The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform
Sakae Kikuyama - One of the best experts on this subject based on the ideXlab platform.
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responsiveness of vomeronasal cells to a newt peptide pheromone Sodefrin as monitored by changes of intracellular calcium concentrations
Peptides, 2013Co-Authors: Takeo Iwata, Fumiyo Toyoda, Tomoaki Nakada, Seiji Shioda, Toshihiko Yada, Sakae KikuyamaAbstract:Abstract A peptide pheromone of the red-bellied male newt, Sodefrin was tested for its ability to increase intracellular concentrations of Ca 2+ ([Ca 2+ ] i ) in the dissociated vomeronasal (VN) cells of females by means of calcium imaging system. The pheromone elicited a marked elevation of [Ca 2+ ] i in a small population of VN cells from sexually developed females. The population of cells exhibiting Sodefrin-induced elevation of [Ca 2+ ] i increased concentration-dependently. A pheromone of a different species was ineffective in this respect. The VN cells from non-reproductive females or from reproductive males scarcely responded to Sodefrin in terms of elevating [Ca 2+ ] i . In the cells from hypophysectomized and ovariectomized females, the Sodefrin-inducible increase of [Ca 2+ ] i never occurred. The cells from the operated newts supplemented with prolactin and estradiol exhibited [Ca 2+ ] i responses to Sodefrin with a high incidence. Thus, sex- and hormone-dependency as well as species-specificity of the responsiveness of the VN cells to Sodefrin was evidenced at the cellular level. Subsequently, possibility of involvement of phospholipase C (PLC)-inositol 1,4,5-trisphosphate (IP 3 ) and/or PLC-diacylglycerol (DAG)-protein kinase C (PKC) pathways in increasing [Ca 2+ ] i in VN cells in response to Sodefrin was explored using pharmacological approaches. The results indicated that PLC is involved in generating the Ca 2+ signal in all Sodefrin-responsive VN cells, whereas IP 3 in approximately 50% of the cells and DAG-PKC in the remaining cells. In the latter case, the increase of [Ca 2+ ] i was postulated to be induced by the influx of Ca 2+ through the L-type channel. The significance of the finding is discussed.
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Sodefrin and Related Pheromones
Handbook of Biologically Active Peptides, 2007Co-Authors: Sakae Kikuyama, Fumiyo Toyoda, Tomoaki Nakada, Takeo Iwata, Kazutoshi Yamamoto, Itaru HasunumaAbstract:ABSTRACT This article describes the current state of understanding of Sodefrin, a peptide pheromone from the newt Cynops pyrrhogaster, and [Leu3, Gln8] Sodefrin (silefrin) from the congeneric species, C. ensicauda. Both pheromones are composed of 10-amino-acid residues and were isolated from the abdominal glands of the male newts. They exhibit a potent female-attracting activity only to the conspecific females, suggesting a contribution of the pheromones to maintaining the reproductive isolation of the species. Both pheromones are generated from 20 kDa precursor molecules. These pheromones are emitted through the cloaca of the male and are directed toward the female partner's snout during courtship to act primarily on the lateral nasal sinus cells. Hormone dependency of secretion of and response to the pheromones has been demonstrated.
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evidence for processing enzymes in the abdominal gland of the newt cynops pyrrhogaster that generate Sodefrin from its biosynthetic precursor
Zoological Science, 2007Co-Authors: Tomoaki Nakada, Michael J Conlon, Fumiyo Toyoda, Yoko Ishizuka, Takeo Iwata, Takashi Kato, Sakae KikuyamaAbstract:Sodefrin (Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys) is a female-attracting peptide pheromone secreted by the abdominal gland of the male red-bellied newt, Cynops pyrrhogaster. Sequence analysis of a cDNA encoding Sodefrin revealed that the peptide is located in the C-terminal region of its precursor protein (residues 177-186 of preproSodefrin) and extended from its C-terminus by the tripeptide sequence Ile(187)-Ser(188)-Ala(189) and flanked at its N-terminus by Leu(174)-Gly(175)-Arg(176). This suggests that Sodefrin is generated by enzymatic cleavage at monobasic (Lys and Arg) sites within the precursor molecule. To demonstrate the presence in the abdominal gland of proteolytic enzymes capable of generating Sodefrin, an enzymatic assay was developed using t-butoxycarbo-nyl (Boc)-Leu-Gly-Arg-4methylcoumaryl-7-amide (MCA) and Boc-Leu-Leu-Lys-MCA as synthetic substrates. A crude extract of the abdominal gland hydrolyzed both substrates to liberate 7-amino-4- methylcoumarin, suggesting that enzymes that generate Sodefrin from its precursor molecule are present in the gland. The activity in the extract for cleaving Boc-Leu-Gly-Arg-MCA was optimal at pH 9.0 and 45 degrees C and for Boc-Leu-Leu-Lys-MCA at pH 9.0 and 40 degrees C. The effects of a range of specific inhibitors on activities in the extract suggest an involvement of enzymes belonging to the serine protease family. It was also demonstrated that enzymatic activity in an extract of the abdominal glands of sexually developed males was significantly (three- to six-fold; p<0.01) higher than that of sexually undeveloped males.
