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Cox CL, Logan ML, Nicholson DJ, Chung AK, Rosso AA, McMillan WO, Cox RM. Species-Specific Expression of Growth-Regulatory Genes in 2 Anoles with Divergent Patterns of Sexual Size Dimorphism. Integr Org Biol 2022; 4:obac025. [PMID: 35958165 PMCID: PMC9362763 DOI: 10.1093/iob/obac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/20/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Synopsis
Sexual size dimorphism is widespread in nature and often develops through sexual divergence in growth trajectories. In vertebrates, the growth hormone/insulin-like growth factor (GH/IGF) network is an important regulator of growth, and components of this network are often regulated in sex-specific fashion during the development of sexual size dimorphism. However, expression of the GH/IGF network is not well characterized outside of mammalian model systems, and the extent to which species differences in sexual size dimorphism are related to differences in GH/IGF network expression is unclear. To begin bridging this gap, we compared GH/IGF network expression in liver and muscle from 2 lizard congeners, one with extreme male-biased sexual size dimorphism (brown anole, Anolis sagrei), and one that is sexually monomorphic in size (slender anole, A. apletophallus). Specifically, we tested whether GH/IGF network expression in adult slender anoles resembles the highly sex-biased expression observed in adult brown anoles or the relatively unbiased expression observed in juvenile brown anoles. We found that adults of the 2 species differed significantly in the strength of sex-biased expression for several key upstream genes in the GH/IGF network, including insulin-like growth factors 1 and 2. However, species differences in sex-biased expression were minor when comparing adult slender anoles to juvenile brown anoles. Moreover, the multivariate expression of the entire GH/IGF network (as represented by the first two principal components describing network expression) was sex-biased for the liver and muscle of adult brown anoles, but not for either tissue in juvenile brown anoles or adult slender anoles. Our work suggests that species differences in sex-biased expression of genes in the GH/IGF network (particularly in the liver) may contribute to the evolution of species differences in sexual size dimorphism.
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Affiliation(s)
- Christian L Cox
- Florida International University , 11200 SW 8th St, Miami, FL 33199 , USA
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
| | - Michael L Logan
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- University of Nevada Reno , 1664 N Virginia St, Reno, NV 89557 , USA
| | - Daniel J Nicholson
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Queen Mary University , Mile End Rd, Bethnal Green, London E1 4NS , UK
- University of Texas-Arlington , 701 S Nedderman Dr. Arlington, TX 76019 , USA
| | - Albert K Chung
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
- University of Texas-Arlington , 701 S Nedderman Dr. Arlington, TX 76019 , USA
- Princeton University , Princeton, NJ 08544 , USA
| | - Adam A Rosso
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
| | - W Owen McMillan
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
| | - Robert M Cox
- University of Virginia , Charlottesville, VA 22904 , USA
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Hale MD, Robinson CD, Cox CL, Cox RM. Ontogenetic Change in Male Expression of Testosterone-Responsive Genes Contributes to the Emergence of Sex-Biased Gene Expression in Anolis sagrei. Front Physiol 2022; 13:886973. [PMID: 35721538 PMCID: PMC9203151 DOI: 10.3389/fphys.2022.886973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/03/2022] [Indexed: 11/13/2022] Open
Abstract
Sex differences in gene expression tend to increase with age across a variety of species, often coincident with the development of sexual dimorphism and maturational changes in hormone levels. However, because most transcriptome-wide characterizations of sexual divergence are framed as comparisons of sex-biased gene expression across ages, it can be difficult to determine the extent to which age-biased gene expression within each sex contributes to the emergence of sex-biased gene expression. Using RNAseq in the liver of the sexually dimorphic brown anole lizard (Anolis sagrei), we found that a pronounced increase in sex-biased gene expression with age was associated with a much greater degree of age-biased gene expression in males than in females. This pattern suggests that developmental changes in males, such as maturational increases in circulating testosterone, contribute disproportionately to the ontogenetic emergence of sex-biased gene expression. To test this hypothesis, we used four different experimental contrasts to independently characterize sets of genes whose expression differed as a function of castration and/or treatment with exogenous testosterone. We found that genes that were significantly male-biased in expression or upregulated as males matured tended to be upregulated by testosterone, whereas genes that were female-biased or downregulated as males matured tended to be downregulated by testosterone. Moreover, the first two principal components describing multivariate gene expression indicated that exogenous testosterone reversed many of the feminizing effects of castration on the liver transcriptome of maturing males. Collectively, our results suggest that developmental changes that occur in males contribute disproportionately to the emergence of sex-biased gene expression in the Anolis liver, and that many of these changes are orchestrated by androgens such as testosterone.
