1
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Wild KH, Roe JH, Schwanz L, Rodgers E, Dissanayake DSB, Georges A, Sarre SD, Noble DWA. Metabolic consequences of sex reversal in two lizard species: a test of the like-genotype and like-phenotype hypotheses. J Exp Biol 2023; 226:jeb245657. [PMID: 37309620 PMCID: PMC10357012 DOI: 10.1242/jeb.245657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 06/05/2023] [Indexed: 06/14/2023]
Abstract
Vertebrate sex is typically determined genetically, but in many ectotherms sex can be determined by genes (genetic sex determination, GSD), temperature (temperature-dependent sex determination, TSD), or interactions between genes and temperature during development. TSD may involve GSD systems with either male or female heterogamety (XX/XY or ZZ/ZW) where temperature overrides chromosomal sex determination to cause a mismatch between genetic sex and phenotypic sex (sex reversal). In these temperature-sensitive lineages, phylogenetic investigations point to recurrent evolutionary shifts between genotypic and temperature-dependent sex determination. These evolutionary transitions in sex determination can occur rapidly if selection favours the reversed sex over the concordant phenotypic sex. To investigate the consequences of sex reversal on offspring phenotypes, we measured two energy-driven traits (metabolism and growth) and 6 month survival in two species of reptile with different patterns of temperature-induced sex reversal. Male sex reversal occurs in Bassiana duperreyi when chromosomal females (female XX) develop male phenotypes (maleSR XX), while female sex reversal occurs in Pogona vitticeps when chromosomal males (male ZZ) develop female phenotypes (femaleSR ZZ). We show metabolism in maleSR XX was like that of male XY; that is, reflective of phenotypic sex and lower than genotypic sex. In contrast, for Pogona vitticeps, femaleSR ZZ metabolism was intermediate between male ZZ and female ZW metabolic rate. For both species, our data indicate that differences in metabolism become more apparent as individuals become larger. Our findings provide some evidence for an energetic advantage from sex reversal in both species but do not exclude energetic processes as a constraint on the distribution of sex reversal in nature.
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Affiliation(s)
- Kristoffer H. Wild
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, AUS
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Canberra, ACT 2617, AUS
| | - John H. Roe
- Department of Biology, University of North Carolina Pembroke, Pembroke, NC 28372-1510, USA
| | - Lisa Schwanz
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Essie Rodgers
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA 6150, Australia
| | - Duminda S. B. Dissanayake
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Canberra, ACT 2617, AUS
| | - Arthur Georges
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Canberra, ACT 2617, AUS
| | - Stephen D. Sarre
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Canberra, ACT 2617, AUS
| | - Daniel W. A. Noble
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, AUS
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2
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Matthews G, Farquhar JE, White CR, Chapple DG. Does thermal biology differ between two colour pattern morphs of a widespread Australian lizard? J Therm Biol 2023; 114:103579. [PMID: 37344018 DOI: 10.1016/j.jtherbio.2023.103579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 06/23/2023]
Abstract
Alternative phenotypes allow individuals to pursue different adaptive pathways in response to the same selective challenge. Colour polymorphic species with geographically varying morph frequencies may reflect multiple adaptations to spatial variables such as temperature and climate. We examined whether thermal biology differed between colour morphs of an Australian lizard, the delicate skink, Lampropholis delicata. The delicate skink has two colour pattern morphs, with frequencies varying across latitude and sex: plain (darker, more common at temperate latitudes, more common in males) or striped (lighter, more common at lower latitudes, more common in females). We tested heating and cooling rate, sprint speed, thermal preference, field body temperature and metabolic rate in both morphs and sexes to determine any link between colour and morph frequency distribution. Plain individuals heated more quickly, but other thermal traits showed little variation among morphs. Lampropholis delicata colour influences rates of heat exchange, but the relationship does not appear to be adaptive, suggesting that behavioural thermoregulation homogenises body temperature in the field. While we find no substantial evidence of thermal differences between the two colour morphs, morph-specific behaviour may buffer against differences in heat exchange. Latitudinal variation in species colour may be driven by selection pressures other than temperature.
