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Topic: Spirotrichs


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  Portal to Protistology: Stichotrich Molecular Biology
Spirotrichs have been studied since the 1800s, the old literature on life history insightfully re-synthesized by Bell (1988).
The present era of molecular genetics of Spirotrichs (review: Klobutcher and Prescott 1986) was opened by Dieter Ammermann's doctoral research, when he demonstrated polytene chromosomes in the developing macronucleus (MAC) of Stylonychia (Ammermann 1964) and laid out the time-course of cytogenetic events of this spectacular process (Ammermann 1965).
A note of caution: Katz and Riley (2001) argue that the process of generation of "gene-sized" MAC chromosomes has evolved independently in a variety of ciliate lineages; hence, this character is not a valid basis for phylogenetic inference.
www.uga.edu /protozoa/portal/stich_molec_bio.html   (2040 words)

  
 A Micronuclear Locus Containing Three Protein-Coding Genes Remains Linked During Macronuclear Development in the ...
Whether this number holds for spirotrich species in general is not known, but it seems reasonable given that the average macronuclear chromosome size is similar in the spirotrichs studied to date (Klobutcher and Herrick 1997; Prescott 1994).
Given the paucity of multi-gene macronuclear chromosomes known in spirotrichs, we were surprised to find what appeared to be a three- gene macronuclear chromosome in a species of Holosticha, a freshwater spirotrich evolutionary distinct from the more commonly studied Euplotids and Oxytrichids.
Cbs sequences in the spirotrichous species Euplotes and Stylonychia are generally found in macronuclear sequences, while the sequences in Tetrahymena are found on micronuclear DNA and removed during macronuclear development.
www.redorbit.com /news/display?id=81639   (5616 words)

  
  Reference.com/Encyclopedia/Spirotrich
The spirotrichs are a large and distinctive group of ciliate protozoa.
As first defined by Bütschli in 1889 the spirotrichs were one of two orders, together with the now-abandoned holotrichs, and included all ciliates with prominent oral cilia: heterotrichs, hypotrichs, oligotrichs, and peritrichs, although the last were soon separated.
The remaining spirotrichs form a monophyletic group, but their relationships are uncertain.
www.reference.com /browse/wiki/Spirotrich   (408 words)

  
  spirotrich   (Site not responding. Last check: 2007-11-06)
The spirotrichs are a large and distinctive class of ciliate protozoa.
The spirotrichs were one of two orders in the first major classification of ciliates, by Otto Bütschli in 1889, together with the now abandoned holotrichs.
Until recently, the heterotrichs were included here, but they show a number of peculiarities that suggest they are not close relatives of the other groups and are now given their own class.
www.abacci.com /wikipedia/topic.aspx?cur_title=spirotrichs   (241 words)

  
 Oligohymenophorea
In one subclass, the Astomatia[?], the mouth and associated structures have been lost altogether.
The class was first defined by de Puytorac in 1974 as one of three, together with the Polyhymenophora (comprising the spirotrichs) and the now abandoned Kinetofragmophora.
Since then the Apostomatia[?] have been added, but otherwise its composition has remained relatively constant, with the main variations being the position of the Peniculida and of the Plagiopylida.
www.ebroadcast.com.au /lookup/encyclopedia/ol/Oligohymenophorea.html   (214 words)

  
 Spirotrich at AllExperts
The spirotrichs are a large and distinctive group of ciliate protozoa.
A few of the smaller groups included with them may be genuine spirotrichs, however, such as the Protocruziida.
The remaining spirotrichs form a monophyletic group, but their relationships are uncertain.
en.allexperts.com /e/s/sp/spirotrich.htm   (426 words)

  
 titelciliaten   (Site not responding. Last check: 2007-11-06)
Spirotrich ciliates of the orders Euplotida (Euplotes, Aspidisca) and Stichotrichida (others in this picture) have cirri (tufts of cilia that are joined together and function as a single organelle), which are used for locomotion, swimming as well as walking over substrates, and to "manipulate" food to the cytostome.
The number and organization of cirri are important characteristics for the identification of species.
Some Spirotrichs are crawling and swimming slowly, as the tiny Aspidisca, but others are moving rapidly.
www.xs4all.nl /~wvraams1/administratie/Ciliatensite/tables_ciliaten/hypotrichea.htm   (89 words)