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Affiliation(s)
- Matthew D. Hale
- Department of Biology, University of Virginia, Charlottesville, VA, United States
- *Correspondence: Matthew D. Hale, ; Robert M. Cox,
| | | | - Christian L. Cox
- College of Arts, Sciences, and Education, Florida International University, Miami, FL, United States
| | - Robert M. Cox
- Department of Biology, University of Virginia, Charlottesville, VA, United States
- *Correspondence: Matthew D. Hale, ; Robert M. Cox,
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Rasys AM, Pau SH, Irwin KE, Luo S, Kim HQ, Wahle MA, Trainor PA, Menke DB, Lauderdale JD. Ocular elongation and retraction in foveated reptiles. Dev Dyn 2021; 250:1584-1599. [PMID: 33866663 PMCID: PMC10731578 DOI: 10.1002/dvdy.348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Pronounced asymmetric changes in ocular globe size during eye development have been observed in a number of species ranging from humans to lizards. In contrast, largely symmetric changes in globe size have been described for other species like rodents. We propose that asymmetric changes in the three-dimensional structure of the developing eye correlate with the types of retinal remodeling needed to produce areas of high photoreceptor density. To test this idea, we systematically examined three-dimensional aspects of globe size as a function of eye development in the bifoveated brown anole, Anolis sagrei. RESULTS During embryonic development, the anole eye undergoes dynamic changes in ocular shape. Initially spherical, the eye elongates in the presumptive foveal regions of the retina and then proceeds through a period of retraction that returns the eye to its spherical shape. During this period of retraction, pit formation and photoreceptor cell packing are observed. We found a similar pattern of elongation and retraction associated with the single fovea of the veiled chameleon, Chamaeleo calyptratus. CONCLUSIONS These results, together with those reported for other foveated species, support the idea that areas of high photoreceptor packing occur in regions where the ocular globe asymmetrically elongates and retracts during development.
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Affiliation(s)
- Ashley M. Rasys
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | - Shana H. Pau
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - Katherine E. Irwin
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | - Sherry Luo
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - Hannah Q. Kim
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | | | - Paul A. Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri
- Department of Anatomy & Cell Biology, The University of Kansas School of Medicine, Kansas City, Kansas
| | - Douglas B. Menke
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - James D. Lauderdale
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
- Neuroscience Division of the Biomedical and Translational Sciences Institute, The University of Georgia, Athens, Georgia
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Morris ZS, Vliet KA, Abzhanov A, Pierce SE. Developmental origins of the crocodylian skull table and platyrostral face. Anat Rec (Hoboken) 2021; 305:2838-2853. [PMID: 34694063 DOI: 10.1002/ar.24802] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/13/2021] [Indexed: 11/10/2022]
Abstract
The dorsoventrally flattened skull typifies extant Crocodylia perhaps more than any other anatomical feature and is generally considered an adaptation for semi-aquatic feeding. Although the evolutionary origins of caniofacial flattening have been extensively studied, the developmental origins have yet to be explored. To understand how the skull table and platyrostral snout develop, we quantified embryonic development and post-hatching growth (ontogeny) of the crocodylian skull in lateral view using geometric morphometrics. Our dataset (n = 103) includes all but one extant genus and all of the major ecomorphs, including the extremely slender-snouted Gavialis and Tomistoma. Our analysis reveals that the embryonic development of the flattened skull is remarkably similar across ecomorphs, including the presence of a conserved initial embryonic skull shape, similar to prior analysis of dorsal snout shape. Although differences during posthatching ontogeny are recovered among ecomorphs, embryonic patterns are not distinct, revealing an important shift in developmental rate near hatching. In particular, the flattened skull table is achieved by the end of embryonic development with no changes after hatching. Further, the rotation of skull roof and facial bones during development is critical for the stereotypical flatness of the crocodylian skull. Our results suggest selection on hatchling performance and constraints on embryonic skull shape may have been important in this pattern of developmental conservation. The appearance of aspects of cranial flatness among Jurassic stem crocodylians suggests key aspects of these cranial developmental patterns may have been conserved for over 200 million years.
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Affiliation(s)
- Zachary S Morris
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Kent A Vliet
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - Arhat Abzhanov
- Department of Life Sciences, Imperial College London, Berkshire, UK.,Natural History Museum, Cromwell Road, London, UK
| | - Stephanie E Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
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Conith AJ, Albertson RC. The cichlid oral and pharyngeal jaws are evolutionarily and genetically coupled. Nat Commun 2021; 12:5477. [PMID: 34531386 PMCID: PMC8445992 DOI: 10.1038/s41467-021-25755-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 08/30/2021] [Indexed: 02/08/2023] Open
Abstract
Evolutionary constraints may significantly bias phenotypic change, while "breaking" from such constraints can lead to expanded ecological opportunity. Ray-finned fishes have broken functional constraints by developing two jaws (oral-pharyngeal), decoupling prey capture (oral jaw) from processing (pharyngeal jaw). It is hypothesized that the oral and pharyngeal jaws represent independent evolutionary modules and this facilitated diversification in feeding architectures. Here we test this hypothesis in African cichlids. Contrary to our expectation, we find integration between jaws at multiple evolutionary levels. Next, we document integration at the genetic level, and identify a candidate gene, smad7, within a pleiotropic locus for oral and pharyngeal jaw shape that exhibits correlated expression between the two tissues. Collectively, our data show that African cichlid evolutionary success has occurred within the context of a coupled jaw system, an attribute that may be driving adaptive evolution in this iconic group by facilitating rapid shifts between foraging habitats, providing an advantage in a stochastic environment such as the East African Rift-Valley.