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Affiliation(s)
- Genevieve Matthews
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Jules E Farquhar
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Craig R White
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia; Centre for Geometric Biology, Monash University, Clayton, Victoria, 3800, Australia
| | - David G Chapple
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia.
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3
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Environmental variation promotes colour morph-specific behavioural differences in a cichlid fish. Anim Behav 2023. [DOI: 10.1016/j.anbehav.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Abstract
AbstractPhenotypic plasticity is an important mechanism that allows populations to adjust to changing environments. Early life experiences can have lasting impacts on how individuals respond to environmental variation later in life (i.e., individual reaction norms), altering the capacity for populations to respond to selection. Here, we incubated lizard embryos (Lampropholis delicata) at two fluctuating developmental temperatures (cold = 23 ºC + / − 3 ºC, hot = 29 ºC + / − 3 ºC, ncold = 26, nhot = 25) to understand how it affected metabolic plasticity to temperature later in life. We repeatedly measured individual reaction norms across six temperatures 10 times over ~ 3.5 months (nobs = 3,818) to estimate the repeatability of average metabolic rate (intercept) and thermal plasticity (slope). The intercept and the slope of the population-level reaction norm was not affected by developmental temperature. Repeatability of average metabolic rate was, on average, 10% lower in hot incubated lizards but stable across all temperatures. The slope of the thermal reaction norm was overall moderately repeatable (R = 0.44, 95% CI = 0.035 – 0.93) suggesting that individual metabolic rate changed consistently with short-term changes in temperature, although credible intervals were quite broad. Importantly, reaction norm repeatability did not depend on early developmental temperature. Identifying factors affecting among-individual variation in thermal plasticity will be increasingly more important for terrestrial ectotherms living in changing climate. Our work implies that thermal metabolic plasticity is robust to early developmental temperatures and has the capacity to evolve, despite there being less consistent variation in metabolic rate under hot environments.
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5
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Comizzoli P, Holt WV. Recent Progress in Spermatology Contributing to the Knowledge and Conservation of Rare and Endangered Species. Annu Rev Anim Biosci 2021; 10:469-490. [PMID: 34758275 DOI: 10.1146/annurev-animal-020420-040600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There is a remarkable diversity in the animal kingdom regarding mechanisms underlying the production, maturation, structure, and function of sperm cells. Spermatology studies contribute to the knowledge of species diversity and also provide information about individual or population fitness. Furthermore, this fundamental research is required before collected spermatozoa can be used for conservation breeding, including assisted reproduction and cryobanking. This article aims to (a) review the most recent knowledge on sperm morphology and function in wild animal species, (b) analyze how this knowledge can be used to save species in their natural habitat or ex situ, and (c) propose future scientific directions in wildlife spermatology that could positively impact animal conservation. Variations in sperm structure and performance within and between species have multiple origins and significance. This collective body of knowledge enables the design and implementation of conservation strategies and action plans that integrate several disciplines. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Pierre Comizzoli
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA;
| | - William V Holt
- Academic Unit of Reproductive and Developmental Medicine, University of Sheffield, United Kingdom;
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6
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Buttemer WA, Careau V, Chappell MA, Griffith SC. Metabolic rates of aggressive and submissive phenotypes are colour blind in the polymorphic Gouldian finch. J Exp Biol 2021; 224:271176. [PMID: 34346502 DOI: 10.1242/jeb.242577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/08/2021] [Indexed: 12/23/2022]
Abstract
Evidence from a number of species suggests that behaviours associated with social rank are positively correlated with metabolic rate. These studies, however, are based on metabolic measurements of isolated individuals, thereby ignoring potential effects of social interactions on metabolic rates. Here, we characterised three pertinent metabolic indices in the two predominant genetic colour morphs of the Gouldian finch (Erythrura gouldiae): diurnal resting metabolic rate (RMR), nocturnal basal metabolic rate (BMR) and exercise-induced maximal metabolic rate (MMR). Research reveals that red-headed morphs consistently dominate the less aggressive black-headed morphs and that the two morphs differ in other behavioural and physiological traits. We measured daytime RMR of intermorph naïve birds (first-year virgin males maintained in total isolation from opposite colour morphs) and their metabolic responses to viewing a socially unfamiliar bird of each colour. Subsequently, each bird was placed in a home cage with an opposite colour morph (intermorph exposed) and the series of measurements was repeated. Daytime RMR was indistinguishable between the two morphs, regardless of whether they were intermorph naïve or intermorph exposed. However, both red- and black-headed birds showed a greater short-term increase in metabolic rate when viewing an unfamiliar red-headed bird than when seeing a black-headed bird, but only when intermorph naïve. Measurements of BMR and exercise-induced MMR did not differ between the two morphs, and consequently, aerobic scope was indistinguishable between them. We propose that the behavioural differences between these two sympatric morphs are functionally complementary and represent evolutionary stable strategies permitting establishment of dominance status in the absence of metabolic costs.
