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Wilson AB, Whittington CM, Meyer A, Scobell SK, Gauthier ME. Prolactin and the evolution of male pregnancy. Gen Comp Endocrinol 2023; 334:114210. [PMID: 36646326 DOI: 10.1016/j.ygcen.2023.114210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 11/04/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Prolactin (PRL) is a multifunctional hormone of broad physiological importance, and is involved in many aspects of fish reproduction, including the regulation of live birth (viviparity) and both male and female parental care. Previous research suggests that PRL also plays an important reproductive role in syngnathid fishes (seahorses, pipefish and seadragons), a group with a highly derived reproductive strategy, male pregnancy - how the PRL axis has come to be co-opted for male pregnancy remains unclear. We investigated the molecular evolution and expression of the genes for prolactin and its receptor (PRLR) in an evolutionarily diverse sampling of syngnathid fishes to explore how the co-option of PRL for male pregnancy has impacted its evolution, and to clarify whether the PRL axis is also involved in regulating reproductive function in species with more rudimentary forms of male pregnancy. In contrast to the majority of teleost fishes, all syngnathid fishes tested carry single copies of PRL and PRLR that cluster genetically within the PRL1 and PRLRa lineages of teleosts, respectively. PRL1 gene expression in seahorses and pipefish is restricted to the pituitary, while PRLRa is expressed in all tissues, including the brood pouch of species with both rudimentary and complex brooding structures. Pituitary PRL1 expression remains stable throughout pregnancy, but PRLRa expression is specifically upregulated in the male brood pouch during pregnancy, consistent with the higher affinity of pouch tissues for PRL hormone during embryonic incubation. Finally, immunohistochemistry of brood pouch tissues reveals that both PRL1 protein and PRLRa and Na+/K+ ATPase-positive cells line the inner pouch epithelium, suggesting that pituitary-derived PRL1 may be involved in brood pouch osmoregulation during pregnancy. Our data provide a unique molecular perspective on the evolution and expression of prolactin and its receptor during male pregnancy, and provide the foundation for further manipulative experiments exploring the role of PRL in this unique form of reproduction.
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Affiliation(s)
- Anthony B Wilson
- Department of Biology, Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, United States; The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, United States; Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich 8057, Switzerland; Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Germany.
| | - Camilla M Whittington
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich 8057, Switzerland; Sydney School of Veterinary Science, University of Sydney, Sydney 2006, Australia; School of Life and Environmental Sciences, University of Sydney, Sydney 2006, Australia
| | - Axel Meyer
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Germany
| | - Sunny K Scobell
- Department of Biology, Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, United States
| | - Marie-Emilie Gauthier
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich 8057, Switzerland
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2
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Dudley J, Paul J, Teh V, Mackenzie T, Butler T, Tolosa J, Smith R, Foley M, Dowland S, Thompson M, Whittington C. Seahorse brood pouch morphology and control of male parturition in Hippocampus abdominalis. Placenta 2022; 127:88-94. [DOI: 10.1016/j.placenta.2022.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 07/07/2022] [Accepted: 07/18/2022] [Indexed: 11/30/2022]
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3
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Parental investment and immune dynamics in sex-role reversed pipefishes. PLoS One 2020; 15:e0228974. [PMID: 32976488 PMCID: PMC7518610 DOI: 10.1371/journal.pone.0228974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/19/2020] [Indexed: 11/19/2022] Open
Abstract
Parental care elevates reproductive success by allocating resources into the upbringing of the offspring. However, it also imposes strong costs for the care-giving parent and can foster sexual dimorphism. Trade-offs between the reproductive system and the immune system may result in differential immunological capacities between the care-providing and the non-care-providing parent. Usually, providing care is restricted to the female sex making it impossible to study a sex-independent influence of parental investment on sexual immune dimorphism. The decoupling of sex-dependent parental investment and their influences on the parental immunological capacity, however, is possible in syngnathids, which evolved the unique male pregnancy on a gradient ranging from a simple carrying of eggs on the trunk (Nerophinae, low paternal investment) to full internal pregnancy (Syngnathus, high paternal investment). In this study, we compared candidate gene expression between females and males of different gravity stages in three species of syngnathids (Syngnathus typhle, Syngnathus rostellatus and Nerophis ophidion) with different male pregnancy intensities to determine how parental investment influences sexual immune dimorphism. While our data failed to detect sexual immune dimorphism in the subset of candidate genes assessed, we show a parental care specific resource-allocation trade-off between investment into pregnancy and immune defense when parental care is provided.