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Affiliation(s)
- Andrew J Conith
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
| | - R Craig Albertson
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
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Duncan CA, Cohick WS, John-Alder HB. Testosterone Reduces Growth and Hepatic IGF-1 mRNA in a Female-Larger Lizard, Sceloporus undulatus: Evidence of an Evolutionary Reversal in Growth Regulation. Integr Org Biol 2021; 2:obaa036. [PMID: 33791574 PMCID: PMC7715992 DOI: 10.1093/iob/obaa036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Previous research has demonstrated that testosterone (T) can inhibit growth in female-larger species and stimulate growth in male-larger species, but the underlying mechanisms of this regulatory bipotentiality have not been investigated. In this study, we investigated the effects of T on the expression of hepatic insulin-like growth factor-1 (IGF-1) mRNA and circulating IGF-1 hormone in Sceloporus undulatus, a species of lizard in which females grow faster to become larger than males and in which T inhibits growth. Experiments were performed in captivity on mature female and male adults in the asymptotic phase of their growth curve and on actively growing, pre-reproductive juveniles. In adult males, the expression of hepatic IGF-1 mRNA increased following surgical castration and returned to control levels with T replacement; in intact adult females, exogenous T had no effect on IGF-1 mRNA expression. In juveniles, T significantly reduced both growth and the expression of hepatic IGF-1 mRNA to similar extents in intact females and in castrated males. The relative inhibitory effects of T on mRNA expression were greater in juveniles than in adults. Plasma IGF-1 hormone was about four times higher in juveniles than in adults, but T had no significant effect on IGF-1 hormone in either sex or in either age group. Our finding of inhibition of the expression of hepatic IGF-1 mRNA stands in contrast to the stimulatory effects of T in the published body of literature. We attribute our novel finding to our use of a species in which T inhibits rather than stimulates growth. Our findings begin to explain how T has the regulatory bipotentiality to be stimulatory in some species and inhibitory in others, requiring only an evolutionary reversal in the molecular regulation of growth-regulatory genes including IGF-1. Further comparative transcriptomic studies will be required to fully resolve the molecular mechanism of growth inhibition.
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Affiliation(s)
| | - Wendie S Cohick
- Graduate Program in Endocrinology and Animal Biosciences, Rutgers University, 84 Lipman Drive, New Brunswick, NJ 08901, USA
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Heading for higher ground: Developmental origins and evolutionary diversification of the amniote face. Curr Top Dev Biol 2021; 141:241-277. [PMID: 33602490 DOI: 10.1016/bs.ctdb.2020.12.003] [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] [Indexed: 12/14/2022]
Abstract
Amniotes, a clade of terrestrial vertebrates, which includes all of the descendants of the last common ancestor of the reptiles (including dinosaurs and birds) and mammals, is one of the most successful group of animals on our planet. In addition to having an egg equipped with an amnion, an adaptation to lay eggs on land, amniotes possess a number of other major morphological characteristics. Chief among them is the amniote skull, which can be classified into several major types distinguished by the presence and number of temporal fenestrae (windows) in the posterior part. Amniotes evolved from ancestors who possessed a skull composed of a complex mosaic of small bones separated by sutures. Changes in skull composition underlie much of the large-scale evolution of amniotes with many lineages showing a trend in reduction of cranial elements known as the "Williston's Law." The skull of amniotes is also arranged into a set of modules of closely co-evolving bones as revealed by modularity and integration tests. One of the most consistently recovered and at the same time most versatile modules is the "face," anatomically defined as the anterior portion of the head. The faces of amniotes display extraordinary amount of variation, with many adaptive radiations showing parallel tendencies in facial scaling, e.g., changes in length or width. This review explores the natural history of the amniote face and discusses how a better understanding of its anatomy and developmental biology helps to explain the outstanding scale of adaptive facial diversity. We propose a model for facial evolution in the amniotes, based on the differential rate of cranial neural crest cell proliferation and the timing of their skeletal differentiation.
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8
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Kitano J, Kakioka R, Ishikawa A, Toyoda A, Kusakabe M. Differences in the contributions of sex linkage and androgen regulation to sex-biased gene expression in juvenile and adult sticklebacks. J Evol Biol 2020; 33:1129-1138. [PMID: 32533720 DOI: 10.1111/jeb.13662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 11/29/2022]
Abstract
Different evolutionary interests between males and females can lead to the evolution of sexual dimorphism. However, intersex genetic correlations due to the shared genome can constrain the evolution of sexual dimorphism, resulting in intra-locus sexual conflict. One of the mechanisms resolving this conflict is sex linkage, which allows males and females to carry different alleles on sex chromosomes. Another is a regulatory mutation causing sex-biased gene expression, which is often mediated by gonadal steroids in vertebrates. How do these two mechanisms differ in the contributions to the resolution of intra-locus sexual conflict? The magnitude of sexual conflict often varies between the juvenile and adult stages. Because gonadal steroids change in titre during development, we hypothesized that gonadal steroids play a role in sexual dimorphism expression only at certain developmental stages, whereas sex linkage is more important for sexual dimorphism expressed throughout life. Our brain transcriptome analysis of juvenile and adult threespine sticklebacks showed that the majority of genes that were sex-biased in both stages were sex-linked. The relative contribution of androgen-dependent regulation to the sex-biased transcriptome increased and that of sex linkage declined in adults compared to juveniles. The magnitude of the sex differences was greater in sex-linked genes than androgen-responsive genes, suggesting that sex linkage is more effective than androgen regulation in the production of large sex differences in gene expression. Overall, our data are consistent with the hypothesis that sex linkage is effective in resolving sexual conflict throughout life, whereas androgen-dependent regulation can contribute to temporary resolution of sexual conflict.
