Host identity influences nuclear dynamics in arbuscular mycorrhizal fungi

Generation of unequal nuclear genotype proportions in Rhizophagus irregularis progeny causes allelic imbalance in gene transcription

“…The current opinion is that high intraspecific genetic diversity in R. irregularis could facilitate evolution by enabling generalist lifestyles and overcoming the danger of becoming too specialized on one host (Chen et al ., 2018b). This relationship was explored and demonstrates that nuclear dynamics may change in response to particular plant hosts for dikaryon AMF (Angelard et al ., 2014; Kokkoris et al ., 2021). In nature, AMF dikaryons may optimize niche adaptation in multiple ecosystems by maintaining both populations of cooperating nuclear genotypes.…”

Homo- and Dikaryons of the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis Differ in Life History Strategy

“…We used 10 strains of R. irregularis (Schenck and Smith). Specifically six homokaryotic strains: Cuba8 (DAOM 984909), 330 (DAOM229455), 66 (DAOM240720), 197198 (DAOM197198), 101 (DAOM240448), and 98 (DAOM240446) and four dikaryotic strains: A4 (DAOM664343), A5 (DAOM664344), SL1 (DAOM240409), and G1 (DAOM970895), which were recently analyzed for nuclear dynamics ( Kokkoris et al, 2021 ). The strains were obtained from the Canadian Collection of Arbuscular Mycorrhizal Fungi (CCAMF), previously known as Glomeromycota In vitro Collection—(GINCO) and from the dikaryotic AMF collection—Corradi Lab at University of Ottawa.…”

“…The AMF harbor thousands of nuclei within a common cytoplasm ( Kokkoris et al, 2020a ), and it has been demonstrated that strains of the model species Rhizophagus irregularis are either “homokaryotic” (AMF homokaryons)—or heterokaryotic (AMF dikaryons) ( Ropars et al, 2016 ; Corradi and Brachmann, 2017 ; Chen et al, 2018 ). In homokaryons, all coexisting nuclei are genetically similar harboring one putative mating-type (MAT)-locus, whereas in dikaryons, two genetically unique nuclear populations, each harboring a unique MAT-locus, co-exist at stable or variable ratios depending on the plant host ( Kokkoris et al, 2021 ). A MAT-locus is a region that governs sexual identity in fungal strains, and the MAT-locus of R. irregularis resembles the MAT-locus of basidiomycetes ( Casselton, 2008 ).…”

“…In AMF, the ratio of co-existing parental nuclei is also actively regulated in response to the host plant identity ( Kokkoris et al, 2021 ), yet the phenotypic consequences of this regulation are currently unknown. More generally, how AMF homokaryons and dikaryons compare in terms of growth and symbiotic potential is unclear.…”

Optimizing Droplet Digital PCR for Environmental Samples

“…First, to identify current threshold determination approaches for environmental studies using ddPCR, we searched Web of Science (Clarivate Analytics 2018). We identified 75 papers including applications in monitoring of invasive species [26,27], detection of microbes in soil, plant tissue and water [28,29,30,31] and testing food for contamination by microbes or non-declared species [32](Table S1). The most common strategy for threshold assignment was the automatic threshold set by QuantaSoft TM , the default software provided by BioRad Technologies, Inc. (2017) followed by manually set threshold, but for the majority of the studies without explained parameters, via the QuantaSoft TM software.…”