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Nicola Saino - One of the best experts on this subject based on the ideXlab platform.
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smrt long reads and direct label and stain optical maps allow the generation of a high quality genome assembly for the european Barn Swallow hirundo rustica rustica
GigaScience, 2019Co-Authors: Giulio Formenti, Luca Canova, Andrea Bonisolialquati, David S Horner, Kees-jan Francoijs, Matteo Chiara, Lucy Poveda, L Gianfranceschi, Nicola SainoAbstract:Background: The Barn Swallow (Hirundo rustica) is a migratory bird that has been the focus of a large number of ecological, behavioral, and genetic studies. To facilitate further population genetics and genomic studies, we present a reference genome assembly for the European subspecies (H. r. rustica). Findings: As part of the Genome10K effort on generating high-quality vertebrate genomes (Vertebrate Genomes Project), we have assembled a highly contiguous genome assembly using single molecule real-time (SMRT) DNA sequencing and several Bionano optical map technologies. We compared and integrated optical maps derived from both the Nick, Label, Repair, and Stain technology and from the Direct Label and Stain (DLS) technology. As proposed by Bionano, DLS more than doubled the scaffold N50 with respect to the nickase. The dual enzyme hybrid scaffold led to a further marginal increase in scaffold N50 and an overall increase of confidence in the scaffolds. After removal of haplotigs, the final assembly is approximately 1.21 Gbp in size, with a scaffold N50 value of more than 25.95 Mbp. Conclusions: This high-quality genome assembly represents a valuable resource for future studies of population genetics and genomics in the Barn Swallow and for studies concerning the evolution of avian genomes. It also represents one of the very first genomes assembled by combining SMRT long-read sequencing with the new Bionano DLS technology for scaffolding. The quality of this assembly demonstrates the potential of this methodology to substantially increase the contiguity of genome assemblies.
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association between extra pair paternity and nestling sex and condition in the Barn Swallow
Behavioral Ecology and Sociobiology, 2018Co-Authors: Alessandra Costanzo, Manuela Caprioli, Roberto Ambrosini, Emanuele Gatti, Andrea Romano, Diego Rubolini, Marco Parolini, L Gianfranceschi, Nicola SainoAbstract:Parents should differentially allocate resources to the production of offspring of either sex depending on their expected fitness return. In sexually promiscuous females, offspring sex ratio should be affected by the sexual attractiveness of biological fathers because sons, but not daughters, will benefit from inheriting genes for sexual attractiveness. Females may acquire benefits for the offspring if the extra-pair male is of superior genetic quality as compared to the social mate, if it carries compatible genes or genes that enhance offspring genetic diversity. If sexually selected ornaments reflect male quality, extra-pair offspring should be more frequently males and of higher quality compared to their half-siblings. Furthermore, the probability of extra-pair offspring to be male should increase with an increasing difference in sexual ornamentation between the extra-pair and the social mate. In this study, we tested if Barn Swallow offspring sex ratio depends on paternity and on sexual ornamentation of the extra-pair father, and whether paternity predicts offspring phenotypic quality. The results partially fulfilled our prediction. We did not provide support for the hypothesis of a differential sex allocation to the production of male offspring by promiscuous females, both at the individual and at the within-brood level. Moreover, the difference in the ornamentation of the extra-pair and the social male did not affect the sex ratio of individual offspring. However, in accordance with the good genes and the genetic compatibility hypotheses, extra-pair offspring were of superior quality as compared to their half-sibling, in terms of body size and feather growth. In sexually promiscuous species, females should differentially allocate resources to the production of offspring of either sex depending on paternity or sexual ornamentation of the social or the extra-pair mate. Moreover, extra-pair offspring may be of superior quality compared to their within-pair half-siblings. In the present study of the Barn Swallow, paternity and the differences in sexual ornamentation between the social and the extra-pair mate did not affect offspring sex ratio. In addition, according to the good genes and the genetic compatibility hypotheses, we found that extra-pair offspring are of superior quality as compared to their within-pair siblings. Despite we failed to provide support to the sex allocation theory, the present study emphasizes the importance of “negative” results to better estimate the generality of the occurrence of adaptive sex allocation strategies in the context of sexual selection studies.
