Limits...
Molecular and functional characterization of the odorant receptor2 (OR2) in the tiger mosquito Aedes albopictus.

Scialò F, Hansson BS, Giordano E, Polito CL, Digilio FA - PLoS ONE (2012)

Bottom Line: Our data indicate that AalOR2 is narrowly tuned to indole, and inhibited by (-)-menthone.In agreement with this results, these two compounds elicit two opposite effects on the olfactory-based behavior of A. albopictus larvae, as determined through a larval behavioral assay.In summary, this work has led to the cloning and de-orphaning of the first Odorant Receptor in the tiger mosquito A. albopictus.

View Article: PubMed Central - PubMed

Affiliation: Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy.

ABSTRACT
In mosquitoes, the olfactory system plays a crucial role in many types of behavior, including nectar feeding, host preference selection and oviposition. Aedes albopictus, known also as the tiger mosquito, is an anthropophilic species, which in the last few years, due to its strong ecological plasticity, has spread throughout the world. Although long considered only a secondary vector of viruses, the potential of its vector capacity may constitute a threat to public health. Based on the idea that an improved understanding of the olfactory system of mosquitoes may assist in the development of control methods that interfere with their behavior, we have undertaken a study aimed at characterizing the A. albopictus Odorant Receptors. Here we report the identification, cloning and functional characterization of the AalOR2 ortholog, that represents the first candidate member of the odorant receptor (OR) family of proteins from A. albopictus. AalOR2 is expressed in the larval heads and antennae of adults. Our data indicate that A. albopictus OR2 (AalOR2) shares a high degree of identity with other mosquito OR2 orthologs characterized to date, confirming that OR2 is one of the most conserved mosquito ORs. Our data indicate that AalOR2 is narrowly tuned to indole, and inhibited by (-)-menthone. In agreement with this results, these two compounds elicit two opposite effects on the olfactory-based behavior of A. albopictus larvae, as determined through a larval behavioral assay. In summary, this work has led to the cloning and de-orphaning of the first Odorant Receptor in the tiger mosquito A. albopictus. In future control strategies this receptor may be used as a potential molecular target.

Show MeSH

Related in: MedlinePlus

Expression profile of the AalOR2 transcript in Aedes albopictus by RT-PCR.A non-quantitative RT-PCR on enriched poly(A)+ RNA showing the expression of AalOR2 mRNA in pre-adult stages, and in antennae from both male and female adult mosquitoes. The lanes are as follows: early larvae (EL), late larvae (LL), pupae (P), adult female antennae (F-ant), adult female carcassae (F-body), adult male antennae (M-ant), adult male carcassae (M-body), negative control obtained by using reaction mix with no cDNA (negative), 1 kb DNA marker-Fermentas (M). All RT-PCR reactions were performed with 40 cycles of amplification on cDNA, except for m-Ant, which was obtained with 35 cycles of amplification on the first-round specific amplificate. Prior to the RT-PCR, the cDNA populations were roughly normalized by RT-PCR to the amount of the AalRpL26 expression levels to ensure an equal input.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3351472&req=5

pone-0036538-g002: Expression profile of the AalOR2 transcript in Aedes albopictus by RT-PCR.A non-quantitative RT-PCR on enriched poly(A)+ RNA showing the expression of AalOR2 mRNA in pre-adult stages, and in antennae from both male and female adult mosquitoes. The lanes are as follows: early larvae (EL), late larvae (LL), pupae (P), adult female antennae (F-ant), adult female carcassae (F-body), adult male antennae (M-ant), adult male carcassae (M-body), negative control obtained by using reaction mix with no cDNA (negative), 1 kb DNA marker-Fermentas (M). All RT-PCR reactions were performed with 40 cycles of amplification on cDNA, except for m-Ant, which was obtained with 35 cycles of amplification on the first-round specific amplificate. Prior to the RT-PCR, the cDNA populations were roughly normalized by RT-PCR to the amount of the AalRpL26 expression levels to ensure an equal input.

Mentions: In A. aegypti and A. gambiae it has been reported that OR2 is expressed both in the larval and adult antennae [15], [20]. We examined the expression pattern of the AalOR2 transcript by RT-PCR analyses of tissues isolated from larval and adult stages. In order to check for false amplification from genomic DNA contamination, we used an intro-spanning primer set (3′RACE1Fw/5′RACE1Rev, see primers section) that allowed us to recognize products from either cDNA 624 bp or genomic DNA 889 bp templates. As expected, AalOR2 mRNA is readily detectable in the larval heads throughout all developmental stages, and in the antennae from both male and female adult mosquitoes (Fig. 2). Because one round of PCR was not sufficient to obtain enough amplificate in nanogram amounts starting from the cDNA from the male antennae, we carried out a second round of PCR with an aliquot of the first round products using the same gene-specific primers. Although we performed a nonquantitative PCR, our data seem to suggest that in A. Albopictus the AalOR2 gene is more expressed in the female antennae than in the male antennae, as previously suggested for the AgOR2 gene [23] (Fig. 2). In these experiments we used AalRpL26 as an internal control to verify the quality of the cDNA.