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4
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Whittington CM, Friesen CR. The evolution and physiology of male pregnancy in syngnathid fishes. Biol Rev Camb Philos Soc 2020; 95:1252-1272. [PMID: 32372478 DOI: 10.1111/brv.12607] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 12/24/2022]
Abstract
The seahorses, pipefishes and seadragons (Syngnathidae) are among the few vertebrates in which pregnant males incubate developing embryos. Syngnathids are popular in studies of sexual selection, sex-role reversal, and reproductive trade-offs, and are now emerging as valuable comparative models for the study of the biology and evolution of reproductive complexity. These fish offer the opportunity to examine the physiology, behavioural implications, and evolutionary origins of embryo incubation, independent of the female reproductive tract and female hormonal milieu. Such studies allow us to examine flexibility in regulatory systems, by determining whether the pathways underpinning female pregnancy are also co-opted in incubating males, or whether novel pathways have evolved in response to the common challenges imposed by incubating developing embryos and releasing live young. The Syngnathidae are also ideal for studies of the evolution of reproductive complexity, because they exhibit multiple parallel origins of complex reproductive phenotypes. Here we assay the taxonomic distribution of syngnathid parity mode, examine the selective pressures that may have led to the emergence of male pregnancy, describe the biology of syngnathid reproduction, and highlight pressing areas for future research. Experimental tests of a range of hypotheses, including many generated with genomic tools, are required to inform overarching theories about the fitness implications of pregnancy and the evolution of male pregnancy. Such information will be widely applicable to our understanding of fundamental reproductive and evolutionary processes in animals.
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Affiliation(s)
- Camilla M Whittington
- The University of Sydney, School of Life and Environmental Sciences, Sydney, New South Wales, 2006, Australia.,The University of Sydney, Sydney School of Veterinary Science, Sydney, New South Wales, 2006, Australia
| | - Christopher R Friesen
- The University of Wollongong, School of Earth, Atmospheric and Life Sciences, Faculty of Science, Medicine and Health, Wollongong, New South Wales, 2522, Australia.,Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales, 2522, Australia
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5
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Hare RM, Simmons LW. Sexual selection and its evolutionary consequences in female animals. Biol Rev Camb Philos Soc 2018; 94:929-956. [DOI: 10.1111/brv.12484] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/31/2018] [Accepted: 11/02/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Robin M. Hare
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
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6
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Cunha M, Berglund A, Mendes S, Monteiro N. The 'Woman in Red' effect: pipefish males curb pregnancies at the sight of an attractive female. Proc Biol Sci 2018; 285:rspb.2018.1335. [PMID: 30135166 DOI: 10.1098/rspb.2018.1335] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/26/2018] [Indexed: 11/12/2022] Open
Abstract
In an old Gene Wilder movie, an attractive woman dressed in red devastated a man's current relationship. We have found a similar 'Woman in Red' effect in pipefish, a group of fish where pregnancy occurs in males. We tested for the existence of pregnancy blocks in pregnant male black-striped pipefish (Syngnathus abaster). We allowed pregnant males to see females that were larger and even more attractive than their original high-quality mates and monitored the survival and growth of developing offspring. After exposure to these extremely attractive females, males produced smaller offspring in more heterogeneous broods and showed a higher rate of spontaneous offspring abortion. Although we did not observe a full pregnancy block, our results show that males are able to reduce investment in current broods when faced with prospects of a more successful future reproduction with a potentially better mate. This 'Woman in Red' life-history trade-off between present and future reproduction has similarities to the Bruce effect, and our study represents, to our knowledge, the first documentation of such a phenomenon outside mammals.
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Affiliation(s)
- M Cunha
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, 4485-661 Vairão, Portugal
| | - A Berglund
- Department of Ecology and Genetics/Animal Ecology, Uppsala University, Uppsala, Sweden
| | - S Mendes
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, 4485-661 Vairão, Portugal
| | - N Monteiro
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, 4485-661 Vairão, Portugal .,CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, rua Carlos da Maia 296, 4200-150 Porto, Portugal
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7
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Zhang H, Qin G, Sun J, Zhang B, Lin Q. The evolution and functional characterization of lined seahorse (Hippocampus erectus) CCKs involved in fasting and thermal stress response. Gen Comp Endocrinol 2018; 255:56-63. [PMID: 29051075 DOI: 10.1016/j.ygcen.2017.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/27/2017] [Accepted: 10/14/2017] [Indexed: 12/19/2022]
Abstract
The peptide cholecystokinin (CCK) plays an important role in the regulation of vertebrate appetite and feeding behaviour. In the present study, the full-length cDNA and genomic DNA sequences of two CCK precursors were cloned and analysed in the Syngnathidae fish, the lined seahorse (Hippocampus erectus). Both CCK1 and CCK2 in the seahorse consist of four exons. The sequence of the octapeptide of seahorse CCK1 (DYMGWMDF) was the same as that of the chicken and human, while the octapeptide of seahorse CCK2 (DYEGWMDF) was unique among vertebrates. According to the phylogenetic analysis, two types of CCKs were produced by teleost-specific genome duplication (TGD). Both CCK1 and CCK2 were highly expressed in the brain, while detectable amounts of CCK1 mRNA in the brood pouch and CCK2 mRNA in the intestine were also found. Both CCK1 and CCK2 mRNA levels significantly increased during the transition from endogenous to exogenous nutrition. Additionally, fasting induced a significant increase in the CCK1 mRNA expression in the brain of juvenile seahorses but had no effect on CCK2 transcript levels. In addition, the CCK1 and CCK2 mRNA levels in the seahorse brain significantly increased after a high-temperature treatment. Thus, the mRNA expression of CCK had obvious tissue specificities and this preliminary study opens new avenues for further functional studies on the endocrine regulations of CCK in the transition from endogenous to exogenous nutrition, food intake regulation and metabolism in the seahorse.