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Affiliation(s)
- William A Buttemer
- School of Earth, Atmospheric, and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vincent Careau
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Mark A Chappell
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - Simon C Griffith
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
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7
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Friesen CR, Wilson M, Rollings N, Sudyka J, Giraudeau M, Whittington CM, Olsson M. Exercise training has morph-specific effects on telomere, body condition and growth dynamics in a color-polymorphic lizard. J Exp Biol 2021; 224:jeb.242164. [PMID: 33785504 DOI: 10.1242/jeb.242164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/22/2021] [Indexed: 12/12/2022]
Abstract
Alternative reproductive tactics (ARTs) are correlated suites of sexually selected traits that are likely to impose differential physiological costs on different individuals. While moderate activity might be beneficial, animals living in the wild often work at the margins of their resources and performance limits. Individuals using ARTs may have divergent capacities for activity. When pushed beyond their respective capacities, they may experience condition loss, oxidative stress, and molecular damage that must be repaired with limited resources. We used the Australian painted dragon lizard that exhibits color polymorphism as a model to experimentally test the effect of exercise on body condition, growth, reactive oxygen species (ROS) and telomere dynamics - a potential marker of stress and aging and a correlate of longevity. For most males, ROS levels tended to be lower with greater exercise; however, males with yellow throat patches - or bibs - had higher ROS levels than non-bibbed males. At the highest level of exercise, bibbed males exhibited telomere loss, while non-bibbed males gained telomere length; the opposite pattern was observed in the no-exercise controls. Growth was positively related to food intake but negatively correlated with telomere length at the end of the experiment. Body condition was not related to food intake but was positively correlated with increases in telomere length. These results, along with our previous work, suggest that aggressive - territory holding - bibbed males suffer physiological costs that may reduce longevity compared with non-bibbed males with superior postcopulatory traits.
