4 research outputs found

    First Report of Leishmania tropica from a Classical Focus of L. major in North-Sinai, Egypt

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    This is the publisher's version, also available electronically from http://www.ajtmh.org/content/81/2/213.long.Cutaneous leishmaniasis (CL) is prevalent in the Egyptian Sinai Peninsula and previous research has consistently documented the etiologic agent to be Leishmania major. We report the first isolation of Leishmania tropica from human cases of CL in a Northern Sinai community bordering Palestine. Parasite culturing, real-time polymerase chain reaction (PCR), gene sequencing, and restriction fragment length polymorphism (RFLP) analyses indicate CL cases in this community were caused by either L. major or L. tropica (three cases each). Two wild-caught rodents (Gerbillus pyramidum floweri) were infected with L. tropica. Phlebotomus papatasi sand flies were found harboring L. major, however only non-infected individuals of Phlebotomus sergenti, a vector for L. tropica, were caught. Patients with L. tropica had not traveled from the region in over a year, suggesting these cases are autochthonous. This scenario is consistent with an incursion of L. tropica from bordering countries and raises concerns about expansion of this parasite further into Egypt

    Creation of cis-regulatory elements during sea urchin evolution by co-option and optimization of a repetitive sequence adjacent to the spec2a gene

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    AbstractThe creation, preservation, and degeneration of cis-regulatory elements controlling developmental gene expression are fundamental genome-level evolutionary processes about which little is known. Here, we identify critical differences in cis-regulatory elements controlling the expression of the sea urchin aboral ectoderm-specific spec genes. We found multiple copies of a repetitive sequence element termed RSR in genomes of species within the Strongylocentrotidae family, but RSRs were not detected in genomes of species outside Strongylocentrotidae. spec genes in Strongylocentrotus purpuratus are invariably associated with RSRs, and the spec2a RSR functioned as a transcriptional enhancer and displayed greater activity than did spec1 or spec2c RSRs. Single-base pair differences at two cis-regulatory elements within the spec2a RSR increased the binding affinities of four transcription factors, SpCCAAT-binding factor at one element and SpOtx, SpGoosecoid, and SpGATA-E at another. The cis-regulatory elements to which these four factors bound were recent evolutionary acquisitions that acted to either activate or repress transcription, depending on the cell type. These elements were found in the spec2a RSR ortholog in Strongylocentrotus pallidus but not in RSR orthologs of Strongylocentrotus droebachiensis or Hemicentrotus pulcherrimus. Our results indicated that a dynamic pattern of cis-regulatory element evolution exists for spec genes despite their conserved aboral ectoderm expression
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