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isolation characterization and bioactivity of a region specific pheromone val8 Sodefrin from the newt cynops pyrrhogaster
Peptides, 2007Co-Authors: Tomoaki Nakada, Michael J Conlon, Fumiyo Toyoda, Takeo Iwata, Takashi Kato, Kazutoshi Yamamoto, Sakae KikuyamaAbstract:Previous analysis of PCR products derived from total RNA from the abdominal gland of the male newt, Cynops pyrrhogaster, inhabiting the Nara area of Japan led to the identification of a gene encoding [Val(8)]Sodefrin, as well as the female-attracting peptide pheromone, Sodefrin. In this study, purification of this Sodefrin variant from the abdominal glands of male newts from the Nara area was accomplished using gel-filtration chromatography and reversed-phase HPLC. Amino acid sequence analysis and mass spectrometry confirmed that the final product was [Val(8)]Sodefrin. A full-length cDNA encoding the biosynthetic precursor of [Val(8)]Sodefrin was cloned and characterized. The deduced amino acid sequence of prepro[Val(8)]Sodefrin showed 86.2% identity with that of the Sodefrin precursor. The [Val(8)]Sodefrin variant potently attracted females from the Nara area, but the variant was much less or not effective in attracting females captured in the Niigata and Chiba areas. The term aonirin ("aoni" from "aoni-yoshi", the conventional epithet of Nara) is proposed to designate this region-specific pheromone. It is speculated that the coevolution of a novel pheromone and its complementary receptor in the Nara newts may lead to reproductive isolation and eventual differentiation into a separate species.
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chapter 48 Sodefrin and related pheromones
Handbook of Biologically Active Peptides, 2006Co-Authors: Sakae KikuyamaAbstract:This article describes the current state of understanding of Sodefrin, a peptide pheromone from the newt Cynops pyrrhogaster, and [Leu3, Gln8] Sodefrin (silefrin) from the congeneric species, C. ensicauda. Both pheromones are composed of 10-amino-acid residues and were isolated from the abdominal glands of the male newts. They exhibit a potent female-attracting activity only to the conspecific females, suggesting a contribution of the pheromones to maintaining the reproductive isolation of the species. Both pheromones are generated from 20 kDa precursor molecules. These pheromones are emitted through the cloaca of the male and are directed toward the female partner's snout during courtship to act primarily on the lateral nasal sinus cells. Hormone dependency of secretion of and response to the pheromones has been demonstrated.
Franky Bossuyt - One of the best experts on this subject based on the ideXlab platform.
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multiple independent recruitment of Sodefrin precursor like factors in anuran sexually dimorphic glands
Molecular Biology and Evolution, 2019Co-Authors: Franky Bossuyt, Margo Maex, Sunita Janssenswillen, Lisa M Schulte, Polina Yu Novikova, S D Biju, Yves Van De Peer, Severine Matthijs, Kim RoelantsAbstract:Chemical signaling in animals often plays a central role in eliciting a variety of responses during reproductive interactions between males and females. One of the best-known vertebrate courtship pheromone systems is Sodefrin precursor-like factors (SPFs), a family of two-domain three-finger proteins with a female-receptivity enhancing function, currently only known from salamanders. The oldest divergence between active components in a single salamander species dates back to the Late Paleozoic, indicating that these proteins potentially gained a pheromone function earlier in amphibian evolution. Here, we combined whole transcriptome sequencing, proteomics, histology, and molecular phylogenetics in a comparative approach to investigate SPF occurrence in male breeding glands across the evolutionary tree of anurans (frogs and toads). Our study shows that multiple families of both terrestrially and aquatically reproducing frogs have substantially increased expression levels of SPFs in male breeding glands. This suggests that multiple anuran lineages make use of SPFs to complement acoustic and visual sexual signaling during courtship. Comparative analyses show that anurans independently recruited these proteins each time the gland location on the male’s body allowed efficient transmission of the secretion to the female’s nares.