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Affiliation(s)
- Huixian Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong 510301, PR China
| | - Geng Qin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong 510301, PR China
| | - Jinhui Sun
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Bo Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qiang Lin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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8
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Pregnant pipefish with a simple brooding surface loose less weight when carrying heavier eggs: evidence of compensation for low oocyte quality? Acta Ethol 2017. [DOI: 10.1007/s10211-017-0268-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Griffith OW, Wagner GP. The placenta as a model for understanding the origin and evolution of vertebrate organs. Nat Ecol Evol 2017; 1:72. [DOI: 10.1038/s41559-017-0072] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 01/06/2017] [Indexed: 12/19/2022]
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10
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Beemelmanns A, Roth O. Grandparental immune priming in the pipefish Syngnathus typhle. BMC Evol Biol 2017; 17:44. [PMID: 28173760 PMCID: PMC5297188 DOI: 10.1186/s12862-017-0885-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 01/16/2017] [Indexed: 11/10/2022] Open
Abstract
Background Phenotypic changes in response to environmental influences can persist from one generation into the next. In many systems parental parasite experience influences offspring immune responses, known as transgenerational immune priming (TGIP). TGIP in vertebrates is mainly maternal and short-term, supporting the adaptive immune system of the offspring during its maturation. However, if fathers and offspring have a close physical connection, evolution of additional paternal immune priming can be adaptive. Biparental TGIP may result in maximized immunological protection. Here, we investigate multigenerational biparental TGIP in the sex-role reversed pipefish Syngnathus typhle by exposing grandparents to an immune challenge with heat-killed bacteria and assessing gene expression (44 target genes) of the F2-generation. Results Grandparental immune challenge induced gene expression of immune genes in one-week-old grandoffspring. Similarly, genes mediating epigenetic regulation including DNA-methylation and histone modifications were involved in grandparental immune priming. While grand-maternal impact was strong on genes of the complement component system, grand-paternal exposure changed expression patterns of genes mediating innate immune defense. Conclusion In a system with male pregnancy, grandparents influenced the immune system of their grandoffspring in a sex-specific manner, demonstrating multigenerational biparental TGIP. The involvement of epigenetic effects suggests that TGIP via the paternal line may not be limited to the pipefish system that displays male pregnancy. While the benefits and costs of grandparental TGIP depend on the temporal heterogeneity of environmental conditions, multigenerational TGIP may affect host-parasite coevolution by dampening the amplitude of Red Queen Dynamics. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0885-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne Beemelmanns
- Evolutionary Ecology of Marine Fishes, Helmholtz-Centre for Ocean Research Kiel (GEOMAR), Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Olivia Roth
- Evolutionary Ecology of Marine Fishes, Helmholtz-Centre for Ocean Research Kiel (GEOMAR), Düsternbrooker Weg 20, 24105, Kiel, Germany.
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11
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The genome of the Gulf pipefish enables understanding of evolutionary innovations. Genome Biol 2016; 17:258. [PMID: 27993155 PMCID: PMC5168715 DOI: 10.1186/s13059-016-1126-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/05/2016] [Indexed: 11/10/2022] Open
Abstract
Background Evolutionary origins of derived morphologies ultimately stem from changes in protein structure, gene regulation, and gene content. A well-assembled, annotated reference genome is a central resource for pursuing these molecular phenomena underlying phenotypic evolution. We explored the genome of the Gulf pipefish (Syngnathus scovelli), which belongs to family Syngnathidae (pipefishes, seahorses, and seadragons). These fishes have dramatically derived bodies and a remarkable novelty among vertebrates, the male brood pouch. Results We produce a reference genome, condensed into chromosomes, for the Gulf pipefish. Gene losses and other changes have occurred in pipefish hox and dlx clusters and in the tbx and pitx gene families, candidate mechanisms for the evolution of syngnathid traits, including an elongated axis and the loss of ribs, pelvic fins, and teeth. We measure gene expression changes in pregnant versus non-pregnant brood pouch tissue and characterize the genomic organization of duplicated metalloprotease genes (patristacins) recruited into the function of this novel structure. Phylogenetic inference using ultraconserved sequences provides an alternative hypothesis for the relationship between orders Syngnathiformes and Scombriformes. Comparisons of chromosome structure among percomorphs show that chromosome number in a pipefish ancestor became reduced via chromosomal fusions. Conclusions The collected findings from this first syngnathid reference genome open a window into the genomic underpinnings of highly derived morphologies, demonstrating that de novo production of high quality and useful reference genomes is within reach of even small research groups. Electronic supplementary material The online version of this article (doi:10.1186/s13059-016-1126-6) contains supplementary material, which is available to authorized users.
