1
|
Tzika AC, Ullate-Agote A, Helleboid PY, Kummrow M. PMEL is involved in snake colour pattern transition from blotches to stripes. Nat Commun 2024; 15:7655. [PMID: 39227572 PMCID: PMC11371805 DOI: 10.1038/s41467-024-51927-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 08/20/2024] [Indexed: 09/05/2024] Open
Abstract
Corn snakes are emerging models for animal colouration studies. Here, we focus on the Terrazzo morph, whose skin pattern is characterized by stripes rather than blotches. Using genome mapping, we discover a disruptive mutation in the coding region of the Premelanosome protein (PMEL) gene. Our transcriptomic analyses reveal that PMEL expression is significantly downregulated in Terrazzo embryonic tissues. We produce corn snake PMEL knockouts, which present a comparable colouration phenotype to Terrazzo and the subcellular structure of their melanosomes and xanthosomes is also similarly impacted. Our single-cell expression analyses of wild-type embryonic dorsal skin demonstrate that all chromatophore progenitors express PMEL at varying levels. Finally, we show that in wild-type embryos PMEL-expressing cells are initially uniformly spread before forming aggregates and eventually blotches, as seen in the adults. In Terrazzo embryos, the aggregates fail to form. Our results provide insights into the mechanisms governing colouration patterning in reptiles.
Collapse
Affiliation(s)
- Athanasia C Tzika
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Geneva, Switzerland.
| | - Asier Ullate-Agote
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Geneva, Switzerland
- Biomedical Engineering Program, Center for Applied Medical Research (CIMA), Universidad de Navarra, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Pierre-Yves Helleboid
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Geneva, Switzerland
| | - Maya Kummrow
- Tierspital, University of Zurich, Zurich, Switzerland
| |
Collapse
|
2
|
Pokrajac NT, Singh AP. Spotting the band. Proc Natl Acad Sci U S A 2024; 121:e2412259121. [PMID: 39102561 PMCID: PMC11331082 DOI: 10.1073/pnas.2412259121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024] Open
Affiliation(s)
- Nenad T. Pokrajac
- Discovery Sciences, Biomedical Research, Novartis, Cambridge, MA02139
| | | |
Collapse
|
3
|
Ullate-Agote A, Tzika AC. The dynamic behavior of chromatophores marks the transition from bands to spots in leopard geckos. Proc Natl Acad Sci U S A 2024; 121:e2400486121. [PMID: 38976731 PMCID: PMC11260152 DOI: 10.1073/pnas.2400486121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 05/31/2024] [Indexed: 07/10/2024] Open
Abstract
Reptilian skin coloration is spectacular and diverse, yet little is known about the ontogenetic processes that govern its establishment and the molecular signaling pathways that determine it. Here, we focus on the development of the banded pattern of leopard gecko hatchlings and the transition to black spots in the adult. With our histological analyses, we show that iridophores are present in the white and yellow bands of the hatchling and they gradually perish in the adult skin. Furthermore, we demonstrate that melanophores can autonomously form spots in the absence of the other chromatophores both on the regenerated skin of the tail and on the dorsal skin of the Mack Super Snow (MSS) leopard geckos. This color morph is characterized by uniform black coloration in hatchlings and black spots in adulthood; we establish that their skin is devoid of xanthophores and iridophores at both stages. Our genetic analyses identified a 13-nucleotide deletion in the PAX7 transcription factor of MSS geckos, affecting its protein coding sequence. With our single-cell transcriptomics analysis of embryonic skin, we confirm that PAX7 is expressed in iridophores and xanthophores, suggesting that it plays a key role in the differentiation of both chromatophores. Our in situ hybridizations on whole-mount embryos document the dynamics of the skin pattern formation and how it is impacted in the PAX7 mutants. We hypothesize that the melanophores-iridophores interactions give rise to the banded pattern of the hatchlings and black spot formation is an intrinsic capacity of melanophores in the postembryonic skin.