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exaptation as a mechanism for functional reinforcement of an animal pheromone system
Current Biology, 2018Co-Authors: Margo Maex, Ines Van Bocxlaer, Dag Treer, Paul Proost, Henri De Greve, Franky BossuytAbstract:Summary Animal sex pheromone systems often exist as multicomponent signals [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] to which chemical cues have been added over evolutionary time. Little is known on why and how additional molecules become recruited and conserved in an already functional pheromone system. Here, we investigated the evolutionary trajectory of a series of 15 kDa proteins—termed persuasins—that were co-opted more recently alongside the ancient Sodefrin precursor-like factor (SPF) courtship pheromone system in salamanders [ 9 , 12 ]. Expression, genomic, and molecular phylogenetic analyses show that persuasins originated from a gene that is expressed as a multi-domain protein in internal organs where it has no pheromone function but underwent gene duplication and neofunctionalization. The subsequent evolution combined domain loss and the introduction of a proteolytic cleavage site in the duplicated gene to give rise to two-domain cysteine rich proteins with structural properties similar to SPF pheromones [ 12 ]. An expression shift to the pheromone-producing glands, where expression of persuasins was immediately spatiotemporally synchronized with the already available pheromone system, completed the birth of a new pheromone. Electrostatic forces between members of both protein families likely enhance co-localization and simultaneous activation of different female olfactory neurons, explaining why persuasins immediately had a selective advantage. In line with this, behavioral assays show that persuasins increase female receptivity on their own but also exert a cumulative or synergistic effect in combination with SPF, clearly reinforcing the pheromone system as a whole. Our study reveals molecular remodeling of an existing protein architecture as an evolutionary mechanism for functional reinforcement of animal pheromone systems.
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divergence of species specific protein sex pheromone blends in two related nonhybridizing newts salamandridae
Molecular Ecology, 2018Co-Authors: Dag Treer, Margo Maex, Ines Van Bocxlaer, Paul Proost, Franky BossuytAbstract:In animals that use chemical communication during courtship and reproduction, speciation is often associated with divergence of their sex pheromones. In multicomponent pheromone systems, divergence can be obtained either by adding or deleting components, or by altering the relative contribution of individual components to the mixture. Protein pheromone systems can additionally evolve by amino acid sequence divergence to produce pheromones with a species-specific effect. The Sodefrin precursor-like factor (SPF) pheromone system, a blend of proteins that essentially enhances receptivity in salamanders, has had a long and dynamic evolution of gene duplications, but the mechanisms that govern interspecific divergence and the role they play in reproductive isolation remain elusive. Here, we use transcriptomics and proteomics to characterize the SPF protein repertoire of the alpine newt (Ichthyosaura alpestris), and compare it to the previously identified repertoire of SPF proteins of the palmate newt (Lissotriton helveticus), a related but nonhybridizing species. Subsequent phylogenetic analyses indicate that, despite the availability of multiple SPF gene copies, both species predominantly express the same subset of orthologs. Our study demonstrates that species specificity in the SPF protein pheromone system can be established by gradual sequence divergence of the same set of proteins alone.
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Beyond Sodefrin: evidence for a multi-component pheromone system in the model newt Cynops pyrrhogaster (Salamandridae).
Scientific Reports, 2016Co-Authors: Ines Van Bocxlaer, Margo Maex, Dag Treer, Sunita Janssenswillen, Rik Janssens, Wim Vandebergh, Paul Proost, Franky BossuytAbstract:Sodefrin, a decapeptide isolated from the male dorsal gland of the Japanese fire belly newt Cynops pyrrhogaster, was the first peptide pheromone identified from a vertebrate. The fire belly salamander and Sodefrin have become a model for sex pheromone investigation in aquatically courting salamanders ever since. Subsequent studies in other salamanders identified SPF protein courtship pheromones of around 20 kDa belonging to the same gene-family. Although transcripts of these proteins could be PCR-amplified in Cynops, it is currently unknown whether they effectively use full-length SPF pheromones next to Sodefrin. Here we combined transcriptomics, proteomics and phylogenetics to investigate SPF pheromone use in Cynops pyrrhogaster. Our data show that not Sodefrin transcripts, but multiple SPF transcripts make up the majority of the expression profile in the dorsal gland of this newt. Proteome analyses of water in which a male has been courting confirm that this protein blend is effectively secreted and tail-fanned to the female. By combining phylogenetics and expression data, we show that independent evolutionary lineages of these SPF’s were already expressed in ancestral Cynops species before the origin of Sodefrin. Extant Cynops species continue to use this multi-component pheromone system, consisting of various proteins in addition to a lineage-specific peptide.
