B-resistant clones showed that the T-DNA integrated at random sites and in multiple copies into the host genome. Furthermore we have been able to ...
متن کامل