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Walter S. Leal - One of the best experts on this subject based on the ideXlab platform.
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deet and other repellents are inhibitors of mosquito odorant receptors for oviposition Attractants
Insect Biochemistry and Molecular Biology, 2019Co-Authors: Pingxi Xu, Fangfang Zeng, Robert H Bedoukian, Walter S. LealAbstract:Abstract In addition to its primary function as an insect repellent, DEET has many “off-label” properties, including a deterrent effect on the attraction of gravid female mosquitoes. DEET negatively affects oviposition sites. While deorphanizing odorant receptors (ORs) using the Xenopus oocyte recording system, we have previously observed that DEET generated outward (inhibitory) currents on ORs sensitive to oviposition Attractants. Here, we systematically investigated these inhibitory currents. We recorded dose-dependent outward currents elicited by DEET and other repellents on ORs from Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae. Similar responses were observed with other plant-derived and plant-inspired compounds, including methyl jasmonate and methyl dihydrojasmolate. Inward (regular) currents elicited by skatole upon activation of CquiOR21 were modulated when this oviposition Attractant was coapplied with a repellent. Compounds that generate outward currents in ORs sensitive to oviposition Attractants elicited inward currents in a DEET-sensitive receptor, CquiOR136. The best ligand for this receptor, methyl dihydrojasmolate, showed repellency activity but was not as strong as DEET in our test protocol.
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deet and other repellents are inhibitors of mosquito odorant receptors for oviposition Attractants
bioRxiv, 2019Co-Authors: Pingxi Xu, Fangfang Zeng, Robert H Bedoukian, Walter S. LealAbstract:Abstract In addition to its primary function as an insect repellent, DEET has many “off-label” properties, including a deterrent effect on attraction of gravid female mosquitoes. DEET negatively affects oviposition sites. While deorphanizing odorant receptors (ORs) using the Xenopus oocyte recording system, we have previously observed that DEET generated outward (inhibitory) currents on ORs sensitive to oviposition Attractants. Here, we systematically investigated these inhibitory currents. We recorded dose-dependent outward currents elicited by DEET and other repellents on ORs from Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae. Similar responses were observed with other plant-derived and plant-inspired compounds, including methyl jasmonate and methyl dihydrojasmolate. Inward (regular) currents elicited by skatole upon activation of CquiOR21 were modulated when this oviposition Attractant was coapplied with a repellent. Compounds that generate outward currents in ORs sensitive to oviposition Attractants elicited inward currents in a DEET-sensitive receptor, CquiOR136. The best ligand for this receptor, methyl dihydrojasmolate, showed repellency activity, but was not as strong as DEET in our test protocol.
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Odorant Receptor from the Southern House Mosquito Narrowly Tuned to the Oviposition Attractant Skatole
Journal of Chemical Ecology, 2010Co-Authors: David T. Hughes, Julien Pelletier, Charles W. Luetje, Walter S. LealAbstract:Oviposition Attractants are environmental cues that allow Culex gravid female mosquitoes to locate suitable sites for egg-laying and, therefore, may be exploited for environmentally friendly strategies for controlling mosquito populations. Naturally occurring skatole has been identified as an oviposition Attractant for the Southern House mosquito, Culex quinquefasciatus. Previously, we identified in Cx. quinquefasciatus female antennae an olfactory receptor neuron (ORN) highly sensitive to skatole and an odorant-binding protein involved in the detection of this semiochemical. Here, we describe the characterization of an odorant receptor (OR), CquiOR10, which is narrowly tuned to skatole when expressed in the Xenopus oocyte system. Odorant-induced response profiles generated by heterologously expressed CquiOR10 suggest that this OR is expressed in the mosquito ORN sensitive to skatole. However, geranylacetone, which stimulates the antennal ORN, was not detected by CquiOR10-expressing oocytes, thus raising interesting questions about reception of oviposition Attractants in mosquitoes.
