The SIDER2 elements, interspersed repeated sequences that populate the Leishmania genomes, constitute subfamilies showing chromosomal proximity relationship

Requena, Jose M.; Folgueira, Cristina; López, Manuel C.; Thomas, M. Carmen
January 2008
BMC Genomics;2008, Vol. 9, Special section p1
Academic Journal
Background: Protozoan parasites of the genus Leishmania are causative agents of a diverse spectrum of human diseases collectively known as leishmaniasis. These eukaryotic pathogens that diverged early from the main eukaryotic lineage possess a number of unusual genomic, molecular and biochemical features. The completion of the genome projects for three Leishmania species has generated invaluable information enabling a direct analysis of genome structure and organization. Results: By using DNA macroarrays, made with Leishmania infantum genomic clones and hybridized with total DNA from the parasite, we identified a clone containing a repeated sequence. An analysis of the recently completed genome sequence of L. infantum, using this repeated sequence as bait, led to the identification of a new class of repeated elements that are interspersed along the different L. infantum chromosomes. These elements turned out to be homologues of SIDER2 sequences, which were recently identified in the Leishmania major genome; thus, we adopted this nomenclature for the Leishmania elements described herein. Since SIDER2 elements are very heterogeneous in sequence, their precise identification is rather laborious. We have characterized 54 LiSIDER2 elements in chromosome 32 and 27 ones in chromosome 20. The mean size for these elements is 550 bp and their sequence is G+C rich (mean value of 66.5%). On the basis of sequence similarity, these elements can be grouped in subfamilies that show a remarkable relationship of proximity, i.e. SIDER2s of a given subfamily locate close in a chromosomal region without intercalating elements. For comparative purposes, we have identified the SIDER2 elements existing in L. major and Leishmania braziliensis chromosomes 32. While SIDER2 elements are highly conserved both in number and location between L. infantum and L. major, no such conservation exists when comparing with SIDER2s in L. braziliensis chromosome 32. Conclusion: SIDER2 elements constitute a relevant piece in the Leishmania genome organization. Sequence characteristics, genomic distribution and evolutionarily conservation of SIDER2s are suggestive of relevant functions for these elements in Leishmania. Apart from a proved involvement in posttrancriptional mechanisms of gene regulation, SIDER2 elements could be involved in DNA amplification processes and, perhaps, in chromosome segregation as centromeric sequences.


Related Articles

  • A new experimental culture medium for cultivation of Leishmania amazonensis: its efficacy for the continuous in vitro growth and differentiation of infective promastigote forms. Rodrigues, Igor de; Silva, Bianca; Santos, André; Vermelho, Alane; Alviano, Celuta; Rosa, Maria do // Parasitology Research;Apr2010, Vol. 106 Issue 5, p1249 

    Parasites from the genus Leishmania cause a variety of disease states in humans and other mammals in tropical and subtropical regions, which include cutaneous, mucocutaneous and visceral leishmaniasis. The elaboration of a culture medium for the in vitro cultivation of Leishmania spp., which...

  • Persistence drives gene clustering in bacterial genomes. Gang Fang; Rocha, Eduardo P. C.; Danchin, Antoine // BMC Genomics;2008, Vol. 9, Special section p1 

    Background: Gene clustering plays an important role in the organization of the bacterial chromosome and several mechanisms have been proposed to explain its extent. However, the controversies raised about the validity of each of these mechanisms remind us that the cause of this gene organization...

  • Comparative genomic analysis of three Leishmania species that cause diverse human disease. Peacock, Christopher S.; Seeger, Kathy; Harris, David; Murphy, Lee; Ruiz, Jeronimo C.; Quail, Michael A.; Peters, Nick; Adlem, Ellen; Tivey, Adrian; Aslett, Martin; Kerhornou, Arnaud; Ivens, Alasdair; Fraser, Audrey; Rajandream, Marie-Adele; Carver, Tim; Norbertczak, Halina; Chillingworth, Tracey; Hance, Zahra; Jagels, Kay; Moule, Sharon // Nature Genetics;Jul2007, Vol. 39 Issue 7, p839 

    Leishmania parasites cause a broad spectrum of clinical disease. Here we report the sequencing of the genomes of two species of Leishmania: Leishmania infantum and Leishmania braziliensis. The comparison of these sequences with the published genome of Leishmania major reveals marked conservation...

