6 results on '"Rogers, David W."'
Search Results
2. Variation in Preference for a Male Ornament Is Positively Associated with Female Eyespan in the Stalk-Eyed Fly Diasemopsis meigenii
- Author
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Cotton, Samuel, Rogers, David W., Small, Jennifer, Pomainkowski, Andrew, and Fowler, Kevin
- Published
- 2006
- Full Text
- View/download PDF
3. Molecular characterization and evolution of a gene family encoding male-specific reproductive proteins in the African malaria vector Anopheles gambiae
- Author
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Sharakhov Igor V, Masiga Daniel, Morlais Isabelle, George Phillip, Serrao Aurelio, Calzetta Maria, Tammaro Federica, Baldini Francesco, Mancini Emiliano, Rogers David W, Catteruccia Flaminia, and della Torre Alessandra
- Subjects
Evolution ,QH359-425 - Abstract
Abstract Background During copulation, the major Afro-tropical malaria vector Anopheles gambiae s.s. transfers male accessory gland (MAG) proteins to females as a solid mass (i.e. the "mating plug"). These proteins are postulated to function as important modulators of female post-mating responses. To understand the role of selective forces underlying the evolution of these proteins in the A. gambiae complex, we carried out an evolutionary analysis of gene sequence and expression divergence on a pair of paralog genes called AgAcp34A-1 and AgAcp34A-2. These encode MAG-specific proteins which, based on homology with Drosophila, have been hypothesized to play a role in sperm viability and function. Results Genetic analysis of 6 species of the A. gambiae complex revealed the existence of a third paralog (68-78% of identity), that we named AgAcp34A-3. FISH assays showed that this gene maps in the same division (34A) of chromosome-3R as the other two paralogs. In particular, immuno-fluorescence assays targeting the C-terminals of AgAcp34A-2 and AgAcp34A-3 revealed that these two proteins are localized in the posterior part of the MAG and concentrated at the apical portion of the mating plug. When transferred to females, this part of the plug lies in proximity to the duct connecting the spermatheca to the uterus, suggesting a potential role for these proteins in regulating sperm motility. AgAcp34A-3 is more polymorphic than the other two paralogs, possibly because of relaxation of purifying selection. Since both unequal crossing-over and gene conversion likely homogenized the members of this gene family, the interpretation of the evolutionary patterns is not straightforward. Although several haplotypes of the three paralogs are shared by most A. gambiae s.l. species, some fixed species-specific replacements (mainly placed in the N- and C-terminal portions of the secreted peptides) were also observed, suggesting some lineage-specific adaptation. Conclusions Progress in understanding the signaling cascade in the A. gambiae reproductive pathway will elucidate the interaction of this MAG-specific protein family with their female counterparts. This knowledge will allow a better evaluation of the relative importance of genes involved in the reproductive isolation and fertility of A. gambiae species and could help the interpretation of the observed evolutionary patterns.
- Published
- 2011
- Full Text
- View/download PDF
4. Male sexual ornament size is positively associated with reproductive morphology and enhanced fertility in the stalk-eyed fly Teleopsis dalmanni
- Author
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Chapman Tracey, Denniff Matthew, Rogers David W, Fowler Kevin, and Pomiankowski Andrew
- Subjects
Evolution ,QH359-425 - Abstract
Abstract Background Exaggerated male ornaments and displays often evolve in species where males only provide females with ejaculates during reproduction. Although "good genes" arguments are typically invoked to explain this phenomenon, a simpler alternative is possible if variation in male reproductive quality (e.g. sperm number, ejaculate content, mating rate) is an important determinant of female reproductive success. The "phenotype-linked fertility hypothesis" states that female preference for male ornaments or displays has been selected to ensure higher levels of fertility and has driven the evolution of exaggerated male traits. Females of the stalk-eyed fly Teleopsis dalmanni must mate frequently to maintain high levels of fertility and prefer to mate with males exhibiting large eyespan, a condition-dependent sexual ornament. If eyespan indicates male reproductive quality, females could directly increase their reproductive success by mating with males with large eyespan. Here we investigate whether male eyespan indicates accessory gland and testis length, and then ask whether mating with large eyespan males affects female fertility. Results Male eyespan was a better predictor of two key male reproductive traits – accessory gland and testis length – than was body size alone. This positive relationship held true over three levels of increasing environmental stress during the maturation of the adult accessory glands and testes. Furthermore, females housed with a large eyespan male exhibited higher levels of fertility than those with small eyespan males. Conclusion Male eyespan in stalk-eyed flies is subject to strong directional mate preference and is a reliable indicator of male reproductive quality – both because males with larger eyespan have bigger accessory glands and testes, and also as they confer higher fertility on females. Fertility enhancement may have arisen because males with larger eyespan mated more often and/or because they transferred more sperm or other substances per ejaculate. The need to ensure high levels of fertility could thus have been an important selective force in the coevolution of female preference and male eyespan in stalk-eyed flies. Our results support the phenotype-linked fertility hypothesis and suggest that it might be of general importance in explaining the evolution of exaggerated male ornaments and displays in species where males only provide females with ejaculates during reproduction.
