A 245 kb mini-chromosome impacts on Leishmania braziliensis infection and survival

Abstract

Leishmania (V.) braziliensis, the causative agent of mucocutaneous leishmaniasis in the New World, may present an LD1 type genomic amplification that appears as a small 245 kb linear chromosome, and is not clearly associated to the presence of a selection agent. A bt1 gene, codifying for a biopterin transporter protein, was identified in this small chromosome. Leishmania are auxotrophic for pterins and one of the proposed explanations for the appearance of this amplification is the improvement of biopterin capture by the parasite. We analyzed some biological aspects of two lineages of L. braziliensis strain M2903, with and without the small amplified chromosome. We showed differences in infectivity of these lineages, in macrophages and the insect vector Lutzomyia longipalpis, as well as in the uptake and metabolization of intermediates of the Leishmania biopterin salvage pathway. Our results suggest that the genomic amplification favors survival due to improved biopterin capture and at the same time hinders the infective capability, suggesting that within a population different parasites can perform different roles.

The genome of Leishmania panamensis: insights into genomics of the L. (Viannia) subgenus.

“…This particular type of minichromosome may be considered a Viannia -specific feature, although it is not present in all strains or in all lineages of the same strains in L. braziliensis . It has been demonstrated that the presence of the minichromosome in L. braziliensis favors the survival of parasites and improves their infectivity in macrophages and in the sandfly vector 44 .…”

Genomic Analysis of Colombian Leishmania panamensis strains with different level of virulence

“…However, in contrast with the previous case, copy number estimation of the four strains UA sequenced in this study supports reference CN = 2 alleles for this region. Sampaio et al ., showed that the presence of a similar mini-chromosome found in L. braziliensis favours the survival and infectivity 21 . Nevertheless, the copy number estimation for this region in the virulent strain UA946 suggests that the number of copies of this minichromosome is not related to the virulence level observed in this study.…”