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Barn Swallow antipredator behavior covaries with melanic coloration and predicts survival
Behavioral Ecology, 2018Co-Authors: Alessandra Costanzo, Luca Canova, Manuela Caprioli, Roberto Ambrosini, Andrea Romano, Diego Rubolini, Marco Parolini, Margherita Corti, Nicola SainoAbstract:Conspecific individuals often consistently differ in their behavioral responses to specific exogenous stimuli. Such individual differences in "personality" have been shown to be heritable, suggesting that selection maintains variation in personality. However, survival selection on a major personality trait, antipredator behavior, and its sex-dependency, has been seldom measured in the wild. Here, we found that yearling Barn Swallows (Hirundo rustica) showed consistency in agitation upon repeated exposure to a restraint-handling protocol, probably reflecting antipredator behavior, and that males were more agitated than females. Females that exhibited larger antipredator behavior were more likely to survive until the next breeding season with no variation among 3 study years nor across 7 breeding colonies, suggesting that variation in antipredator behavior is not maintained by spatiotemporal variation in viability selection on antipredator behavior. In both sexes, the intensity of melanin-based ventral plumage coloration positively covaried with antipredator behavior, consistent with previous observations from diverse vertebrate species. In some Barn Swallow populations, male coloration is targeted by directional intersexual selection, suggesting that melanization signals antipredator behavior to prospecting females and that sexual selection for antipredator behavior, or other correlated personality traits, can drive the evolution of sexual color dimorphism in Barn Swallows. Thus, we showed that viability selection occurs on antipredator behavior and that spatiotemporal variation in selection has no major role in promoting variation in antipredator behavior. More melanized individuals were more agitated, implying that melanization may signal personality in a sexual communication context in a species where male coloration is an epigamic trait.
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smrt long read sequencing and direct label and stain optical maps allow the generation of a high quality genome assembly for the european Barn Swallow hirundo rustica rustica
bioRxiv, 2018Co-Authors: Giulio Formenti, Luca Canova, Andrea Bonisolialquati, Luca Enrico Angelo Gianfranceschi, David S Horner, Kees-jan Francoijs, Matteo Chiara, Lucy Poveda, Nicola SainoAbstract:Background: The Barn Swallow (Hirundo rustica) is a migratory bird that has been the focus of a large number of ecological, behavioural and genetic studies. To facilitate further population genetics and genomic studies, here we present a reference genome assembly for the European subspecies (Hirundo rustica rustica). Findings: As part of the Genome10K (G10K) effort on generating high quality vertebrate genomes, we have assembled a highly contiguous genome assembly using Single Molecule Real-Time (SMRT) DNA sequencing and several Bionano optical map technologies. We compared and integrated optical maps derived both from the Nick, Label, Repair and Stain and from the Direct Label and Stain technologies. As proposed by Bionano, the direct labelling system more than doubled the scaffold N50 with respect to the nickase system. The dual enzyme hybrid scaffold led to a further marginal increase in scaffold N50 and an overall increase of confidence in scaffolds. After removal of haplotigs, the final assembly is approximately 1.21 Gbp in size, with a scaffold N50 value of over 25.95 Mbp. Conclusions: This high-quality genome assembly represents a valuable resource for further studies of population genetics of the Barn Swallow and for studies concerning the evolution of avian genomes. It also represents one of the very first genomes assembled combining SMRT long-read sequencing with the new Bionano Direct Label and Stain technology for scaffolding, highlighting the potential of this methodology to contribute to substantial increases in the contiguity of genome assemblies.
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smrt long read sequencing and direct label and stain optical maps allow the generation of a high quality genome assembly for the european Barn Swallow hirundo rustica rustica
bioRxiv, 2018Co-Authors: Giulio Formenti, Luca Canova, Andrea Bonisolialquati, David S Horner, Kees-jan Francoijs, Matteo Chiara, Lucy Poveda, L Gianfranceschi, Nicola SainoAbstract:Background: The Barn Swallow (Hirundo rustica) is a migratory bird that has been the focus of a large number of ecological, behavioural and genetic studies. To facilitate further population genetics and genomic studies, here we present a high-quality genome for the European subspecies (Hirundo rustica rustica). Findings: We have assembled a highly contiguous genome sequence using Single Molecule Real-Time (SMRT) DNA sequencing and Bionano optical maps. We compared and integrated optical maps derived both from the Nick, Label, Repair and Stain and from Direct Label and Stain technologies. For our SMRT-only assembly, the direct labelling system more than doubled the assembly N50 with respect to the nickase system. The dual enzyme hybrid scaffold led to a further marginal increase in scaffold N50 and an overall increase of confidence in scaffolds. After removal of haplotigs, the final assembly is approximately 1.21 Gbp in size, with an N50 value of over 25.95 Mbp, representing an improvement in N50 of over 650 fold with respect to a previously reported assembly based on paired-end short read data. Conclusions: This high-quality genome assembly represents a valuable resource for further studies of population genetics of the Barn Swallow and for studies concerning the evolution of avian genomes. It also represents the first genome assembled combining SMRT sequencing with the new Bionano Direct Label and Stain technology for scaffolding, highlighting the potential of this methodology to contribute to substantial increases in the contiguity of genome assemblies.
