Sex in Leishmania

Abstract

In their Report “Demonstration of genetic exchange during cyclical development of Leishmania in the sand fly vector” (10 April, p. [265][1]), N. S. Akopyants et al. provided evidence for sexual recombination. The next priority should be to apply high-resolution imaging with molecular markers to determine when, where (i.e., in which part of sand fly gut), and how the “mating” events occur. Genetic exchange is crucial for adaptation to stressful environments. However, in Leishmania , exposure to specific stressful conditions in the sand fly gut is likely to induce genetic exchange. Access to the sand fly genome is now urgently required to facilitate the search for factors that stimulate Leishmania sex. The epidemiological consequences of genetic exchange in Leishmania are potentially alarming. Akopyants et al. demonstrate two distinct virulence traits among hybrid Leishmania clones but do not document the effect of genetic exchange on development of Leishmania in the vector. There is, however, proof that sex enhances Leishmania fitness and transmission in the sand fly. Leishmania infantum and L. major are divergent species, transmitted by different vectors to different mammalian reservoirs. Nevertheless, L. infantum/L. major hybrids ([ 1 ][2]) complete the life cycle in Phlebotomus papatasi , the specific vector of L. major that does not support L. infantum . Hybrids thrive in the aggressive, widespread human-biting P. papatasi , as well as in a principal vector of L. infantum, Lutzomyia longipalpis ([ 2 ][3]). Other naturally occurring interspecific Leishmania hybrids may spread to new vectors, with geographical expansion and carriage of traits such as visceralization and metastasis in humans. 1. [↵][4]1. C. Ravel 2. et al ., Int. J. Parasitol. 36, 1383 (2006). [OpenUrl][5][CrossRef][6][PubMed][7][Web of Science][8] 2. [↵][9]1. P. Volf 2. et al ., Int. J. Parasitol. 37, 589 (2007). [OpenUrl][10][CrossRef][11][PubMed][12][Web of Science][13] [1]: /lookup/doi/10.1126/science.1169464 [2]: #ref-1 [3]: #ref-2 [4]: #xref-ref-1-1 View reference 1 in text [5]: {openurl}?query=rft.jtitle%253DInternational%2Bjournal%2Bfor%2Bparasitology%26rft.stitle%253DInt%2BJ%2BParasitol%26rft.aulast%253DRavel%26rft.auinit1%253DC.%26rft.volume%253D36%26rft.issue%253D13%26rft.spage%253D1383%26rft.epage%253D1388%26rft.atitle%253DFirst%2Breport%2Bof%2Bgenetic%2Bhybrids%2Bbetween%2Btwo%2Bvery%2Bdivergent%2BLeishmania%2Bspecies%253A%2BLeishmania%2Binfantum%2Band%2BLeishmania%2Bmajor.%26rft_id%253Dinfo%253Adoi%252F10.1016%252Fj.ijpara.2006.06.019%26rft_id%253Dinfo%253Apmid%252F16930606%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [6]: /lookup/external-ref?access_num=10.1016/j.ijpara.2006.06.019&link_type=DOI [7]: /lookup/external-ref?access_num=16930606&link_type=MED&atom=%2Fsci%2F324%2F5935%2F1644.2.atom [8]: /lookup/external-ref?access_num=000241646900007&link_type=ISI [9]: #xref-ref-2-1 View reference 2 in text [10]: {openurl}?query=rft.jtitle%253DInternational%2Bjournal%2Bfor%2Bparasitology%26rft.stitle%253DInt%2BJ%2BParasitol%26rft.aulast%253DKyvsgaard%26rft.auinit1%253DN.%2BC.%26rft.volume%253D37%26rft.issue%253D6%26rft.spage%253D589%26rft.epage%253D593%26rft.atitle%253DIncreased%2Btransmission%2Bpotential%2Bof%2BLeishmania%2Bmajor%252FLeishmania%2Binfantum%2Bhybrids.%26rft_id%253Dinfo%253Adoi%252F10.1016%252Fj.ijpara.2007.02.002%26rft_id%253Dinfo%253Apmid%252F17376453%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [11]: /lookup/external-ref?access_num=10.1016/j.ijpara.2007.02.002&link_type=DOI [12]: /lookup/external-ref?access_num=17376453&link_type=MED&atom=%2Fsci%2F324%2F5935%2F1644.2.atom [13]: /lookup/external-ref?access_num=000246047300002&link_type=ISI