Results 311 to 320 of about 120,971 (346)

18S rRNA sequences and phylogeny of platyhelminthes

Biochemical Systematics and Ecology, 1993
Abstract The phyletic relationships, and hence the systematic position, of freshwater planarians (Tricladida, Turbellaria, Platyhelminthes) within the Turbellaria, and of Platyhelminthes within the Metazoa are uncertain. This stems partially from the shortcomings of the characters and techniques clasically used in the systematic study of these groups.
Marta Riutort, Kate G. Field, Rudolf A. Raff, Jaume Baguña   +3 more
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Performance of 18S rRNA in Littorinid Phylogeny (Gastropoda: Caenogastropoda)

Journal of Molecular Evolution, 1998
In the past, 18S rRNA sequences have proved to be very useful for tracing ancient divergences but were rarely used for resolving more recent ones. Moreover, it was suggested that the molecule does not contain useful information to resolve divergences which took place during less than 40 Myr.
B M, Winnepenninckx, D G, Reid, T, Backeljau   +2 more
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Intermolecular hybridization of 5S rRNA with 18S rRNA: Identification of a 5′-terminally-located nucleotide sequence in mouse 5S rRNA which base-pairs with two specific complementary sequences in 18S rRNA

Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression, 1991
Eukaryotic 5S rRNA hybridizes specifically with 18S rRNA in vitro to form a stable intermolecular RNA:RNA hybrid. We have used 5S rRNA/18S rRNA fragment hybridization studies coupled with ribonuclease digestion and primer extension/chain termination analysis of 5S rRNA:18S rRNA hybrids to more completely map those mouse 5S rRNA and 18S rRNA sequences ...
K D, Sarge, E S, Maxwell
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18S rRNA sequences of Leishmania enriettii promastigote and amastigote

International Journal for Parasitology, 1991
Dideoxy sequencing with reverse transcriptase and universal primers was used to obtain partial sequences of the 18S rRNAs from the promastigote and amastigote life-cycle stages of L. enriettii. Approximately 1400 nucleotides of sequence from the two stages were compared.
K G, Field, S M, Landfear, S J, Giovannoni   +2 more
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Novelty in Phylogeny of Gastrotricha: Evidence from 18S rRNA Gene

Molecular Phylogenetics and Evolution, 1999
Gastrotricha form a phylum which is crucial for defining the origin of pseudocoelomates, in that they share a number of characters with Rotifera and Nematoda but also with acoelomates, and even the evolutionary relationships within the phylum are anything but defined.
WIRZ A, PUCCIARELLI, Sandra, MICELI, Cristina, TONGIORGI P, BALSAMO M.   +4 more
openaire   +3 more sources

The phylogenetic position of Siboglinidae (Annelida) inferred from 18S rRNA, 28S rRNA and morphological data

Cladistics, 2004
AbstractWe assess the phylogenetic position of Siboglinidae (previously known as the phyla Pogonophora and Vestimentifera, but now referred to Annelida) in parsimony analyses of 1100 bp from 18S rRNA, 320 bp from the D1 region of 28S rRNA, and 107 morphological characters, totaling 667 parsimony informative characters.
Rousset, Vincent, Rouse, Greg W., Siddall, Mark E., Tillier, Annie, Pleijel, Fredrik   +4 more
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The phylogenetic position of taxaceae based on 18S rRNA sequences

Journal of Molecular Evolution, 1993
The evolutionary position of the yew family, Taxaceae, has been very controversial. Some plant taxonomists strongly advocate excluding Taxaceae from the conifer order and raising its taxonomic status to a new order or even class because of its absence of seed cones, contrary to the case in the majority of conifers.
S M, Chaw, H, Long, B S, Wang, A, Zharkikh, W H, Li   +4 more
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Phylogeny of Hydradephagan Water Beetles Inferred from 18S rRNA Sequences

Molecular Phylogenetics and Evolution, 2002
Several families in the beetle suborder Adephaga have an aquatic life style and are commonly grouped in the "Hydradephaga," but their monophyly is contentious and relationships between and within these families are poorly understood. Here we present full-length 18S rRNA sequence for 84 species of Hydradephaga, including representatives of most major ...
Ignacio, Ribera, James E, Hogan, Alfried P, Vogler   +2 more
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Geographical variation in 18S rRNA gene sequence of Cryptosporidium parvum

International Journal for Parasitology, 1994
Using 18S rRNA as a probe, an EcoR1 fragment containing 1507 nt of 18S rRNA from C. parvum was identified, cloned and sequenced. Comparison of this sequence with the partial sequence of the small subunit rRNA of Cryptosporidium published by Johnson, Fielke, Lumb & Baverstock (International Journal for Parasitology 20: 141-147, 1990) and 1516 bp of the ...
R T, Kilani, W M, Wenman
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18S rRNA suggests that Entoprocta are protostomes, unrelated to Ectoprocta

Journal of Molecular Evolution, 1996
The Ento- and Ectoprocta are sometimes placed together in the Bryozoa, which have variously been regarded as proto- or deuterostomes. However, Entoprocta have also been allied to the pseudocoelomates, while Ectoprocta are often united with the Brachiopoda and Phoronida in the (super)phylum Lophophorata.
Mackey, L.Y., Winnepenninckx, Birgitta, de Wachter, Rupert, Backeljau, Thierry, Emschermann, P., Garey, J.R.   +5 more
openaire   +3 more sources