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culex mosquitoes diptera culicidae egg laying in traps loaded with bacillus thuringiensis variety israelensis and baited with skatole
Journal of Medical Entomology, 2010Co-Authors: Rosângela M R Barbosa, Leda Regis, Roberto Vasconcelos, Walter S. LealAbstract:The Southern house mosquito, Culex quinquefasciatus, is an important human health pest as a vector of several pathogens, including agents of lymphatic filariasis and arboviruses like West Nile virus. We conducted preliminary experiments in Recife, Brazil, to explore applications of Culex oviposition Attractants in combination with Bacillus thuringiensis variety israelensis (Bti) in an attract-and-kill approach. Simple, cost-effective oviposition traps, BR-OVT, loaded with Bti and baited with or without Attractant, were deployed in 10 homes for 30 d in 2 consecutive yr. Significantly higher numbers of egg rafts were deposited in traps baited with skatole or infusion than the control water traps. In the first year, 2006, significantly higher numbers of eggs were deposited in infusion-baited traps, particularly in the first 15 d of the experiment, than in skatole traps, but in the following year no significant difference was observed between synthetic and natural Attractants. The tests strongly demonstrate that skatole or infusion can be used to enhance the number of egg rafts deposited on Bti-treated oviposition traps.
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an odorant receptor from the southern house mosquito culex pipiens quinquefasciatus sensitive to oviposition Attractants
PLOS ONE, 2010Co-Authors: Julien Pelletier, Charles W. Luetje, David Hughes, Walter S. LealAbstract:Background Insect odorant receptors (ORs) are heteromers comprised of highly variable odorant-binding subunits associated with one conserved co-receptor. They are potential molecular targets for the development of novel mosquito Attractants and repellents. ORs have been identified in the malaria mosquito, Anopheles gambiae, and in the yellow fever mosquito, Aedes aegypti. However, they are still unknown in the Southern house mosquito, Culex quinquefasciatus, which transmits pathogens that cause human diseases throughout the world, including West Nile Virus in the United States. Methodology We have employed a combination of bioinformatics, molecular cloning and electrophysiology approaches to identify and characterize the response profile of an OR in Cx. quinquefasciatus. First, we have unveiled a large multigenic family of one-hundred-fifty-eight putative ORs in this species, including a subgroup of conserved ORs in three mosquito species. Using the Xenopus oocytes expression system, we have determined the response profile of CquiOR2, an antennae-specific OR, which shares high identity with putative orthologs in Anopheles gambiae (AgamOR2) and Aedes aegypti (AaegOR2). Conclusion We show that CquiOR2 is highly sensitive to indole, an oviposition Attractant for Cx. quinquefasciatus. The response profile of CquiOR2 expressed in Xenopus oocytes resembles that of an olfactory receptor neuron housed in the antennal short blunt-tipped sensilla (A2) of Cx. quinquefasciatus, which are natural detectors for oviposition Attractants. This first Culex OR de-orphanized is, therefore, a potential molecular target for screening oviposition Attractants.