Collapse
Affiliation(s)
- Asier Ullate-Agote
- Laboratory of Artificial & Natural Evolution, Department of Genetics & Evolution, University of Geneva, Geneva1211, Switzerland
| | - Athanasia C. Tzika
- Laboratory of Artificial & Natural Evolution, Department of Genetics & Evolution, University of Geneva, Geneva1211, Switzerland
| |
Collapse
|
4
|
Blumer MJ, Surapaneni VA, Ciecierska-Holmes J, Redl S, Pechriggl EJ, Mollen FH, Dean MN. Intermediate filaments spatially organize intracellular nanostructures to produce the bright structural blue of ribbontail stingrays across ontogeny. Front Cell Dev Biol 2024; 12:1393237. [PMID: 39050893 PMCID: PMC11266302 DOI: 10.3389/fcell.2024.1393237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/03/2024] [Indexed: 07/27/2024] Open
Abstract
In animals, pigments but also nanostructures determine skin coloration, and many shades are produced by combining both mechanisms. Recently, we discovered a new mechanism for blue coloration in the ribbontail stingray Taeniura lymma, a species with electric blue spots on its yellow-brown skin. Here, we characterize finescale differences in cell composition and architecture distinguishing blue from non-blue regions, the first description of elasmobranch chromatophores and the nanostructures responsible for the stingray's novel structural blue, contrasting with other known mechanisms for making nature's rarest color. In blue regions, the upper dermis comprised a layer of chromatophore units -iridophores and melanophores entwined in compact clusters framed by collagen bundles- this structural stability perhaps the root of the skin color's robustness. Stingray iridophores were notably different from other vertebrate light-reflecting cells in having numerous fingerlike processes, which surrounded nearby melanophores like fists clenching a black stone. Iridophores contained spherical iridosomes enclosing guanine nanocrystals, suspended in a 3D quasi-order, linked by a cytoskeleton of intermediate filaments. We argue that intermediate filaments form a structural scaffold with a distinct optical role, providing the iridosome spacing critical to produce the blue color. In contrast, black-pigmented melanosomes within melanophores showed space-efficient packing, consistent with their hypothesized role as broadband-absorbers for enhancing blue color saturation. The chromatophore layer's ultrastructure was similar in juvenile and adult animals, indicating that skin color and perhaps its ecological role are likely consistent through ontogeny. In non-blue areas, iridophores were replaced by pale cells, resembling iridophores in some morphological and nanoscale features, but lacking guanine crystals, suggesting that the cell types arise from a common progenitor cell. The particular cellular associations and structural interactions we demonstrate in stingray skin suggest that pigment cells induce differentiation in the progenitor cells of iridophores, and that some features driving color production may be shared with bony fishes, although the lineages diverged hundreds of millions of years ago and the iridophores themselves differ drastically.
Collapse
Affiliation(s)
- Michael J. Blumer
- Institute of Clinical and Functional Anatomy, Medical University Innsbruck, Innsbruck, Austria
| | - Venkata A. Surapaneni
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Jana Ciecierska-Holmes
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Stefan Redl
- Institute of Neuroanatomy, Medical University Innsbruck, Innsbruck, Austria
| | - Elisabeth J. Pechriggl
- Institute of Clinical and Functional Anatomy, Medical University Innsbruck, Innsbruck, Austria
| | | | - Mason N. Dean
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| |
Collapse
|
5
|
Martinson WD, Volkening A, Schmidtchen M, Venkataraman C, Carrillo JA. Linking discrete and continuous models of cell birth and migration. ROYAL SOCIETY OPEN SCIENCE 2024; 11:232002. [PMID: 39021774 PMCID: PMC11252671 DOI: 10.1098/rsos.232002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 05/10/2024] [Indexed: 07/20/2024]
Abstract
Self-organization of individuals within large collectives occurs throughout biology. Mathematical models can help elucidate the individual-level mechanisms behind these dynamics, but analytical tractability often comes at the cost of biological intuition. Discrete models provide straightforward interpretations by tracking each individual yet can be computationally expensive. Alternatively, continuous models supply a large-scale perspective by representing the 'effective' dynamics of infinite agents, but their results are often difficult to translate into experimentally relevant insights. We address this challenge by quantitatively linking spatio-temporal dynamics of continuous models and individual-based data in settings with biologically realistic, time-varying cell numbers. Specifically, we introduce and fit scaling parameters in continuous models to account for discrepancies that can arise from low cell numbers and localized interactions. We illustrate our approach on an example motivated by zebrafish-skin pattern formation, in which we create a continuous framework describing the movement and proliferation of a single cell population by upscaling rules from a discrete model. Our resulting continuous models accurately depict ensemble average agent-based solutions when migration or proliferation act alone. Interestingly, the same parameters are not optimal when both processes act simultaneously, highlighting a rich difference in how combining migration and proliferation affects discrete and continuous dynamics.
