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Akef MS. Reproductive and Morphological Characteristics of Hemidactylus turcicus (Squamata: Gekkonidae) and Tarentola annularis (Squamata: Phyllodactylidae) in Southern Egypt. ICHTHYOLOGY & HERPETOLOGY 2023. [DOI: 10.1643/h2021109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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2
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Raynal RS, Schwanz LE, Riley JL, Umbers KDL. Genetic and environmental drivers of colour and pattern in the Australian jacky dragon (Amphibolurus muricatus). J Evol Biol 2022; 35:1229-1239. [PMID: 35861703 PMCID: PMC9544122 DOI: 10.1111/jeb.14066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/06/2022] [Accepted: 06/29/2022] [Indexed: 11/26/2022]
Abstract
The underlying drivers of variation in the colouration (colour and pattern) of animals can be genetic, non‐genetic, or more likely, a combination of both. Understanding the role of heritable genetic elements, as well as non‐genetic factors such as age, habitat or temperature, in shaping colouration can provide insight into the evolution and function of these traits, as well as the speed of response to changing environments. This project examined the genetic and non‐genetic drivers of continuous variation in colouration in a lizard, the jacky dragon (Amphibolurus muricatus). We leveraged a large captive experiment that manipulated parental and offspring thermal environment to simultaneously estimate the genetic and non‐genetic drivers of variation in colouration. We found that the overall brightness, the elongation of the longitudinal stripes on the dorsum and the contrast between light and dark patches of the pattern were all heritable. Colouration varied according to the age of the hatchling; however, the thermal environment of neither the parents nor offspring contributed significantly to colouration. It appears that developmental plasticity and maternal effects associated with temperature are not important drivers of variation in our measures of colouration.
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Affiliation(s)
- Rebecca S Raynal
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Lisa E Schwanz
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Julia L Riley
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.,Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Kate D L Umbers
- School of Science, Western Sydney University, Penrith, New South Wales, Australia.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
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3
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Nie H, Wen Y, Zhang R, Wu M, Zhang Y, Xu Y, Zhan J, Wu X. Histology, ultrastructure, and differential gene expression in relation to seasonal sperm storage in the oviduct of the Chinese alligator, Alligator sinensis. Reprod Fertil Dev 2022; 34:819-832. [PMID: 35577543 DOI: 10.1071/rd21191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 04/13/2022] [Indexed: 11/23/2022] Open
Abstract
Although oviductal sperm storage are essential steps in reproduction for female animals with internal fertilisation, no systematic study on the identification of genes involving sperm storage has been performed in crocodilian species. In the present research, the relationship between morphological variation related to sperm storage in the oviduct and gene expression patterns derived from RNA sequencing analyses between active period (AP), breeding period (BP), and hibernation period (HP) were investigated. The corresponding results indicated that sperm were observed not only in the ciliated cells within infundibulum and mucosal layer of uterus during BP, but also been detected in the spermatosperm storage tube (SST) in the anterior uterus at HP stage. The further transmission electron microscopy analysis indicated that the differences in the number and activity of the secretory cells likely to attributed to the seasonal variation of microenvironment related to the sperm storage. Based on the RNA-sequecing, 13147 DEGs related to the Peroxisome proliferator-activated receptors (PPARs) and FOXO signalling were identified, including these, the down-regulated ATG12 and BCL2L11 in the HP group may thus constitute an important point of convergence between autophagy and apoptosis involving the FOXO1 pathway. The genes involved in the PPARs pathway might modulate the immune response and thereby contribute to prolong the life span of stored spermatozoa in Alligator sinensis. The outcomes of this study provide fundamental insights into the mechanism of sperm storage in A. sinensis.