Anders Pape Moller - One of the best experts on this subject based on the ideXlab platform.
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viability and expression of sexual ornaments in the Barn Swallow hirundo rustica a meta analysis
Journal of Evolutionary Biology, 2017Co-Authors: Andrea Romano, Nicola Saino, Anders Pape MollerAbstract:: Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta-analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the Barn Swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084-0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.
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Viability and expression of sexual ornaments in the Barn Swallow Hirundo rustica: a meta‐analysis
Journal of Evolutionary Biology, 2017Co-Authors: Andrea Romano, Nicola Saino, Anders Pape MollerAbstract:Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the Barn Swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.
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intensity of melanin based color and risk of predation in the Barn Swallow hirundo rustica
Acta Ornithologica, 2014Co-Authors: Ismael Galvan, Jan Tottrup Nielsen, Anders Pape MollerAbstract:Abstract. Predators are supposed to exert strong selection pressures on their prey, especially when phenotypic traits such as secondary sexual characters promote mating success at the expense of costs in terms of natural selection. Signaling theory predicts that individuals of superior phenotypic quality will enjoy an advantage in term of mating success, but also in term of natural selection, if such individuals are in prime condition both before and after development of exaggerated secondary sexual characters. We tested this prediction in the Barn Swallow Hirundo rustica being preyed upon by the Eurasian Sparrowhawk Accipiter nisus, using extensive samples of feathers from prey and non-prey. We measured tail length and coloration of outermost tail feathers in the black area of the proximal and distal part of tail feathers, but also the white spot of the tail feathers. Prey had significantly less dark distal, but not proximal parts of their tails, while there was no difference in coloration of the white s...
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eggshell bacterial load is related to antimicrobial properties of feathers lining Barn Swallow nests
Microbial Ecology, 2014Co-Authors: Juan Manuel Peraltasanchez, Juan José Soler, Antonio M Martinplatero, Rob Knight, Manuel Martinezbueno, Anders Pape MollerAbstract:The use of feathers to line bird’s nests has traditionally been interpreted as having a thermoregulatory function. Feather-degrading bacteria growing on feathers lining nests may have antimicrobial properties, which may provide an additional benefit to lining nests with feathers. We test the hypothesis that the production of antimicrobial substances by feather bacteria affects the microbiological environment of the nest, and therefore the bacterial density on eggshells and, indirectly, hatching success. These effects would be expected to differ between nests lined with pigmented and white feathers, because bacteria grow differently on feathers of different colors. We experimentally manipulated the composition of pigmented and unpigmented feathers in nests of the Barn Swallow (Hirundo rustica) and studied the antimicrobial properties against the keratin-degrading bacterium Bacillus licheniformis of bacteria isolated from feathers of each color. Analyzed feathers were collected at the end of the incubation period, and antimicrobial activity was defined as the proportion of bacteria from the feathers that produce antibacterial substances effective against B. licheniformis. Our experimental manipulation affected antimicrobial activity, which was higher in nests with only white feathers at the beginning of incubation. Moreover, white feathers showed higher antimicrobial activity than black ones. Interestingly, antimicrobial activity in feathers of one of the colors correlated negatively with bacterial density on feather of the opposite color. Finally, antimicrobial activity of white feathers was negatively related to eggshell bacterial load. These results suggest that antimicrobial properties of feathers in general and of white feathers in particular affect the bacterial environment in nests. This environment in turn affects the bacterial load on eggshells, which may affect hatching success.
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immune and stress responses covary with melanin based coloration in the Barn Swallow
Evolutionary Biology-new York, 2013Co-Authors: Nicola Saino, Luca Canova, Diego Rubolini, Alessandra Costanzo, Alexandre Roulin, Anders Pape MollerAbstract:Eumelanin and pheomelanin are the main endogenous pigments in animals and melanin-based coloration has multiple functions. Melanization is associated with major life-history traits, including immune and stress response, possibly because of pleiotropic effects of genes that control melanogenesis. The net effects on pheo- versus eumelanization and other life-history traits may depend on the antagonistic effects of the genes that trigger the biosynthesis of either melanin form. Covariation between melanin-based pigmentation and fitness traits enforced by pleiotropic genes has major evolutionary implications particularly for socio-sexual communication. However, evidence from non-model organisms in the wild is limited to very few species. Here, we tested the hypothesis that melanin-based coloration of Barn Swallow (Hirundo rustica) throat and belly feathers covaries with acquired immunity and activation of the hypothalamic–pituitary–adrenal (HPA) axis, as gauged by corticosterone plasma levels. Individuals of both sexes with darker brownish belly feathers had weaker humoral immune response, while darker males had higher circulating corticosterone levels only when parental workload was experimentally reduced. Because color of belly feathers depends on both eu- and pheomelanin, and its darkness decreases with an increase in the concentration of eu- relative to pheomelanin, these results are consistent with our expectation that relatively more eu- than pheomelanized individuals have better immune response and smaller activation of the HPA-axis. Covariation of immune and stress response arose for belly but not throat feather color, suggesting that any function of color as a signal of individual quality or of alternative life-history strategies depends on plumage region.