Collapse
Affiliation(s)
| | | | - Markus Schmidtchen
- Institute of Scientific Computing, Technische Universität Dresden, Dresden, Germany
| | | | | |
Collapse
|
6
|
Clark B, Hickey A, Marconi A, Fischer B, Elkin J, Mateus R, Santos ME. Developmental plasticity and variability in the formation of egg-spots, a pigmentation ornament in the cichlid Astatotilapia calliptera. Evol Dev 2024; 26:e12475. [PMID: 38555511 DOI: 10.1111/ede.12475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 03/14/2024] [Accepted: 03/18/2024] [Indexed: 04/02/2024]
Abstract
Vertebrate pigmentation patterns are highly diverse, yet we have a limited understanding of how evolutionary changes to genetic, cellular, and developmental mechanisms generate variation. To address this, we examine the formation of a sexually-selected male ornament exhibiting inter- and intraspecific variation, the egg-spot pattern, consisting of circular yellow-orange markings on the male anal fins of haplochromine cichlid fishes. We focus on Astatotilapia calliptera, the ancestor-type species of the Malawi cichlid adaptive radiation of over 850 species. We identify a key role for iridophores in initializing egg-spot aggregations composed of iridophore-xanthophore associations. Despite adult sexual dimorphism, aggregations initially form in both males and females, with development only diverging between the sexes at later stages. Unexpectedly, we found that the timing of egg-spot initialization is plastic. The earlier individuals are socially isolated, the earlier the aggregations form, with iridophores being the cell type that responds to changes to the social environment. Furthermore, we observe apparent competitive interactions between adjacent egg-spot aggregations, which strongly suggests that egg-spot patterning results mostly from cell-autonomous cellular interactions. Together, these results demonstrate that A. calliptera egg-spot development is an exciting model for investigating pigment pattern formation at the cellular level in a system with developmental plasticity, sexual dimorphism, and intraspecific variation. As A. calliptera represents the ancestral bauplan for egg-spots, these findings provide a baseline for informed comparisons across the incredibly diverse Malawi cichlid radiation.
Collapse
Affiliation(s)
- Bethan Clark
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Aaron Hickey
- Department of Zoology, University of Cambridge, Cambridge, UK
| | | | - Bettina Fischer
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Joel Elkin
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Rita Mateus
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
| | - M Emília Santos
- Department of Zoology, University of Cambridge, Cambridge, UK
| |
Collapse
|
7
|
Chen J, Wang H, Wu S, Zhang A, Qiu Z, Huang P, Qu JY, Xu J. col1a2+ fibroblasts/muscle progenitors finetune xanthophore countershading by differentially expressing csf1a/1b in embryonic zebrafish. SCIENCE ADVANCES 2024; 10:eadj9637. [PMID: 38578990 PMCID: PMC10997200 DOI: 10.1126/sciadv.adj9637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 02/29/2024] [Indexed: 04/07/2024]
Abstract
Animals evolve diverse pigment patterns to adapt to the natural environment. Countershading, characterized by a dark-colored dorsum and a light-colored ventrum, is one of the most prevalent pigment patterns observed in vertebrates. In this study, we reveal a mechanism regulating xanthophore countershading in zebrafish embryos. We found that csf1a and csf1b mutants altered xanthophore countershading differently: csf1a mutants lack ventral xanthophores, while csf1b mutants have reduced dorsal xanthophores. Further study revealed that csf1a is expressed throughout the trunk, whereas csf1b is expressed dorsally. Ectopic expression of csf1a or csf1b in neurons attracted xanthophores into the spinal cord. Blocking csf1 signaling by csf1ra mutants disrupts spinal cord distribution and normal xanthophores countershading. Single-cell RNA sequencing identified two col1a2+ populations: csf1ahighcsf1bhigh muscle progenitors and csf1ahighcsf1blow fibroblast progenitors. Ablation of col1a2+ fibroblast and muscle progenitors abolished xanthophore patterns. Our study suggests that fibroblast and muscle progenitors differentially express csf1a and csf1b to modulate xanthophore patterning, providing insights into the mechanism of countershading.