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Affiliation(s)
- Haitao Nie
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yue Wen
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Ruidong Zhang
- College of Life Sciences, Inner Mongolia Normal University, Hohhot, Inner Mongolia 010022, China
| | - Mengjuan Wu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yuqian Zhang
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yunlu Xu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Jixiang Zhan
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xiaobing Wu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
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4
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Dong CM, Rankin KJ, McLean CA, Stuart-Fox D. Maternal reproductive output and F1 hybrid fitness may influence contact zone dynamics. J Evol Biol 2021; 34:680-694. [PMID: 33580546 DOI: 10.1111/jeb.13772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022]
Abstract
The outcome of secondary contact between divergent lineages or species may be influenced by both the reproductive traits of parental species and the fitness of offspring; however, their relative contributions have rarely been evaluated, particularly in longer-lived vertebrate species. We performed pure and reciprocal laboratory crosses between Ctenophorus decresii (tawny dragon) and C. modestus (swift dragon) to examine how parental reproductive traits and ecologically relevant offspring fitness traits may explain contact zone dynamics in the wild. The two species meet in a contact zone of post-F1 hybrids with asymmetric backcrossing and predominantly C. modestus mtDNA haplotypes. We found no evidence for reduced parental fecundity or offspring fitness for F1 hybrid crosses. However, maternal reproductive strategy differed between species, irrespective of the species of their mate. Ctenophorus modestus females had higher fecundity and produced more and larger clutches with lower embryonic mortality. Parental species also influenced sex ratios and offspring traits, with C. modestus ♀ × C. decresii ♂ hybrids exhibiting higher trait values for more fitness measures (growth rate, sprint speed, bite force) than offspring from all other pairings. Together, these patterns are consistent with the prevalence of C. modestus mtDNA in the contact zone, and asymmetric backcrossing likely reflects fitness effects that manifest in the F2 generation. Our results highlight how parental species can influence multiple offspring traits in different ways, which together may combine to influence offspring fitness and shape contact zone dynamics.
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Affiliation(s)
- Caroline M Dong
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia.,Sciences Department, Museums Victoria, Melbourne, Vic., Australia
| | - Katrina J Rankin
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia
| | - Claire A McLean
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia.,Sciences Department, Museums Victoria, Melbourne, Vic., Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia
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5
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Friesen CR, Kahrl AF, Olsson M. Sperm competition in squamate reptiles. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200079. [PMID: 33070739 DOI: 10.1098/rstb.2020.0079] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Multiple paternity is ubiquitous within the polyphyletic group called 'reptiles', especially within the lizards and snakes. Therefore, the probability of sperm competition occurring, and being intense, is high. Squamates exhibit a diversity of tactics to ensure fertilization success in the face of sperm competition. The duration of female sperm storage, which can be many months and even years in some species, remains an enigma. Here, we emphasize some mechanisms that might affect patterns of paternity, the source and function of ejaculates and features of the female reproductive tract that may aid in long-term sperm storage. In doing so, we present a new analysis of the relationship between sperm size, the strength of sperm competition and the duration of female sperm storage. Lizards and snakes are a diverse group that has provided many excellent models for the study of an array of life-history strategies. However, when it comes to postcopulatory sexual selection, there is much left to discover. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.,Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Ariel F Kahrl
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Mats Olsson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.,Department of Biological and Environmental Science, University of Gothenburg, Goteborg, Sweden
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6
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Aldridge RD, Siegel DS, Goldberg SR, Pyron RA. Seasonal Timing of Spermatogenesis and Mating in Squamates: A Reinterpretation. COPEIA 2020. [DOI: 10.1643/ch-19-230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Robert D. Aldridge
- Department of Biology, Saint Louis University (Emeritus), St. Louis, Missouri 63103; . Send reprint requests to this address
| | - Dustin S. Siegel
- Department of Biology, Southeast Missouri State University, Cape Girardeau, Missouri 63701;
| | | | - R. Alexander Pyron
- Department of Biological Sciences, The George Washington University, Washington, D.C. 20052;
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7
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McLean CA, Bartle RA, Dong CM, Rankin KJ, Stuart-Fox D. Divergent male and female mate preferences do not explain incipient speciation between lizard lineages. Curr Zool 2020; 66:485-492. [PMID: 33293929 PMCID: PMC7705505 DOI: 10.1093/cz/zoaa010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/09/2020] [Indexed: 11/13/2022] Open
Abstract
Diversification in sexual signals is often taken as evidence for the importance of sexual selection in speciation. However, in order for sexual selection to generate reproductive isolation between populations, both signals and mate preferences must diverge together. Furthermore, assortative mating may result from multiple behavioral mechanisms, including female mate preferences, male mate preferences, and male–male competition; yet their relative contributions are rarely evaluated. Here, we explored the role of mate preferences and male competitive ability as potential barriers to gene flow between 2 divergent lineages of the tawny dragon lizard, Ctenophorus decresii, which differ in male throat coloration. We found stronger behavioral barriers to pairings between southern lineage males and northern lineage females than between northern males and southern females, indicating incomplete and asymmetric behavioral isolating barriers. These results were driven by both male and female mate preferences rather than lineage differences in male competitive ability. Intrasexual selection is therefore unlikely to drive the outcome of secondary contact in C. decresii, despite its widely acknowledged importance in lizards. Our results are consistent with the emerging view that although both male and female mate preferences can diverge alongside sexual signals, speciation is rarely driven by divergent sexual selection alone.
