Molecular-genetic diversity of the ascomycetous yeast genus Arthroascus: Arthroascus babjevae sp. nov., Arthroascus fermentans var. arxii var. nov. and geographical populations of Arthroascus schoenii

Abstract

Using molecular and genetic analyses, 28 Arthroascus strains were analysed, isolated from widely different geographical localities in Europe, North America, Far-East Asia and Hawaii. Most of the strains have been assigned to the species Arthroascus schoenii. PCR-RAPD revealed two Japanese Arthroascus strains (UCD 67-278 and IFO 10138) to have peculiar patterns. Comparative rDNA (D1/D2 26S, ITS1 and ITS2) sequence analysis showed that the two strains respectively represent a novel species and a novel variety. Based on the results of sequence analysis, genetic hybridization and DNA–DNA reassociation, two new members of the genus Arthroascus are formally described, Arthroascus babjevae sp. nov. (type strain UCD 67-278T=CBS 9167T) and Arthroascus fermentans var. arxii var. nov. (type strain IFO 10138T=CBS 9168T). These results show that A. schoenii has a worldwide distribution, while the species Arthroascus javanensis is represented only by the type culture CBS 2555T, isolated in Indonesia. Cluster analysis revealed a correlation between PCR-RAPD fingerprints and geographical origin of the A. schoenii strains. Despite this molecular differentiation, A. schoenii strains collected in different regions of the world formed predominantly fertile hybrids, with normal recombination of control markers.

Two novel Saccharomycopsis species isolated from black olive brines and a tropical plant. Description of Saccharomycopsis olivae f. a., sp. nov. and Saccharomycopsis guyanensis f. a., sp. nov. Reassignment of Candida amapae to Saccharomycopsis amapae f. a., comb. nov., Candida lassenensis to Saccharomycopsis lassenensis f. a., comb. nov. and Arthroascus babjevae to Saccharomycopsis babjevae f. a., comb. nov.

“…Differentiation of Arthoascus schoenii strains from different origins led to debate, including the proposal of reinstating the genus Arthroascus von Arx (Naumov et al , 2003). Further work by the same authors proposed the placement of four species into Arthroascus : Arthroascus javanensis , two varieties of Arthroascus fermentans and A. schoenii as well as a newly described species Arthroascus babjevae (Naumov et al , 2006). In their review of the genus Saccharomycopsis , Kurtzman & Smith (2011) proposed that species of the genus Saccharomycopsis form a distinct clade within the Saccharomycetales and also proposed that the species of the genus Arthroascus , including A. babjavae , be included in the genus Saccharomycopsis .…”

The yeast Komagataella: A genetic genus in accordance with interspecies hybridization

“…Nevertheless, genetic genera incorporate real biological species exhibiting postzy gotic isolation-nonviable meiosis products (ascospores) of hybrids. Thirty five years later we can state that not only the genus Saccharomyces [19][20][21][22] but also other revised genera correspond to the genetic concept of genus: [23][24][25][26][27][28][29]. Tak ing into account the literature data [30][31][32][33], the small spore species of Metschnikowia Kamienski 1899 (sensu stricto) and large spore Metschnikowia species (sensu lato) are likely to be considered as different genetic genera.…”

Molecular evolution of cyclin proteins in animals and fungi

“…This implies the gradual evolution we detected for fungal CDC13. However, events like polyploidization [113-115] or megaduplication [116], might have contributed largely to fungal speciation. This evolutionary pattern is punctuational.…”

“…In fact, functional specialization in paralogous genes changed during evolution [116]. Ultimately, the newly arisen fungal species (including polyploid species) formed an ecosystem with ancestors [113-115,117,118]. A good example is the punctual evolution of cyclins CLB3-4 in Ascomycota.…”