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Courtship Pheromone Use in a Model Urodele, the Mexican Axolotl (Ambystoma mexicanum)
Scientific Reports, 2016Co-Authors: Margo Maex, Ines Van Bocxlaer, Anneleen Mortier, Franky BossuytAbstract:Sex pheromones have been shown to constitute a crucial aspect of salamander reproduction. Until now, courtship pheromones of Salamandridae and Plethodontidae have been intensively studied, but information on chemical communication in other urodelan families is essentially lacking. The axolotl ( Ambystoma mexicanum , Ambystomatidae) has a courtship display that suggests a key role for chemical communication in the orchestration of its sexual behavior, but no sex pheromones have yet been characterized from this species. Here we combined whole transcriptome analyses of the male cloaca with proteomic analyses of water in which axolotls were allowed to court to show that male axolotls secrete multiple ca. 20 kDa glycosylated Sodefrin precursor-like factor (SPF) proteins during courtship. In combination with phylogenetic analyses, our data show that the male cloaca essentially secretes a courtship-specific clade of SPF proteins that is orthologous to salamandrid courtship pheromones. In addition, we identified an SPF protein for which no orthologs have been described from other salamanders so far. Overall, our study advocates a central role for SPF proteins during the courtship display of axolotls and adds knowledge on pheromone use in a previously unexplored deep evolutionary branch of salamander evolution.
Fumiyo Toyoda - One of the best experts on this subject based on the ideXlab platform.
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responsiveness of vomeronasal cells to a newt peptide pheromone Sodefrin as monitored by changes of intracellular calcium concentrations
Peptides, 2013Co-Authors: Takeo Iwata, Fumiyo Toyoda, Tomoaki Nakada, Seiji Shioda, Toshihiko Yada, Sakae KikuyamaAbstract:Abstract A peptide pheromone of the red-bellied male newt, Sodefrin was tested for its ability to increase intracellular concentrations of Ca 2+ ([Ca 2+ ] i ) in the dissociated vomeronasal (VN) cells of females by means of calcium imaging system. The pheromone elicited a marked elevation of [Ca 2+ ] i in a small population of VN cells from sexually developed females. The population of cells exhibiting Sodefrin-induced elevation of [Ca 2+ ] i increased concentration-dependently. A pheromone of a different species was ineffective in this respect. The VN cells from non-reproductive females or from reproductive males scarcely responded to Sodefrin in terms of elevating [Ca 2+ ] i . In the cells from hypophysectomized and ovariectomized females, the Sodefrin-inducible increase of [Ca 2+ ] i never occurred. The cells from the operated newts supplemented with prolactin and estradiol exhibited [Ca 2+ ] i responses to Sodefrin with a high incidence. Thus, sex- and hormone-dependency as well as species-specificity of the responsiveness of the VN cells to Sodefrin was evidenced at the cellular level. Subsequently, possibility of involvement of phospholipase C (PLC)-inositol 1,4,5-trisphosphate (IP 3 ) and/or PLC-diacylglycerol (DAG)-protein kinase C (PKC) pathways in increasing [Ca 2+ ] i in VN cells in response to Sodefrin was explored using pharmacological approaches. The results indicated that PLC is involved in generating the Ca 2+ signal in all Sodefrin-responsive VN cells, whereas IP 3 in approximately 50% of the cells and DAG-PKC in the remaining cells. In the latter case, the increase of [Ca 2+ ] i was postulated to be induced by the influx of Ca 2+ through the L-type channel. The significance of the finding is discussed.
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Sodefrin and Related Pheromones
Handbook of Biologically Active Peptides, 2007Co-Authors: Sakae Kikuyama, Fumiyo Toyoda, Tomoaki Nakada, Takeo Iwata, Kazutoshi Yamamoto, Itaru HasunumaAbstract:ABSTRACT This article describes the current state of understanding of Sodefrin, a peptide pheromone from the newt Cynops pyrrhogaster, and [Leu3, Gln8] Sodefrin (silefrin) from the congeneric species, C. ensicauda. Both pheromones are composed of 10-amino-acid residues and were isolated from the abdominal glands of the male newts. They exhibit a potent female-attracting activity only to the conspecific females, suggesting a contribution of the pheromones to maintaining the reproductive isolation of the species. Both pheromones are generated from 20 kDa precursor molecules. These pheromones are emitted through the cloaca of the male and are directed toward the female partner's snout during courtship to act primarily on the lateral nasal sinus cells. Hormone dependency of secretion of and response to the pheromones has been demonstrated.
