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A Cautionary Tale of Sexing by Methylation: Hybrid Bisulfite-Conversion Sequencing of Immunoprecipitated Methylated DNA in Chrysemys picta Turtles with Temperature-Dependent Sex Determination Reveals Contrasting Patterns of Somatic and Gonadal Methylation, but No Unobtrusive Sex Diagnostic. Animals (Basel) 2022; 13:ani13010117. [PMID: 36611726 PMCID: PMC9817949 DOI: 10.3390/ani13010117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Background: The gonads of Chrysemys picta, a turtle with temperature-dependent sex determination (TSD), exhibit differential DNA methylation between males and females, but whether the same is true in somatic tissues remains unknown. Such differential DNA methylation in the soma would provide a non-lethal sex diagnostic for TSD turtle hatchings who lack visually detectable sexual dimorphism when young. Methods: Here, we tested multiple approaches to study DNA methylation in tail clips of Chrysemys picta hatchlings, to identify differentially methylated candidate regions/sites that could serve as molecular sex markers To detect global differential methylation in the tails we used methylation-sensitive ELISA, and to test for differential local methylation we developed a novel hybrid method by sequencing immunoprecipitated and bisulfite converted DNA (MeDIP-BS-seq) followed by PCR validation of candidate regions/sites after digestion with a methylation-sensitive restriction enzyme. Results: We detected no global differences in methylation between males and females via ELISA. While we detected inter-individual variation in DNA methylation in the tails, this variation was not sexually dimorphic, in contrast with hatchling gonads. Conclusions: Results highlight that differential DNA methylation is tissue-specific and plays a key role in gonadal formation (primary sexual development) and maintenance post-hatching, but not in the somatic tail tissue.
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Camillo CS, Valenzuela N, Johnson SA. Effects of semi-constant temperature on embryonic and hatchling phenotypes of six-tubercled Amazon River turtles, Podocnemis sextuberculata. J Therm Biol 2022; 108:103292. [DOI: 10.1016/j.jtherbio.2022.103292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/21/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022]
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Bronikowski AM, Meisel RP, Biga PR, Walters J, Mank JE, Larschan E, Wilkinson GS, Valenzuela N, Conard AM, de Magalhães JP, Duan J, Elias AE, Gamble T, Graze R, Gribble KE, Kreiling JA, Riddle NC. Sex-specific aging in animals: Perspective and future directions. Aging Cell 2022; 21:e13542. [PMID: 35072344 PMCID: PMC8844111 DOI: 10.1111/acel.13542] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/15/2021] [Accepted: 12/11/2021] [Indexed: 12/14/2022] Open
Abstract
Sex differences in aging occur in many animal species, and they include sex differences in lifespan, in the onset and progression of age-associated decline, and in physiological and molecular markers of aging. Sex differences in aging vary greatly across the animal kingdom. For example, there are species with longer-lived females, species where males live longer, and species lacking sex differences in lifespan. The underlying causes of sex differences in aging remain mostly unknown. Currently, we do not understand the molecular drivers of sex differences in aging, or whether they are related to the accepted hallmarks or pillars of aging or linked to other well-characterized processes. In particular, understanding the role of sex-determination mechanisms and sex differences in aging is relatively understudied. Here, we take a comparative, interdisciplinary approach to explore various hypotheses about how sex differences in aging arise. We discuss genomic, morphological, and environmental differences between the sexes and how these relate to sex differences in aging. Finally, we present some suggestions for future research in this area and provide recommendations for promising experimental designs.