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Affiliation(s)
- Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.,Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia.,Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Mark Wilson
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Nicky Rollings
- Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Joanna Sudyka
- Institute of Environmental Sciences, Jagiellonian University, 30-060 Krakow, Poland
| | - Mathieu Giraudeau
- CREEC, UMR IRD 224-CNRS 5290-Université de Montpellier, F34394 Montpellier, France.,CREES Centre for Research on the Ecology and Evolution of Disease, 34394 Montpellier, France
| | - Camilla M Whittington
- Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Mats Olsson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.,Department of Biological & Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
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8
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Kar F, Nakagawa S, Friesen CR, Noble DWA. Individual variation in thermal plasticity and its impact on mass‐scaling. OIKOS 2021. [DOI: 10.1111/oik.08122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Fonti Kar
- School of Biological Earth and Environmental Sciences, Ecology and Evolution Research Centre, Univ. of New South Wales Sydney NSW Australia
| | - Shinichi Nakagawa
- School of Biological Earth and Environmental Sciences, Ecology and Evolution Research Centre, Univ. of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division, Garvan Inst. of Medical Research, Darlinghurst Sydney NSW Australia
| | - Christopher R. Friesen
- School of Earth, Atmospheric and Life Sciences, Faculty of Science, Medicine and Health, Univ. of Wollongong Wollongong NSW Australia
| | - Daniel W. A. Noble
- School of Biological Earth and Environmental Sciences, Ecology and Evolution Research Centre, Univ. of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division, Garvan Inst. of Medical Research, Darlinghurst Sydney NSW Australia
- Division of Ecology and Evolution, Research School of Biology, The Australian National Univ. Canberra ACT Australia
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9
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Stuart‐Fox D, Aulsebrook A, Rankin KJ, Dong CM, McLean CA. Convergence and divergence in lizard colour polymorphisms. Biol Rev Camb Philos Soc 2020; 96:289-309. [DOI: 10.1111/brv.12656] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Devi Stuart‐Fox
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Anne Aulsebrook
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Katrina J. Rankin
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
| | - Caroline M. Dong
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
- Sciences Department Museums Victoria 11 Nicholson Street Carlton Gardens VIC 3053 Australia
| | - Claire A. McLean
- School of BioSciences The University of Melbourne Royal Parade Parkville VIC 3010 Australia
- Sciences Department Museums Victoria 11 Nicholson Street Carlton Gardens VIC 3053 Australia
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10
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Friesen CR, Rollings N, Wilson M, Whittington CM, Shine R, Olsson M. Covariation in superoxide, sperm telomere length and sperm velocity in a polymorphic reptile. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-020-02855-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Plasman M, Bautista A, McCUE MD, DÍaz DE LA Vega-PÉrez AH. Resting metabolic rates increase with elevation in a mountain-dwelling lizard. Integr Zool 2020; 15:363-374. [PMID: 32306560 DOI: 10.1111/1749-4877.12434] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Individuals that inhabit broad elevational ranges may experience unique environmental challenges. Because temperature decreases with increased elevation, the ectotherms living at high elevations have to manage limited activity time and high thermoregulatory effort. The resting metabolic rate (RMR) of a postabsorptive animal is related to its total energy requirements as well as many other fitness traits. Mesquite lizards (Sceloporus grammicus) living on La Malinche Volcano, Mexico, inhabit a wide elevational range with some populations apparently thriving above the tree line. We measured the RMR of lizards from different elevations (i.e., 2,600, 3,200, and 4,100 m) at four ecologically relevant temperatures (i.e., 15, 25, 30, and 35 °C) and found that RMR of mesquite lizards increased with temperature and body mass. More importantly, lizards from the high-elevation population had mass specific RMR that was higher at all temperatures. While the higher RMRs of high-elevation populations imply higher metabolic costs at a given temperature these lizards were also smaller. Both of these traits may allow these high elevation populations to thrive in the face of the thermal challenges imposed by their environment.
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Affiliation(s)
- Melissa Plasman
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Amando Bautista
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | | | - Aníbal H DÍaz DE LA Vega-PÉrez
- Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México
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12
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Van Dyke JU, Thompson MB, Burridge CP, Castelli MA, Clulow S, Dissanayake DSB, Dong CM, Doody JS, Edwards DL, Ezaz T, Friesen CR, Gardner MG, Georges A, Higgie M, Hill PL, Holleley CE, Hoops D, Hoskin CJ, Merry DL, Riley JL, Wapstra E, While GM, Whiteley SL, Whiting MJ, Zozaya SM, Whittington CM. Australian lizards are outstanding models for reproductive biology research. AUST J ZOOL 2020. [DOI: 10.1071/zo21017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Australian lizards are a diverse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable diversity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship; mechanisms involved in mating, egg production, and sperm competition; nesting and gestation; sex determination; and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.
