The nuclear-encoded inteins of fungi

Phylogenetic analysis of PRP8 intein in Paracoccidioides brasiliensis species complex

“…There are more than 100 known inteins and they are distributed among approximately 30 host proteins with distinct functions, some of which occur in different and phylogenetically distant organisms (Liu, 2000). This can explain the presence of PRP8 intein in distant pathogenic fungi, such as Cryptococcus species (Basidiomycetes) and different orders of Euascomycetes, Poulter et al (2007) suggested that the horizontal transference of PRP8 intein between some Ascomycetes and Basidiomycetes could have occurred when cells from the different pathogens were phagocytized by saprophytic microorganisms from the soil (in a saprobic environment), or during a co-infection with two pathogens (in an animal-host environment). The vertical transference occurs during sexual reproduction when the alleles HEG + and HEG À come into contact, thus contributing to the homing process.…”

PRP8 inteins in species of the genus Botrytis and other ascomycetes

“…This resembles the situation in S. cerevisiae where two VMA1 intein alleles are present in the population, together with empty VMA alleles (Okuda et al, 2003). There is no evidence of the HEG being degraded in any Botrytis species, as has occurred in Saccharomycete yeasts (Posey et al, 2004); nor is there evidence for internal deletions that give rise to mini-inteins as in PRP8 inteins of some Aspergillus species (Poulter et al, 2007). The intein in B. cinerea appears to have persisted without reaching fixation, in agreement with the equilibrium model of Yahara et al (2009) and the model of Goddard and Burt (1999).…”

Risks from GMOs due to Horizontal Gene Transfer

“…Major types of MGE include DNA transposons, retrotransposons, plasmids, composite mobile elements such as conjugative transposons, genomic islands, pathogenicity islands, integrative conjugative plasmids, mobilisable transposons (Burrus and Waldor, 2004;Osborn and Böltner, 2002), mobile introns/inteins (Lambowitz and Zimmerly, 2004;Poulter et al, 2007;Yamanaka et al, 2002) and non-autonomous mobile elements that lack encoded enzymes or suitable recognition sequences necessary for mobility. For example, the miniature inverted-repeat transposable elements (MITE, Feschotte et al, 2002), short interspersed nuclear elements (SINE, Moran and Gilbert, 2002) and processed pseudogenes (Kazazian, 2004) all lack a recombinase or reverse Risks from GMOs due to Horizontal Gene Transfer transcriptase gene necessary for independent mobility.…”