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Affiliation(s)
- Anne M. Bronikowski
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Richard P. Meisel
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| | - Peggy R. Biga
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
| | - James R. Walters
- Department of Ecology and Evolutionary BiologyThe University of KansasLawrenceKansasUSA
| | - Judith E. Mank
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BioscienceUniversity of ExeterPenrynUK
| | - Erica Larschan
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | | | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Ashley Mae Conard
- Department of Computer ScienceCenter for Computational and Molecular BiologyBrown UniversityProvidenceRhode IslandUSA
| | - João Pedro de Magalhães
- Integrative Genomics of Ageing GroupInstitute of Ageing and Chronic DiseaseUniversity of LiverpoolLiverpoolUK
| | | | - Amy E. Elias
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Tony Gamble
- Department of Biological SciencesMarquette UniversityMilwaukeeWisconsinUSA
- Milwaukee Public MuseumMilwaukeeWisconsinUSA
- Bell Museum of Natural HistoryUniversity of MinnesotaSaint PaulMinnesotaUSA
| | - Rita M. Graze
- Department of Biological SciencesAuburn UniversityAuburnAlabamaUSA
| | - Kristin E. Gribble
- Josephine Bay Paul Center for Comparative Molecular Biology and EvolutionMarine Biological LaboratoryWoods HoleMassachusettsUSA
| | - Jill A. Kreiling
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Nicole C. Riddle
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
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Topping NE, Valenzuela N. Turtle Nest-Site Choice, Anthropogenic Challenges, and Evolutionary Potential for Adaptation. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.808621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Oviparous animals, such as turtles, lay eggs whose success or demise depends on environmental conditions that influence offspring phenotype (morphology, physiology, and in many reptiles, also sex determination), growth, and survival, while in the nest and post-hatching. Consequently, because turtles display little parental care, maternal provisioning of the eggs and female nesting behavior are under strong selection. But the consequences of when and where nests are laid are affected by anthropogenic habitat disturbances that alter suitable nesting areas, expose eggs to contaminants in the wild, and modify the thermal and hydric environment experienced by developing embryos, thus impacting hatchling survival and the sexual fate of taxa with temperature-dependent sex determination (TSD) and genotypic sex determination (GSD). Indeed, global and local environmental change influences air, water, and soil temperature and moisture, which impact basking behavior, egg development, and conditions within the nest, potentially rendering current nesting strategies maladaptive as offspring mortality increases and TSD sex ratios become drastically skewed. Endocrine disruptors can sex reverse TSD and GSD embryos alike. Adapting to these challenges depends on genetic variation, and little to no heritability has been detected for nest-site behavior. However, modest heritability in threshold temperature (above and below which females or males develop in TSD taxa, respectively) exists in the wild, as well as interpopulation differences in the reaction norm of sex ratio to temperature, and potentially also in the expression of gene regulators of sexual development. If this variation reflects additive genetic components, some adaptation might be expected, provided that the pace of environmental change does not exceed the rate of evolution. Research remains urgently needed to fill current gaps in our understanding of the ecology and evolution of nest-site choice and its adaptive potential, integrating across multiple levels of organization.
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Mendoza P, Cerdan I, Garcia B, Furuta C, Di Santo L, Sanfilippo LF, Bícego KC, Carciofi AC. Influence of incubation temperature on embryo development, hatchling morphology and early growth rate in red-footed tortoise (Chelonoidis carbonaria). Comp Biochem Physiol A Mol Integr Physiol 2021; 259:110999. [PMID: 34098130 DOI: 10.1016/j.cbpa.2021.110999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/02/2021] [Accepted: 05/31/2021] [Indexed: 11/19/2022]
Abstract
Reptile embryos respond to temperature changes with metabolic and physiological adjustments that influence hatchling success, phenotype, behaviour, and growth rate. Climate change and global warming can affect the reptile population by altering the frequencies of hatchling survival and phenotypes. Therefore, previous studies proposed artificial incubation as a potential strategy for mitigating these effects. Red-footed tortoise (Chelonoidis carbonaria) eggs were collected and incubated at constant temperatures of 27.5 °C and 29.5 °C to investigate the physiological effects of temperature on embryo development, hatchling morphology, and early post-hatch growth rate. The direct effect of temperature on the incubation period, egg mass loss, hatching success, hatchling size, and mass was evaluated at hatching and three months of age. Hatchlings from 29.5 °C presented a shorter incubation period (141 days) than those from 27.5 °C (201 days; p < 0.05). Egg mass loss, hatchling mass, and size at hatching were not different between the incubation temperatures (p > 0.05). However, the hatching success (survival rate) was lower (64.5% versus 100%) in eggs incubated at 29.5 °C, but the hatchling mass and straight plastron width were higher at three months of age than those from eggs incubated at 27.5 °C (p < 0.05). These results indicate that incubation temperature influences hatching success and hatchling size and mass in the first months by influencing the early growth rate.