Collapse
Affiliation(s)
- Jiahao Chen
- Department of Neurology, the Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Innovation Centre of Ministry of Education for Development and Diseases, School of Medicine, South China University of Technology, Guangzhou 510006, China
| | - Honggao Wang
- Innovation Centre of Ministry of Education for Development and Diseases, School of Medicine, South China University of Technology, Guangzhou 510006, China
| | - Shuting Wu
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Ao Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, PRC
| | - Zhongkai Qiu
- Innovation Centre of Ministry of Education for Development and Diseases, School of Medicine, South China University of Technology, Guangzhou 510006, China
| | - Peng Huang
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jianan Y Qu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Kowloon, China
| | - Jin Xu
- Department of Neurology, the Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Innovation Centre of Ministry of Education for Development and Diseases, School of Medicine, South China University of Technology, Guangzhou 510006, China
| |
Collapse
|
8
|
Abstract
Vertebrates exhibit a wide range of color patterns, which play critical roles in mediating intra- and interspecific communication. Because of their diversity and visual accessibility, color patterns offer a unique and fascinating window into the processes underlying biological organization. In this review, we focus on describing many of the general principles governing the formation and evolution of color patterns in different vertebrate groups. We characterize the types of patterns, review the molecular and developmental mechanisms by which they originate, and discuss their role in constraining or facilitating evolutionary change. Lastly, we outline outstanding questions in the field and discuss different approaches that can be used to address them. Overall, we provide a unifying conceptual framework among vertebrate systems that may guide research into naturally evolved mechanisms underlying color pattern formation and evolution.
Collapse
Affiliation(s)
| | - Ricardo Mallarino
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA;
| |
Collapse
|
9
|
Guo L, Kruglyak L. Genetics and biology of coloration in reptiles: the curious case of the Lemon Frost geckos. Physiol Genomics 2023; 55:479-486. [PMID: 37642275 DOI: 10.1152/physiolgenomics.00015.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
Although there are more than 10,000 reptile species, and reptiles have historically contributed to our understanding of biology, genetics research into class Reptilia has lagged compared with other animals. Here, we summarize recent progress in genetics of coloration in reptiles, with a focus on the leopard gecko, Eublepharis macularius. We highlight genetic approaches that have been used to examine variation in color and pattern formation in this species as well as to provide insights into mechanisms underlying skin cancer. We propose that their long breeding history in captivity makes leopard geckos one of the most promising emerging reptilian models for genetic studies. More broadly, technological advances in genetics, genomics, and gene editing may herald a golden era for studies of reptile biology.
Collapse
Affiliation(s)
- Longhua Guo
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States
- Geriatrics Center and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States
| | - Leonid Kruglyak
- Department of Human Genetics, University of California, Los Angeles, California, United States
- Department of Biological Chemistry, University of California, Los Angeles, California, United States
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States
| |
Collapse
|
10
|
Milinkovitch MC, Jahanbakhsh E, Zakany S. The Unreasonable Effectiveness of Reaction Diffusion in Vertebrate Skin Color Patterning. Annu Rev Cell Dev Biol 2023; 39:145-174. [PMID: 37843926 DOI: 10.1146/annurev-cellbio-120319-024414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
In 1952, Alan Turing published the reaction-diffusion (RD) mathematical framework, laying the foundations of morphogenesis as a self-organized process emerging from physicochemical first principles. Regrettably, this approach has been widely doubted in the field of developmental biology. First, we summarize Turing's line of thoughts to alleviate the misconception that RD is an artificial mathematical construct. Second, we discuss why phenomenological RD models are particularly effective for understanding skin color patterning at the meso/macroscopic scales, without the need to parameterize the profusion of variables at lower scales. More specifically, we discuss how RD models (a) recapitulate the diversity of actual skin patterns, (b) capture the underlying dynamics of cellular interactions, (c) interact with tissue size and shape, (d) can lead to ordered sequential patterning, (e) generate cellular automaton dynamics in lizards and snakes, (f) predict actual patterns beyond their statistical features, and (g) are robust to model variations. Third, we discuss the utility of linear stability analysis and perform numerical simulations to demonstrate how deterministic RD emerges from the underlying chaotic microscopic agents.
