A complex of closely related Mallomonas taxa belonging to the section Papillosae, M. kalinae Řezáčová and M. rasilis Dürrschmidt, has been studied in detail by molecular and morphometric methods. Our investigations uncovered the existence of a new species found in water bodies in Vietnam, which we describe here as Mallomonas furtiva sp. nov. This taxon is morphologically very similar to M. kalinae, from which it differs by minute, but statistically significant morphological differences on the structure of silica scales. Indeed, the principal component analysis of morphological traits measured on silica scales significantly separates all three species in the complex. Mallomonas kalinae and M. furtiva differ by number of papillae on the shield and the dome, as well as by the scale sizes. Likewise, Mallomonas rasilis and M. furtiva are primarily differentiated by the absence of submarginal anterior ribs on silica scales of the former species. Phylogenetic analyses showed that Mallomonas furtiva is closely related to M. kalinae, with which it formed a highly supported lineage. Distribution patterns of all three studied taxa are further discussed.

• Klíčová slova
• Molecular analysis, Synurales, new species, scale ultrastructure, section Papillosae,
• MeSH
• bílkoviny řas analýza   MeSH
• DNA řas analýza   MeSH
• fylogeneze MeSH
• Heterokontophyta klasifikace   genetika   ultrastruktura   MeSH
• mikrobiota * MeSH
• mikroskopie elektronová rastrovací MeSH
• mokřady MeSH
• ribozomální DNA analýza   MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Vietnam MeSH
• Názvy látek
• bílkoviny řas MeSH
• DNA řas MeSH
• ribozomální DNA MeSH

The RAB GTPases, which are involved in regulation of endomembrane trafficking, exhibit a complex but incompletely understood evolutionary history. We elucidated the evolution of the RAB1 subfamily ancestrally implicated in the endoplasmic reticulum-to-Golgi traffic. We found that RAB1 paralogs have been generated over the course of eukaryotic evolution, with some duplications coinciding with the advent of major eukaryotic lineages (e.g. Metazoa, haptophytes). We also identified a unique, derived RAB1 paralog, orthologous to the Plasmodium Rab1A, that occurs in stramenopiles, alveolates, and Rhizaria, represented by the chlorarachniophyte Gymnochlora stellata. This finding is consistent with the recently documented existence of a major eukaryotic clade ("SAR") comprising these three lineages. We further found a Rab1A-like protein in the cryptophyte Guillardia theta, but it exhibits unusual features among RAB proteins: absence of a C-terminal prenylation motif and an N-terminal extension with two MSP domains; and its phylogenetic relationships could not be established convincingly due to its divergent nature. Our results nevertheless point to a unique membrane trafficking pathway shared by at least some lineages of chromalveolates and Rhizaria, an insight that has implications towards interpreting the early evolution of eukaryotes and the endomembrane system.

• MeSH
• aminokyselinové motivy MeSH
• Cryptophyta enzymologie   genetika   MeSH
• DNA řas analýza   genetika   MeSH
• fylogeneze MeSH
• molekulární evoluce MeSH
• molekulární sekvence - údaje MeSH
• Plasmodium falciparum enzymologie   genetika   MeSH
• protozoální DNA analýza   genetika   MeSH
• Rab1 proteiny vázající GTP chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• terciární struktura proteinů MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• DNA řas MeSH
• protozoální DNA MeSH
• Rab1 proteiny vázající GTP MeSH

We developed an alternative method of staining cell nuclei and chloroplast nucleoids of algal cells using SYBR Green I (the fluorescent dye used commonly for detecting dsDNA in agarose and polyacrylamide gels as an alternative to highly mutagenic ethidium bromide and for DNA staining of viruses and bacteria followed by flow cytometry, digital image analysis or real-time PCR), which enabled routine staining in vivo. Cells do not need to be fixed or treated chemically or physically before staining, thus the shape, size and position of DNA-containing structures are not affected. The fluorescence signal is sharp and reproducible. Examples of application of the method are shown in color microphotographs for representatives of eukaryotic algae from the taxa Chlorophyta, Rhodophyta and the prokaryotic Cyanophyta. The method is also useful for studying progress of the cell cycle in algal cells dividing by multiple fission, as shown by observation of changes in nuclear number during the cell cycle of the green alga Chlamydomonas reinhardtii and Scenedesmus quadricauda. Staining with SYBR Green I can be recommended as a fast, safe and efficient method for the detection of DNA-containing structures in vivo.

• MeSH
• barvení a značení metody   MeSH
• benzothiazoly MeSH
• buněčný cyklus MeSH
• chinoliny MeSH
• Chlorophyta genetika   fyziologie   ultrastruktura   MeSH
• diaminy MeSH
• DNA řas analýza   MeSH
• fluorescenční barviva metabolismus   MeSH
• organické látky metabolismus   MeSH
• permeabilita buněčné membrány MeSH
• počítačové zpracování obrazu MeSH
• polymerázová řetězová reakce MeSH
• průtoková cytometrie MeSH
• reprodukovatelnost výsledků MeSH
• Rhodophyta genetika   fyziologie   ultrastruktura   MeSH
• sinice genetika   fyziologie   ultrastruktura   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• benzothiazoly MeSH
• chinoliny MeSH
• diaminy MeSH
• DNA řas MeSH
• fluorescenční barviva MeSH
• organické látky MeSH
• SYBR Green I MeSH Prohlížeč