کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8979688 | 1107333 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Genomic organization of telomeric and subtelomeric sequences of Leishmania (Leishmania) amazonensis
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
ایمنی شناسی و میکروب شناسی
انگل شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Telomeres are DNA-protein complexes that protect linear chromosomes from degradation and fusions. Telomeric DNA is repetitive and G-rich, and protrudes towards the end of the chromosomes as 3â²G-overhangs. In Leishmania spp., sequences adjacent to telomeres comprise the Leishmania conserved telomere associated sequences (LCTAS) that are around 100Â bp long and contain two conserved sequence elements (CSB1 and CSB2), in addition to non-conserved sequences. The aim of this work was to study the genomic organization of Leishmania (Leishmania) amazonensis telomeric/subtelomeric sequences. Leishmania amazonensis chromosomes were separated in a single Pulsed Field Gel Electrophoresis (PFGE) gel as 25 ethidium bromide-stained bands. All of the bands hybridized with the telomeric probe (5â²-TTAGGG-3â²)3 and with probes generated from the conserved subtelomeric elements (CSB1, CSB2). Terminal restriction fragments (TRF) of L. amazonensis chromosomes were analyzed by hybridizing restriction digested genomic DNA and chromosomal DNA separated in 2D-PFGE with the telomeric probe. The L. amazonensis TRF was estimated to be â¼3.3Â kb long and the telomeres were polymorphic and ranged in size from 0.2 to 1.0Â kb. Afa I restriction sites within the conserved CSB1 elements released the telomeres from the rest of the chromosome. Bal 31-sensitive analysis confirmed the presence of terminal Afa I restriction sites and served to differentiate telomeric fragments from interstitial internal sequences. The size of the L. amazonensis 3â² G-overhang was estimated by non-denaturing Southern blotting to be â¼12Â nt long. Using similar approaches, the subtelomeric domains CSB1 and CSB2 were found to be present in a low copy number compared to telomeres and were organized in blocks of 0.3-1.5Â kb flanked by Hinf I and Hae III restriction sites. A model for the organization of L. amazonensis chromosomal ends is provided.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal for Parasitology - Volume 35, Issue 13, November 2005, Pages 1435-1443
Journal: International Journal for Parasitology - Volume 35, Issue 13, November 2005, Pages 1435-1443
نویسندگان
F.F. Conte, M.I.N. Cano,