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Goncalves IB, Ahnesjö I, Kvarnemo C. Embryo oxygenation in pipefish brood pouches: novel insights. ACTA ACUST UNITED AC 2016; 218:1639-46. [PMID: 26041030 DOI: 10.1242/jeb.120907] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pipefish brood pouch presents a unique mode of parental care that enables males to protect, osmoregulate, nourish and oxygenate the developing young. Using a very fine O2 probe, we assessed the extent to which males of the broad-nosed pipefish (Syngnathus typhle) oxygenate the developing embryos and are able to maintain pouch fluid O2 levels when brooding in normoxia (100% O2 saturation) and hypoxia (40% O2 saturation) for 24 days. In both treatments, pouch fluid O2 saturation levels were lower compared with the surrounding water and decreased throughout the brooding period, reflecting greater offspring demand for O2 during development and/or decreasing paternal ability to provide O2 to the embryos. Male condition (hepatosomatic index) was negatively affected by hypoxia. Larger males had higher pouch fluid O2 saturation levels compared with smaller males, and levels were higher in the bottom section of the pouch compared with other sections. Embryo size was positively correlated with O2 availability, irrespective of their position in the pouch. Two important conclusions can be drawn from our findings. First, our results highlight a potential limitation to brooding within the pouch and dismiss the notion of closed brood pouches as well-oxygenated structures promoting the evolution of larger eggs in syngnathids. Second, we provide direct evidence that paternal care improves with male size in this species. This finding offers an explanation for the documented strong female preference for larger partners because, in terms of oxygenation, the brood pouch can restrict embryo growth.
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Affiliation(s)
- Ines Braga Goncalves
- Institute of Evolutionary Biology and Environmental Studies, Animal Behaviour, University of Zurich, Winterthurerstrasse 190, Zürich 8057, Switzerland Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, Gothenburg SE-40530, Sweden
| | - Ingrid Ahnesjö
- Department of Ecology and Genetics/Animal Ecology, Uppsala University, Norbyvägen 18D, Uppsala SE-75236, Sweden
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, Gothenburg SE-40530, Sweden
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Sagebakken G, Ahnesjö I, Kvarnemo C. Costs and Benefits to Pregnant Male Pipefish Caring for Broods of Different Sizes. PLoS One 2016; 11:e0156484. [PMID: 27243937 PMCID: PMC4886961 DOI: 10.1371/journal.pone.0156484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 05/16/2016] [Indexed: 11/20/2022] Open
Abstract
Trade-offs between brood size and offspring size, offspring survival, parental condition or parental survival are classic assumptions in life history biology. A reduction in brood size may lessen these costs of care, but offspring mortality can also result in an energetic gain, if parents are able to utilize the nutrients from the demised young. Males of the broad-nosed pipefish (Syngnathus typhle) care for the offspring by brooding embryos in a brood pouch. Brooding males can absorb nutrients that emanate from embryos, and there is often a reduction in offspring number over the brooding period. In this study, using two experimentally determined brood sizes (partially and fully filled brood pouches), we found that full broods resulted in larger number of developing offspring, despite significantly higher absolute and relative embryo mortality, compared to partial broods. Male survival was also affected by brood size, with males caring for full broods having poorer survival, an effect that together with the reduced embryo survival was found to negate the benefit of large broods. We found that embryo mortality was lower when the brooding males were in good initial condition, that embryos in broods with low embryo mortality weighed more, and surprisingly, that males in higher initial condition had embryos of lower weight. Brood size, however, did not affect embryo weight. Male final condition, but not initial condition, correlated with higher male survival. Taken together, our results show costs and benefits of caring for large brood sizes, where the numerical benefits come with costs in terms of both embryo survival and survival of the brooding father, effects that are often mediated via male condition.
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Affiliation(s)
- Gry Sagebakken
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Ingrid Ahnesjö
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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14
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Braga Goncalves I, Ahnesjö I, Kvarnemo C. Evolutionary ecology of pipefish brooding structures: embryo survival and growth do not improve with a pouch. Ecol Evol 2016; 6:3608-3620. [PMID: 27231531 PMCID: PMC4864203 DOI: 10.1002/ece3.2139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/16/2016] [Accepted: 03/21/2016] [Indexed: 12/03/2022] Open
Abstract
For animals that reproduce in water, many adaptations in life‐history traits such as egg size, parental care, and behaviors that relate to embryo oxygenation are still poorly understood. In pipefishes, seahorses and seadragons, males care for the embryos either in some sort of brood pouch, or attached ventrally to the skin on their belly or tail. Typically, egg size is larger in the brood pouch group and it has been suggested that oxygen supplied via the pouch buffers the developing embryos against hypoxia and as such is an adaptation that has facilitated the evolution of larger eggs. Here, using four pipefish species, we tested whether the presence or absence of brood pouch relates to how male behavior, embryo size, and survival are affected by hypoxia, with normoxia as control. Two of our studied species Entelurus aequoreus and Nerophis ophidion (both having small eggs) have simple ventral attachment of eggs onto the male trunk, and the other two, Syngnathus typhle (large eggs) and S. rostellatus (small eggs), have fully enclosed brood pouches on the tail. Under hypoxia, all species showed lower embryo survival, while species with brood pouches suffered greater embryo mortality compared to pouchless species, irrespective of oxygen treatment. Behaviorally, species without pouches spent more time closer to the surface, possibly to improve oxygenation. Overall, we found no significant benefits of brood pouches in terms of embryo survival and size under hypoxia. Instead, our results suggest negative effects of large egg size, despite the protection of brood pouches.