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Affiliation(s)
- Pierina Mendoza
- Department of Animal Science, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil; W.A.R.M.I. Wildlife Animal Research and Management Integration, Lima, Peru.
| | - Isaura Cerdan
- Department of Biology Sciences, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Beatriz Garcia
- Department of Biology Sciences, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Camila Furuta
- Department of Animal Science, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Ludmilla Di Santo
- Department of Clinic and Veterinary Surgery, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Luiz F Sanfilippo
- Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 2415 - Butantã, São Paulo, SP, 05508-900, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), 14884-900, Jaboticabal, São Paulo, Brazil
| | - Aulus C Carciofi
- Department of Clinic and Veterinary Surgery, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
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Gaviria-Hernández J, Páez VP, Ramírez DM, Ceballos CP. Embryo Development and Sex Ratios in the Red-Footed Tortoise (Chelonoidis carbonarius) at Masculinizing Temperatures. CHELONIAN CONSERVATION AND BIOLOGY 2021. [DOI: 10.2744/ccb-1441.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Juliana Gaviria-Hernández
- Grupo GAMMA, Escuela de Medicina Veterinaria, Facultad de Ciencias Agrarias, Universidad de Antioquia, Calle 70 N° 52-21, Medellín, Colombia [; ]
| | - Vivian P. Páez
- Grupo Herpetológico de Antioquia, Instituto de Biología, Universidad de Antioquia, Calle 70 N° 52-21, Medellín, Colombia []
| | - Diber M. Ramírez
- Centro de Atención y Valoración del Área Metropolitana del Valle de Aburrá, Medellín, Colombia []
| | - Claudia P. Ceballos
- Grupo GAMMA, Escuela de Medicina Veterinaria, Facultad de Ciencias Agrarias, Universidad de Antioquia, Calle 70 N° 52-21, Medellín, Colombia [; ]
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Valenzuela N. Podocnemis expansa Turtles Hint to a Unifying Explanation for the Evolution of Temperature-Dependent Sex Determination in Long-Lived and Short-Lived Vertebrates. Sex Dev 2021; 15:23-37. [PMID: 34004596 DOI: 10.1159/000515208] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/07/2021] [Indexed: 11/19/2022] Open
Abstract
The adaptive significance of temperature-dependent sex determination (TSD) remains elusive for many long-lived reptiles. Various hypotheses proposed potential ecological drivers of TSD. The Charnov-Bull'77 model remains the most robust and explains the maintenance of TSD in short-lived vertebrates, where sex ratios correlate with seasonal temperatures within years that confer sex-specific fitness (colder springs produce females who grow larger and gain in fecundity, whereas warmer summers produce males who mature at smaller size). Yet, evidence of fitness differentials correlated with incubation temperature is scarce for long-lived taxa. Here, it is proposed that the Charnov-Bull'77 model applies similarly to long-lived taxa, but at a longer temporal scale, by revisiting ecological and genetic data from the long-lived turtle Podocnemis expansa. After ruling out multiple alternatives, it is hypothesized that warmer-drier years overproduce females and correlate with optimal resource availability in the flood plains, benefitting daughters more than sons, whereas resources are scarcer (due to reduced flowering/fruiting) during colder-rainier years that overproduce males, whose fitness is less impacted by slower growth rates. New technical advances and collaborative interdisciplinary efforts are delineated that should facilitate testing this hypothesis directly, illuminating the understanding of TSD evolution in P. expansa and other long-lived TSD reptiles.
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Affiliation(s)
- Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
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Variation in shell morphology of the European pond turtle, Emys orbicularis, in fragmented central European populations. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The European pond turtle (Emys orbicularis) is a widely distributed freshwater species inhabiting much of Europe, but it is often in population decrease or is locally extinct. In this study, we sampled five central European populations, of which four were autochthonous and one was introduced outside the native range. Moreover, two of the native populations were relatively isolated and at the periphery of the species, range. Using the frequency of shell anomalies, a geometric morphometric framework and an analysis of fluctuating asymmetry, we aimed to determine the degree of morphological differentiation among different populations. Significantly, a smaller number of individuals with a malformed shell or scutes occurred in the native core range population, which potentially has a high level of gene flow (Hungary). Although neither canonical variate analysis nor the morphological disparity analysis showed distinct differences between populations, we found significantly higher shell asymmetry in the two marginal populations (Austria and Slovakia) compared with the core range populations. Our results might thus support the central–marginal hypothesis and indicate potential genetically based conservation problems owing to demographic bottlenecks and/or isolation in marginal populations.