Roberto Ambrosini - One of the best experts on this subject based on the ideXlab platform.
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association between extra pair paternity and nestling sex and condition in the Barn Swallow
Behavioral Ecology and Sociobiology, 2018Co-Authors: Alessandra Costanzo, Manuela Caprioli, Roberto Ambrosini, Emanuele Gatti, Andrea Romano, Diego Rubolini, Marco Parolini, L Gianfranceschi, Nicola SainoAbstract:Parents should differentially allocate resources to the production of offspring of either sex depending on their expected fitness return. In sexually promiscuous females, offspring sex ratio should be affected by the sexual attractiveness of biological fathers because sons, but not daughters, will benefit from inheriting genes for sexual attractiveness. Females may acquire benefits for the offspring if the extra-pair male is of superior genetic quality as compared to the social mate, if it carries compatible genes or genes that enhance offspring genetic diversity. If sexually selected ornaments reflect male quality, extra-pair offspring should be more frequently males and of higher quality compared to their half-siblings. Furthermore, the probability of extra-pair offspring to be male should increase with an increasing difference in sexual ornamentation between the extra-pair and the social mate. In this study, we tested if Barn Swallow offspring sex ratio depends on paternity and on sexual ornamentation of the extra-pair father, and whether paternity predicts offspring phenotypic quality. The results partially fulfilled our prediction. We did not provide support for the hypothesis of a differential sex allocation to the production of male offspring by promiscuous females, both at the individual and at the within-brood level. Moreover, the difference in the ornamentation of the extra-pair and the social male did not affect the sex ratio of individual offspring. However, in accordance with the good genes and the genetic compatibility hypotheses, extra-pair offspring were of superior quality as compared to their half-sibling, in terms of body size and feather growth. In sexually promiscuous species, females should differentially allocate resources to the production of offspring of either sex depending on paternity or sexual ornamentation of the social or the extra-pair mate. Moreover, extra-pair offspring may be of superior quality compared to their within-pair half-siblings. In the present study of the Barn Swallow, paternity and the differences in sexual ornamentation between the social and the extra-pair mate did not affect offspring sex ratio. In addition, according to the good genes and the genetic compatibility hypotheses, we found that extra-pair offspring are of superior quality as compared to their within-pair siblings. Despite we failed to provide support to the sex allocation theory, the present study emphasizes the importance of “negative” results to better estimate the generality of the occurrence of adaptive sex allocation strategies in the context of sexual selection studies.
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Barn Swallow antipredator behavior covaries with melanic coloration and predicts survival
Behavioral Ecology, 2018Co-Authors: Alessandra Costanzo, Luca Canova, Manuela Caprioli, Roberto Ambrosini, Andrea Romano, Diego Rubolini, Marco Parolini, Margherita Corti, Nicola SainoAbstract:Conspecific individuals often consistently differ in their behavioral responses to specific exogenous stimuli. Such individual differences in "personality" have been shown to be heritable, suggesting that selection maintains variation in personality. However, survival selection on a major personality trait, antipredator behavior, and its sex-dependency, has been seldom measured in the wild. Here, we found that yearling Barn Swallows (Hirundo rustica) showed consistency in agitation upon repeated exposure to a restraint-handling protocol, probably reflecting antipredator behavior, and that males were more agitated than females. Females that exhibited larger antipredator behavior were more likely to survive until the next breeding season with no variation among 3 study years nor across 7 breeding colonies, suggesting that variation in antipredator behavior is not maintained by spatiotemporal variation in viability selection on antipredator behavior. In both sexes, the intensity of melanin-based ventral plumage coloration positively covaried with antipredator behavior, consistent with previous observations from diverse vertebrate species. In some Barn Swallow populations, male coloration is targeted by directional intersexual selection, suggesting that melanization signals antipredator behavior to prospecting females and that sexual selection for antipredator behavior, or other correlated personality traits, can drive the evolution of sexual color dimorphism in Barn Swallows. Thus, we showed that viability selection occurs on antipredator behavior and that spatiotemporal variation in selection has no major role in promoting variation in antipredator behavior. More melanized individuals were more agitated, implying that melanization may signal personality in a sexual communication context in a species where male coloration is an epigamic trait.