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Affiliation(s)
- Ines Braga Goncalves
- Department of Evolutionary Biology and Environmental Studies, Animal Behaviour University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland.,Department of Biological and Environmental Sciences University of Gothenburg PO Box 463 40530 Gothenburg Sweden
| | - Ingrid Ahnesjö
- Department of Ecology and Genetics/Animal Ecology Uppsala University Norbyvägen 18D 75236 Uppsala Sweden
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences University of Gothenburg PO Box 463 40530 Gothenburg Sweden
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15
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Tsuboi M, Shoji J, Sogabe A, Ahnesjö I, Kolm N. Within species support for the expensive tissue hypothesis: a negative association between brain size and visceral fat storage in females of the Pacific seaweed pipefish. Ecol Evol 2016; 6:647-55. [PMID: 26865955 PMCID: PMC4739565 DOI: 10.1002/ece3.1873] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 11/11/2022] Open
Abstract
The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the high cost of brain development and maintenance is predicted to constrain adaptive brain size evolution (the expensive tissue hypothesis, ETH). Here, we test the ETH in a teleost fish with predominant female mating competition (reversed sex roles) and male pregnancy, the pacific seaweed pipefish Syngnathus schlegeli. The relative size of the brain and other energetically expensive organs (kidney, liver, heart, gut, visceral fat, and ovary/testis) was compared among three groups: pregnant males, nonpregnant males and egg producing females. Brood size in pregnant males was unrelated to brain size or the size of any other organ, whereas positive relationships were found between ovary size, kidney size, and liver size in females. Moreover, we found that the size of energetically expensive organs (brain, heart, gut, kidney, and liver) as well as the amount of visceral fat did not differ between pregnant and nonpregnant males. However, we found marked differences in relative size of the expensive organs between sexes. Females had larger liver and kidney than males, whereas males stored more visceral fat than females. Furthermore, in females we found a negative correlation between brain size and the amount of visceral fat, whereas in males, a positive trend between brain size and both liver and heart size was found. These results suggest that, while the majority of variation in the size of various expensive organs in this species likely reflects that individuals in good condition can afford to allocate resources to several organs, the cost of the expensive brain was visible in the visceral fat content of females, possibly due to the high costs associated with female egg production.
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Affiliation(s)
- Masahito Tsuboi
- Department of Ecology and Genetics/Animal Ecology Evolutionary Biology Centre Uppsala University Norbyvägen 18D SE-75236 Uppsala Sweden
| | - Jun Shoji
- Center for Field Science of the Seto Inland Sea Hiroshima University 5-8-1, Minatomachi 725-0024 Takehara City Hiroshima Japan
| | - Atsushi Sogabe
- Department of Biology Faculty of Agriculture and Life Science Hirosaki University 1-1, Bunkyo-cho 036-8560 Hirosaki Aomori Japan
| | - Ingrid Ahnesjö
- Department of Ecology and Genetics/Animal Ecology Evolutionary Biology Centre Uppsala University Norbyvägen 18D SE-75236 Uppsala Sweden
| | - Niclas Kolm
- Department of Zoology/Ethology Stockholm University Svante Arrhenius väg 18B SE-10691 Stockholm Sweden
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Abstract
Cannibalism provides energetic benefits but is also potentially costly, especially when directed towards kin. Since fitness costs increase with time and energy invested in offspring, cannibalism should be infrequent when parental investment is high. Thus, filial cannibalism in male syngnathids, a group known for the occurrence of male pregnancy, should be rare. Using the pipefish (Syngnathus abaster) we aimed to investigate whether cannibalism does occur in both sexes and how it is affected by reproductive and nutritional states. Although rare, we witnessed cannibalism both in the wild and in the laboratory. Unlike non-pregnant males and females, pregnant and post-partum males largely refrained from cannibalising juveniles. Reproducing males decreased their feeding activity, thus rendering cannibalism, towards kin or non-kin, less likely to occur. However, if not continuously fed, all pipefish adopted a cannibal strategy, revealing that sex and life history stages influenced the ratio between the benefits and costs of cannibalism.
