AUTHOR=Bakuła Zofia , Gromadka Robert , Gawor Jan , Siedlecki Paweł , Pomorski Jan J. , Maciszewski Kacper , Gromadka Agnieszka , Karnkowska Anna , Jagielski Tomasz 

TITLE=Sequencing and Analysis of the Complete Organellar Genomes of Prototheca wickerhamii

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.01296

DOI=10.3389/fpls.2020.01296

ISSN=1664-462X

ABSTRACT=<p>Of the <italic>Prototheca</italic> genus, <italic>Prototheca</italic><italic>wickerhamii</italic> has the highest clinical significance in humans. However, neither nuclear nor organellar genomes of this species were sequenced until now. The hitherto determined and analyzed mitochondrial and plastid genomes of the alleged <italic>P. wickerhamii</italic> species belong in fact to another species, recently named <italic>Prototheca xanthoria</italic>e. This study provides a first insight into the organellar genomes of a true <italic>P. wickerhamii</italic> (type strain ATCC 16529). The <italic>P. wickerhamii</italic> mitochondrion had a 53.8-kb genome, which was considerably larger than that of <italic>Prototheca</italic><italic>ciferrii</italic> (formerly <italic>Prototheca zopfii</italic> gen. 1) and <italic>Prototheca bovis</italic> (formerly <italic>Prototheca zopfii</italic> gen. 2), yet similarly functional, with the differences in size attributable to a higher number of introns and the presence of extra unique putative genes. The 48-kb plastid genome of <italic>P. wickerhamii</italic>, compared to autotrophic Trebouxiophyceae, was highly reduced due to the elimination of the photosynthesis-related genes. The gene content of the plastid genome of <italic>P. wickerhamii</italic> was, however, very similar to other colorless <italic>Prototheca</italic> species. Plastid genome-based phylogeny reinforced the polyphyly of the genus <italic>Prototheca</italic>, with <italic>Helicosporidium</italic> and <italic>Auxenochlorella</italic> branching within clades of <italic>Prototheca</italic> species. Phylogenetic reconstruction also confirmed the close relationship of <italic>P. wickerhamii</italic> and <italic>P. xanthoriae</italic>, which is reflected in the synteny of their organellar genomes. Interestingly, the entire set of <italic>atp</italic> genes was lost in <italic>P. wickerhamii</italic> plastid genome while being preserved in <italic>P. xanthoriae</italic>.</p>