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Tezak B, Sifuentes-Romero I, Milton S, Wyneken J. Identifying Sex of Neonate Turtles with Temperature-dependent Sex Determination via Small Blood Samples. Sci Rep 2020; 10:5012. [PMID: 32193464 PMCID: PMC7081227 DOI: 10.1038/s41598-020-61984-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/21/2020] [Indexed: 12/04/2022] Open
Abstract
Temperature-dependent sex determination, present in most turtle species, is a mechanism that uses temperature to direct the sex of the embryo. The rapid increase of global temperatures highlights the need for a clear assessment of how sex ratios of organisms with TSD are affected. In turtles with TSD, quantifying primary sex ratios is challenging because they lack external dimorphism and heteromorphic sex chromosomes. Here we describe a new technique used to identify sex in neonate turtles of two TSD species, a freshwater turtle (Trachemys scripta) and a marine turtle (Caretta caretta) via analysis of small blood samples. We used an immunoassay approach to test samples for the presence of several proteins known to play an important role in sex differentiation. Our results show that Anti-Mullerian Hormone (AMH) can be reliably detected in blood samples from neonate male turtles but not females and can be used as a sex-specific marker. Verification of sex via histology or laparoscopy revealed that this method was 100% reliable for identifying sex in both T. scripta and C. caretta 1-2 day-old hatchlings and 90% reliable for identifying sex in 83-177 day-old (120-160 g) loggerhead juveniles. The method described here is minimally invasive, and for the first time, greatly enhances our ability to measure neonate turtle sex ratios at population levels across nesting sites worldwide, a crucial step in assessing the impact of climate change on imperiled turtle species.
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Affiliation(s)
- Boris Tezak
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431-0991, USA.
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Itzel Sifuentes-Romero
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431-0991, USA
| | - Sarah Milton
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431-0991, USA
| | - Jeanette Wyneken
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431-0991, USA
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Mitchell TS, Janzen FJ, Warner DA. Quantifying the effects of embryonic phenotypic plasticity on adult phenotypes in reptiles: A review of current knowledge and major gaps. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:203-214. [DOI: 10.1002/jez.2187] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/10/2018] [Accepted: 05/12/2018] [Indexed: 01/10/2023]
Affiliation(s)
- Timothy S. Mitchell
- Department of Biological Sciences Auburn University Auburn Alabama
- Department of Ecology, Evolution and Behavior University of Minnesota Saint Paul Minnesota
| | - Fredric J. Janzen
- Department of Ecology, Evolution, and Organismal Biology Iowa State University Ames Iowa
| | - Daniel A. Warner
- Department of Biological Sciences Auburn University Auburn Alabama
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Hernández-Montoya V, Páez VP, Ceballos CP. Effects of Temperature on Sex Determination and Embryonic Development in the Red-footed Tortoise,Chelonoidis carbonarius. CHELONIAN CONSERVATION AND BIOLOGY 2017. [DOI: 10.2744/ccb-1267.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Viviana Hernández-Montoya
- Grupo GaMMA, Escuela de Medicina Veterinaria, Facultad de Ciencias Agrarias, Universidad de Antioquia, Carrera 75 N° 65-87, Medellín, Colombia []
| | - Vivian P. Páez
- Grupo Herpetológico de Antioquia, Instituto de Biología, Universidad de Antioquia, Calle 70 N° 52-21, Medellín, Colombia []
| | - Claudia P. Ceballos
- Grupo GaMMA, Escuela de Medicina Veterinaria, Facultad de Ciencias Agrarias, Universidad de Antioquia, Carrera 75 N° 65-87, Medellín, Colombia []
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12
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Brown GP, Madsen TRL, Shine R. Resource availability and sexual size dimorphism: differential effects of prey abundance on the growth rates of tropical snakes. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12877] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Gregory P. Brown
- School of Life and Environmental Sciences University of Sydney Heydon‐Laurence Building A08 Sydney NSW2006 Australia
| | - Thomas R. L. Madsen
- School of Life and Environmental Sciences Deakin University Burwood VIC3217 Australia
| | - Rick Shine