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better surviving Barn Swallow mothers produce more and better surviving sons
Evolution, 2016Co-Authors: Andrea Romano, Manuela Caprioli, Roberto Ambrosini, Diego Rubolini, Marco Parolini, Alessandra Costanzo, Nicola SainoAbstract:Sex allocation theory predicts that parents are selected to bias their progeny sex ratio (SR) toward the sex that will benefit the most from parental quality. Because parental quality may differentially affect survival of sons and daughters, a pivotal test of the adaptive value of SR adjustment is whether parents overproduce offspring of the sex that accrues larger fitness advantages from high parental quality. However, this crucial test of the long-term fitness consequences of sex allocation decisions has seldom been performed. In this study of the Barn Swallow (Hirundo rustica), we showed a positive correlation between the proportion of sons and maternal annual survival. We then experimentally demonstrated that this association did not depend on the differential costs of rearing offspring of either sex. Finally, we showed that maternal lifespan positively predicted lifespan of sons but not of daughters. Because in Barn Swallows lifespan is a strong determinant of lifetime reproductive success, the results suggest that mothers overproduce offspring of the sex that benefits the most from maternal quality. Hence, irrespective of mechanisms causing the SR bias and mother-son covariation in lifespan, we provide strong evidence that sex allocation decisions of mothers can highly impact on their lifetime fitness.
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clock gene polymorphism and scheduling of migration a geolocator study of the Barn Swallow hirundo rustica
Scientific Reports, 2015Co-Authors: Gaia Bazzi, Manuela Caprioli, Roberto Ambrosini, Emanuele Gatti, Andrea Romano, Alessandra Costanzo, Felix Liechti, L Gianfranceschi, Stefano Podofillini, Maria RomanòAbstract:Circannual rhythms often rely on endogenous seasonal photoperiodic timers involving ‘clock’ genes, and Clock gene polymorphism has been associated to variation in phenology in some bird species. In the long-distance migratory Barn Swallow Hirundo rustica, individuals bearing the rare Clock allele with the largest number of C-terminal polyglutamine repeats found in this species (Q8) show a delayed reproduction and moult later. We explored the association between Clock polymorphism and migration scheduling, as gauged by light-level geolocators, in two Barn Swallow populations (Switzerland; Po Plain, Italy). Genetic polymorphism was low: 91% of the 64 individuals tracked year-round were Q7/Q7 homozygotes. We compared the phenology of the rare genotypes with the phenotypic distribution of Q7/Q7 homozygotes within each population. In Switzerland, compared to Q7/Q7, two Q6/Q7 males departed earlier from the wintering grounds and arrived earlier to their colony in spring, while a single Q7/Q8 female was delayed for both phenophases. On the other hand, in the Po Plain, three Q6/Q7 individuals had a similar phenology compared to Q7/Q7. The Swiss data are suggestive for a role of genetic polymorphism at a candidate phenological gene in shaping migration traits, and support the idea that Clock polymorphism underlies phenological variation in birds.
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viability is associated with melanin based coloration in the Barn Swallow hirundo rustica
PLOS ONE, 2013Co-Authors: Nicola Saino, Luca Canova, Manuela Caprioli, Roberto Ambrosini, Diego Rubolini, Maria Romanò, Alessandra Costanzo, Aldo Milzani, Graziano Colombo, Kazumasa WakamatsuAbstract:Pigmentation of body surface in animals can have multiple determinants and accomplish diverse functions. Eumelanin and pheomelanin are the main animal pigments, being responsible of yellow, brownish-red and black hues, and have partly common biosynthetic pathways. Many populations of vertebrates show individual variation in melanism, putatively with large heritable component. Genes responsible for eu- or pheomelanogenesis have pleiotropic but contrasting effects on life-history traits, explaining the patterns of covariation observed between melanization and physiology (e.g. immunity and stress response), sexual behavior and other characters in diverse taxa. Yet, very few studies in the wild have investigated if eu- and pheomelanization predict major fitness traits like viability or fecundity. In this correlative study, by contrasting adult Barn Swallows (Hirundo rustica) matched for age, sex, breeding site, and year and date of sampling, we show that males but not females that survived until the next year had paler, relatively more eu- than pheomelanic pigmentation of ventral body feathers. Better performance of individuals that allocate relatively more to eumelanogenesis was expected based on previous evidence on covariation between eumelanic pigmentation and specific traits related to immunity and susceptibility to stress. However, together with the evidence of no covariation between viability and melanization among females, this finding raises the question of the mechanisms that maintain variation in genes for melanogenesis. We discuss the possibility that eu- and pheomelanization are under contrasting viability and sexual selection, as suggested by larger breeding and sperm competition success of darker males from other Barn Swallow subspecies.
