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Tissue And Life Stage Distribution Of A Defensin-Like Gene In The Lone Star Tick Amblyomma Americanum, S. Michelle Todd, Daniel E. Sonenshine, Wayne L. Hynes
Tissue And Life Stage Distribution Of A Defensin-Like Gene In The Lone Star Tick Amblyomma Americanum, S. Michelle Todd, Daniel E. Sonenshine, Wayne L. Hynes
Biological Sciences Faculty Publications
The transcript sequence of the Amblyomma americanum Linnaeus (Acari: Ixodidae) defensin, termed amercin (amn), was ascertained and a 219-bp amn coding region identified. The gene encodes a 72-amino acid prepropeptide with a putative 37-amino acid mature peptide. This gene shows little similarity to either of the defensins from Amblyomma hebraeum Koch, the only other Amblyomma species for which a defensin has been described. Sequence comparisons with other tick defensins reveal amn to be shorter (6 bp or 2 amino acids) than the Ixodes scapularis Linnaeus (Acari: Ixodidae) and Dermacentor variabilis (Say) (Acari: Ixodidae) defensin sequences. The amercin prepropeptide …
Identification Of A Defensin From The Hemolymph Of The American Dog Tick, Dermacentor Variabilis, Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes
Identification Of A Defensin From The Hemolymph Of The American Dog Tick, Dermacentor Variabilis, Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes
Biological Sciences Faculty Publications
Hemolymph from partially fed virgin Dermacentor variabilis females was collected following Borrelia burgdorferi challenge and assayed for antimicrobial activity against Bacillus subtilis and B. burgdorferi. A small inducible cationic peptide was identified by SDS-PAGE in the hemolymph of these ticks as early as 1h post challenge. Following purification by a three-step procedure involving sequential SepPak elution, reversed phase high performance liquid chromatography (RP-HPLC) and gel electrophoresis, the yield of the active peptide was approximately 0.1% of the total protein in the hemolymph plasma. The molecular weight, 4.2kDa, was determined by MALDI-TOF mass spectrometry. N-terminal sequencing by the Edman degradation …