The results of the AnoRep project will be disseminated at conferences, seminar, publications and other communication means.

Publishable Summary

In the first term of this project, male and female factors that play key roles in shaping the reproductive success of Anopheles gambiae mosquitoes, the major vectors of malaria, have been identified. It has been determined that male hormones transferred during mating increase the reproductive output of females, and molecular interactions between these male hormones transferred during mating and female proteins induced by copulation specifically in the female lower reproductive tract have been identified. This is the first example of male-female reproductive partnerships found in An.gambiae, and the molecular pathways triggered by these interactions are obvious targets for future vector control strategies aimed at suppressing field mosquito populations. It has been also determined the mechanisms by which females preserve the viability and function of the spermatozoa they receive during copulation. As An. gambiae females mate a single time in their lives, they need to store sperm in a dedicated storage organ called spermatheca. Analyzing high-throughput gene expression data from this tissue after sex has allowed to identify a number of genes that are involved in regulating sperm function, including enzymes that reduce oxidative damage to sperm. The spermatheca environment becomes competent for sperm storage after mating, however remarkably changes in the physiology of this organ are not triggered by the presence of sperm. This finding suggests that seminal secretions produced in the male accessory glands and transferred to the spermatheca during copulation are responsible for preparing the female for sperm storage. For the first time, mechanisms of sperm viability have been identified in mosquitoes and can now be targeted to induce sterility.

In parallel, tools for field applications aimed at vector control are in development. One of the project targets for fertility is the mating plug, a gelatinous structure formed by coagulated seminal secretions that is transferred to females during sex and digested in the space of a day or two. It has been previously shown that the transfer of the plug is important to ensure correct sperm storage by the female. In the current project, it has been developed an inhibitors of AgTG3, a transglutaminase enzyme specifically active in the male accessory glands that catalyzes plug formation through its cross linking activity on other seminal proteins, and demonstrated that the plug is essential for egg laying: mated females that do not receive sperm are still capable of ovipositing, but they fail to do so if they do not receive a plug. This suggests that the plug transfers seminal material that triggers the release of the eggs from the ovaries, allowing oviposition. This inhibitor is now being tested for improved performance, and if successful, this or similar compounds could be utilized in field conditions to limit the mosquito insemination rates.

 

Publications

Achinko D, Thailayil J, Paton D, Mireji PO, Talesa V, Masiga D, Catteruccia F. Swarming and mating activity of Anopheles gambiae mosquitoes in semi-field enclosures. Med Vet Entomol. 2015 Oct 28. doi: 10.1111/mve.12143

Shaw WR, Attardo GM, Aksoy S, Catteruccia F. A comparative analysis of reproductive biology of insect vectors of human disease. Curr Opin Insect Sci. 2015 Aug 1;10:142-148

Mitchell SN, Kakani EG, South A, Howell PI, Waterhouse RM, Catteruccia F. Mosquito biology. Evolution of sexual traits influencing vectorial capacity in anopheline mosquitoes. Science. 2015 Feb 27;347(6225):985-8. doi: 10.1126/science.1259435

Neafsey DE, Waterhouse RM, Abai MR, Aganezov SS, Alekseyev MA, Allen JE, Amon J, Arcà B, Arensburger P, Artemov G, Assour LA, Basseri H, Berlin A, Birren BW, Blandin SA, Brockman AI, Burkot TR, Burt A, Chan CS, Chauve C, Chiu JC, Christensen M, Costantini C, Davidson VL, Deligianni E, Dottorini T, Dritsou V, Gabriel SB, Guelbeogo WM, Hall AB, Han MV, Hlaing T, Hughes DS, Jenkins AM, Jiang X, Jungreis I, Kakani EG, Kamali M, Kemppainen P, Kennedy RC, Kirmitzoglou IK, Koekemoer LL, Laban N, Langridge N, Lawniczak MK, Lirakis M, Lobo NF, Lowy E, MacCallum RM, Mao C, Maslen G, Mbogo C, McCarthy J, Michel K, Mitchell SN, Moore W, Murphy KA, Naumenko AN, Nolan T, Novoa EM, O’Loughlin S, Oringanje C, Oshaghi MA, Pakpour N, Papathanos PA, Peery AN, Povelones M, Prakash A, Price DP, Rajaraman A, Reimer LJ, Rinker DC, Rokas A, Russell TL, Sagnon N, Sharakhova MV, Shea T, Simão FA, Simard F, Slotman MA, Somboon P, Stegniy V, Struchiner CJ, Thomas GW, Tojo M, Topalis P, Tubio JM, Unger MF, Vontas J, Walton C, Wilding CS, Willis JH, Wu YC, Yan G, Zdobnov EM, Zhou X, Catteruccia F, Christophides GK, Collins FH, Cornman RS, Crisanti A, Donnelly MJ, Emrich SJ, Fontaine MC, Gelbart W, Hahn MW, Hansen IA, Howell PI, Kafatos FC, Kellis M, Lawson D, Louis C, Luckhart S, Muskavitch MA, Ribeiro JM, Riehle MA, Sharakhov IV, Tu Z, Zwiebel LJ, Besansky NJ. Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes. Science. 2015 Jan 2;347(6217):1258522. doi: 10.1126/science.1258522. Epub 2014 Nov 27