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Affiliation(s)
- Jun Kitano
- Ecological Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Ryo Kakioka
- Ecological Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Asano Ishikawa
- Ecological Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Makoto Kusakabe
- Department of Biological Sciences, Faculty of Science, Shizuoka University, Surugaku, Shizuoka, Japan
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9
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Camacho J, Heyde A, Bhullar BAS, Haelewaters D, Simmons NB, Abzhanov A. Peramorphosis, an evolutionary developmental mechanism in neotropical bat skull diversity. Dev Dyn 2019; 248:1129-1143. [PMID: 31348570 DOI: 10.1002/dvdy.90] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/06/2019] [Accepted: 07/04/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The neotropical leaf-nosed bats (Chiroptera, Phyllostomidae) are an ecologically diverse group of mammals with distinctive morphological adaptations associated with specialized modes of feeding. The dramatic skull shape changes between related species result from changes in the craniofacial development process, which brings into focus the nature of the underlying evolutionary developmental processes. RESULTS In this study, we use three-dimensional geometric morphometrics to describe, quantify, and compare morphological modifications unfolding during evolution and development of phyllostomid bats. We examine how changes in development of the cranium may contribute to the evolution of the bat craniofacial skeleton. Comparisons of ontogenetic trajectories to evolutionary trajectories reveal two separate evolutionary developmental growth processes contributing to modifications in skull morphogenesis: acceleration and hypermorphosis. CONCLUSION These findings are consistent with a role for peramorphosis, a form of heterochrony, in the evolution of bat dietary specialists.
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Affiliation(s)
- Jasmin Camacho
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Alexander Heyde
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Bhart-Anjan S Bhullar
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts.,Department of Geology and Geophysics, Yale Peabody Museum of Natural History, Yale University, New Haven, Connecticut
| | - Danny Haelewaters
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Nancy B Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, New York
| | - Arhat Abzhanov
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
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10
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Morris ZS, Vliet KA, Abzhanov A, Pierce SE. Heterochronic shifts and conserved embryonic shape underlie crocodylian craniofacial disparity and convergence. Proc Biol Sci 2019; 286:20182389. [PMID: 30963831 PMCID: PMC6408887 DOI: 10.1098/rspb.2018.2389] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/25/2019] [Indexed: 12/29/2022] Open
Abstract
The distinctive anatomy of the crocodylian skull is intimately linked with dietary ecology, resulting in repeated convergence on blunt- and slender-snouted ecomorphs. These evolutionary shifts depend upon modifications of the developmental processes which direct growth and morphogenesis. Here we examine the evolution of cranial ontogenetic trajectories to shed light on the mechanisms underlying convergent snout evolution. We use geometric morphometrics to quantify skeletogenesis in an evolutionary context and reconstruct ancestral patterns of ontogenetic allometry to understand the developmental drivers of craniofacial diversity within Crocodylia. Our analyses uncovered a conserved embryonic region of morphospace (CER) shared by all non-gavialid crocodylians regardless of their eventual adult ecomorph. This observation suggests the presence of conserved developmental processes during early development (before Ferguson stage 20) across most of Crocodylia. Ancestral state reconstruction of ontogenetic trajectories revealed heterochrony, developmental constraint, and developmental systems drift have all played essential roles in the evolution of ecomorphs. Based on these observations, we conclude that two separate, but interconnected, developmental programmes controlling craniofacial morphogenesis and growth enabled the evolutionary plasticity of skull shape in crocodylians.
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Affiliation(s)
- Zachary S. Morris
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Kent A. Vliet
- Department of Biology, University of Florida, 876 Newell Drive, Gainesville, FL 32611, USA
| | - Arhat Abzhanov
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, UK
- Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Stephanie E. Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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11
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Rico-Guevara A, Hurme KJ. Intrasexually selected weapons. Biol Rev Camb Philos Soc 2019; 94:60-101. [PMID: 29924496 DOI: 10.1111/brv.12436] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 01/24/2023]
Abstract
We propose a practical concept that distinguishes the particular kind of weaponry that has evolved to be used in combat between individuals of the same species and sex, which we term intrasexually selected weapons (ISWs). We present a treatise of ISWs in nature, aiming to understand their distinction and evolution from other secondary sex traits, including from 'sexually selected weapons', and from sexually dimorphic and monomorphic weaponry. We focus on the subset of secondary sex traits that are the result of same-sex combat, defined here as ISWs, provide not previously reported evolutionary patterns, and offer hypotheses to answer questions such as: why have only some species evolved weapons to fight for the opposite sex or breeding resources? We examined traits that seem to have evolved as ISWs in the entire animal phylogeny, restricting the classification of ISW to traits that are only present or enlarged in adults of one of the sexes, and are used as weapons during intrasexual fights. Because of the absence of behavioural data and, in many cases, lack of sexually discriminated series from juveniles to adults, we exclude the fossil record from this review. We merge morphological, ontogenetic, and behavioural information, and for the first time thoroughly review the tree of life to identify separate evolution of ISWs. We found that ISWs are only found in bilateral animals, appearing independently in nematodes, various groups of arthropods, and vertebrates. Our review sets a reference point to explore other taxa that we identify with potential ISWs for which behavioural or morphological studies are warranted. We establish that most ISWs come in pairs, are located in or near the head, are endo- or exoskeletal modifications, are overdeveloped structures compared with those found in females, are modified feeding structures and/or locomotor appendages, are most common in terrestrial taxa, are frequently used to guard females, territories, or both, and are also used in signalling displays to deter rivals and/or attract females. We also found that most taxa lack ISWs, that females of only a few species possess better-developed weapons than males, that the cases of independent evolution of ISWs are not evenly distributed across the phylogeny, and that animals possessing the most developed ISWs have non-hunting habits (e.g. herbivores) or are faunivores that prey on very small prey relative to their body size (e.g. insectivores). Bringing together perspectives from studies on a variety of taxa, we conceptualize that there are five ways in which a sexually dimorphic trait, apart from the primary sex traits, can be fixed: sexual selection, fecundity selection, parental role division, differential niche occupation between the sexes, and interference competition. We discuss these trends and the factors involved in the evolution of intrasexually selected weaponry in nature.
