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Anthwal N, Urban DJ, Sadier A, Takenaka R, Spiro S, Simmons N, Behringer RR, Cretekos CJ, Rasweiler JJ, Sears KE. Insights into the formation and diversification of a novel chiropteran wing membrane from embryonic development. BMC Biol 2023; 21:101. [PMID: 37143038 PMCID: PMC10161559 DOI: 10.1186/s12915-023-01598-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 04/13/2023] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND Through the evolution of novel wing structures, bats (Order Chiroptera) became the only mammalian group to achieve powered flight. This achievement preceded the massive adaptive radiation of bats into diverse ecological niches. We investigate some of the developmental processes that underlie the origin and subsequent diversification of one of the novel membranes of the bat wing: the plagiopatagium, which connects the fore- and hind limb in all bat species. RESULTS Our results suggest that the plagiopatagium initially arises through novel outgrowths from the body flank that subsequently merge with the limbs to generate the wing airfoil. Our findings further suggest that this merging process, which is highly conserved across bats, occurs through modulation of the programs controlling the development of the periderm of the epidermal epithelium. Finally, our results suggest that the shape of the plagiopatagium begins to diversify in bats only after this merging has occurred. CONCLUSIONS This study demonstrates how focusing on the evolution of cellular processes can inform an understanding of the developmental factors shaping the evolution of novel, highly adaptive structures.
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Affiliation(s)
- Neal Anthwal
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Daniel J Urban
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, USA
- Department of Mammalogy, Division of Vertebrate Biology, American Museum of Natural History, New York, USA
| | - Alexa Sadier
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
- Department of Molecular, Cell, and Developmental Biology, UCLA, Los Angeles, USA
| | - Risa Takenaka
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | | | - Nancy Simmons
- Department of Mammalogy, Division of Vertebrate Biology, American Museum of Natural History, New York, USA
| | - Richard R Behringer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, USA
| | | | - John J Rasweiler
- Department of Obstetrics and Gynecology, State University of New York Downstate Medical Center, New York, USA
| | - Karen E Sears
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA.
- Department of Molecular, Cell, and Developmental Biology, UCLA, Los Angeles, USA.
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Butterfly eyespots evolved via cooption of an ancestral gene-regulatory network that also patterns antennae, legs, and wings. Proc Natl Acad Sci U S A 2022; 119:2108661119. [PMID: 35169073 PMCID: PMC8872758 DOI: 10.1073/pnas.2108661119] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2022] [Indexed: 12/13/2022] Open
Abstract
Where do butterfly eyespots come from? One of the long-standing questions in the field of evolution concerns addressing where novel complex traits come from. Here we show that butterfly eyespots, a novel complex trait, likely originated from the redeployment of a preexisting gene-regulatory network regulating antennae, legs, and wings, to novel locations on the wing. Butterfly eyespots are beautiful novel traits with an unknown developmental origin. Here we show that eyespots likely originated via cooption of parts of an ancestral appendage gene-regulatory network (GRN) to novel locations on the wing. Using comparative transcriptome analysis, we show that eyespots cluster most closely with antennae, relative to multiple other tissues. Furthermore, three genes essential for eyespot development, Distal-less (Dll), spalt (sal), and Antennapedia (Antp), share similar regulatory connections as those observed in the antennal GRN. CRISPR knockout of cis-regulatory elements (CREs) for Dll and sal led to the loss of eyespots, antennae, legs, and also wings, demonstrating that these CREs are highly pleiotropic. We conclude that eyespots likely reused an ancient GRN for their development, a network also previously implicated in the development of antennae, legs, and wings.