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Affiliation(s)
- Claire A McLean
- School of BioSciences, The University of Melbourne, Parkville VIC 3010, Australia.,Sciences Department, Museums Victoria, Carlton VIC 3053, Australia
| | - Richard A Bartle
- School of BioSciences, The University of Melbourne, Parkville VIC 3010, Australia
| | - Caroline M Dong
- School of BioSciences, The University of Melbourne, Parkville VIC 3010, Australia.,Sciences Department, Museums Victoria, Carlton VIC 3053, Australia
| | - Katrina J Rankin
- School of BioSciences, The University of Melbourne, Parkville VIC 3010, Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville VIC 3010, Australia
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8
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Melo GC, Nascimento LB, Galdino CAB. Lizard reproductive biology beyond the gonads: An investigation of sperm storage structures and renal sexual segments. ZOOLOGY 2019; 135:125690. [PMID: 31383295 DOI: 10.1016/j.zool.2019.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/17/2019] [Accepted: 05/14/2019] [Indexed: 11/25/2022]
Abstract
In this study, we investigated the reproductive biology of the small lizard Eurolophosaurus nanuzae based on evidence of sperm storage by females and variations of the renal sexual segment (RSS) in males. We found a remarkable occurrence of crypts containing bundles of sperm and secretions in the epithelium of E. nanuzae oviducts. The chemical composition of the secretions associated with the sperm within the crypts was similar to secretions from the oviductal epithelium, which suggests that females can produce substances involved in the maintenance of stored sperm. Female sperm storage does not occur over the span of years for long-term reproduction; the majority of females with stored sperm occurred during the peak and late periods of the reproductive season. We discuss this result in relation to post-copulatory sexual selection strategies in the context of sperm competition for restricted successful fertilisation. In males, testicular activity was continuous, while RSS activity varied seasonally, in synchrony with female reproductive activity. Throughout the reproductive season, the RSS was hypertrophied, with maximum activity during the peak of the reproductive season. The lowest RSS activity occurred when females were not reproductive (non-reproductive season). Considering that RSS secretions are essential for reproduction, an absence or reduction of these secretions during the non-reproductive season may imply the reduced functionality of sperm during this period. Since sperm production continues throughout the whole reproductive cycle in E. nanuzae males, RSS activity could be an important indicator of reproduction, beyond testicular activity.
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Affiliation(s)
- Gabriela C Melo
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil; Neotropical Lizard Behavioural Ecology Research Group (NeoLiBE), Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil.
| | - Luciana B Nascimento
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil
| | - Conrado A B Galdino
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil; Neotropical Lizard Behavioural Ecology Research Group (NeoLiBE), Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil
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9
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Chen H, Liu T, Holt WV, Yang P, Zhang L, Zhang L, Han X, Bian X, Chen Q. Advances in understanding mechanisms of long-term sperm storage-the soft-shelled turtle model. Histol Histopathol 2019; 35:1-23. [PMID: 31290136 DOI: 10.14670/hh-18-148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Long-term sperm storage is a special reproductive strategy, which can extend the time window between mating and fertilization in some animal species. Spermatozoa of the soft-shelled turtle, Pelodiscus sinensis, can be stored in the epididymis and oviduct for at least six months and one year, respectively. How spermatozoa can be stored in vivo for such a prolonged period is yet to be explained. We analyze the mechanisms that contribute to long-term sperm storage in P. sinensis, and compare them with other species from three different perspectives: the spermatozoon itself, the storage microenvironment and the interaction between the spermatozoon and microenvironment. Characteristics of soft-shelled turtle spermatozoa itself, such as the huge cytoplasmic droplet with its content of several large lipid droplets (LDs) and onion-like mitochondira, facilitate long-term sperm storage. The microenvironment of reproductive tract, involving in the secretions, structural barriers, exosomes, androgen receptors, Toll-like receptors and survival factor Bcl-2, are important for the maintenance of spermatozoa long-term storage. Sperm heads are always embedded among the oviductal cilia and even intercalate into the apical hollowness of the ciliated cells, indicating that the ciliated cells support the stored spermatozoa. RNA seq is firstly used to detect the molecular mechanism of sperm storage, which shows that autophagy, apoptosis and immune take part in the long-term sperm storage in this species.