Fontaine MC, Pease JB, Steele A, Waterhouse RM, Neafsey DE, Sharakhov IV, Jiang X, Hall AB, Catteruccia F, Kakani E, Mitchell SN, Wu YC, Smith HA, Love RR, Lawniczak MK, Slotman MA, Emrich SJ, Hahn MW, Besansky NJ. Extensive introgression in a malaria vector species complex revealed by phylogenomics. Science. 2015 Jan 2;347(6217):1258524. doi: 10.1126/science.1258524. Epub 2014 Nov 27

Gabrieli P, Smidler A, Catteruccia F. Engineering the control of mosquito-borne infectious diseases. Genome Biol. 2014 Nov 15;15(11):535. doi: 10.1186/s13059-014-0535-7

Gabrieli P, Kakani EG, Mitchell SN, Mameli E, Want EJ, Mariezcurrena Anton A, Serrao A, Baldini F, Catteruccia F. Sexual transfer of the steroid hormone 20E induces the postmating switch in Anopheles gambiae. Proc Natl Acad Sci U S A. 2014 Nov 18;111(46):16353-8. doi: 10.1073/pnas.1410488111. Epub 2014 Nov 3

Baldini F, Segata N, Pompon J, Marcenac P, Robert Shaw W, Dabiré RK, Diabaté A, Levashina EA, Catteruccia F. Evidence of natural Wolbachia infections in field populations of Anopheles gambiae. Nat Commun. 2014 Jun 6;5:3985. doi: 10.1038/ncomms4985

Shaw WR, Teodori E, Mitchell SN, Baldini F, Gabrieli P, Rogers DW, Catteruccia F. Mating activates the heme peroxidase HPX15 in the sperm storage organ to ensure fertility in Anopheles gambiae. Proc Natl Acad Sci U S A. 2014 Apr 22;111(16):5854-9. doi: 10.1073/pnas.1401715111. Epub 2014 Apr 7

Baldini F, Gabrieli P, South A, Valim C, Mancini F, Catteruccia F. The interaction between a sexually transferred steroid hormone and a female protein regulates oogenesis in the malaria mosquito Anopheles gambiae. PLoS Biology 2013, Epub 2013 Oct 29

Le BV, Nguyen JB, Logarajah S, Wang B, Marcus J, Williams HP, Catteruccia F, Baxter RH. Characterization of Anopheles gambiae transglutaminase 3 (AgTG3) and its native substrate Plugin. J Biol Chem. 2013 Feb 15; 288(7):4844-53. doi: 10.1074/jbc.M112.435347. Epub 2013 Jan 3

Baldini F, Gabrieli P, Rogers DW, Catteruccia F. Function and composition of male accessory gland secretions in Anopheles gambiae: a comparison with other insect vectors of infectious diseases. Pathogens and Global Health, 2012 May; p. 82-93, ISSN: 2047-7724

Marois E, Scali C, Soichot J, Kappler C, Levashina EA, Catteruccia F. High-throughput sorting of mosquito larvae for laboratory studies and for future vector control interventions. Malaria Journal, 2012 Aug 28, ISSN: 1475-2875

Mancini E, Baldini F, Tammaro F, Calzetta M, Serrao A, George P, Morlais I, Masiga D, Sharakhov IV, Rogers DW, Catteruccia F, della Torre A. Molecular characterization and evolution of a gene family encoding male-specific reproductive proteins in the African malaria vector Anopheles gambiae. BMC Evol Biol. 2011 Oct 6;11:292. doi: 10.1186/1471-2148-11-292