- Published
- 2008
- Full Text
- View/download PDF
5. Mating-induced reduction in accessory reproductive organ size in the stalk-eyed fly Cyrtodiopsis dalmanni
- Author
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Fowler Kevin, Chapman Tracey, Rogers David W, and Pomiankowski Andrew
- Subjects
Evolution ,QH359-425 - Abstract
Abstract Background Internal reproductive organ size is an important determinant of male reproductive success. While the response of testis length to variation in the intensity of sperm competition is well documented across many taxa, few studies address the importance of testis size in determining other components of male reproductive success (such as mating frequency) or the significance of size variation in accessory reproductive organs. Accessory gland length, but not testis length, is both phenotypically and genetically correlated with male mating frequency in the stalk-eyed fly Cyrtodiopsis dalmanni. Here we directly manipulate male mating status to investigate the effect of copulation on the size of both the testes and the accessory glands of C. dalmanni. Results Accessory gland length was positively correlated with male mating frequency. Copulation induced a significant decrease in accessory gland size. The size of the accessory glands then recovered slowly over the next 8–48 hours. Neither testis length nor testis area was altered by copulation. Conclusion These results reveal that the time course of accessory gland recovery corresponds to field observations of mating behaviour and suggest that accessory gland size may limit male mating frequency in C. dalmanni.
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- 2005
- Full Text
- View/download PDF
6. BMC EVOLUTIONARY BIOLOGY
- Author
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Mancini, Emiliano, Francesco, Baldini, Tammaro, Federica, Calzetta, Maria, Aurelio, Serrao, George, Phillip, George, P., Isabelle, Morlais, Sharakov, I. V., Daniel, Masiga, Sharakhov, Igor V., Rogers, David W., Flaminia, Catteruccia, DELLA TORRE, Alessandra, Laboratorio Pasteur [Istituto Pasteur-Fondazione Cenci Bolognetti, Rome], Institut Pasteur, Fondation Cenci Bolognetti - Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Università degli Studi di Perugia (UNIPG), Virginia Tech [Blacksburg], Laboratoire d’Entomologie Médicale [Yaounde, Cameroon], Institut de Recherche pour le Développement (IRD)-Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, International Centre of Insect Physiology and Ecology (ICIPE), ICIPE, Max Planck Institute for Evolutionary Biology, Max-Planck-Gesellschaft, Imperial College London, The work was supported by EC FP7 HEALTH Collaborative Project 'MALVECBLOK' (Grant ID: 223601) to AdT and FC (Grant ID: 223601). The European Research Council has provided financial support under the EC FP7 ERC Starting Grant 'AnoRep' to FC (Grant ID: 260897). FISH experiments were funded by National Institutes of Health (Grant ID: 5R21AI081023). FC was supported by the Medical Research Council Career Development Award (Agreement ID: 78415, File number: G0600062) and EM by the Ateneo Federato delle Scienze delle Politiche Pubbliche e Sanitarie, Sapienza University of Rome and by C.I.R.M. - Italian Malaria Network., We thank F. Santolamazza for helping in A. gambiae species identification, F. Lombardo for technical help with cDNA preparation and S. Demin for explaining the image processing procedure. We thank our colleagues who allowed this study by providing samples, in particular: D. Charlwood (DBL, Fredriksberg, Denmark), J. Pinto (CMDT, Lisbon, Portugal), H. Ranson and M. Donnelly (LSTM, Liverpool, UK) and S. Torr and G. Vale (University of Greenwich, UK). We are also grateful to J. Bielawski, B. Caputo, M.K. Lawniczak, T. Lehmann, E. Levashina, V. Petrarca, J. Thailayil and A. Tramontano's research group for fruitful discussions., Mancini, Emiliano, Francesco, Baldini, Federica, Tammaro, Maria, Calzetta, Aurelio, Serrao, George, Phillip, P., George, Isabelle, Morlai, I. V., Sharakov, Daniel, Masiga, Igor V., Sharakhov, David W., Roger, Flaminia, Catteruccia, Alessandra Della, Torre, Entomology, and Università degli Studi di Perugia = University of Perugia (UNIPG)
