The new genus Bryorutstroemia is established for the red-brown, stipitate, bryoparasitic discomycete Helotium fulvum Boud. Combined phylogenetic analysis of ITS and LSU rDNA and EF1α revealed that Bryorutstroemia fulva belongs to the sclerotiniaceous clade, which comprises the paraphyletic families Rutstroemiaceae and Sclerotiniaceae. Bryorutstroemia formed with Clarireedia a supported clade (Rutstroemiaceae s.l.), though with high distance. Bryorutstroemia closely resembles other Rutstroemiaceae in having uninucleate ascospores with high lipid content and an ectal excipulum of textura porrecta, but is unique because of its bryophilous lifestyle and is extraordinary with its thick-walled inamyloid ascus apex. Although B. fulva was described in 1897, very few records came to our notice. The present study summarizes the known distribution of the species, including 25 personal collections from the years 2001-2022. Bryorutstroemia fulva was most often encountered on Dicranella heteromalla, and rarely on other members of Dicranales or Grimmiales, while inducing necrobiosis of the leaves. A detailed description based on mainly fresh apothecia is provided together with a rich photographic documentation. Six new combinations are proposed based on our phylogenetic results and unpublished personal morphological studies: Clarireedia asphodeli, C. calopus, C. gladioli, C. henningsiana, C. maritima, and C. narcissi.
- Publikační typ
- časopisecké články MeSH
TPX2 (Targeting Protein for Xklp2) is an evolutionary conserved microtubule-associated protein important for microtubule nucleation and mitotic spindle assembly. The protein was described as an activator of the mitotic kinase Aurora A in humans and the Arabidopsis AURORA1 (AUR1) kinase. In contrast to animal genomes that encode only one TPX2 gene, higher plant genomes encode a family with several TPX2-LIKE gene members (TPXL). TPXL genes of Arabidopsis can be divided into two groups. Group A proteins (TPXL2, 3, 4, and 8) contain Aurora binding and TPX2_importin domains, while group B proteins (TPXL1, 5, 6, and 7) harbor an Xklp2 domain. Canonical TPX2 contains all the above-mentioned domains. We confirmed using in vitro kinase assays that the group A proteins contain a functional Aurora kinase binding domain. Transient expression of Arabidopsis TPX2-like proteins in Nicotiana benthamiana revealed preferential localization to microtubules and nuclei. Co-expression of AUR1 together with TPX2-like proteins changed the localization of AUR1, indicating that these proteins serve as targeting factors for Aurora kinases. Taken together, we visualize the various localizations of the TPX2-LIKE family in Arabidopsis as a proxy to their functional divergence and provide evidence of their role in the targeted regulation of AUR1 kinase activity.
- MeSH
- Arabidopsis cytologie genetika metabolismus MeSH
- kinasy aurora metabolismus MeSH
- mikrotubuly metabolismus MeSH
- proteinové domény MeSH
- proteiny asociované s mikrotubuly analýza genetika metabolismus MeSH
- proteiny huseníčku analýza genetika metabolismus MeSH
- rostlinné geny MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
Diatoms are one of the most abundant and arguably the most species-rich group of protists. Diatom species delimitation has often been based exclusively on the recognition of morphological discontinuities without investigation of other lines of evidence. Even though DNA sequences and reproductive experiments have revealed several examples of (pseudo)cryptic diversity, our understanding of diatom species boundaries and diversity remains limited. The cosmopolitan pennate raphid diatom genus Pinnularia represents one of the most taxon-rich diatom genera. In this study, we focused on the delimitation of species in one of the major clades of the genus, the Pinnularia subgibba group, based on 105 strains from a worldwide origin. We compared genetic distances between the sequences of seven molecular markers and selected the most variable pair, the mitochondrial cox1 and nuclear encoded LSU rDNA, to formulate a primary hypothesis on the species limits using three single-locus automated species delimitation methods. We compared the DNA-based primary hypotheses with morphology and with other available lines of evidence. The results indicate that our data set comprised 15 species of the P. subgibba group. The vast majority of these taxa have an uncertain taxonomic identity, suggesting that several may be unknown to science and/or members of (pseudo)cryptic species complexes within the P. subgibba group.
- MeSH
- fylogeneze MeSH
- ribozomální DNA MeSH
- rozsivky * MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