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Affiliation(s)
- M. Cunha
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Rua Padre Armando Quintas, 4485-661 Vairão, Portugal
- Faculdade de Ciências da Universidade do Porto, rua do Campo Alegre, 4169-007 Porto, Portugal
| | - A. Berglund
- Department of Animal Ecology, Evolutionary Biology Centre (EBC), Uppsala University, Norbyvägen 14, 752 36, Uppsala, Sweden
| | - T. Alves
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Rua Padre Armando Quintas, 4485-661 Vairão, Portugal
| | - N.M. Monteiro
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Rua Padre Armando Quintas, 4485-661 Vairão, Portugal
- Faculdade de Ciências da Universidade do Porto, rua do Campo Alegre, 4169-007 Porto, Portugal
- CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Rua Carlos da Maia 296, 4200-150 Porto, Portugal
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17
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Whittington CM, Griffith OW, Qi W, Thompson MB, Wilson AB. Seahorse Brood Pouch Transcriptome Reveals Common Genes Associated with Vertebrate Pregnancy. Mol Biol Evol 2015; 32:3114-31. [PMID: 26330546 DOI: 10.1093/molbev/msv177] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Viviparity (live birth) has evolved more than 150 times in vertebrates, and represents an excellent model system for studying the evolution of complex traits. There are at least 23 independent origins of viviparity in fishes, with syngnathid fishes (seahorses and pipefish) unique in exhibiting male pregnancy. Male seahorses and pipefish have evolved specialized brooding pouches that provide protection, gas exchange, osmoregulation, and limited nutrient provisioning to developing embryos. Pouch structures differ widely across the Syngnathidae, offering an ideal opportunity to study the evolution of reproductive complexity. However, the physiological and genetic changes facilitating male pregnancy are largely unknown. We used transcriptome profiling to examine pouch gene expression at successive gestational stages in a syngnathid with the most complex brood pouch morphology, the seahorse Hippocampus abdominalis. Using a unique time-calibrated RNA-seq data set including brood pouch at key stages of embryonic development, we identified transcriptional changes associated with brood pouch remodeling, nutrient and waste transport, gas exchange, osmoregulation, and immunological protection of developing embryos at conception, development and parturition. Key seahorse transcripts share homology with genes of reproductive function in pregnant mammals, reptiles, and other live-bearing fish, suggesting a common toolkit of genes regulating pregnancy in divergent evolutionary lineages.
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Affiliation(s)
- Camilla M Whittington
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Oliver W Griffith
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Weihong Qi
- Functional Genomics Centre, University of Zurich, Zurich, Switzerland
| | - Michael B Thompson
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Anthony B Wilson
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia Department of Biology, Brooklyn College The Graduate Center, City University of New York
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18
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Paczolt KA, Jones AG. The effects of food limitation on life history tradeoffs in pregnant male gulf pipefish. PLoS One 2015; 10:e0124147. [PMID: 25970284 PMCID: PMC4430282 DOI: 10.1371/journal.pone.0124147] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 03/11/2015] [Indexed: 11/22/2022] Open
Abstract
Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male’s body, often within a structure known as a brood pouch. Evidence suggests that this pouch plays a role in mediating postcopulatory sexual selection and that males have some control over the events occurring within the pouch during the pregnancy. These observations lead to the prediction that males should invest differently in broods depending on the availability of food. Here, we use the Gulf pipefish to test this prediction by monitoring growth rate and offspring survivorship during the pregnancies of males under low- or high-food conditions. Our results show that pregnant males grow less rapidly on average than non-pregnant males, and pregnant males under low-food conditions grow less than pregnant males under high-food conditions. Offspring survivorship, on the other hand, does not differ between food treatments, suggesting that male Gulf pipefish sacrifice investment in somatic growth, and thus indirectly sacrifice future reproduction, in favor of current reproduction. However, a positive relationship between number of failed eggs and male growth rate in our low-food treatments suggests that undeveloped eggs reduce the pregnancy’s overall cost to the male compared to broods containing only viable offspring.
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Affiliation(s)
- Kimberly A. Paczolt
- Department of Biology, 3258 TAMU, Texas A&M University, College Station, Texas, 77843, United States of America
- * E-mail:
| | - Adam G. Jones
- Department of Biology, 3258 TAMU, Texas A&M University, College Station, Texas, 77843, United States of America
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19
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Small CM, Harlin-Cognato AD, Jones AG. Functional similarity and molecular divergence of a novel reproductive transcriptome in two male-pregnant Syngnathus pipefish species. Ecol Evol 2013; 3:4092-108. [PMID: 24324861 PMCID: PMC3853555 DOI: 10.1002/ece3.763] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/06/2013] [Accepted: 08/12/2013] [Indexed: 11/09/2022] Open
Abstract
Evolutionary studies have revealed that reproductive proteins in animals and plants often evolve more rapidly than the genome-wide average. The causes of this pattern, which may include relaxed purifying selection, sexual selection, sexual conflict, pathogen resistance, reinforcement, or gene duplication, remain elusive. Investigative expansions to additional taxa and reproductive tissues have the potential to shed new light on this unresolved problem. Here, we embark on such an expansion, in a comparison of the brood-pouch transcriptome between two male-pregnant species of the pipefish genus Syngnathus. Male brooding tissues in syngnathid fishes represent a novel, nonurogenital reproductive trait, heretofore mostly uncharacterized from a molecular perspective. We leveraged next-generation sequencing (Roche 454 pyrosequencing) to compare transcript abundance in the male brooding tissues of pregnant with nonpregnant samples from Gulf (S. scovelli) and dusky (S. floridae) pipefish. A core set of protein-coding genes, including multiple members of astacin metalloprotease and c-type lectin gene families, is consistent between species in both the direction and magnitude of expression bias. As predicted, coding DNA sequence analysis of these putative "male pregnancy proteins" suggests rapid evolution relative to nondifferentially expressed genes and reflects signatures of adaptation similar in magnitude to those reported from Drosophila male accessory gland proteins. Although the precise drivers of male pregnancy protein divergence remain unknown, we argue that the male pregnancy transcriptome in syngnathid fishes, a clade diverse with respect to brooding morphology and mating system, represents a unique and promising object of study for understanding the perplexing evolutionary nature of reproductive molecules.