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evidence for processing enzymes in the abdominal gland of the newt cynops pyrrhogaster that generate Sodefrin from its biosynthetic precursor
Zoological Science, 2007Co-Authors: Tomoaki Nakada, Michael J Conlon, Fumiyo Toyoda, Yoko Ishizuka, Takeo Iwata, Takashi Kato, Sakae KikuyamaAbstract:Sodefrin (Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys) is a female-attracting peptide pheromone secreted by the abdominal gland of the male red-bellied newt, Cynops pyrrhogaster. Sequence analysis of a cDNA encoding Sodefrin revealed that the peptide is located in the C-terminal region of its precursor protein (residues 177-186 of preproSodefrin) and extended from its C-terminus by the tripeptide sequence Ile(187)-Ser(188)-Ala(189) and flanked at its N-terminus by Leu(174)-Gly(175)-Arg(176). This suggests that Sodefrin is generated by enzymatic cleavage at monobasic (Lys and Arg) sites within the precursor molecule. To demonstrate the presence in the abdominal gland of proteolytic enzymes capable of generating Sodefrin, an enzymatic assay was developed using t-butoxycarbo-nyl (Boc)-Leu-Gly-Arg-4methylcoumaryl-7-amide (MCA) and Boc-Leu-Leu-Lys-MCA as synthetic substrates. A crude extract of the abdominal gland hydrolyzed both substrates to liberate 7-amino-4- methylcoumarin, suggesting that enzymes that generate Sodefrin from its precursor molecule are present in the gland. The activity in the extract for cleaving Boc-Leu-Gly-Arg-MCA was optimal at pH 9.0 and 45 degrees C and for Boc-Leu-Leu-Lys-MCA at pH 9.0 and 40 degrees C. The effects of a range of specific inhibitors on activities in the extract suggest an involvement of enzymes belonging to the serine protease family. It was also demonstrated that enzymatic activity in an extract of the abdominal glands of sexually developed males was significantly (three- to six-fold; p<0.01) higher than that of sexually undeveloped males.
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isolation characterization and bioactivity of a region specific pheromone val8 Sodefrin from the newt cynops pyrrhogaster
Peptides, 2007Co-Authors: Tomoaki Nakada, Michael J Conlon, Fumiyo Toyoda, Takeo Iwata, Takashi Kato, Kazutoshi Yamamoto, Sakae KikuyamaAbstract:Previous analysis of PCR products derived from total RNA from the abdominal gland of the male newt, Cynops pyrrhogaster, inhabiting the Nara area of Japan led to the identification of a gene encoding [Val(8)]Sodefrin, as well as the female-attracting peptide pheromone, Sodefrin. In this study, purification of this Sodefrin variant from the abdominal glands of male newts from the Nara area was accomplished using gel-filtration chromatography and reversed-phase HPLC. Amino acid sequence analysis and mass spectrometry confirmed that the final product was [Val(8)]Sodefrin. A full-length cDNA encoding the biosynthetic precursor of [Val(8)]Sodefrin was cloned and characterized. The deduced amino acid sequence of prepro[Val(8)]Sodefrin showed 86.2% identity with that of the Sodefrin precursor. The [Val(8)]Sodefrin variant potently attracted females from the Nara area, but the variant was much less or not effective in attracting females captured in the Niigata and Chiba areas. The term aonirin ("aoni" from "aoni-yoshi", the conventional epithet of Nara) is proposed to designate this region-specific pheromone. It is speculated that the coevolution of a novel pheromone and its complementary receptor in the Nara newts may lead to reproductive isolation and eventual differentiation into a separate species.
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regionally specific occurrence of an active Sodefrin variant in the red bellied newt
Annals of the New York Academy of Sciences, 2005Co-Authors: Takeo Iwata, Fumiyo Toyoda, Tomoaki Nakada, Yoko Ishizuka, Kazutoshi Yamamoto, J M Conlon, Sakae KikuyamaAbstract:Sodefrin (SIPSKDALLK) is a female-attracting pheromone that is secreted by the abdominal gland of the male red-bellied newt. We found that mRNA encoding a Sodefrin variant, [Val 8 ] Sodefrin, is expressed exclusively in specimens captured in the Nara area of Japan. The synthetic peptide was tested for its activity. It attracted females from Nara, but not those from other regions, suggesting that there is a geographic variation in the pheromone molecule and in the responsiveness to the pheromone. Employing an abdominal gland extract and synthetic substrates, the possibility of generation of the putative pheromone, [Val 8 ] Sodefrin, from the precursor molecule was demonstrated.
