Bisetegn, Habtye, Dias de Oliveira, Beatriz Cristina, Passos, Arthur de Oliveira, Alves, Cristiane de Santis, Ernst, Evan, Nogueira Cano, Maria Isabel (January 2026) An intimate view of Leishmania infantum chromosome ends reveals less conserved subtelomeric regions and variations in the telomeric repeat. International Journal for Parasitology. p. 104769. ISSN 0020-7519
Abstract
Leishmania infantum is an intracellular protozoan parasite that causes visceral leishmaniasis, predominantly affecting marginalized populations in tropical and subtropical countries. The parasite genome comprises 36 chromosomes whose ends have not been characterized. In most eukaryotes, chromosome termini are capped by telomeres and associated proteins, forming nucleoprotein structures that maintain genome stability and prevent the ends from being mistaken as broken DNA. Leishmania telomeres are composed of G-rich repetitive DNA replenished by telomerase activity. Here, we showed a detailed view and assessment of the 72 chromosome end termini of L. infantum reference strain JPCM5 using Southern blot and Oxford nanopore (ONT) whole genome sequence. L. infantum telomeres, besides the canonical hexameric repeat, contain hexamer variants. The subtelomeres comprise frequent octameric repeats intercalated by interstitial telomeric hexamers and a 62 bp Leishmania conserved telomere-associated sequence containing the Conserved Sequence Block 2 (CSB2) and other elements. The ONT data also provided a complete panorama of L. infantum chromosome termini, showing clusters of high gene density, and determining the telomere size in all chromosome arms. The estimated L. infantum TRF (terminal restriction fragment) length, ranging from 100-500 bp, is sensitive to T5 exonuclease digestion, confirming they are at the termini; a similar strategy was used to assess the subtelomeric octameric repeats. Also, procyclic and metacyclic promastigotes showed similar TRF profiles, and promastigote telomeres show different nuclear distributions depending on the cell cycle phase. Our results showed that L. infantum chromosome ends show a mosaic organization, adding valuable information about its genomic architecture and evolution.
| Item Type: | Paper |
|---|---|
| Subjects: | bioinformatics bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification bioinformatics > genomics and proteomics > genetics & nucleic acid processing bioinformatics > genomics and proteomics bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > telomeres |
| CSHL Authors: | |
| Communities: | CSHL labs > Martienssen lab CSHL Post Doctoral Fellows |
| SWORD Depositor: | CSHL Elements |
| Depositing User: | CSHL Elements |
| Date: | 5 January 2026 |
| Date Deposited: | 12 Jan 2026 13:57 |
| Last Modified: | 12 Jan 2026 13:57 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/42064 |
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