Florentino De Lope - One of the best experts on this subject based on the ideXlab platform.
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variation in sperm morphometry and sperm competition among Barn Swallow hirundo rustica populations
Behavioral Ecology and Sociobiology, 2013Co-Authors: Terje Laskemoen, Andrea Bonisolialquati, Jaroslav Cepák, Ignacio G Hermosell, Lars Erik Johannessen, Florentino De Lope, Oddmund Kleven, Tomas Albrecht, Alfonso MarzalAbstract:Spermatozoa vary greatly in size and shape among species across the animal kingdom. Postcopulatory sexual selection is thought to be the major evolutionary force driving this diversity. In contrast, less is known about how sperm size varies among populations of the same species. Here, we investigate geographic variation in sperm size in Barn Swallows Hirundo rustica, a socially monogamous passerine with a wide Holarctic breeding distribution. We included samples from seven populations and three subspecies: five populations of ssp. rustica in Europe (Czech, Italy, Norway, Spain, and Ukraine), one population of ssp. transitiva in Israel, and one population of ssp. erythrogaster in Canada. All sperm traits (head length, midpiece length, tail length, and total length) varied significantly among populations. The variation among the European rustica populations was much lower than the differences among subspecies, indicating that sperm traits reflect phylogenetic distance. We also performed a test of the relationship between the coefficient of between-male variation in total sperm length and extrapair paternity levels across different populations within a species. Recent studies have found a strong negative relationship between sperm size variation and extrapair paternity among species. Here, we show a similar negative relationship among six Barn Swallow populations, which suggests that the variance in male sperm length in a population is shaped by the strength of stabilizing postcopulatory sexual selection.
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variation in sperm morphometry and sperm competition among Barn Swallow hirundo rustica populations
Behavioral Ecology and Sociobiology, 2013Co-Authors: Terje Laskemoen, Andrea Bonisolialquati, Jaroslav Cepák, Ignacio G Hermosell, Lars Erik Johannessen, Florentino De Lope, Oddmund Kleven, Tomas Albrecht, Alfonso MarzalAbstract:Spermatozoa vary greatly in size and shape among species across the animal kingdom. Postcopulatory sexual selection is thought to be the major evolutionary force driving this diversity. In contrast, less is known about how sperm size varies among populations of the same species. Here, we investigate geographic variation in sperm size in Barn Swallows Hirundo rustica, a socially monogamous passerine with a wide Holarctic breeding distribution. We included samples from seven populations and three subspecies: five populations of ssp. rustica in Europe (Czech, Italy, Norway, Spain, and Ukraine), one population of ssp. transitiva in Israel, and one population of ssp. erythrogaster in Canada. All sperm traits (head length, midpiece length, tail length, and total length) varied significantly among populations. The variation among the European rustica populations was much lower than the differences among subspecies, indicating that sperm traits reflect phylogenetic distance. We also performed a test of the relationship between the coefficient of between-male variation in total sperm length and extrapair paternity levels across different populations within a species. Recent studies have found a strong negative relationship between sperm size variation and extrapair paternity among species. Here, we show a similar negative relationship among six Barn Swallow populations, which suggests that the variance in male sperm length in a population is shaped by the strength of stabilizing postcopulatory sexual selection.
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yolk androgens in the Barn Swallow hirundo rustica a test of some adaptive hypotheses
Journal of Evolutionary Biology, 2006Co-Authors: Paola Ninni, Andre Lacroix, Claire Tirard, Alfonso Marzal, Florentino De Lope, Pape A MollerAbstract:Maternal effects such as androgen in avian eggs can mediate evolutionary responses to selection, allowing manipulation of offspring phenotype and promoting trans-generational adaptive effects. We tested the predictions of two adaptive hypotheses that have been proposed to explain female variation in yolk androgen allocation in birds, using the Barn Swallow Hirundo rustica as a model. We found no support for the first hypothesis proposing that yolk androgen varies as a function of breeding density in order to prepare offspring for different breeding densities. However, we found experimental support for the hypothesis that female yolk androgen allocation depends on mate attractiveness and that it constitutes an example of differential allocation. Females increased the concentration of androgens in their eggs when mated to males with experimentally elongated tails. Female phenotypic quality as measured by arrival date and clutch size was positively related to egg androgen concentration, consistent with the hypothesis that this is a costly investment, constrained by female condition. We found correlative evidence of a direct relationship between egg androgen concentration and performance of offspring as measured by mass increase.