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Wound healing, calcium signaling, and other novel pathways are associated with the formation of butterfly eyespots. BMC Genomics 2017; 18:788. [PMID: 29037153 PMCID: PMC5644175 DOI: 10.1186/s12864-017-4175-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/05/2017] [Indexed: 01/21/2023] Open
Abstract
Background One hypothesis surrounding the origin of novel traits is that they originate from the co-option of pre-existing genes or larger gene regulatory networks into novel developmental contexts. Insights into a trait’s evolutionary origins can, thus, be gained via identification of the genes underlying trait development, and exploring whether those genes also function in other developmental contexts. Here we investigate the set of genes associated with the development of eyespot color patterns, a trait that originated once within the Nymphalid family of butterflies. Although several genes associated with eyespot development have been identified, the eyespot gene regulatory network remains largely unknown. Results In this study, next-generation sequencing and transcriptome analyses were used to identify a large set of genes associated with eyespot development of Bicyclus anynana butterflies, at 3-6 h after pupation, prior to the differentiation of the color rings. Eyespot-associated genes were identified by comparing the transcriptomes of homologous micro-dissected wing tissues that either develop or do not develop eyespots in wild-type and a mutant line of butterflies, Spotty, with extra eyespots. Overall, 186 genes were significantly up and down-regulated in wing tissues that develop eyespots compared to wing tissues that do not. Many of the differentially expressed genes have yet to be annotated. New signaling pathways, including the Toll, Fibroblast Growth Factor (FGF), extracellular signal–regulated kinase (ERK) and/or Jun N-terminal kinase (JNK) signaling pathways are associated for the first time with eyespot development. In addition, several genes involved in wound healing and calcium signaling were also found to be associated with eyespots. Conclusions Overall, this study provides the identity of many new genes and signaling pathways associated with eyespots, and suggests that the ancient wound healing gene regulatory network may have been co-opted to cells at the center of the pattern to aid in eyespot origins. New transcription factors that may be providing different identities to distinct wing sectors, and genes with sexually dimorphic expression in the eyespots were also identified. Electronic supplementary material The online version of this article (10.1186/s12864-017-4175-7) contains supplementary material, which is available to authorized users.
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Beldade P, Peralta CM. Developmental and evolutionary mechanisms shaping butterfly eyespots. CURRENT OPINION IN INSECT SCIENCE 2017; 19:22-29. [PMID: 28521939 DOI: 10.1016/j.cois.2016.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/20/2016] [Accepted: 10/24/2016] [Indexed: 06/07/2023]
Abstract
Butterfly eyespots are visually compelling models to study the reciprocal interactions between evolutionary and developmental processes that shape phenotypic variation. They are evolutionarily diversified, ecologically relevant, and developmentally tractable, and have made key contributions to linking genotype, development, phenotype and fitness. Advances in the availability of analytical tools (e.g. gene editing and visualization techniques) and resources (e.g. genomic and transcriptomic data) are boosting the detailed dissection of the mechanisms underlying eyespot development and evolution. Here, we review current knowledge on the ecology, development, and evolution of butterfly eyespots, with focus on recent advances. We also highlight a number of unsolved mysteries in our understanding of the patterns and processes underlying the diversification of these structures.
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Affiliation(s)
- Patrícia Beldade
- Instituto Gulbenkian de Ciência, Oeiras, Portugal; UMR5174, University of Toulouse, France.
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Abbasi R, Marcus JM. Colour pattern homology and evolution inVanessabutterflies (Nymphalidae: Nymphalini): eyespot characters. J Evol Biol 2015; 28:2009-26. [DOI: 10.1111/jeb.12716] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 06/11/2015] [Accepted: 07/31/2015] [Indexed: 11/30/2022]
Affiliation(s)
- R. Abbasi
- Department of Biological Sciences; University of Manitoba; Winnipeg MB Canada
| | - J. M. Marcus
- Department of Biological Sciences; University of Manitoba; Winnipeg MB Canada
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Schachat SR, Oliver JC, Monteiro A. Nymphalid eyespots are co-opted to novel wing locations following a similar pattern in independent lineages. BMC Evol Biol 2015; 15:20. [PMID: 25886182 PMCID: PMC4335541 DOI: 10.1186/s12862-015-0300-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Variation in the number of repeated traits, or serial homologs, has contributed greatly to animal body plan diversity. Eyespot color patterns of nymphalid butterflies, like arthropod and vertebrate limbs, are an example of serial homologs. These eyespot color patterns originated in a small number of wing sectors on the ventral hindwing surface and later appeared in novel wing sectors, novel wings, and novel wing surfaces. However, the details of how eyespots were co-opted to these novel wing locations are currently unknown. RESULTS We used a large data matrix of eyespot/presence absence data, previously assembled from photographs of contemporary species, to perform a phylogenetic investigation of eyespot origins in nine independent nymphalid lineages. To determine how the eyespot gene regulatory network acquired novel positional information, we used phylogenetic correlation analyses to test for non-independence in the origination of eyespots. We found consistent patterns of eyespot gene network redeployment in the nine lineages, where eyespots first redeployed from the ventral hindwing to the ventral forewing, then to new sectors within the ventral wing surface, and finally to the dorsal wing surface. Eyespots that appeared in novel wing sectors modified the positional information of their serial homolog ancestors in one of two ways: by changing the wing or surface identity while retaining sector identity, or by changing the sector identity while retaining wing and surface identity. CONCLUSIONS Eyespot redeployment to novel sectors, wings, and surfaces happened multiple times in different nymphalid subfamilies following a similar pattern. This indicates that parallel mutations altering expression of the eyespot gene regulatory network led to its co-option to novel wing locations over time.