Kazutoshi Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Sodefrin and Related Pheromones
Handbook of Biologically Active Peptides, 2007Co-Authors: Sakae Kikuyama, Fumiyo Toyoda, Tomoaki Nakada, Takeo Iwata, Kazutoshi Yamamoto, Itaru HasunumaAbstract:ABSTRACT This article describes the current state of understanding of Sodefrin, a peptide pheromone from the newt Cynops pyrrhogaster, and [Leu3, Gln8] Sodefrin (silefrin) from the congeneric species, C. ensicauda. Both pheromones are composed of 10-amino-acid residues and were isolated from the abdominal glands of the male newts. They exhibit a potent female-attracting activity only to the conspecific females, suggesting a contribution of the pheromones to maintaining the reproductive isolation of the species. Both pheromones are generated from 20 kDa precursor molecules. These pheromones are emitted through the cloaca of the male and are directed toward the female partner's snout during courtship to act primarily on the lateral nasal sinus cells. Hormone dependency of secretion of and response to the pheromones has been demonstrated.
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isolation characterization and bioactivity of a region specific pheromone val8 Sodefrin from the newt cynops pyrrhogaster
Peptides, 2007Co-Authors: Tomoaki Nakada, Michael J Conlon, Fumiyo Toyoda, Takeo Iwata, Takashi Kato, Kazutoshi Yamamoto, Sakae KikuyamaAbstract:Previous analysis of PCR products derived from total RNA from the abdominal gland of the male newt, Cynops pyrrhogaster, inhabiting the Nara area of Japan led to the identification of a gene encoding [Val(8)]Sodefrin, as well as the female-attracting peptide pheromone, Sodefrin. In this study, purification of this Sodefrin variant from the abdominal glands of male newts from the Nara area was accomplished using gel-filtration chromatography and reversed-phase HPLC. Amino acid sequence analysis and mass spectrometry confirmed that the final product was [Val(8)]Sodefrin. A full-length cDNA encoding the biosynthetic precursor of [Val(8)]Sodefrin was cloned and characterized. The deduced amino acid sequence of prepro[Val(8)]Sodefrin showed 86.2% identity with that of the Sodefrin precursor. The [Val(8)]Sodefrin variant potently attracted females from the Nara area, but the variant was much less or not effective in attracting females captured in the Niigata and Chiba areas. The term aonirin ("aoni" from "aoni-yoshi", the conventional epithet of Nara) is proposed to designate this region-specific pheromone. It is speculated that the coevolution of a novel pheromone and its complementary receptor in the Nara newts may lead to reproductive isolation and eventual differentiation into a separate species.
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regionally specific occurrence of an active Sodefrin variant in the red bellied newt
Annals of the New York Academy of Sciences, 2005Co-Authors: Takeo Iwata, Fumiyo Toyoda, Tomoaki Nakada, Yoko Ishizuka, Kazutoshi Yamamoto, J M Conlon, Sakae KikuyamaAbstract:Sodefrin (SIPSKDALLK) is a female-attracting pheromone that is secreted by the abdominal gland of the male red-bellied newt. We found that mRNA encoding a Sodefrin variant, [Val 8 ] Sodefrin, is expressed exclusively in specimens captured in the Nara area of Japan. The synthetic peptide was tested for its activity. It attracted females from Nara, but not those from other regions, suggesting that there is a geographic variation in the pheromone molecule and in the responsiveness to the pheromone. Employing an abdominal gland extract and synthetic substrates, the possibility of generation of the putative pheromone, [Val 8 ] Sodefrin, from the precursor molecule was demonstrated.
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processing of multiple forms of preproSodefrin in the abdominal gland of the red bellied newt cynops pyrrhogaster regional and individual differences in preproSodefrin gene expression
Peptides, 2004Co-Authors: Takeo Iwata, Michael J Conlon, Fumiyo Toyoda, Tomoaki Nakada, Kazutoshi Yamamoto, Sakae KikuyamaAbstract:Peptides derived from the post-translational processing of preproSodefrin were isolated from an extract of the abdominal glands of male red-bellied newts Cynops pyrrhogaster obtained 5 months prior to the onset of the breeding season. Structural characterization of the peptides showed that the pheromone Sodefrin (SIPSKDALLK) is stored in a biologically inactive COOH-terminally extended form (SIPSKDALLKISA). It follows, therefore, that the activation of a protease that cleaves at a Lys-Ile bond to generate the active pheromone must occur by the time of onset of reproductive behavior. Additional peptides (representing preproSodefrin-(146-175)-peptide and preproSodefrin-(159-173)-peptide), that are derived from the precursor by cleavage at monobasic and dibasic processing sites, were also purified from the extract. The isolation of paralogs of these peptides, including an inactive COOH-terminally extended form of [Asn10]Sodefrin, provides evidence for the expression of multiple genes encoding preproSodefrin. PCR products derived from total RNAs from the abdominal gland of individual newts collected from three different regions of Japan were analyzed. The data confirm the existence of multiple genes encoding Sodefrin and its variants whose expression varied according to the individuals and the regions. However, genes encoding Sodefrin were found to be expressed in all the specimens sampled.
