“Everything You Always Wanted to Know about Sex (but Were Afraid to Ask)” in Leishmania after Two Decades of Laboratory and Field Analyses

PLoS Pathogens

Sandrine Kako Ouraga¹  Virginie Rougeron²  Mallorie Hide²  Anne-Laure Bañuls²  Thierry De Meeûs³ 

[1] CNRS, Délégation Languedoc-Roussillon, Montpellier, France;Génétique et Evolution des Maladies Infectieuses, IRD/CNRS/UM1 (UMR 2724), Montpellier, France;IRD, UMR 177 IRD-CIRAD, Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), Bobo-Dioulasso, Burkina-Faso

关键词: Leishmania;    Parasitic diseases;    Population genetics;    DNA recombination;    Parasitic life cycles;    Trypanosoma;    S;    flies;    Modes of reproduction;   

DOI  :  10.1371/journal.ppat.1001004

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Leishmaniases remain a major public health problem today (350 million people at risk, 12 million infected, and 2 million new infections per year). Despite the considerable progress in cellular and molecular biology and in evolutionary genetics since 1990, the debate on the population structure and reproductive mode of Leishmania is far from being settled and therefore deserves further investigation. Two major hypotheses coexist: clonality versus sexuality. However, because of the lack of clear evidence (experimental or biological confirmation) of sexuality in Leishmania parasites, until today it has been suggested and even accepted that Leishmania species were mainly clonal with infrequent genetic recombination (see [1] for review). Two recent publications, one on Leishmania major (an in vitro experimental study) and one on Leishmania braziliensis (a population genetics analysis), once again have challenged the hypothesis of clonal reproduction. Indeed, the first study experimentally evidenced genetic recombination and proposed that Leishmania parasites are capable of having a sexual cycle consistent with meiotic processes inside the insect vector. The second investigation, based on population genetics studies, showed strong homozygosities, an observation that is incompatible with a predominantly clonal mode of reproduction at an ecological time scale (∼20–500 generations). These studies highlight the need to advance the knowledge of Leishmania biology. In this paper, we first review the reasons stimulating the continued debate and then detail the next essential steps to be taken to clarify the Leishmania reproduction model. Finally, we widen the discussion to other Trypanosomatidae and show that the progress in Leishmania biology can improve our knowledge of the evolutionary genetics of American and African trypanosomes.

【 授权许可】

CC BY