- School of Life and Environmental Sciences University of Sydney Heydon‐Laurence Building A08 Sydney NSW2006 Australia
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Literman R, Radhakrishnan S, Tamplin J, Burke R, Dresser C, Valenzuela N. Development of sexing primers in Glyptemys insculpta and Apalone spinifera turtles uncovers an XX/XY sex-determining system in the critically-endangered bog turtle Glyptemys muhlenbergii. CONSERV GENET RESOUR 2017. [DOI: 10.1007/s12686-017-0711-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Regis KW, Meik JM. Allometry of sexual size dimorphism in turtles: a comparison of mass and length data. PeerJ 2017; 5:e2914. [PMID: 28149687 PMCID: PMC5267567 DOI: 10.7717/peerj.2914] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/14/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The macroevolutionary pattern of Rensch's Rule (positive allometry of sexual size dimorphism) has had mixed support in turtles. Using the largest carapace length dataset and only large-scale body mass dataset assembled for this group, we determine (a) whether turtles conform to Rensch's Rule at the order, suborder, and family levels, and (b) whether inferences regarding allometry of sexual size dimorphism differ based on choice of body size metric used for analyses. METHODS We compiled databases of mean body mass and carapace length for males and females for as many populations and species of turtles as possible. We then determined scaling relationships between males and females for average body mass and straight carapace length using traditional and phylogenetic comparative methods. We also used regression analyses to evalutate sex-specific differences in the variance explained by carapace length on body mass. RESULTS Using traditional (non-phylogenetic) analyses, body mass supports Rensch's Rule, whereas straight carapace length supports isometry. Using phylogenetic independent contrasts, both body mass and straight carapace length support Rensch's Rule with strong congruence between metrics. At the family level, support for Rensch's Rule is more frequent when mass is used and in phylogenetic comparative analyses. Turtles do not differ in slopes of sex-specific mass-to-length regressions and more variance in body size within each sex is explained by mass than by carapace length. DISCUSSION Turtles display Rensch's Rule overall and within families of Cryptodires, but not within Pleurodire families. Mass and length are strongly congruent with respect to Rensch's Rule across turtles, and discrepancies are observed mostly at the family level (the level where Rensch's Rule is most often evaluated). At macroevolutionary scales, the purported advantages of length measurements over weight are not supported in turtles.
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Affiliation(s)
- Koy W Regis
- Department of Biological Sciences, Tarleton State University , Stephenville , TX , United States
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University , Stephenville , TX , United States
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Gómez-Saldarriaga C, Valenzuela N, Ceballos CP. Effects of Incubation Temperature on Sex Determination in the Endangered Magdalena River Turtle,Podocnemis lewyana. CHELONIAN CONSERVATION AND BIOLOGY 2016. [DOI: 10.2744/ccb-1170.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Literman R, Badenhorst D, Valenzuela N. qPCR-based molecular sexing by copy number variation in rRNA genes and its utility for sex identification in soft-shell turtles. Methods Ecol Evol 2014. [DOI: 10.1111/2041-210x.12228] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Robert Literman
- Department of Ecology, Evolution and Organismal Biology; Iowa State University; 251 Bessey Hall Ames IA 50011 USA
| | - Daleen Badenhorst
- Department of Ecology, Evolution and Organismal Biology; Iowa State University; 251 Bessey Hall Ames IA 50011 USA
| | - Nicole Valenzuela
- Department of Ecology, Evolution and Organismal Biology; Iowa State University; 251 Bessey Hall Ames IA 50011 USA
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Ceballos CP, Brand WA. Morphometric Characterization of the Mesoamerican Slider (Trachemys venusta, Emydidae) from the Atrato river basin, Colombia. ACTA BIOLÓGICA COLOMBIANA 2014. [DOI: 10.15446/abc.v19n3.42195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Ceballos CP, Romero I, Gómez Saldarriaga C, Miranda K. REPRODUCTION AND CONSERVATION OF THE MAGDALENA RIVER TURTLE (Podocnemis lewyana) IN THE CLARO COCORNÁ SUR RIVER, COLOMBIA. ACTA BIOLÓGICA COLOMBIANA 2014. [DOI: 10.15446/abc.v19n3.41366] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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