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involvement of arginine vasotocin in reproductive events in the male newt cynops pyrrhogaster
Hormones and Behavior, 2003Co-Authors: Fumiyo Toyoda, Yoichi Ito, Kazutoshi Yamamoto, Shigeyasu Tanaka, Masayuki Yamashita, Sakae KikuyamaAbstract:Abstract Effects of arginine vasotocin (AVT) on reproductive events such as courtship behavior, pheromone release, and spermatophore discharge were investigated in the male newt Cynops pyrrhogaster. AVT enhanced the incidence and frequency of androgen-induced courtship behavior. In this case, AVT was likely to act centrally because the behavior was evoked with a much smaller amount of AVT when the hormone was administered intracerebroventricularly than when given intraperitoneally. Involvement of endogenous AVT in spontaneously occurring courtship behavior was also evidenced by the fact that administration of a V1 (vasopressor) receptor antagonist, [d(CH2)51, Tyr(Me)2, Arg8-vasopressin] suppressed the expression of the courtship behavior. The water in which AVT-treated males had been kept showed considerable female-attracting activity as compared with the water in which saline-injected males had been kept. Moreover, the content of Sodefrin, a female-attracting pheromone in the abdominal gland, was decreased by the intraperitoneal injection of AVT, suggesting that the neurohypophyseal hormone stimulated the release of Sodefrin from the abdominal gland into the water. AVT induced contraction of the excised abdominal gland concentration-dependently, and, again, the V1 receptor antagonist suppressed the AVT-induced contraction. Thus, we concluded that AVT induces the pheromone discharge, acting peripherally on a contractile structure of the abdominal gland. AVT was also found to induce spermatophore deposition in the male kept in the absence of the female. Administration of the V1 receptor blocker to the sexually developed males suppressed the spermatophore deposition. All these results indicate the involvement of AVT in reproductive events acting centrally and peripherally.
Margo Maex - One of the best experts on this subject based on the ideXlab platform.
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multiple independent recruitment of Sodefrin precursor like factors in anuran sexually dimorphic glands
Molecular Biology and Evolution, 2019Co-Authors: Franky Bossuyt, Margo Maex, Sunita Janssenswillen, Lisa M Schulte, Polina Yu Novikova, S D Biju, Yves Van De Peer, Severine Matthijs, Kim RoelantsAbstract:Chemical signaling in animals often plays a central role in eliciting a variety of responses during reproductive interactions between males and females. One of the best-known vertebrate courtship pheromone systems is Sodefrin precursor-like factors (SPFs), a family of two-domain three-finger proteins with a female-receptivity enhancing function, currently only known from salamanders. The oldest divergence between active components in a single salamander species dates back to the Late Paleozoic, indicating that these proteins potentially gained a pheromone function earlier in amphibian evolution. Here, we combined whole transcriptome sequencing, proteomics, histology, and molecular phylogenetics in a comparative approach to investigate SPF occurrence in male breeding glands across the evolutionary tree of anurans (frogs and toads). Our study shows that multiple families of both terrestrially and aquatically reproducing frogs have substantially increased expression levels of SPFs in male breeding glands. This suggests that multiple anuran lineages make use of SPFs to complement acoustic and visual sexual signaling during courtship. Comparative analyses show that anurans independently recruited these proteins each time the gland location on the male’s body allowed efficient transmission of the secretion to the female’s nares.
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exaptation as a mechanism for functional reinforcement of an animal pheromone system
Current Biology, 2018Co-Authors: Margo Maex, Ines Van Bocxlaer, Dag Treer, Paul Proost, Henri De Greve, Franky BossuytAbstract:Summary Animal sex pheromone systems often exist as multicomponent signals [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] to which chemical cues have been added over evolutionary time. Little is known on why and how additional molecules become recruited and conserved in an already functional pheromone system. Here, we investigated the evolutionary trajectory of a series of 15 kDa proteins—termed persuasins—that were co-opted more recently alongside the ancient Sodefrin precursor-like factor (SPF) courtship pheromone system in salamanders [ 9 , 12 ]. Expression, genomic, and molecular phylogenetic analyses show that persuasins originated from a gene that is expressed as a multi-domain protein in internal organs where it has no pheromone function but underwent gene duplication and neofunctionalization. The subsequent evolution combined domain loss and the introduction of a proteolytic cleavage site in the duplicated gene to give rise to two-domain cysteine rich proteins with structural properties similar to SPF pheromones [ 12 ]. An expression shift to the pheromone-producing glands, where expression of persuasins was immediately spatiotemporally synchronized with the already available pheromone system, completed the birth of a new pheromone. Electrostatic forces between members of both protein families likely enhance co-localization and simultaneous activation of different female olfactory neurons, explaining why persuasins immediately had a selective advantage. In line with this, behavioral assays show that persuasins increase female receptivity on their own but also exert a cumulative or synergistic effect in combination with SPF, clearly reinforcing the pheromone system as a whole. Our study reveals molecular remodeling of an existing protein architecture as an evolutionary mechanism for functional reinforcement of animal pheromone systems.