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Affiliation(s)
- Clayton M Small
- Department of Biology, Texas A&M University College Station, Texas, 77843, USA ; Institute of Ecology and Evolution, University of Oregon Eugene, Oregon, 97403, USA
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20
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Freret-Meurer NV, Andreata JV, Alves MAS. Activity rate of the seahorse Hippocampus reidi Ginsburg, 1933 (Syngnathidae). Acta Ethol 2012. [DOI: 10.1007/s10211-012-0125-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Lin Q, Li G, Qin G, Lin J, Huang L, Sun H, Feng P. The dynamics of reproductive rate, offspring survivorship and growth in the lined seahorse, Hippocampus erectus Perry, 1810. Biol Open 2012; 1:391-6. [PMID: 23213429 PMCID: PMC3509459 DOI: 10.1242/bio.2012398] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Seahorses are the vertebrate group with the embryonic development occurring within a special pouch in males. To understand the reproductive efficiency of the lined seahorse, Hippocampus erectus Perry, 1810 under controlled breeding experiments, we investigated the dynamics of reproductive rate, offspring survivorship and growth over births by the same male seahorses. The mean brood size of the 1-year old pairs in the 1st birth was 85.4±56.9 per brood, which was significantly smaller than that in the 6th birth (465.9±136.4 per brood) (P<0.001). The offspring survivorship and growth rate increased with the births. The fecundity was positively correlated with the length of brood pouches of males and trunk of females. The fecundity of 1-year old male and 2-year old female pairs was significantly higher than that from 1-year old couples (P<0.001). The brood size (552.7±150.4) of the males who mated with females that were isolated for the gamete-preparation, was larger than those (467.8±141.2) from the long-term pairs (P<0.05). Moreover, the offspring from the isolated females had higher survival and growth rates. Our results showed that the potential reproductive rate of seahorses H. erectus increased with the brood pouch development.
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Affiliation(s)
- Qiang Lin
- Key Laboratory of Marine Bio-resource Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences , Guangzhou 510301 , P. R. China ; Vero Beach Marine Laboratory, Florida Institute of Technology , Vero Beach, FL 32963 , USA
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22
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Abstract
Few studies have examined the underlying hormonal mechanisms that mediate reproductive cyclicity, male pregnancy and reproductive behaviour in syngnathids. Progress in these areas has been hampered by the small size of most species in the family and a lack of validated techniques for assessing endocrine function. Research on a relatively small number of species has suggested that androgens are likely regulators of spermatogenesis and the development of the male brood pouch prior to pregnancy whereas prolactin and corticosteroids synergistically promote brood pouch function during pregnancy. No evidence supports a reversal of reproductive steroid hormone function in sex-role reversed behaviour, but neuropeptides such as arginine vasotocin or isotocin should be examined for their role in regulating parturition and mating behaviour. The diversity of reproductive patterns exhibited by syngnathids suggests that they will provide a unique opportunity to assess how hormonal regulation of integumentary function, gametogenesis and reproductive behaviour have evolved within a teleost lineage. Additionally, their coastal distribution and embryo retention make them potentially important subjects for studies on the effect of endocrine disruption on fitness.
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Affiliation(s)
- S K Scobell
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843, USA.
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23
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Braga Goncalves I, Ahnesjö I, Kvarnemo C. The relationship between female body size and egg size in pipefishes. JOURNAL OF FISH BIOLOGY 2011; 78:1847-1854. [PMID: 21651532 DOI: 10.1111/j.1095-8649.2011.02984.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Comparing five species of pipefish, egg size was significantly larger in species with brood pouches (Syngnathus typhle, Syngnathus acus and Syngnathus rostellatus) than in species without brood pouches (Entelurus aequoreus and Nerophis ophidion). Egg size correlated positively with female body size in species with brood pouches, but was similar across female sizes in the species lacking pouches. These results may reflect differences in offspring competition as a consequence of variable offspring relatedness within a brood, due to the mating systems adopted by the different species and the presence or absence of a brood pouch.
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Affiliation(s)
- I Braga Goncalves
- Department of Zoology, University of Gothenburg, Box 463, SE-40530 Gothenburg, Sweden.
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24
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Sagebakken G, Ahnesjö I, Braga Goncalves I, Kvarnemo C. Multiply mated males show higher embryo survival in a paternally caring fish. Behav Ecol 2011. [DOI: 10.1093/beheco/arr023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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25
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Ripley JL, Foran CM. Elevated whole brain arginine vasotocin with Aroclor 1254 exposure in two Syngnathus pipefishes. FISH PHYSIOLOGY AND BIOCHEMISTRY 2010; 36:917-921. [PMID: 19924554 DOI: 10.1007/s10695-009-9368-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 11/04/2009] [Indexed: 05/28/2023]
Abstract
The neurohypophysial hormone arginine vasotocin (AVT) and the neuroendocrine system strongly interact with the rest of the teleostean endocrine system. The aim of this study is to investigate the effects of exposure to an endocrine disruptor on whole brain AVT concentrations for the pipefishes Syngnathus floridae and S. fuscus. Following treatment over the entire brood period, AVT concentrations were significantly higher for Aroclor 1254-exposed, post-brooding males compared to controls for both species. Considering both previously documented seventeen-fold increases in AVT for brooding males with embryos in some developmental stages and changes in parental nutrient concentrations after Aroclor 1254 exposure, these data begin to address potential physiological mechanisms that may underlie paternal activities in syngnathid males.