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Affiliation(s)
- Sandra R Schachat
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS, 39762, USA. .,Department of Paleobiology, Smithsonian Institution, Washington, DC, 20013, USA.
| | - Jeffrey C Oliver
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Antónia Monteiro
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, 06520, USA. .,Department of Biological Sciences, National University of Singapore, 117543, Singapore, Singapore. .,Yale-NUS College, 138614, Singapore, Singapore.
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Oliver JC, Beaulieu JM, Gall LF, Piel WH, Monteiro A. Nymphalid eyespot serial homologues originate as a few individualized modules. Proc Biol Sci 2015; 281:rspb.2013.3262. [PMID: 24870037 DOI: 10.1098/rspb.2013.3262] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Serial homologues are repeated traits that share similar development but occur in different parts of the body. Variation in number of repeats accounts for substantial diversity in animal form and considerable work has focused on identifying the factors accounting for this variation. Little is known, however, about how serial homologues originally become repeated, or about the relative timing of repeat individuation relative to repeat origin. Here, we show that the serially repeated eyespots on nymphalid butterfly wings most likely arose as a small cluster of units on the ventral hindwing that were later co-opted to the dorsal and anterior wing surfaces. Based on comparative analyses of over 400 species, we found support for a model of eyespot origin followed by redeployment, rather than by the conventional model, where eyespots arose as a complete row of undifferentiated units that later gained individuation. In addition, eyespots most likely evolved from simpler pattern elements, single-coloured spots, which were already individuated among different wing sectors. Finally, the late appearance of eyespots on the dorsal, hidden wing surface further suggests that these novel complex traits originally evolved for one function (thwarting predator attacks) and acquired a second function (sexual signalling) when moved to a different body location. This broad comparative analysis illustrates how serial homologues may initially evolve as a few units serving a particular function and subsequently become repeated in novel body locations with new functions.
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Affiliation(s)
- Jeffrey C Oliver
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Jeremy M Beaulieu
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA National Institute for Biological and Mathematical Synthesis, University of Tennessee, Knoxville, TN 37996, USA
| | - Lawrence F Gall
- Yale Peabody Museum of Natural History, Yale University, New Haven, CT 06520, USA
| | - William H Piel
- Yale Peabody Museum of Natural History, Yale University, New Haven, CT 06520, USA Department of Biological Sciences, National University of Singapore, 117543 Singapore, Republic of Singapore Yale-NUS College, 138614 Singapore, Republic of Singapore
| | - Antónia Monteiro
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA Department of Biological Sciences, National University of Singapore, 117543 Singapore, Republic of Singapore Yale-NUS College, 138614 Singapore, Republic of Singapore
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Abstract
This article reviews the latest developments in our understanding of the origin, development, and evolution of nymphalid butterfly eyespots. Recent contributions to this field include insights into the evolutionary and developmental origin of eyespots and their ancestral deployment on the wing, the evolution of eyespot number and eyespot sexual dimorphism, and the identification of genes affecting eyespot development and black pigmentation. I also compare features of old and more recently proposed models of eyespot development and propose a schematic for the genetic regulatory architecture of eyespots. Using this schematic I propose two hypotheses for why we observe limits to morphological diversity across these serially homologous traits.
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Affiliation(s)
- Antónia Monteiro
- Biological Sciences, National University of Singapore, and Yale-NUS-College, Singapore;
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Armbruster WS, Pélabon C, Bolstad GH, Hansen TF. Integrated phenotypes: understanding trait covariation in plants and animals. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130245. [PMID: 25002693 PMCID: PMC4084533 DOI: 10.1098/rstb.2013.0245] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Integration and modularity refer to the patterns and processes of trait interaction and independence. Both terms have complex histories with respect to both conceptualization and quantification, resulting in a plethora of integration indices in use. We review briefly the divergent definitions, uses and measures of integration and modularity and make conceptual links to allometry. We also discuss how integration and modularity might evolve. Although integration is generally thought to be generated and maintained by correlational selection, theoretical considerations suggest the relationship is not straightforward. We caution here against uncontrolled comparisons of indices across studies. In the absence of controls for trait number, dimensionality, homology, development and function, it is difficult, or even impossible, to compare integration indices across organisms or traits. We suggest that care be invested in relating measurement to underlying theory or hypotheses, and that summative, theory-free descriptors of integration generally be avoided. The papers that follow in this Theme Issue illustrate the diversity of approaches to studying integration and modularity, highlighting strengths and pitfalls that await researchers investigating integration in plants and animals.
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Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO12DY, UK Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Christophe Pélabon
- Center for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Geir H Bolstad
- Center for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Thomas F Hansen
- Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, PO Box 1066, 0316 Oslo, Norway
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