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Yolk androgens in the Barn Swallow (Hirundo rustica): a test of some adaptive hypotheses
Journal of Evolutionary Biology, 2006Co-Authors: Diego Gil, Andre Lacroix, Claire Tirard, Alfonso Marzal, Florentino De Lope, Paola Ninni, A. Pape MollerAbstract:UNCORRECTED PROOF Maternal effects such as androgen in avian eggs can mediate evolutionary responses to selection, allowing manipulation of offspring phenotype and promoting trans-generational adaptive effects. We tested the predictions of two adaptive hypotheses that have been proposed to explain female variation in yolk androgen allocation in birds, using the Barn Swallow Hirundo rustica as a model. We found no support for the first hypothesis proposing that yolk androgen varies as a function of breeding density in order to prepare offspring for different breeding densities. However, we found experimental support for the hypothesis that female yolk androgen allocation depends on mate attractiveness and that it constitutes an example of differential allocation. Females increased the concentration of androgens in their eggs when mated to males with experimentally elongated tails. Female phenotypic quality in terms of arrival date and clutch size was positively related to egg androgen concentration, consistent with the hypothesis that this is a costly investment, constrained by female condition. We found correlative evidence of a direct relationship between egg androgen concentration and performance of offspring as measured by mass increase.
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Age-dependent health status and song characteristics in the Barn Swallow
Behavioral Ecology, 2005Co-Authors: László Z. Garamszegi, Dieter Heylen, Anders Møller, Marcel Eens, Florentino De LopeAbstract:Bird song has been hypothesized to evolve, partly, to signal health status of males, and song features should therefore correlate with parasite load. Immune function, parasitism, and secondary sexual characters can, however, differ between age classes, and any apparent relationship between song and parasite loads can be the result of systematic age effects. We tested for an age-dependent relationship between sexually selected characters and measures of parasitism in a Spanish population of the Barn Swallow Hirundo rustica. A comparison across age classes revealed that chewing lice load, song duration, mean peak amplitude frequency of songs, and tail length differed significantly between yearlings and adults. In a longitudinal analysis, we found significant evidence for mean peak amplitude frequency of songs, tail length and chewing louse parasitism, and a nonsignificant tendency for song duration to change with age of an individual. We found a significant association between song duration and chewing louse load and between hematocrit and peak amplitude frequency of the rattle, the typical harsh terminal syllable. In tests for associations between song traits and health status, while controlling for age, age and chewing louse load were independently related to song duration. We found a significant relationship between pairing success and song duration, implying that females may use this song trait in their choice of parasite-free males. Although the song of the Barn Swallow may provide information about both male age and parasite resistance, signaling of health status appears to be independent of age effects, in accordance with the theory of parasite-mediated sexual selection, suggesting that male signals can be used as reliable indicators of parasitism.
Andrea Romano - One of the best experts on this subject based on the ideXlab platform.
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association between extra pair paternity and nestling sex and condition in the Barn Swallow
Behavioral Ecology and Sociobiology, 2018Co-Authors: Alessandra Costanzo, Manuela Caprioli, Roberto Ambrosini, Emanuele Gatti, Andrea Romano, Diego Rubolini, Marco Parolini, L Gianfranceschi, Nicola SainoAbstract:Parents should differentially allocate resources to the production of offspring of either sex depending on their expected fitness return. In sexually promiscuous females, offspring sex ratio should be affected by the sexual attractiveness of biological fathers because sons, but not daughters, will benefit from inheriting genes for sexual attractiveness. Females may acquire benefits for the offspring if the extra-pair male is of superior genetic quality as compared to the social mate, if it carries compatible genes or genes that enhance offspring genetic diversity. If sexually selected ornaments reflect male quality, extra-pair offspring should be more frequently males and of higher quality compared to their half-siblings. Furthermore, the probability of extra-pair offspring to be male should increase with an increasing difference in sexual ornamentation between the extra-pair and the social mate. In this study, we tested if Barn Swallow offspring sex ratio depends on paternity and on sexual ornamentation of the extra-pair father, and whether paternity predicts offspring phenotypic quality. The results partially fulfilled our prediction. We did not provide support for the hypothesis of a differential sex allocation to the production of male offspring by promiscuous females, both at the individual and at the within-brood level. Moreover, the difference in the ornamentation of the extra-pair and the social male did not affect the sex ratio of individual offspring. However, in accordance with the good genes and the genetic compatibility hypotheses, extra-pair offspring were of superior quality as compared to their half-sibling, in terms of body size and feather growth. In sexually promiscuous species, females should differentially allocate resources to the production of offspring of either sex depending on paternity or sexual ornamentation of the social or the extra-pair mate. Moreover, extra-pair offspring may be of superior quality compared to their within-pair half-siblings. In the present study of the Barn Swallow, paternity and the differences in sexual ornamentation between the social and the extra-pair mate did not affect offspring sex ratio. In addition, according to the good genes and the genetic compatibility hypotheses, we found that extra-pair offspring are of superior quality as compared to their within-pair siblings. Despite we failed to provide support to the sex allocation theory, the present study emphasizes the importance of “negative” results to better estimate the generality of the occurrence of adaptive sex allocation strategies in the context of sexual selection studies.
