The raphid pennates
WebbSome apparently benthic raphid pennates can be found in the plankton as well, but these seem to use the marine snow as a substratum. Others live in the brine channels of seasonal sea ice. A possible reason why so few pennate diatoms are truly planktonic may have to do with their mode of sexual reproduction (see Figure 3C). Webb16 aug. 2024 · Instead, the group consists of the so-called "basal araphids", sister to all remaining raphid and araphid pennates, and the "core araphids" which are sister to raphid pennate diatoms [28–32]. Irrespective of the study, most agree that one of the earliest pennate divergences contains rhaphoneidacean, asterionellopsid and …
The raphid pennates
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Webb2 The raphid pennates (order Bacillariales) are a diverse group of diatoms easily recognized by 3. having a slit in the siliceous cell wall, called the raphe, with functions in … WebbBoth centric and pennate diatoms are further divided into two sub-groups: the centrics into radial and polar types, based on descriptors of frustule symmetry, and the pennates into raphid and araphid types, based on the presence or absence, respectively, of a slit known as raphe at the centre of the frustule that facilitates motility on surfaces …
Webbraphid pennates, has been documented using SSU rDNA and rbcL sequences (e.g. Kooistra et al., 2003; Sorhannus, 2004, 2007). Since their origin, raphid pennate diatoms have diversified enormously and account for the majority of the over 200,000 extant species estimated to exist (Mann and Droop, 1996), indicating the evolu- WebbAccueil - Archive ouverte HAL
WebbChitin synthases are widespread among eukaryotes and known to have a complex evolutionary history in some of the groups. We have reconstructed the chitin synthase phylogeny using the most taxonomically comprehensive dataset currently available and have shown the presence of independently formed paralogous groups in oomycetes, … Webb7 okt. 2008 · Pennate diatoms are monophyletic. Their principal cell wall elements, called valves, are shaped like a ship’s hull. Within the pennates, the araphids are paraphyletic; …
Webb31 jan. 2024 · The raphid pennates (order Bacillariales) are a diverse group of diatoms easily recognized by having a slit in the siliceous cell wall, called the raphe, with …
Webb16 aug. 2024 · There is a long-standing consensus that araphid pennates emerged from among the polar centrics, and that raphid diatoms diverged from araphid ancestors … iosh construction meaningWebb8 juni 2024 · The diatom Phaeodactylum tricornutum has been used as a model for cell biologists and ecologists for over a century. We have incorporated several new raphid pennates into a three gene phylogenetic dataset (SSU, rbcL, psbC), and recover Gomphonemopsis sp. as sister to P. tricornutum with 100% BS supp … iosh consultancy guideWebb10 juli 2013 · A set of proposals for the terminology of processes and structures associated with sexual reproduction and for the resting stages of diatoms, some of which have at times been confused with each other are presented. The past few decades have brought about a significant expansion in our understanding of the diatom life cycle, … iosh confined spaceWebbeach major lineage (centrics, araphid pennates, raphid pennates) was derived separately from a pool of “Ur-diatom” forms. In short, each of these major groups has been … on the willows godspell lyricsWebbRaphid pennate diatoms possess a pair of longitudinal slits along the apical axis (the raphe system) (Fig. 1), from which extra- cellular polymeric substances are exuded and used in locomotion and for adhesion to the substratum (Round et al., 1990). on the windfallWebb15 mars 2012 · There are four major structural groups, radial centrics, polar centrics, araphid pennates and raphid pennates. Among the four major structural groups of diatoms, only the raphid pennates are robustly supported as monophyletic. Diatoms dominate the world's oceans, lakes and streams, conducting more than 20% of the world's … iosh corporate governanceWebb18 aug. 2024 · There are two main groups of diatoms, the centrics and the pennates, which differ markedly regarding key cytological, biological, and ecological aspects, that include cell wall symmetry, chloroplast number and morphology, sexual reproduction, and motility (Pickett-Heaps 2003). on the wind meaning