Acid Sequence Data (acid + sequence_data)

Distribution by Scientific Domains


Selected Abstracts


Robust support for tardigrade clades and their ages from three protein-coding nuclear genes

INVERTEBRATE BIOLOGY, Issue 2 2004
Jerome C. Regier
Abstract. Coding sequences (5,334 nt total) from elongation factor-1,, elongation factor-2, and the largest subunit of RNA polymerase II were determined for 6 species of Tardigrada, 2 of Arthropoda, and 2 of Onychophora. Parsimony and likelihood analyses of nucleotides and amino acids yielded strong support for Tardigrada and all internal nodes (i.e., 100% bootstrap support for Tardigrada, Eutardigrada, Parachela, Hypsibiidae, and Macrobiotidae). Results are in agreement with morphology and an earlier molecular study based on analysis of 18S ribosomal sequences. Divergence times have been estimated from amino acid sequence data using an empirical Bayesian statistical approach, which does not assume a strict molecular clock. Divergence time estimates are pre-Vendian for Tardigrada/Arthropoda, Vendian or earlier for Eutardigrada/Heterotardigrada, Silurian to Ordovician for Parachela/Apochela, Permian to Carboniferous for Hypsibiidae and Macrobiotidae, and Mesozoic for Isohypsibius/Thulinia (both within Hypsibiidae) and Macrobiotus/Richtersius (both within Macrobiotidae). [source]


Ribosomal DNA sequences indicate isolated populations of Ichthyophonus hoferi in geographic sympatry in the north-eastern Pacific Ocean

JOURNAL OF FISH DISEASES, Issue 10 2002
C D Criscione
Abstract Infections of Ichthyophonus hoferi, a cosmopolitan parasite of marine fish, have recently been reported in rockfish, Sebastes spp., from the north-eastern Pacific. Because I. hoferi also infects Pacific herring, Clupea pallasi Valenciennes, and salmonids in this region, we wanted to determine if Ichthyophonus parasites from rockfishes, Pacific herring and chinook salmon, Oncorhynchus tshawytscha (Walbaum), were the same. Small subunit ribosomal deoxyribonucleic acid sequence data revealed two haplotypes that were fixed among host species in geographic sympatry, one from rockfish and the other from both Pacific herring and salmon. These isolated populations of Ichthyophonus could be part of the same species that are ecologically separated because of host behaviours, or they could be distinct species that are host specific. Dietary patterns of the hosts indicate that ecological separation among hosts is possible, but the presence of distinct species may better explain the observed Ichthyophonus haplotype association with host species. [source]


Relative protective properties of three membrane glycoprotein fractions from Haemonchus contortus

PARASITE IMMUNOLOGY, Issue 2 2000
Smith
Jacalin lectin was used as a ligand to isolate a fraction containing two distinct protective antigens from detergent extracts of membranes from Haemonchus contortus. The first antigen was identified as a complex which appeared very similar to Haemonchus galactose-containing glycoprotein (H-gal-GP), which is a previously described protective protease complex, except that it was substantially depleted of one of the main H-gal-GP components, a 230 kDa metallopeptidase-containing band. The new complex was termed Haemonchus sialylated galactose-containing glycoprotein (H-sialgal-GP), because it bound to jacalin but not to peanut lectin and only jacalin will bind the sialylated form of galactosyl (,-1,3) N -acetylgalactosamine. Two protection trials with sheep showed that H-sialgal-GP and H-gal-GP were equally efficacious, reducing numbers of Haemonchus eggs by between 86% and 93% and worms by between 52% and 75%, respectively. The second jacalin-binding protective antigen fraction was separated from H-sialgal-GP by ion exchange and gel filtration chromatography. It was greatly enriched for two proteins termed p46 and p52 according to their apparent molecular weights. Immunization of sheep with these proteins gave protection values of 78% for eggs and 33% for worms, which are significantly lower than those obtained with either H-gal-GP or H-sialgal-GP. N -terminal amino acid sequence data from p46 and p52 showed that both proteins were closely related to a previously described 45 kDa Haemonchus membrane protein, which had conferred protection against Haemonchus in guinea-pigs. [source]


Development of an immuno tandem mass spectrometry (iMALDI) assay for EGFR diagnosis

PROTEOMICS - CLINICAL APPLICATIONS, Issue 12 2007
Jian Jiang
Abstract The epidermal growth factor receptor (EGFR) is highly expressed in a variety of tumors, and is therefore an important biomarker for cancer diagnosis and a target for cancer therapy. We have developed a novel peptide-based immuno tandem mass spectrometry (iMALDI) diagnostic assay for highly sensitive, highly specific, and quantitative analysis of EGFR, which we have applied to the detection of the EGFR peptide in three cell lines and in a tumor biopsy sample. This assay is capable of detecting the EGFR target peptide bound to the antibody beads at attomole levels. The ability to directly obtain amino acid sequence data by MS/MS on any affinity-captured peptides provides specificity to this diagnostic technique. This avoids the problem of "false positives" which can result from the nonspecific binding that can occur with any affinity-based technique. The addition of stable-labeled versions of the target peptide (synthesized from stable-isotope coded amino acids) as internal standards allows absolute quantitation of the target protein. [source]