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divergence of species specific protein sex pheromone blends in two related nonhybridizing newts salamandridae
Molecular Ecology, 2018Co-Authors: Dag Treer, Margo Maex, Ines Van Bocxlaer, Paul Proost, Franky BossuytAbstract:In animals that use chemical communication during courtship and reproduction, speciation is often associated with divergence of their sex pheromones. In multicomponent pheromone systems, divergence can be obtained either by adding or deleting components, or by altering the relative contribution of individual components to the mixture. Protein pheromone systems can additionally evolve by amino acid sequence divergence to produce pheromones with a species-specific effect. The Sodefrin precursor-like factor (SPF) pheromone system, a blend of proteins that essentially enhances receptivity in salamanders, has had a long and dynamic evolution of gene duplications, but the mechanisms that govern interspecific divergence and the role they play in reproductive isolation remain elusive. Here, we use transcriptomics and proteomics to characterize the SPF protein repertoire of the alpine newt (Ichthyosaura alpestris), and compare it to the previously identified repertoire of SPF proteins of the palmate newt (Lissotriton helveticus), a related but nonhybridizing species. Subsequent phylogenetic analyses indicate that, despite the availability of multiple SPF gene copies, both species predominantly express the same subset of orthologs. Our study demonstrates that species specificity in the SPF protein pheromone system can be established by gradual sequence divergence of the same set of proteins alone.
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Beyond Sodefrin: evidence for a multi-component pheromone system in the model newt Cynops pyrrhogaster (Salamandridae).
Scientific Reports, 2016Co-Authors: Ines Van Bocxlaer, Margo Maex, Dag Treer, Sunita Janssenswillen, Rik Janssens, Wim Vandebergh, Paul Proost, Franky BossuytAbstract:Sodefrin, a decapeptide isolated from the male dorsal gland of the Japanese fire belly newt Cynops pyrrhogaster, was the first peptide pheromone identified from a vertebrate. The fire belly salamander and Sodefrin have become a model for sex pheromone investigation in aquatically courting salamanders ever since. Subsequent studies in other salamanders identified SPF protein courtship pheromones of around 20 kDa belonging to the same gene-family. Although transcripts of these proteins could be PCR-amplified in Cynops, it is currently unknown whether they effectively use full-length SPF pheromones next to Sodefrin. Here we combined transcriptomics, proteomics and phylogenetics to investigate SPF pheromone use in Cynops pyrrhogaster. Our data show that not Sodefrin transcripts, but multiple SPF transcripts make up the majority of the expression profile in the dorsal gland of this newt. Proteome analyses of water in which a male has been courting confirm that this protein blend is effectively secreted and tail-fanned to the female. By combining phylogenetics and expression data, we show that independent evolutionary lineages of these SPF’s were already expressed in ancestral Cynops species before the origin of Sodefrin. Extant Cynops species continue to use this multi-component pheromone system, consisting of various proteins in addition to a lineage-specific peptide.
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Courtship Pheromone Use in a Model Urodele, the Mexican Axolotl (Ambystoma mexicanum)
Scientific Reports, 2016Co-Authors: Margo Maex, Ines Van Bocxlaer, Anneleen Mortier, Franky BossuytAbstract:Sex pheromones have been shown to constitute a crucial aspect of salamander reproduction. Until now, courtship pheromones of Salamandridae and Plethodontidae have been intensively studied, but information on chemical communication in other urodelan families is essentially lacking. The axolotl ( Ambystoma mexicanum , Ambystomatidae) has a courtship display that suggests a key role for chemical communication in the orchestration of its sexual behavior, but no sex pheromones have yet been characterized from this species. Here we combined whole transcriptome analyses of the male cloaca with proteomic analyses of water in which axolotls were allowed to court to show that male axolotls secrete multiple ca. 20 kDa glycosylated Sodefrin precursor-like factor (SPF) proteins during courtship. In combination with phylogenetic analyses, our data show that the male cloaca essentially secretes a courtship-specific clade of SPF proteins that is orthologous to salamandrid courtship pheromones. In addition, we identified an SPF protein for which no orthologs have been described from other salamanders so far. Overall, our study advocates a central role for SPF proteins during the courtship display of axolotls and adds knowledge on pheromone use in a previously unexplored deep evolutionary branch of salamander evolution.