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13
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Friesen CR, de Graaf SP, Olsson M. The relationship of body condition, superoxide dismutase, and superoxide with sperm performance. Behav Ecol 2019. [DOI: 10.1093/beheco/arz086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Abstract
Sperm competition theory predicts a negative correlation between somatic investment and traits that aid in pre- and postcopulatory sexual selection. Sperm performance is critical for postcopulatory success but sperm are susceptible to damage by free radicals such as superoxide radicals generated during mitochondrial respiration (mtSOx). Males can ameliorate damage to spermatozoa by investing in the production of antioxidants, like superoxide dismutase (SOD), which may act as a mechanistic link to pre- and postcopulatory trade-offs. Some male Australian, color-polymorphic painted dragon lizards (Ctenophorus pictus) possess a yellow throat patch (bib) that females prefer over nonbibbed males and are also more likely to win male–male contests indicating that males with bibs may be better at monopolizing females. We tested whether the sperm performance in nonbibbed males was superior to that of bibbed males. We show that overall sperm performance was not different between the bib-morphs, however, higher mtSOx levels were negatively correlated with sperm performance in bibbed males, but not of nonbibbed males. Blood cell mtSOx levels are negatively correlated with SOD activity in the plasma in all males early in the breeding season but SOD was lower in bibbed males. Nonbibbed males maintain a positive correlation between body condition and SOD activity over time while bibbed males do not. Together, these data suggest physiological associations between body condition, SOD activity, and sperm performance are linked to the expression of a yellow gular patch, which may be related to intrinsic differences in the metabolism of bibbed versus nonbibbed males.
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Affiliation(s)
- Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, Ross St. Camperdown, NSW Australia, Australia
| | - Simon P de Graaf
- Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, Ross St. Camperdown, NSW Australia, Australia
| | - Mats Olsson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Department of Biological & Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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14
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Olsson M, Friesen CR, Rollings N, Sudyka J, Lindsay W, Whittington CM, Wilson M. Long-term effects of superoxide and DNA repair on lizard telomeres. Mol Ecol 2018; 27:5154-5164. [PMID: 30368957 DOI: 10.1111/mec.14913] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 07/25/2018] [Accepted: 08/07/2018] [Indexed: 02/06/2023]
Abstract
Telomeres are the non-coding protein-nucleotide "caps" at chromosome ends that contribute to chromosomal stability by protecting the coding parts of the linear DNA from shortening at cell division, and from erosion by reactive molecules. Recently, there has been some controversy between molecular and cell biologists, on the one hand, and evolutionary ecologists on the other, regarding whether reactive molecules erode telomeres during oxidative stress. Many studies of biochemistry and medicine have verified these relationships in cell culture, but other researchers have failed to find such effects in free-living vertebrates. Here, we use a novel approach to measure free radicals (superoxide), mitochondrial "content" (a combined measure of mitochondrial number and size in cells), telomere length and DNA damage at two primary time points during the mating season of an annual lizard species (Ctenophorus pictus). Superoxide levels early in the mating season vary widely and elevated levels predict shorter telomeres both at that time as well as several months later. These effects are likely driven by mitochondrial content, which significantly impacts late season superoxide (cells with more mitochondria have more superoxide), but superoxide effects on telomeres are counteracted by DNA repair as revealed by 8-hydroxy-2'-deoxyguanosine assays. We conclude that reactive oxygen species and DNA repair are fundamental for both short- and long-term regulation of lizard telomere length with pronounced effects of early season cellular stress detectable on telomere length near lizard death.
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Affiliation(s)
- Mats Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
- School of Biological Sciences, The University of Wollongong, Wollongong, New South Wales, Australia
| | - Christopher R Friesen
- School of Biological Sciences, The University of Wollongong, Wollongong, New South Wales, Australia
| | - Nicky Rollings
- School of Life and Environmental Sciences, Heydon-Laurence Building (A08), University of Sydney, Sydney, New South Wales, Australia
| | - Joanna Sudyka
- Wild Urban Evolution and Ecology Lab, Centre of New Technologies (CeNT), University of Warsaw, Warsaw, Poland
| | - Willow Lindsay
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Camilla M Whittington
- School of Life and Environmental Sciences, Heydon-Laurence Building (A08), University of Sydney, Sydney, New South Wales, Australia
| | - Mark Wilson
- School of Biological Sciences, The University of Wollongong, Wollongong, New South Wales, Australia
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