Molecular and functional characterization of the odorant receptor2 (OR2) in the tiger mosquito Aedes albopictus.

Scialò F, Hansson BS, Giordano E, Polito CL, Digilio FA - PLoS ONE (2012)

Expression profile of the AalOR2 transcript in Aedes albopictus by RT-PCR.A non-quantitative RT-PCR on enriched poly(A)+ RNA showing the expression of AalOR2 mRNA in pre-adult stages, and in antennae from both male and female adult mosquitoes. The lanes are as follows: early larvae (EL), late larvae (LL), pupae (P), adult female antennae (F-ant), adult female carcassae (F-body), adult male antennae (M-ant), adult male carcassae (M-body), negative control obtained by using reaction mix with no cDNA (negative), 1 kb DNA marker-Fermentas (M). All RT-PCR reactions were performed with 40 cycles of amplification on cDNA, except for m-Ant, which was obtained with 35 cycles of amplification on the first-round specific amplificate. Prior to the RT-PCR, the cDNA populations were roughly normalized by RT-PCR to the amount of the AalRpL26 expression levels to ensure an equal input.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351472&req=5

pone-0036538-g002: Expression profile of the AalOR2 transcript in Aedes albopictus by RT-PCR.A non-quantitative RT-PCR on enriched poly(A)+ RNA showing the expression of AalOR2 mRNA in pre-adult stages, and in antennae from both male and female adult mosquitoes. The lanes are as follows: early larvae (EL), late larvae (LL), pupae (P), adult female antennae (F-ant), adult female carcassae (F-body), adult male antennae (M-ant), adult male carcassae (M-body), negative control obtained by using reaction mix with no cDNA (negative), 1 kb DNA marker-Fermentas (M). All RT-PCR reactions were performed with 40 cycles of amplification on cDNA, except for m-Ant, which was obtained with 35 cycles of amplification on the first-round specific amplificate. Prior to the RT-PCR, the cDNA populations were roughly normalized by RT-PCR to the amount of the AalRpL26 expression levels to ensure an equal input.
Mentions: In A. aegypti and A. gambiae it has been reported that OR2 is expressed both in the larval and adult antennae [15], [20]. We examined the expression pattern of the AalOR2 transcript by RT-PCR analyses of tissues isolated from larval and adult stages. In order to check for false amplification from genomic DNA contamination, we used an intro-spanning primer set (3′RACE1Fw/5′RACE1Rev, see primers section) that allowed us to recognize products from either cDNA 624 bp or genomic DNA 889 bp templates. As expected, AalOR2 mRNA is readily detectable in the larval heads throughout all developmental stages, and in the antennae from both male and female adult mosquitoes (Fig. 2). Because one round of PCR was not sufficient to obtain enough amplificate in nanogram amounts starting from the cDNA from the male antennae, we carried out a second round of PCR with an aliquot of the first round products using the same gene-specific primers. Although we performed a nonquantitative PCR, our data seem to suggest that in A. Albopictus the AalOR2 gene is more expressed in the female antennae than in the male antennae, as previously suggested for the AgOR2 gene [23] (Fig. 2). In these experiments we used AalRpL26 as an internal control to verify the quality of the cDNA.

Bottom Line: Our data indicate that AalOR2 is narrowly tuned to indole, and inhibited by (-)-menthone.In agreement with this results, these two compounds elicit two opposite effects on the olfactory-based behavior of A. albopictus larvae, as determined through a larval behavioral assay.In summary, this work has led to the cloning and de-orphaning of the first Odorant Receptor in the tiger mosquito A. albopictus.

View Article: PubMed Central - PubMed

Affiliation: Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy.

ABSTRACT
In mosquitoes, the olfactory system plays a crucial role in many types of behavior, including nectar feeding, host preference selection and oviposition. Aedes albopictus, known also as the tiger mosquito, is an anthropophilic species, which in the last few years, due to its strong ecological plasticity, has spread throughout the world. Although long considered only a secondary vector of viruses, the potential of its vector capacity may constitute a threat to public health. Based on the idea that an improved understanding of the olfactory system of mosquitoes may assist in the development of control methods that interfere with their behavior, we have undertaken a study aimed at characterizing the A. albopictus Odorant Receptors. Here we report the identification, cloning and functional characterization of the AalOR2 ortholog, that represents the first candidate member of the odorant receptor (OR) family of proteins from A. albopictus. AalOR2 is expressed in the larval heads and antennae of adults. Our data indicate that A. albopictus OR2 (AalOR2) shares a high degree of identity with other mosquito OR2 orthologs characterized to date, confirming that OR2 is one of the most conserved mosquito ORs. Our data indicate that AalOR2 is narrowly tuned to indole, and inhibited by (-)-menthone. In agreement with this results, these two compounds elicit two opposite effects on the olfactory-based behavior of A. albopictus larvae, as determined through a larval behavioral assay. In summary, this work has led to the cloning and de-orphaning of the first Odorant Receptor in the tiger mosquito A. albopictus. In future control strategies this receptor may be used as a potential molecular target.

Show MeSH
Related in: MedlinePlus