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Affiliation(s)
- Alejandro Rico-Guevara
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A.,Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Código Postal 11001, Bogotá DC, Colombia
| | - Kristiina J Hurme
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A
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Haaland ØA, Lie RT, Romanowska J, Gjerdevik M, Gjessing HK, Jugessur A. A Genome-Wide Search for Gene-Environment Effects in Isolated Cleft Lip with or without Cleft Palate Triads Points to an Interaction between Maternal Periconceptional Vitamin Use and Variants in ESRRG. Front Genet 2018. [PMID: 29535761 PMCID: PMC5834486 DOI: 10.3389/fgene.2018.00060] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: It is widely accepted that cleft lip with or without cleft palate (CL/P) results from the complex interplay between multiple genetic and environmental factors. However, a robust investigation of these gene-environment (GxE) interactions at a genome-wide level is still lacking for isolated CL/P. Materials and Methods: We used our R-package Haplin to perform a genome-wide search for GxE effects in isolated CL/P. From a previously published GWAS, genotypes and information on maternal periconceptional cigarette smoking, alcohol intake, and vitamin use were available on 1908 isolated CL/P triads of predominantly European or Asian ancestry. A GxE effect is present if the relative risk estimates for gene-effects in the offspring are different across exposure strata. We tested this using the relative risk ratio (RRR). Besides analyzing all ethnicities combined ("pooled analysis"), separate analyses were conducted on Europeans and Asians to investigate ethnicity-specific effects. To control for multiple testing, q-values were calculated from the p-values. Results: We identified significant GxVitamin interactions with three SNPs in "Estrogen-related receptor gamma" (ESRRG) in the pooled analysis. The RRRs (95% confidence intervals) were 0.56 (0.45-0.69) with rs1339221 (q = 0.011), 0.57 (0.46-0.70) with rs11117745 (q = 0.011), and 0.62 (0.50-0.76) with rs2099557 (q = 0.037). The associations were stronger when these SNPs were analyzed as haplotypes composed of two-SNP and three-SNP combinations. The strongest effect was with the "t-t-t" haplotype of the rs1339221-rs11117745-rs2099557 combination [RRR = 0.50 (0.40-0.64)], suggesting that the effects observed with the other SNP combinations, including those in the single-SNP analyses, were mainly driven by this haplotype. Although there were potential GxVitamin effects with rs17734557 and rs1316471 and GxAlcohol effects with rs9653456 and rs921876 in the European sample, respectively, none of the SNPs was located in or near genes with strong links to orofacial clefts. GxAlcohol and GxSmoke effects were not assessed in the Asian sample because of a lack of observations for these exposures. Discussion/Conclusion: We identified significant interactions between vitamin use and variants in ESRRG in the pooled analysis. These GxE effects are novel and warrant further investigations to elucidate their roles in orofacial clefting. If validated, they could provide prospects for exploring the impact of estrogens and vitamins on clefting, with potential translational applications.
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Affiliation(s)
- Øystein A Haaland
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Rolv T Lie
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Julia Romanowska
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Computational Biology Unit, University of Bergen, Bergen, Norway
| | - Miriam Gjerdevik
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo, Norway
| | - Håkon K Gjessing
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Astanand Jugessur
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway.,Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo, Norway
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13
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Johnson MA, Kircher BK, Castro DJ. The evolution of androgen receptor expression and behavior in Anolis lizard forelimb muscles. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 204:71-79. [PMID: 29143128 DOI: 10.1007/s00359-017-1228-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/12/2017] [Accepted: 11/09/2017] [Indexed: 10/18/2022]
Abstract
The motor systems that produce behavioral movements are among the primary targets for the action of steroid hormones, including androgens. Androgens such as testosterone bind to androgen receptors (AR) to induce physiological changes in the size, strength, and energetic capacity of skeletal muscles, which can directly influence the performance of behaviors in which those muscles are used. Because tissues differentially express AR, resulting in tissue-specific sensitivity to androgens, AR expression may be a major target of selection for the evolution of behavior. Anolis lizards (i.e., anoles) provide a robust system for the study of androgen-regulated traits, including the behavioral traits that facilitate social display and locomotion. In this study, we examined six anole species that demonstrate significant variation in the behavioral use of the forelimbs to measure the proportion of myonuclei in the bicep muscles that express AR. Using phylogenetic comparative analyses, we found that species with a greater proportion of nuclei positive for AR expression in the biceps exhibited greater frequencies of locomotor movements and pushup displays. These results suggest that AR expression in skeletal muscles may influence the evolution of androgen-regulated behaviors in this group.