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Affiliation(s)
- Jennifer L Ripley
- Department of Biology, West Virginia University, Morgantown, WV, USA.
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26
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Ripley JL, Foran CM. Quantification of whole brain arginine vasotocin for two Syngnathus pipefishes: elevated concentrations correlated with paternal brooding. FISH PHYSIOLOGY AND BIOCHEMISTRY 2010; 36:867-874. [PMID: 19821043 DOI: 10.1007/s10695-009-9361-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 09/24/2009] [Indexed: 05/28/2023]
Abstract
Arginine vasotocin (AVT) regulates many aspects of fish physiology and behavior including courtship and reproduction. This study begins to address whether paternal functions for AVT have independently evolved in species in which paternal behavior has evolved. We quantified AVT in the brains of Syngnathus fuscus and Syngnathus floridae which, like other pipefishes and seahorses of the family Syngnathidae, brood embryos within specialized structures of the male. For both species, we measured AVT concentrations seventeenfold higher for some males during brooding compared to post-brooding males. Comparable whole brain AVT concentrations between gravid females and males with broods at some embryonic development stages suggest physiological similarities that we hypothesize is related to nutrient provisioning but should be elucidated with further studies including a detailed anatomical analysis of AVT production. Earlier studies have identified differences in the brooding structures of these species. Here we documented interspecific differences in the variability and mean AVT concentration for non-brooding males, the brood stage showing a return to post-brooding concentrations, and the variability of AVT concentrations for brooding males with embryos in some development stages. Future investigations should use these data to investigate the potential for divergent AVT function between species, sexes, and brooding males with embryos of different developmental stages.
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Affiliation(s)
- Jennifer L Ripley
- Department of Biology, West Virginia University, Morgantown, WV, USA.
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27
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Ripley JL, Williams PS, Foran CM. Morphological and quantitative changes in paternal brood-pouch vasculature during embryonic development in two Syngnathus pipefishes. JOURNAL OF FISH BIOLOGY 2010; 77:67-79. [PMID: 20646139 DOI: 10.1111/j.1095-8649.2010.02659.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Vascular corrosion casts of Syngnathus floridae and Syngnathus fuscus brood pouches were examined by scanning electron microscopy. Morphological and quantitative data on the vasculature of the paternal brood pouch during each stage of embryonic development were investigated to explore potential changes during brooding, to consider interspecific differences and to provide structural evidence for previously reported functional roles of the brood pouch. The brood pouches of both species are highly vascularized structures with cup-like arrangements of brood-pouch vasculature developing around each embryo shortly after fertilization and breaking down before fry release. The density and size of paternally derived blood vessels in contact with the embryos were found to be consistent for S. fuscus once this structure was established early in development. On the contrary, these vasculature measurements varied with early S. floridae brood stages when the embryo still relied heavily on the yolk sac. Diameter measurements of S. fuscus brood-pouch blood vessels were also comparatively smaller during these early developmental stages, suggesting that the structural stability and opportunity for greater transport via slower blood flow may contribute to greater paternal allocation. This is the first study to document changes in brood-pouch vasculature during specific stages of embryonic development, to show regression of this vasculature before fry release and to provide morphological data for two syngnathid species for which information on brood-pouch physiology is available.
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Affiliation(s)
- J L Ripley
- Department of Biology, West Virginia University, Morgantown, WV 26506, USA.
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28
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Wildt DE, Comizzoli P, Pukazhenthi B, Songsasen N. Lessons from biodiversity--the value of nontraditional species to advance reproductive science, conservation, and human health. Mol Reprod Dev 2010; 77:397-409. [PMID: 19967718 PMCID: PMC3929270 DOI: 10.1002/mrd.21137] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Reproduction is quintessential to species survival. But what is underappreciated for this discipline is the wondrous array of reproductive mechanisms among species- variations as diverse as the morphology of the species themselves (more than 55,000 vertebrate and 1.1 million invertebrate types). We have investigated only a tiny fraction of these species in reproductive science. Besides the need to fill enormous gaps in a scholarly database, this knowledge has value for recovering and genetically managing rare species as well as addressing certain reproductive issues in humans. This article provides examples, first to advise against oversimplifying reproduction and then to show how such knowledge can have practical use for managing whole animals, populations, or even saving an entire species. We also address the expected challenges and opportunities that could lead to creative shifts in philosophy and effective actions to benefit more species as well as a future generation of reproductive scientists.
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Affiliation(s)
- David E Wildt
- Department of Reproductive Sciences, Center for Species Survival, Smithsonian's National Zoological Park, Conservation & Research Center, Front Royal, Virginia 22630, USA.
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29
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30
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Post-copulatory sexual selection and sexual conflict in the evolution of male pregnancy. Nature 2010; 464:401-4. [DOI: 10.1038/nature08861] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 01/22/2010] [Indexed: 11/09/2022]
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