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Affiliation(s)
- Hong Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Tengfei Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - William V Holt
- Academic Unit of Reproductive and Developmental Medicine, University of Sheffield, United Kingdom
| | - Ping Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Linli Zhang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Li Zhang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Xiangkun Han
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Xunguang Bian
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Qiusheng Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China.
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10
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Gasparini C, Daymond E, Evans JP. Extreme fertilization bias towards freshly inseminated sperm in a species exhibiting prolonged female sperm storage. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172195. [PMID: 29657813 PMCID: PMC5882737 DOI: 10.1098/rsos.172195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/02/2018] [Indexed: 06/01/2023]
Abstract
The storage of sperm by females across successive reproductive cycles is well documented in internal fertilizers, yet the fate of stored sperm when they compete with 'new' sperm to fertilize a female's eggs has rarely been considered. This gap in our understanding is likely due to the logistical difficulties of controlling behavioural interactions during or after mating, which in turn may influence how many sperm are inseminated and how stored sperm are ultimately used during successive bouts of sperm competition with freshly inseminated sperm. Here, we use artificial insemination (AI) in guppies (Poecilia reticulata), a polyandrous live-bearing poeciliid fish exhibiting prolonged sperm storage by females, to overcome these challenges. The use of AI enables us to control potential differential maternal effects (e.g. behaviourally mediated cryptic female choice) and specifically test for post-copulatory paternity biases that favour either stored or fresh sperm when they compete to fertilize eggs. Our paternity analyses revealed the almost complete dominance of freshly inseminated sperm over stored sperm, supporting previous studies reporting similar patterns following natural matings across successive brood cycles. However, our use of AI, which excluded behavioural interactions between males and females, most likely generated a far stronger pattern of fresh sperm precedence compared with those reported in previous studies, possibly implicating 'cryptic' forms of selection by females that may sometimes bolster the success of stored sperm.
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11
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Giraudeau M, Friesen CR, Sudyka J, Rollings N, Whittington CM, Wilson MR, Olsson M. Ageing and the cost of maintaining coloration in the Australian painted dragon. Biol Lett 2017; 12:rsbl.2016.0077. [PMID: 27405377 DOI: 10.1098/rsbl.2016.0077] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/21/2016] [Indexed: 12/19/2022] Open
Abstract
There is now good evidence in several taxa that animal coloration positively reflects an individual's antioxidant capacity. However, even though telomeres, a marker of ageing, are known to be vulnerable to reactive oxygen species (ROS) attacks, no studies have ever assessed whether colour fading reflects the rate of biological ageing in any taxa. Here, we measured colour fading, telomere erosion (a measure of biological ageing) and ROS levels in painted dragons. We show that individuals that were better at maintaining their coloration during the three months of the study suffered a higher cost in terms of telomere erosion, but overall ROS levels measured at the start of the study were not significantly related to colour maintenance and telomere shortening. We therefore suggest that colour maintenance is a costly phenomenon in terms of telomere erosion, and that overall ROS levels do not seem to be a crucial component linking ornamental coloration and telomere erosion in our study system.
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Affiliation(s)
- Mathieu Giraudeau
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia School of Life Sciences, Arizona State University, Tempe, AZ, USA Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK
| | - Christopher R Friesen
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Joanna Sudyka
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland
| | - Nicky Rollings
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Camilla M Whittington
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Mark R Wilson
- School of Biological Sciences, University of Wollongong, New South Wales, Australia
| | - Mats Olsson
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
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12
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Hacking J, Stuart-Fox D, Gardner M. Very low rate of multiple paternity detected in clutches of a wild agamid lizard. AUST J ZOOL 2017. [DOI: 10.1071/zo18006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Genetic mating systems described for squamate reptiles range from primarily monogamous to completely polygynandrous. The presence of female multiple mating is almost ubiquitous among squamates and even occurs, albeit at a low rate, in socially monogamous species. Here we examine the genetic mating system of the territorial tawny dragon lizard (Ctenophorus decresii). Paternity was assigned to captive-born hatchlings using eight microsatellite loci, revealing a 4% rate of multiple paternity. One-quarter of males sired more than one clutch, although multiple mating by males is likely underestimated. The rate of multiple paternity in C. decresii represents one of the lowest among squamates and may be a result of successful male territoriality. However, the observed low rate of multiple paternity does not eliminate the possibility of widespread female multiple mating due to the potential for sperm storage and sperm competition. We conclude that the tawny dragon lizard employs a predominantly polygynous genetic mating system.