  • First Autochthonous Case of Canine Visceral Leishmaniasis in the Center of Rio Grande do Sul State, Brazil. Schafer Da Silva, Aleksandro; França, Raqueli Teresinha; Richini-Pereira, Virginia Bodelão; Langoni, Helio; Gonzalez Monteiro, Silvia; Dos Anjos Lopes, Sonia Terezinha // Acta Scientiae Veterinariae;Mar2011, Vol. 39 Issue 2, Special section p1 

    Background: Leishmaniasis is one of the most important vector-borne diseases of humans. This parasitic disease can be caused by many species of Leishmania. In humans, different species of the parasite are associated with different forms of the disease, cutaneous and visceral. Among domesticated...

  • DIAGNOSTIC VALUE OF RK39 DIPSTICK IN ZOONOTIC VISCERAL LEISHMANIASIS IN TURKEY. Toz, Seray Ozensoy; Kwang-Poo Chang; Ozbel, Yusuf; Alkan, M. Ziya // Journal of Parasitology;Dec2004, Vol. 90 Issue 6, p1484 

    Presents a study on the diagnostic value of recombinant K39 dipstick in zoonotic visceral leishmaniasis in Turkey. Identification of K39 as a repetitive immunodominant epitope in a kinesin-related protein; Comparison with other conventional diagnostic methods; Determination of the presence of...

  • THE HUMAN CYTOKINE RESPONSE TO LEISHMANIA MAJOR EARLY AFTER EXPOSURE TO THE PARASITE IN VITRO. Roger, Kathleen A.; Titus, Richard G. // Journal of Parasitology;Jun2004, Vol. 90 Issue 3, p557 

    Examines the human cytokine response to Leishmania major early after exposure to the parasite in vitro. Cause of leishmaniasis; Effects in the secretion of interferon-gamma for clearing the infection; Production of IL-5.

  • In Vitro Infectivity of Leishmania major Isolated from Patients with Different Clinical Forms of Cutaneous Leishmaniasis and Its Association with Parasite Zymodems. Hatam, G. R.; Rezanezhad, H.; Motazedian, M. H.; Sarkari, B. // Iranian Journal of Parasitology;2009, Vol. 4 Issue 3, p52 

    Background: The aim of this study was to characterize the Leishmania parasites isolated from cutaneous leishmaniasis (CL) patients in Fars Province in Iran and to compare the potential infectivity of the isolates in macrophage cell line. Moreover, attempt was made to find out the association...

  • Exposure of Phosphatidylserine on Leishmania amazonensis Isolates Is Associated with Diffuse Cutaneous Leishmaniasis and Parasite Infectivity. França-Costa, Jaqueline; Wanderley, João Luiz Mendes; Deolindo, Poliana; Zarattini, Jessica B.; Costa, Jackson; Soong, Lynn; Barcinski, Marcello André; Barral, Aldina; Borges, Valeria M. // PLoS ONE;May2012, Vol. 7 Issue 5, p1 

    Diffuse cutaneous leishmaniasis (DCL) is a rare clinical manifestation of leishmaniasis, characterized by an inefficient parasite-specific cellular response and heavily parasitized macrophages. In Brazil, Leishmania (Leishmania) amazonensis is the main species involved in DCL cases. In the...

  • Leishmania donovani and Cutaneous Leishmaniasis, Sri Lanka. Siriwardana, H. V. Yamuna D.; Noyes, Harry A.; Beeching, Nicholas J.; Chance, Michael L.; Karunaweera, Nadira D.; Bates, Paul A. // Emerging Infectious Diseases;Mar2007, Vol. 13 Issue 3, p476 

    To investigate the relationship of cutaneous leishmaniasis isolates from Sri Lanka to known species, we performed DNA sequencing and microsatellite analyses. We identified Leishmania donovani as the agent of Sri Lanka cutaneous leishmaniasis and showed that these parasites are closely related to...


Other Topics