Daichi Susaki - One of the best experts on this subject based on the ideXlab platform.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Daichi Susaki, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Nao KawanoAbstract:Precise pollen tube guidance is critical for the successful fertilization of flowering plants. The concept of a pollen tube Attractant was proposed in the late nineteenth century when pollen tubes were found to grow towards excised pistil tissues on medium. In 2001 the synergid cells, situated next to the egg, were shown to secrete a soluble factor that guides the growing pollen tube towards the embryo sac. Now at long last, these pollen tube Attractants have been identified. Synergid cells were isolated from Torenia fournieri ('wishbone flower') plants, which are unique in having a protruding embryo sac. The secreted guidance factors were identified as cysteine-rich polypeptides belonging to the sub group of defensin-like proteins, and named LUREs. In this study, Higashiyama and colleagues examine pollen tube guidance in Torenia fournieri and identify the secreted guidance factors. These are cysteine-rich polypeptides belonging to the subgroup of defensin-like proteins (designated as LUREs), which are predominantly expressed in synergid cells and are required for pollen tube guidance. For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules1. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance1,2,3. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Ryoko Yui, Daichi SusakiAbstract:For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
Satohiro Okuda - One of the best experts on this subject based on the ideXlab platform.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Daichi Susaki, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Nao KawanoAbstract:Precise pollen tube guidance is critical for the successful fertilization of flowering plants. The concept of a pollen tube Attractant was proposed in the late nineteenth century when pollen tubes were found to grow towards excised pistil tissues on medium. In 2001 the synergid cells, situated next to the egg, were shown to secrete a soluble factor that guides the growing pollen tube towards the embryo sac. Now at long last, these pollen tube Attractants have been identified. Synergid cells were isolated from Torenia fournieri ('wishbone flower') plants, which are unique in having a protruding embryo sac. The secreted guidance factors were identified as cysteine-rich polypeptides belonging to the sub group of defensin-like proteins, and named LUREs. In this study, Higashiyama and colleagues examine pollen tube guidance in Torenia fournieri and identify the secreted guidance factors. These are cysteine-rich polypeptides belonging to the subgroup of defensin-like proteins (designated as LUREs), which are predominantly expressed in synergid cells and are required for pollen tube guidance. For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules1. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance1,2,3. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Ryoko Yui, Daichi SusakiAbstract:For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
Nao Kawano - One of the best experts on this subject based on the ideXlab platform.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Daichi Susaki, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Nao KawanoAbstract:Precise pollen tube guidance is critical for the successful fertilization of flowering plants. The concept of a pollen tube Attractant was proposed in the late nineteenth century when pollen tubes were found to grow towards excised pistil tissues on medium. In 2001 the synergid cells, situated next to the egg, were shown to secrete a soluble factor that guides the growing pollen tube towards the embryo sac. Now at long last, these pollen tube Attractants have been identified. Synergid cells were isolated from Torenia fournieri ('wishbone flower') plants, which are unique in having a protruding embryo sac. The secreted guidance factors were identified as cysteine-rich polypeptides belonging to the sub group of defensin-like proteins, and named LUREs. In this study, Higashiyama and colleagues examine pollen tube guidance in Torenia fournieri and identify the secreted guidance factors. These are cysteine-rich polypeptides belonging to the subgroup of defensin-like proteins (designated as LUREs), which are predominantly expressed in synergid cells and are required for pollen tube guidance. For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules1. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance1,2,3. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
Hiroki Tsutsui - One of the best experts on this subject based on the ideXlab platform.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Daichi Susaki, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Nao KawanoAbstract:Precise pollen tube guidance is critical for the successful fertilization of flowering plants. The concept of a pollen tube Attractant was proposed in the late nineteenth century when pollen tubes were found to grow towards excised pistil tissues on medium. In 2001 the synergid cells, situated next to the egg, were shown to secrete a soluble factor that guides the growing pollen tube towards the embryo sac. Now at long last, these pollen tube Attractants have been identified. Synergid cells were isolated from Torenia fournieri ('wishbone flower') plants, which are unique in having a protruding embryo sac. The secreted guidance factors were identified as cysteine-rich polypeptides belonging to the sub group of defensin-like proteins, and named LUREs. In this study, Higashiyama and colleagues examine pollen tube guidance in Torenia fournieri and identify the secreted guidance factors. These are cysteine-rich polypeptides belonging to the subgroup of defensin-like proteins (designated as LUREs), which are predominantly expressed in synergid cells and are required for pollen tube guidance. For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules1. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance1,2,3. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
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defensin like polypeptide lures are pollen tube Attractants secreted from synergid cells
Nature, 2009Co-Authors: Satohiro Okuda, Hidenori Takeuchi, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Ryoko Yui, Daichi SusakiAbstract:For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoAttractants derived from target ovules. However, there has been no convincing evidence of any particular molecule being the true Attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are Attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoAttractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the Attractants derived from the synergid cells of T. fournieri.
