Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424 vol. 102, suppl. 1, May 2005
iii-iv, 6615-6635 s. : il., tab. ; 28 cm
- MeSH
- Biological Evolution MeSH
- Biological Science Disciplines MeSH
- Publication type
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Biologické vědy
- NML Fields
- biologie
elektronický časopis
elektronický časopis
- Conspectus
- Veřejné zdraví a hygiena
- NML Fields
- environmentální vědy
- NML Publication type
- elektronické časopisy
Amoeboid protists are extremely abundant and diverse in natural systems where they often play outstanding ecological roles. They can be found in almost all major eukaryotic divisions, and genomic approaches are bringing major changes in our perception of their deep evolutionary relationships. At fine taxonomic levels, the generalization of barcoding is revealing a considerable and unsuspected specific diversity that can be appreciated with careful morphometric analyses based on light and electron microscopic observations. We provide examples on the difficulties and advances in amoeboid protists systematics in a selection of groups that were presented at the VIIIth ECOP/ISOP meeting in Rome, 2019. We conclude that, in all studied groups, important taxonomical rearrangements will certainly take place in the next few years, and systematics must be adapted to incorporate these changes. Notably, nomenclature should be flexible enough to integrate many new high level taxa, and a unified policy must be adopted to species description and to the establishment of types.
- MeSH
- Amoebozoa classification MeSH
- Biodiversity MeSH
- Classification * MeSH
- Terminology as Topic MeSH
- Research trends MeSH
- Publication type
- Congress MeSH
Terminology for microtriches, the surface features both unique to and ubiquitous among cestodes, is standardised based on discussions that occurred at the International Workshops on Cestode Systematics in Storrs, Connecticut, USA in 2002, in České Budějovice, Czech Republic in 2005 and in Smolenice, Slovakia in 2008. The following terms were endorsed for the components of individual microtriches: The distal, electron-dense portion is the cap, the proximal more electron-lucent region is the base. These two elements are separated from one another by the baseplate. The base is composed of, among other elements, microfilaments. The cap is composed of cap tubules. The electron-lucent central portion of the base is referred to as the core. The core may be surrounded by an electron-dense tunic. The entire microthrix is bounded by a plasma membrane, the external layer of which is referred to as the glycocalyx. Two distinct sizes of microtriches are recognised: those ? 200 nm in basal width, termed filitriches, and those >200 nm in basal width, termed spinitriches. Filitriches are considered to occur in three lengths: papilliform (? 2 times as long as wide), acicular (2–6 times as long as wide), and capilliform (>6 times as long as wide). In instances in which filitriches appear to be doubled at their base, the modifier duplicated is used. Spinitriches are much more variable in form. At present a total of 25 spinithrix shapes are recognised. These consist of 13 in which the width greatly exceeds the thickness (i.e., bifid, bifurcate, cordate, gladiate, hamulate, lanceolate, lineate, lingulate, palmate, pectinate, spathulate, trifid, and trifurcate), and 12 in which width and thickness are approximately equal (i.e., chelate, clavate, columnar, coniform, costate, cyrillionate, hastate, rostrate, scolopate, stellate, trullate, and uncinate). Spiniform microtriches can bear marginal (serrate) and/or dorsoventral (gongylate) elaborations; they can also bear apical features (aristate). The latter two modifiers should be used only if the features are present. The terminology to describe the overall form of a spinithrix should be used in the following order: tip, margins, shape. Each type of microthrix variation is defined and illustrated with one or more scanning electron micrographs. An indication of the taxa in which each of the microthrix forms is found is also provided.
elektronický časopis
- Conspectus
- Biologické vědy
- NML Fields
- biologie
- veterinární lékařství
- NML Publication type
- elektronické časopisy
While dixenous trypanosomatids represent one of the most dangerous pathogens for humans and domestic animals, their monoxenous relatives have frequently become model organisms for studies of diversity of parasitic protists and host-parasite associations. Yet, the classification of the family Trypanosomatidae is not finalized and often confusing. Here we attempt to make a blueprint for future studies in this field. We would like to elicit a discussion about an updated procedure, as traditional taxonomy was not primarily designed to be used for protists, nor can molecular phylogenetics solve all the problems alone. The current status, specific cases, and examples of generalized solutions are presented under conditions where practicality is openly favored over rigid taxonomic codes or blind phylogenetic approach.
elektronický časopis
- Conspectus
- Veřejné zdraví a hygiena
- NML Fields
- environmentální vědy
- NML Publication type
- elektronické časopisy
- ročenky
svazky
- MeSH
- Biochemical Phenomena MeSH
- Publication type
- Periodical MeSH
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- biochemie