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13
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Rankin KJ, McLean CA, Kemp DJ, Stuart-Fox D. The genetic basis of discrete and quantitative colour variation in the polymorphic lizard, Ctenophorus decresii. BMC Evol Biol 2016; 16:179. [PMID: 27600682 PMCID: PMC5012029 DOI: 10.1186/s12862-016-0757-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/31/2016] [Indexed: 11/15/2022] Open
Abstract
Background Colour polymorphic species provide invaluable insight into processes that generate and maintain intra-specific variation. Despite an increasing understanding of the genetic basis of discrete morphs, sources of colour variation within morphs remain poorly understood. Here we use the polymorphic tawny dragon lizard Ctenophorus decresii to test simple Mendelian models for the inheritance of discrete morphs, and to investigate the genetic basis of continuous variation among individuals across morphs. Males of this species express either orange, yellow, orange surrounded by yellow, or grey throats. Although four discrete morphs are recognised, the extent of orange and yellow varies greatly. We artificially elevated testosterone in F0 females and F1 juveniles to induce them to express the male throat colour polymorphism, and quantified colour variation across the pedigree. Results Inheritance of discrete morphs in C. decresii best fit a model whereby two autosomal loci with complete dominance respectively determine the presence of orange and yellow. However, a single locus model with three co-dominant alleles for orange, yellow and grey could not be definitively rejected. Additionally, quantitative expression of the proportion of orange and yellow on the throat was strongly heritable (orange: h2 = 0.84 ± 0.14; yellow: h2 = 0.67 ± 0.19), with some evidence for covariance between the two. Conclusions Our study supports the theoretical prediction that polymorphism should be governed by few genes of major effect, but implies broader genetic influence on variation in constituent morph traits. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0757-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katrina J Rankin
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Claire A McLean
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Sciences, Museum Victoria, Carlton Gardens, VIC, 3053, Australia
| | - Darrell J Kemp
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
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14
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Devigili A, Di Nisio A, Grapputo A, Pilastro A. Directional postcopulatory sexual selection is associated with female sperm storage in Trinidadian guppies. Evolution 2016; 70:1829-43. [PMID: 27345870 DOI: 10.1111/evo.12989] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 12/17/2022]
Abstract
Female sperm storage (FSS) is taxonomically widespread and often associated with intense sperm competition, yet its consequences on postcopulatory sexual selection (PCSS) are poorly known. Theory predicts that FSS will reduce the strength of PCSS, because sperm characteristics favored before and after FSS may be traded-off, and opportunities for nondirectional PCSS should increase. We explored these questions in the guppy (Poecilia reticulata), by allowing females to mate multiply and by comparing the paternity pattern in two successive broods. Contrary to predictions, the variance in male fertilization success increased after FSS, driven by a change in male paternity share across broods. This change was positively associated with sperm velocity (measured before FSS) but not with the duration of FSS, indirectly suggesting that faster sperm were better in entering female storage organs, rather than in persisting within them. Other male traits, such as male size and orange color, heterozygosity, and relatedness to the female, did not influence paternity after FSS. These results indicate that processes associated with FSS tend to reinforce the strength of PCSS in guppies, rather than weaken it. Further work is necessary to test whether this pattern changes in case of more prolonged FSS.
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Affiliation(s)
| | - Andrea Di Nisio
- Department of Biology, University of Padua, I-35131, Padova, Italy
| | | | - Andrea Pilastro
- Department of Biology, University of Padua, I-35131, Padova, Italy.
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15
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Friesen CR, Kerns AR, Mason RT. Factors influencing paternity in multiply mated female red-sided garter snakes and the persistent use of sperm stored over winter. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1749-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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