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Affiliation(s)
- Michele A Johnson
- Department of Biology, Trinity University, San Antonio, TX, 78212, USA.
| | - Bonnie K Kircher
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Diego J Castro
- Department of Biology, Trinity University, San Antonio, TX, 78212, USA.,Escuela Internacional Sampedrana, San Pedro Sula, Honduras
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14
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Lencer ES, Warren WC, Harrison R, McCune AR. The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species. BMC Genomics 2017; 18:424. [PMID: 28558659 PMCID: PMC5450241 DOI: 10.1186/s12864-017-3810-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/22/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Understanding the genetic and developmental origins of phenotypic novelty is central to the study of biological diversity. In this study we identify modifications to the expression of genes at four developmental stages that may underlie jaw morphological differences among three closely related species of pupfish (genus Cyprinodon) from San Salvador Island, Bahamas. Pupfishes on San Salvador Island are trophically differentiated and include two endemic species that have evolved jaw morphologies unlike that of any other species in the genus Cyprinodon. RESULTS We find that gene expression differs significantly across recently diverged species of pupfish. Genes such as Bmp4 and calmodulin, previously implicated in jaw diversification in African cichlid fishes and Galapagos finches, were not found to be differentially expressed among species of pupfish. Instead we find multiple growth factors and cytokine/chemokine genes to be differentially expressed among these pupfish taxa. These include both genes and pathways known to affect craniofacial development, such as Wnt signaling, as well as novel genes and pathways not previously implicated in craniofacial development. These data highlight both shared and potentially unique sources of jaw diversity in pupfish and those identified in other evolutionary model systems such as Galapagos finches and African cichlids. CONCLUSIONS We identify modifications to the expression of genes involved in Wnt signaling, Igf signaling, and the inflammation response as promising avenues for future research. Our project provides insight into the magnitude of gene expression changes contributing to the evolution of morphological novelties, such as jaw structure, in recently diverged pupfish species.
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Affiliation(s)
- Ezra S Lencer
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA.
| | - Wesley C Warren
- McDonnell Genome Institute, Washington University School of Medicine, St Louis, MO, 63108, USA
| | - Richard Harrison
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Amy R McCune
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
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15
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De Meyer J, Maes GE, Dirks RP, Adriaens D. Differential gene expression in narrow- and broad-headed European glass eels (Anguilla anguilla) points to a transcriptomic link of head shape dimorphism with growth rate and chemotaxis. Mol Ecol 2017; 26:3943-3953. [PMID: 28437580 DOI: 10.1111/mec.14155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 03/20/2017] [Accepted: 04/12/2017] [Indexed: 01/09/2023]
Abstract
One of the major challenges in evolutionary biology is to understand the mechanisms underlying morphological dimorphism and plasticity, including the genomic basis of traits and links to ecology. At the yellow eel stage of the European eel (Anguilla anguilla), two morphotypes are found: broad- and narrow-heads. This dimorphism has been linked to dietary differences, with broad-heads feeding on harder, larger prey than narrow-heads. However, recent research showed that both morphotypes could be distinguished at the glass eel stage, the nonfeeding predecessor of the yellow eel stage, implying that nondietary factors play a role in the development of this head shape dimorphism. Here, we used transcriptome profiling (RNAseq) to identify differentially expressed genes between broad- and narrow-headed glass eels. We found 260 significantly differentially expressed genes between the morphotypes, of which most were related to defence and immune responses. Interestingly, two genes involved in growth (soma and igf2) were significantly upregulated in narrow-heads, while nine genes involved in chemotaxis showed significant differential expression. Thus, we found support for the observation that head shape is associated with somatic growth, with fast-growing eels developing a narrower head. Additionally, observations in the wild have shown that slow-growers prefer freshwater, while fast-growers prefer brackish water. The differential expression of genes involved in chemotaxis seems to indicate that glass eel growth rate and habitat choice are linked. We hypothesize that two levels of segregation could take place in the European eel: first according to habitat choice and second according to feeding preference.
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Affiliation(s)
- J De Meyer
- Evolutionary Morphology of Vertebrates, University Ghent, Ghent, Belgium
| | - G E Maes
- Centre for Sustainable Tropical Fisheries and Aquaculture, Comparative Genomics Centre, College of Sciences and Engineering, James Cook University, Townsville, Qld, Australia.,Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven (KU Leuven), Leuven, Belgium.,Center for Human Genetics, Genomics Core, KU Leuven, Leuven, Belgium
| | - R P Dirks
- ZF-screens B.V., Leiden, The Netherlands
| | - D Adriaens
- Evolutionary Morphology of Vertebrates, University Ghent, Ghent, Belgium
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16
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Sanger TJ, Kircher BK. Model Clades Versus Model Species: Anolis Lizards as an Integrative Model of Anatomical Evolution. Methods Mol Biol 2017; 1650:285-297. [PMID: 28809029 DOI: 10.1007/978-1-4939-7216-6_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Anolis lizards , known for their replicated patterns of morphological diversification, are widely studied in the fields of evolution and ecology. As a textbook example of adaptive radiation, this genus has supported decades of intense study in natural history, behavior, morphological evolution, and systematics. Following the publication of the A. carolinensis genome, research on Anolis lizards has expanded into new areas, toward obtaining an understanding the developmental and genetic bases of anole diversity. Here, we discuss recent progress in these areas and the burgeoning methodological toolkit that has been used to elucidate the genetic mechanisms underlying anatomical variation in this group. We also highlight the growing number of studies that have used A. carolinensis as the representative squamate in large-scale comparison of amniote evolution and development . Finally, we address one of the largest technical challenges biologists are facing in making Anolis a model for integrative studies of ecology, evolution, development , and genetics, the development of ex-ovo culturing techniques that have broad utility. Ultimately, with the power to ask questions across all biological scales in this diverse genus full, anoles are rapidly becoming a uniquely integrative and powerful biological system.
