Project description:Transcriptional analysis of L. infantum promastigote compared to L. infantum intracellular amastigote and transcriptional analysis of L. infantum promastigote compared to L. infantum axenic amastigote. The full-genome DNA microarrays includes one 70-oligonucleotides probe for each gene of L.infantum. Keywords: stage and culture condition Intracellular amastigote analysis: Two-condition experiment, promastigote stage vs intracellular amastigote stage. Six biological replicates for each stage, independently grown and harvested. One replicate per array Axenic amastigote analysis: Two-condition experiment, promastigote stage vs axenic amastigote stage. Four biological replicates for each stage, independently grown and harvested. One replicate per array.
Project description:Transcriptional analysis of L. infantum promastigote compared to L. infantum intracellular amastigote and transcriptional analysis of L. infantum promastigote compared to L. infantum axenic amastigote. The full-genome DNA microarrays includes one 70-oligonucleotides probe for each gene of L.infantum. Keywords: stage and culture condition
Project description:The genomic DNAs of strains JPCM5 and 263 of L. infantum, strains LV39 and Friedlin of L. major and strains Parrot-TarII and S125 of L. tarentolae were used in comparative genomic hybridizations to reveal the intra-species and inter-species gene content, and to validate L. tarentolae Parrot-TarII genome sequencing results. Leishmania (Sauroleishmania) tarentolae was first isolated in the lizard Tarentola mauritanica. This species is not known to be pathogenic to humans but is often used as a model organism for molecular analyses or protein overproduction. The Leishmania tarentolae Parrot-TarII strain genome sequence was resolved by high-throughput sequencing technologies. The L. tarentolae genome was first assembled de novo and then aligned against the reference L. major Friedlin genome to facilitate contig positioning and annotation, providing a 23-fold coverage of the genome. This is the first non-pathogenic to humans kinetoplastid protozoan genome to be described, and it provides an opportunity for comparison with the completed genomes of the pathogenic Leishmania species. A high synteny was observed in de novo assembled contigs between all sequenced Leishmania species. A number of limited chromosomal regions diverged between L. tarentolae and L. infantum, while remaining syntenic with L. major. Globally, over 90% of the L. tarentolae gene content was shared with the other Leishmania species. There were 250 L. major genes absent from L. tarentolae, and interestingly these missing genes were primarily expressed in the intracellular amastigote stage of the pathogenic parasites. This implies that L. tarentolae may have impaired ability to survive as an intracellular parasite. In contrast to other Leishmania genomes, two gene families were expanded in L. tarentolae, namely the leishmanolysin (GP63) and a gene related to the promastigote surface antigen (PSA31C). Overall, L. tarentolae appears to have a gene content more adapted to the insect stage rather than the mammalian one. This may partly explain its inability to replicate within mammalian macrophages and its suspected preferred life style as promastigote in the lizards.
Project description:The genomic DNAs of strains JPCM5 and 263 of L. infantum, strains LV39 and Friedlin of L. major and strains Parrot-TarII and S125 of L. tarentolae were used in comparative genomic hybridizations to reveal the intra-species and inter-species gene content, and to validate L. tarentolae Parrot-TarII genome sequencing results. Leishmania (Sauroleishmania) tarentolae was first isolated in the lizard Tarentola mauritanica. This species is not known to be pathogenic to humans but is often used as a model organism for molecular analyses or protein overproduction. The Leishmania tarentolae Parrot-TarII strain genome sequence was resolved by high-throughput sequencing technologies. The L. tarentolae genome was first assembled de novo and then aligned against the reference L. major Friedlin genome to facilitate contig positioning and annotation, providing a 23-fold coverage of the genome. This is the first non-pathogenic to humans kinetoplastid protozoan genome to be described, and it provides an opportunity for comparison with the completed genomes of the pathogenic Leishmania species. A high synteny was observed in de novo assembled contigs between all sequenced Leishmania species. A number of limited chromosomal regions diverged between L. tarentolae and L. infantum, while remaining syntenic with L. major. Globally, over 90% of the L. tarentolae gene content was shared with the other Leishmania species. There were 250 L. major genes absent from L. tarentolae, and interestingly these missing genes were primarily expressed in the intracellular amastigote stage of the pathogenic parasites. This implies that L. tarentolae may have impaired ability to survive as an intracellular parasite. In contrast to other Leishmania genomes, two gene families were expanded in L. tarentolae, namely the leishmanolysin (GP63) and a gene related to the promastigote surface antigen (PSA31C). Overall, L. tarentolae appears to have a gene content more adapted to the insect stage rather than the mammalian one. This may partly explain its inability to replicate within mammalian macrophages and its suspected preferred life style as promastigote in the lizards. Six strains of three Leishmania species were hybridizated to 12 microarrays, each with four biological replicates (independent cultures). Supplementary file: Represents final results obtained after statistical analysis of all replicates.
Project description:Leishmania infantum is the causative agent of zoonotic visceral leishmaniasis in Mediterranean areas and also acts as an opportunistic parasite in HIV patients. Metacyclic promastigotes are transmitted during bloodmeals of the sand-fly host after development. Metacyclogenesis can be micmiked in axenic cultures and peanut lectin (PNA) agglutination followed by two-step centrifugation allows the separation of procyclic and metacyclic promastigotes in L. major. The purpose of this study is to isolate both fractions simultaneously from the same population of L. infantum in stationary phase of axenic culture and compare their expression profiles through DNA microarrays, specially focusing on metacyclic promastigotes. Whole-genome shotgun DNA microarrays were constructed and used to analyse the stationary-phase procyclic and metacyclic expression profiles. Four biological replicates of the experiment were performed and analysed, so that 322 clones with meaningful values of stage-specific regulation were selected. We found several genes dealing with primary metabolism, differentiation in procyclic promastigotes and with development of infectivity in metacyclic promastigotes. The differences we have found between the procyclic (PNA+) and metacyclic (PNA-) transcriptomes demonstrate that negative selection of metacyclic promastigotes through PNA agglutination is suitable in L. infantum and both fractions can be isolated. In addition, up-regulation of genes implied in lipophosphoglycan (LPG), proteophosphoglycan (PPG) and glycoprotein biosynthesis indicate that metacyclic promastigotes are related with infectivity. Keywords: comparative hybridization between cDNAs from procyclic PNA+ and metacyclic PNA- promastigotes of L.infantum
Project description:Gene expression profiling to address the effects of infection with Leishmania infantum during distinct clinical outcomes as active visceral leishmaniasis (VL), remission of disease and asymptomatic infection.