Biology subjects

Martin-Martin, I.

Publications and source records attributed to Martin-Martin, I..

3 recordsLinked to original sources

bioRxiv2026

Are mosquito species present in Spain competent for Oropouche virus?

Oropouche virus (OROV; Orthobunyavirus) is an emerging arbovirus endemic to South America and the Caribbean, with imported cases in European countries, including Spain. Although primarily transmitted by biting midges (Culicoides spp.), OROV has been detected in several mosquito species, raising concerns about potential establishment in non-endemic regions. European populations of Aedes albopictus, and Culex pipiens, as well as the invasive Aedes aegypti, represent relevant models for assessing vector competence. Here, we evaluated vector competence of Spanish Cx. pipiens biotype molestus, Spanish Ae. albopictus, and Ae. aegypti (Liverpool strain), for the 2024 OROV outbreak strain. Female mosquitoes were orally exposed to infectious blood meals and maintained under controlled insectary conditions. In addition, an additional group received a second non-infectious blood meal. The survival of the mosquitoes was monitored, and infection, dissemination, and transmission rates were assessed at 7-, 14-, and 21-days post-infection. Vertical transmission of the virus to the progenies was also analyzed. Overall, Ae. albopictus exhibited low infection rates, with occasional dissemination and transmission events. Aedes aegypti and Cx. pipiens showed infection and occasional dissemination, but no evidence of transmission. A second non-infectious blood meal did not significantly affect infection, dissemination, or transmission rates in any species. Viral loads in bodies and legs were low and did not differ significantly between species, time points, or feeding regimens. Survival was not affected by infection or blood-feeding regime. We did not find vertical transmission of OROV to the progenies. Regardless of virus dissemination in mosquitoes, our study indicates poor vector competence of Spanish Ae. albopictus and a lack of competence in Ae. aegypti and Cx. pipiens for the circulating OROV strain. These findings suggest a low risk for local OROV establishment in Spain, although continuous surveillance and research are warranted to monitor potential vector-virus adaptation.

microbiology↗

bioRxiv2023

Anopheles salivary apyrase regulates blood meal hemostasis and drives malaria parasite transmission

Mosquito salivary proteins play a crucial role in regulating hemostatic responses at the bite site during blood feeding. In this study, we investigate the function of Anopheles gambiae salivary apyrase (AgApyrase) in Plasmodium transmission. Our results demonstrate that salivary apyrase interacts with and activates tissue plasminogen activator, facilitating the conversion of plasminogen to plasmin, a human protein previously shown to be required for Plasmodium transmission. Microscopy imaging shows that mosquitoes ingest a substantial amount of apyrase during blood feeding which reduces coagulation in the blood meal by enhancing fibrin degradation and inhibiting platelet aggregation. Supplementation of Plasmodium infected blood with apyrase significantly enhanced Plasmodium infection in the mosquito midgut. In contrast, AgApyrase immunization inhibited Plasmodium mosquito infection and sporozoite transmission. This study highlights a pivotal role for mosquito salivary apyrase for regulation of hemostasis in the mosquito blood meal and for Plasmodium transmission to mosquitoes and to the mammal host, underscoring the potential for new strategies to prevent malaria transmission.

microbiology↗

bioRxiv2020

Novel function acquired by the Culex quinquefasciatus mosquito D7 salivary protein enhances blood feeding on mammals

Adult female mosquitoes require a vertebrate blood meal to develop eggs and continue their life cycle. During blood feeding, mosquito saliva is injected at the bite site to facilitate blood meal acquisition through anti-hemostatic compounds that counteract blood clotting, platelet aggregation, vasoconstriction and host immune responses. D7 proteins are among the most abundant components of the salivary glands of several blood feeding insects. They are members of a family of proteins that have evolved through gene duplication events to encode D7 proteins of several lengths. Here, we examine the ligand binding specificity and physiological relevance of two D7 long proteins, CxD7L1 and CxD7L2, from Culex quinquefasciatus mosquitoes, the vector of medical and veterinary diseases such as filariasis, avian malaria, and West Nile virus infections. CxD7L1 and CxD7L2 were assayed by microcalorimetry for binding of potential host ligands involved in hemostasis, including bioactive lipids, biogenic amines, and nucleotides/nucleosides. CxD7L2 binds serotonin, histamine, and epinephrine with high affinity as well as the thromboxane A2 analog U-46619 and several cysteinyl leukotrienes, as previously described for other D7 proteins. CxD7L1 does not bind any of the ligands that are bound by CxD7L2. Unexpectedly, CxD7L1 exhibited high affinity for adenine nucleotides and nucleosides, a binding capacity not reported in any D7 family member. We solved the crystal structure of CxD7L1 in complex with bound ADP to 1.97 [A] resolution. The binding pocket for ADP is located between the two domains of CxD7L1, whereas all known D7s bind ligands either within the N-terminal or the C-terminal domains. We demonstrated that these two CxD7 long proteins inhibit human platelet aggregation in ex vivo experiments. CxD7L1 and CxD7L2 help blood feeding in mosquitoes by scavenging host molecules that promote vasoconstriction, platelet aggregation, itch, and pain at the bite site. The novel ADP-binding function acquired by CxD7L1 evolved to enhance blood feeding in mammals where ADP plays a key role in platelet aggregation.

biochemistry↗