  
 Reconciling Classical and Molecular Phylogenies in the Stichotrichines (Ciliophora, Spirotrichea), Including New ...   (Site not responding. Last check: 2007-11-06)
The heterotrichs, which were considered as typical spirotrichs for a long time (Btschli 1889; Kahl 1932; Corliss 1979), are now regarded as a separate class within the subphylum Postciliodesmatophora due to their special somatic ultrastructure (postciliodesmata) and the macronucleus, which divides by extramacronuclear microtubules (Lynn and Small 1997).
Principally and in agreement with Petz and Foissner (1992), we are not opposed to consider halteriids as nearest relatives of the stichotrichine spirotrichs.
We shall not discuss as to whether the oligotrichs or the euplotid hypotrichs are the sister group of the stichotrichs (Petz and Foissner 1992; Chen and Song 2002; Strder-Kypke and Lynn 2003).
www.redorbit.com /news/science/122482/reconciling_classical_and_molecular_phylogenies_in_the_stichotrichines_ciliophora_spirotrichea/index.html   (6906 words)

  
 BioMed Central | Full text | Telomere formation on macronuclear chromosomes of Oxytricha trifallax and O. fallax: ...
In the Spirotrichs (previously Hypotrichs), the Stichotrichs –; Oxytricha and Stylonychia species – and the early-diverged Euplotids have been intensely studied for their dramatic extents of developmental chromosome fragmentation and elimination of MIC-limited sequences.
Of the Spirotrich telomerases, Euplotes' has been studied most intensely, although likely it is very similar to Oxytricha's [11-13].
Near the end of endo-replication in Spirotrichs many transposons and transposon-like sequences are eliminated by precise excision (Internal Eliminated Sequences or IESs [23]).
www.biomedcentral.com /1471-2156/3/16   (6948 words)

  
 Litostomatea
In trichostomes it lies in a depression, or vestibule, containing modified somatic cilia.
In one order, the Entodiniomorphida, the cilia are arranged into tufts or bands, and may be packed together to form syncilia, resembling the membranelles and cirri of spirotrichs (with which they were originally classified) and other ciliates.
In haptorians the mouth is typically surrounded by a ring of coronal cilia, arising from dikinetids derived from the anterior of the body kineties, and a ring of characteristic extrusomes called toxicysts.
www.ebroadcast.com.au /lookup/encyclopedia/li/Litostomatea.html   (221 words)

  
 tricho-, trich-, -tricha, -trichia, -trichan, -trichic, -trichosis, -trichous, -thrix, -trichum, -trichy + (Greek: hair ...
Minute, hair-like structures found on the wings of certain insects; they resemble small covering hairs, but the absence of basal articulation distinguishes them; fixed hairs; aculei; minute non-movable hairs formed from cuticle; may produce an impression of cloudiness or color.
The oligotrichs are a group of ciliate protozoa, included among the spirotrichs.
They have prominent oral cilia, which are arranged as a collar and lapel, in contrast to the choreotrichs where they form a complete circle.
www.wordinfo.info /words/index/info/view_unit/2179/4/?spage=7&letter=T   (405 words)

  
 Pellicle   (Site not responding. Last check: 2007-11-06)
Semiconductor materials are insulators at zero temperature that conduct electricity in a depression, or vestibule, containing modified somatic cilia.
More recent schemes reverse this move, and some molecular studies suggest they may be packed together to form syncilia, resembling the membranelles and cirri of spirotrichs with which they were originally classified and other ciliates.
Contributions from 18 international research groups cover various aspects of this exposition, a variety of articles was around 10.
www.iggint.com /Pellicle.html   (1262 words)

  
 [No title]   (Site not responding. Last check: 2007-11-06)
There is a large peristomial area extending from the apical region to the equator occupying about half of the surface are of the anterior half of the ventral side.
There are pairs of kinetosomes surrounding the peristome which form a zone closely resembling an adoral zone of membranelles as found in the spirotrichs.
A deep buccal cavity leads posteriorly from the end of the peristome to terminate in a cytostome in the posterior body quarter, it contains 3 membranelles that spiral down from the equatorial region to the cytostome.
www.nies.go.jp /chiiki1/protoz/morpho/neobursa.htm   (195 words)

  
 HSLS: MDS_IES_DB -- a database of macronuclear and micronuclear genes in spirotrichous ciliates   (Site not responding. Last check: 2007-11-06)
HSLS: MDS_IES_DB -- a database of macronuclear and micronuclear genes in spirotrichous ciliates
MDS_IES_DB -- a database of macronuclear and micronuclear genes in spirotrichous ciliates
This a database that contains all spirotrich genes for which both MAC and MIC versions are sequenced, with consistent annotation and easy access to all the features.
www.hsls.pitt.edu /guides/genetics/obrc/genomics/non_vertebrates/invertebrates/URL1105459779/info?print_format=true   (167 words)

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