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Barn Swallow antipredator behavior covaries with melanic coloration and predicts survival
Behavioral Ecology, 2018Co-Authors: Alessandra Costanzo, Luca Canova, Manuela Caprioli, Roberto Ambrosini, Andrea Romano, Diego Rubolini, Marco Parolini, Margherita Corti, Nicola SainoAbstract:Conspecific individuals often consistently differ in their behavioral responses to specific exogenous stimuli. Such individual differences in "personality" have been shown to be heritable, suggesting that selection maintains variation in personality. However, survival selection on a major personality trait, antipredator behavior, and its sex-dependency, has been seldom measured in the wild. Here, we found that yearling Barn Swallows (Hirundo rustica) showed consistency in agitation upon repeated exposure to a restraint-handling protocol, probably reflecting antipredator behavior, and that males were more agitated than females. Females that exhibited larger antipredator behavior were more likely to survive until the next breeding season with no variation among 3 study years nor across 7 breeding colonies, suggesting that variation in antipredator behavior is not maintained by spatiotemporal variation in viability selection on antipredator behavior. In both sexes, the intensity of melanin-based ventral plumage coloration positively covaried with antipredator behavior, consistent with previous observations from diverse vertebrate species. In some Barn Swallow populations, male coloration is targeted by directional intersexual selection, suggesting that melanization signals antipredator behavior to prospecting females and that sexual selection for antipredator behavior, or other correlated personality traits, can drive the evolution of sexual color dimorphism in Barn Swallows. Thus, we showed that viability selection occurs on antipredator behavior and that spatiotemporal variation in selection has no major role in promoting variation in antipredator behavior. More melanized individuals were more agitated, implying that melanization may signal personality in a sexual communication context in a species where male coloration is an epigamic trait.
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viability and expression of sexual ornaments in the Barn Swallow hirundo rustica a meta analysis
Journal of Evolutionary Biology, 2017Co-Authors: Andrea Romano, Nicola Saino, Anders Pape MollerAbstract:: Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta-analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the Barn Swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084-0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.
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telomere length is reflected by plumage coloration and predicts seasonal reproductive success in the Barn Swallow
Molecular Ecology, 2017Co-Authors: Marco Parolini, Luca Canova, Andrea Romano, Diego Rubolini, Alessandra Costanzo, Lela Khoriauli, Marco Santagostino, Solomon G Nergadze, Elena Giulotto, Nicola SainoAbstract:Individuals differ in realized fitness but the genetic/phenotypic traits that underpin such variation are often unknown. Telomere dynamics may be a major source of variation in fitness traits because physiological telomere shortening depends on environmental and genetic factors and may impair individual performance. Here, we showed that, in a population of a socially monogamous, biparental passerine bird, the Barn Swallow (Hirundo rustica) breeding in Northern Italy, telomere length (TL) of both adult males and females positively correlated with seasonal reproductive and fledging success, as expected because long telomeres are supposed to boost performance. Telomere length was correlated with sexually dimorphic coloration in both sexes, showing for the first time in any species that coloration reliably reflects TL and may mediate mutual mate choice, leading to the observed positive assortative mating for TL in the Barn Swallow. Thus, TL appears to be associated with variation in a major fitness trait and may be an ultimate target of mate choice, as individuals of both sexes can use coloration to adaptively choose high-quality mates that possess long telomeres. This article is protected by copyright. All rights reserved.
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Viability and expression of sexual ornaments in the Barn Swallow Hirundo rustica: a meta‐analysis
Journal of Evolutionary Biology, 2017Co-Authors: Andrea Romano, Nicola Saino, Anders Pape MollerAbstract:Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the Barn Swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.