Experimental Hybridization in Leishmania: Tools for the Study of Genetic Exchange

Abstract

Despite major advances over the last decade in our understanding of Leishmania reproductive strategies, the sexual cycle in Leishmania has defied direct observation and remains poorly investigated due to experimental constraints. Here, we summarize the findings and conclusions drawn from genetic analysis of experimental hybrids generated in sand flies and highlight the recent advances in generating hybrids in vitro. The ability to hybridize between culture forms of different species and strains of Leishmania should invite more intensive investigation of the mechanisms underlying genetic exchange and provide a rich source of recombinant parasites for future genetic analyses.

Natural infection with Leishmania (Mundinia) martiniquensis supports Culicoides peregrinus (Diptera: Ceratopogonidae) as a potential vector of leishmaniasis and characterization of a Crithidia sp. isolated from the midges

“…Thus, the isolation of parasites from is required to not only the vector competence of the insects but also the prevalence of the AmpB-resistant phenotype parasites in natural insect populations. Furthermore, the insect-isolated parasites would be useful sources for genetic analyses to intensively investigate the mechanisms underlying genetic exchange of the parasites in the insects as the sexual cycle of Leishmania parasites has been largely confined to promastigotes developing in the midgut of the vectors (Sadlova et al, 2011;Inbar et al, 2013;Ferreira and Sacks, 2022). Unlike Leishmania parasites, monoxenous trypanosomatids, insect-restricted parasites, are more easily isolated and cultured in the laboratory (Lukeš and Votýpka, 2020).…”

Life in plastic, it’s fantastic! How Leishmania exploit genome instability to shape gene expression

“…For instance, two chromosome fusion events in Leishmania mexicana may indicate genetic streamlining from the original parents. Moreover, a meiotic-like cycle may exist in Leishmania ( Lanotte and Rioux, 1990 ; Weedall and Hall, 2015 ; Inbar et al, 2017 ; Inbar et al, 2019 ), and the generation of viable experimental hybrids can be enhanced following parasite exposure to genotoxins, indicating DNA repair plays a role in this process ( Louradour et al., 2020 ; Ferreira and Sacks, 2022 ). However, exposure to genotoxic agents results in polyploid hybrids, which are different to the typical disomic hybrids observed in natural non-genotoxic exposed sandfly infections ( Inbar et al., 2019 ).…”

“…However, exposure to genotoxic agents results in polyploid hybrids, which are different to the typical disomic hybrids observed in natural non-genotoxic exposed sandfly infections ( Inbar et al., 2019 ). On the other hand, a mix of diploid, triploid and tetraploid hybrids were observed following L. tropica hybridisation in vitro , suggesting that polyploidy could arise even in the absence of genotoxic agents ( Louradour et al., 2020 ; Ferreira and Sacks, 2022 ). Moreover, a recent study by Ferreira et al.…”

Comparative genomics of Leishmania donovani progeny from genetic crosses in two sand fly species and impact on the diversity of diagnostic and vaccine candidates

“…infantum , and L . braziliensis have been achieved in vitro , facilitated when the Leishmania were exposed to stress and DNA damage, with intraspecific hybridisation, although principally producing tetraploid hybrids [ 11 – 13 ]. Similarly, interspecies crosses between L .…”

“…However, aneuploidy, recurrent triploidy and loss of heterozygosity (LOH) were also observed [9,10]. More recently, genetic crosses of L. donovani, L. infantum, and L. braziliensis have been achieved in vitro, facilitated when the Leishmania were exposed to stress and DNA damage, with intraspecific hybridisation, although principally producing tetraploid hybrids [11][12][13]. Similarly, interspecies crosses between L. donovani and L. major, and L. donovani and L. tropica, have been achieved in vitro [14].…”