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Affiliation(s)
- Thomas J Sanger
- Department of Biology, Loyola University Chicago, Chicago, IL, 60660, USA.
| | - Bonnie K Kircher
- Department of Biology, University of Florida, Gainesville, FL, 32601, USA
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17
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Patterns of growth in monitor lizards (Varanidae) as revealed by computed tomography of femoral growth plates. ZOOMORPHOLOGY 2016. [DOI: 10.1007/s00435-016-0338-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Lencer ES, Riccio ML, McCune AR. Changes in growth rates of oral jaw elements produce evolutionary novelty in bahamian pupfish. J Morphol 2016; 277:935-47. [DOI: 10.1002/jmor.20547] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/29/2016] [Accepted: 04/01/2016] [Indexed: 11/11/2022]
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19
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Kramer AG, Vuthiganon J, Lassiter CS. Bis-GMA affects craniofacial development in zebrafish embryos (Danio rerio). ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2016; 43:159-165. [PMID: 26994444 DOI: 10.1016/j.etap.2016.02.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/23/2016] [Accepted: 02/24/2016] [Indexed: 06/05/2023]
Abstract
Estrogen is a steroid hormone that is vital in vertebrate development and plays a role in a variety of developmental processes including cartilage and craniofacial formation. The effects of estrogen can be mimicked by other compounds found in the environment known as xenoestrogens. Bisphenol-A (BPA) is a known xenoestrogen and is combined with glycidyl methacrylate to make Bisphenol A glycidyl methacrylate (Bis-GMA), a major component in dental resin based composites (RBCs). Bis-GMA based RBCs can release their components into the saliva and bloodstream. Exposure to 1μM and 10μM Bis-GMA in Danio rerio embryos results in increased mortality of approximately 30% and 45% respectively. Changes to gross morphology, specifically craniofacial abnormalities, were seen at concentrations as low as 10nM. While the molecular pathways of Bis-GMA effects have not been studied extensively, more is known about one of the components, BPA. Further research of Bis-GMA could lead to a better understanding of xenoestrogenic activity resulting in improved public and environmental health.
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Affiliation(s)
- Alexander G Kramer
- Department of Biology, Roanoke College, 221 College Lane, Salem VA 24153, USA
| | - Jompobe Vuthiganon
- Department of Oral Rehabilitation, College of Dental Medicine, Medical University of South Carolina, 173 Ashley Avenue, Charleston SC 29425, USA
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20
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Pashay Ahi E, Walker BS, Lassiter CS, Jónsson ZO. Investigation of the effects of estrogen on skeletal gene expression during zebrafish larval head development. PeerJ 2016; 4:e1878. [PMID: 27069811 PMCID: PMC4824909 DOI: 10.7717/peerj.1878] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 03/11/2016] [Indexed: 11/20/2022] Open
Abstract
The development of craniofacial skeletal structures requires well-orchestrated tissue interactions controlled by distinct molecular signals. Disruptions in normal function of these molecular signals have been associated with a wide range of craniofacial malformations. A pathway mediated by estrogens is one of those molecular signals that plays role in formation of bone and cartilage including craniofacial skeletogenesis. Studies in zebrafish have shown that while higher concentrations of 17-β estradiol (E 2) cause severe craniofacial defects, treatment with lower concentrations result in subtle changes in head morphology characterized with shorter snouts and flatter faces. The molecular basis for these morphological changes, particularly the subtle skeletal effects mediated by lower E 2 concentrations, remains unexplored. In the present study we address these effects at a molecular level by quantitative expression analysis of sets of candidate genes in developing heads of zebrafish larvae treated with two different E 2 concentrations. To this end, we first validated three suitable reference genes, ppia2, rpl8 and tbp, to permit sensitive quantitative real-time PCR analysis. Next, we profiled the expression of 28 skeletogenesis-associated genes that potentially respond to estrogen signals and play role in craniofacial development. We found E 2 mediated differential expression of genes involved in extracellular matrix (ECM) remodelling, mmp2/9/13, sparc and timp2a, as well as components of skeletogenic pathways, bmp2a, erf, ptch1/2, rankl, rarab and sfrp1a. Furthermore, we identified a co-expressed network of genes, including cpn1, dnajc3, esr1, lman1, rrbp1a, ssr1 and tram1 with a stronger inductive response to a lower dose of E 2 during larval head development.