- Subjects
0106 biological sciences ,Male ,MESH: Insect Hormones/genetics ,MESH: Multigene Family/genetics ,Anopheles gambiae ,MESH: Microscopy, Fluorescence ,01 natural sciences ,Homology (biology) ,Gene duplication ,RAPID EVOLUTION ,Drosophila Proteins ,MESH: Drosophila Proteins/genetics ,MESH: Animals ,MESH: In Situ Hybridization, Fluorescence ,MESH: Models, Genetic ,In Situ Hybridization, Fluorescence ,Genetics ,Genetics & Heredity ,0303 health sciences ,Chromosome Mapping ,MESH: Peptides/genetics ,3. Good health ,ADAPTIVE EVOLUTION ,GENOME ,ARABIENSIS ,MESH: Anopheles/genetics ,duplication ,Insect Hormones ,Multigene Family ,Intercellular Signaling Peptides and Proteins ,Female ,ACCESSORY-GLAND PROTEINS ,Drosophila melanogaster ,MESH: Haplotypes/genetics ,Research Article ,MESH: Computational Biology ,Protein family ,MESH: Bayes Theorem ,Blotting, Western ,malaria ,Biology ,010603 evolutionary biology ,[SDV.BDLR.RS]Life Sciences [q-bio]/Reproductive Biology/Sexual reproduction ,Evolution, Molecular ,03 medical and health sciences ,MESH: Insect Hormones/metabolism ,DNA POLYMORPHISM ,Anopheles ,MESH: Evolution, Molecular ,evolution ,QH359-425 ,Gene family ,Animals ,MESH: Blotting, Western ,Gene conversion ,POPULATION-GENETICS ,Mating plug ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Evolutionary Biology ,COMPLEX ,Models, Genetic ,Computational Biology ,Bayes Theorem ,biology.organism_classification ,MESH: Male ,[SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics ,Haplotypes ,Microscopy, Fluorescence ,Evolutionary biology ,DROSOPHILA-MELANOGASTER ,CONSECUTIVE MATINGS ,Peptides ,MESH: Chromosome Mapping ,MESH: Female - Abstract
Background During copulation, the major Afro-tropical malaria vector Anopheles gambiae s.s. transfers male accessory gland (MAG) proteins to females as a solid mass (i.e. the "mating plug"). These proteins are postulated to function as important modulators of female post-mating responses. To understand the role of selective forces underlying the evolution of these proteins in the A. gambiae complex, we carried out an evolutionary analysis of gene sequence and expression divergence on a pair of paralog genes called AgAcp34A-1 and AgAcp34A-2. These encode MAG-specific proteins which, based on homology with Drosophila, have been hypothesized to play a role in sperm viability and function. Results Genetic analysis of 6 species of the A. gambiae complex revealed the existence of a third paralog (68-78% of identity), that we named AgAcp34A-3. FISH assays showed that this gene maps in the same division (34A) of chromosome-3R as the other two paralogs. In particular, immuno-fluorescence assays targeting the C-terminals of AgAcp34A-2 and AgAcp34A-3 revealed that these two proteins are localized in the posterior part of the MAG and concentrated at the apical portion of the mating plug. When transferred to females, this part of the plug lies in proximity to the duct connecting the spermatheca to the uterus, suggesting a potential role for these proteins in regulating sperm motility. AgAcp34A-3 is more polymorphic than the other two paralogs, possibly because of relaxation of purifying selection. Since both unequal crossing-over and gene conversion likely homogenized the members of this gene family, the interpretation of the evolutionary patterns is not straightforward. Although several haplotypes of the three paralogs are shared by most A. gambiae s.l. species, some fixed species-specific replacements (mainly placed in the N- and C-terminal portions of the secreted peptides) were also observed, suggesting some lineage-specific adaptation. Conclusions Progress in understanding the signaling cascade in the A. gambiae reproductive pathway will elucidate the interaction of this MAG-specific protein family with their female counterparts. This knowledge will allow a better evaluation of the relative importance of genes involved in the reproductive isolation and fertility of A. gambiae species and could help the interpretation of the observed evolutionary patterns.
- Published
- 2011
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