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Affiliation(s)
- Ehsan Pashay Ahi
- Institute of Life and Environmental Sciences, University of Iceland , Reykjavik , Iceland
| | | | | | - Zophonías O Jónsson
- Institute of Life and Environmental Sciences, University of Iceland, Reykjavik, Iceland; Biomedical Center, University of Iceland, Reykjavik, Iceland
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21
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Kubička L, Starostová Z, Kratochvíl L. Endogenous control of sexual size dimorphism: Gonadal androgens have neither direct nor indirect effect on male growth in a Madagascar ground gecko (Paroedura picta). Gen Comp Endocrinol 2015; 224:273-7. [PMID: 26431613 DOI: 10.1016/j.ygcen.2015.09.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/07/2015] [Accepted: 09/26/2015] [Indexed: 10/23/2022]
Abstract
Changes in the effect of gonadal androgens on male growth are considered as a possible mechanism allowing shifts in magnitude and even direction of sexual size dimorphism in vertebrates, particularly squamate reptiles. Positive effects of gonadal androgens on male growth were found in several male-larger species of lizards. Contrastingly, we document that in the male-larger Madagascar ground gecko (Paroedura picta) gonadal androgens do not affect male growth under constant thermal conditions. However, the absence of a thermal gradient might prevent the potential indirect effect of gonadal androgens on growth via the influence of circulating hormones on an individual's thermoregulation and hence metabolic rate. In order to study this, we monitored the growth and body temperature of socially isolated sham-operated and castrated males of the same species in a thermal gradient. We also compared the oxygen consumption and activity between the treatment groups in the open field to test the effect of gonadal hormones on these traits potentially affecting growth. Even under a thermal gradient we found no effect of gonadal androgens on growth rate or final body dimensions. Castration also did not significantly affect oxygen consumption or activity in the open field test. Together with our previous findings, we can exclude both the direct effect of male gonadal androgens on the ontogeny of sexual size dimorphism via the influence on the growth axis, and the indirect influence of gonadal androgens acting on the ontogeny of SSD through the effect on thermoregulation, metabolic rate and activity.
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Affiliation(s)
- Lukáš Kubička
- Faculty of Science, Charles University in Prague, Department of Ecology, Viničná 7, 128 44 Praha 2, Czech Republic.
| | - Zuzana Starostová
- Faculty of Science, Charles University in Prague, Department of Zoology, Viničná 7, 128 44 Praha 2, Czech Republic
| | - Lukáš Kratochvíl
- Faculty of Science, Charles University in Prague, Department of Ecology, Viničná 7, 128 44 Praha 2, Czech Republic
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22
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Golinski A, Kubička L, John-Alder H, Kratochvíl L. Androgenic control of male-typical behavior, morphology and sex recognition is independent of the mode of sex determination: A case study on Lichtenfelder's gecko (Eublepharidae: Goniurosaurus lichtenfelderi). Horm Behav 2015; 72:49-59. [PMID: 25967849 DOI: 10.1016/j.yhbeh.2015.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 04/10/2015] [Accepted: 04/11/2015] [Indexed: 11/21/2022]
Abstract
Previous work on lizards has shown that many sexually dimorphic traits depend on testosterone (T), but the details of this control can vary among species. Here, we tested the role of T on the expression of morphological, physiological, and behavioral traits in Lichtenfelder's gecko (Goniurosaurus lichtenfelderi), from the lizard family Eublepharidae notable for interspecific variation in sexually dimorphic traits and the mode of sex determination. Experiments included three groups of males (intact control, surgically castrated, castrated with T replacement) and two groups of females (intact control, T supplemented). In males, castration caused reductions in 1) the size of hemipenes, 2) offensive aggression, 3) male sexual behavior in a neutral arena, 4) activity of precloacal glands, and 5) loss of male chemical cues for sex recognition. These reductions were not observed in castrated males with T replacement. Interestingly, castrated males performed sexual behavior in their home cages, which shows that the effect of T depends on the environmental context. Notably, tail vibration, previously reported as a courtship behavior in other eublepharids, is displayed by males of G. lichtenfelderi during interactions with conspecifics of both sexes, suggesting an evolutionary shift in the meaning of this signal. In females, T induced growth of hemipenes and male-typical courtship but did not induce precloacal pore activity, aggression, or mounting. In comparison to previous reports on Eublepharis macularius, our results indicate that effects of T do not depend on the mode of sex determination. Further, our results extend our understanding of the complexity of control of male traits and illustrate how lability in the effects of T can be a general mechanism causing evolutionary changes in the components of suites of functionally correlated traits.
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Affiliation(s)
- Alison Golinski
- Graduate Program in Endocrinology and Animal Biosciences, Rutgers University, 84 Lipman Drive, New Brunswick, NJ 08901, USA
| | - Lukáš Kubička
- Faculty of Science, Charles University in Prague, Department of Ecology, Viničná 7, 128 44 Praha 2, Czech Republic
| | - Henry John-Alder
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA
| | - Lukáš Kratochvíl
- Faculty of Science, Charles University in Prague, Department of Ecology, Viničná 7, 128 44 Praha 2, Czech Republic.
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23
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Cox CL, Hanninen AF, Reedy AM, Cox RM. Female anoles retain responsiveness to testosterone despite the evolution of androgen‐mediated sexual dimorphism. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12383] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Christian L. Cox
- Department of Biology University of Virginia Charlottesville VirginiaUSA
| | - Amanda F. Hanninen
- Department of Biology University of Virginia Charlottesville VirginiaUSA
| | - Aaron M. Reedy
- Department of Biology University of Virginia Charlottesville VirginiaUSA
| | - Robert M. Cox
- Department of Biology University of Virginia Charlottesville VirginiaUSA
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24
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Gredler ML, Sanger TJ, Cohn MJ. Development of the Cloaca, Hemipenes, and Hemiclitores in the Green Anole, Anolis carolinensis. Sex Dev 2014; 9:21-33. [DOI: 10.1159/000363757] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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