Collapse
Affiliation(s)
- Michel C Milinkovitch
- Laboratory of Artificial and Natural Evolution, Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland;
| | - Ebrahim Jahanbakhsh
- Laboratory of Artificial and Natural Evolution, Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland;
| | - Szabolcs Zakany
- Laboratory of Artificial and Natural Evolution, Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland;
| |
Collapse
|
11
|
Podobnik M, Singh AP, Fu Z, Dooley CM, Frohnhöfer HG, Firlej M, Stednitz SJ, Elhabashy H, Weyand S, Weir JR, Lu J, Nüsslein-Volhard C, Irion U. kcnj13 regulates pigment cell shapes in zebrafish and has diverged by cis-regulatory evolution between Danio species. Development 2023; 150:dev201627. [PMID: 37530080 PMCID: PMC10482006 DOI: 10.1242/dev.201627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/21/2023] [Indexed: 08/03/2023]
Abstract
Teleost fish of the genus Danio are excellent models to study the genetic and cellular bases of pigment pattern variation in vertebrates. The two sister species Danio rerio and Danio aesculapii show divergent patterns of horizontal stripes and vertical bars that are partly caused by the divergence of the potassium channel gene kcnj13. Here, we show that kcnj13 is required only in melanophores for interactions with xanthophores and iridophores, which cause location-specific pigment cell shapes and thereby influence colour pattern and contrast in D. rerio. Cis-regulatory rather than protein coding changes underlie kcnj13 divergence between the two Danio species. Our results suggest that homotypic and heterotypic interactions between the pigment cells and their shapes diverged between species by quantitative changes in kcnj13 expression during pigment pattern diversification.
Collapse
Affiliation(s)
- Marco Podobnik
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Ajeet P. Singh
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Zhenqiang Fu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China
| | - Christopher M. Dooley
- Department of Genetics, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | | | - Magdalena Firlej
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Sarah J. Stednitz
- Department of Anatomy & Physiology, University of Melbourne, Victoria, 3010, Melbourne, Australia
| | - Hadeer Elhabashy
- Department of Protein Evolution, Max Planck Institute for Biology, 72076 Tübingen, Germany
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, 72076 Tübingen, Germany
- Department of Computer Science, University of Tübingen, 72076 Tübingen, Germany
| | - Simone Weyand
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - John R. Weir
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Jianguo Lu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China
| | | | - Uwe Irion
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| |
Collapse
|
12
|
Dao UM, Lederer I, Tabor RL, Shahid B, Graves CW, Seidel HS. Stripes and loss of color in ball pythons (Python regius) are associated with variants affecting endothelin signaling. G3 (BETHESDA, MD.) 2023; 13:jkad063. [PMID: 37191439 PMCID: PMC10320763 DOI: 10.1093/g3journal/jkad063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/10/2023] [Indexed: 05/17/2023]
Abstract
Color patterns in nonavian reptiles are beautifully diverse, but little is known about the genetics and development of these patterns. Here, we investigated color patterning in pet ball pythons (Python regius), which have been bred to show color phenotypes that differ dramatically from the wildtype form. We report that several color phenotypes in pet animals are associated with putative loss-of-function variants in the gene encoding endothelin receptor EDNRB1: (1) frameshift variants in EDNRB1 are associated with conversion of the normal mottled color pattern to skin that is almost fully white, (2) missense variants affecting conserved sites of the EDNRB1 protein are associated with dorsal, longitudinal stripes, and (3) substitutions at EDNRB1 splice donors are associated with subtle changes in patterning compared to wildtype. We propose that these phenotypes are caused by loss of specialized color cells (chromatophores), with loss ranging from severe (fully white) to moderate (dorsal striping) to mild (subtle changes in patterning). Our study is the first to describe variants affecting endothelin signaling in a nonavian reptile and suggests that reductions in endothelin signaling in ball pythons can produce a variety of color phenotypes, depending on the degree of color cell loss.
Collapse
Affiliation(s)
- Uyen M Dao
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Izabella Lederer
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Ray L Tabor
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Basmah Shahid
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Chiron W Graves
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Hannah S Seidel
- Department of Biology, Eastern Michigan University, Ypsilanti, MI 48197, USA
| |
Collapse
|
13
|
Kabangu M, Cecil R, Strohl L, Timoshevskaya N, Smith JJ, Voss SR. Leukocyte Tyrosine Kinase ( Ltk) Is the Mendelian Determinant of the Axolotl Melanoid Color Variant. Genes (Basel) 2023; 14:904. [PMID: 37107662 PMCID: PMC10137446 DOI: 10.3390/genes14040904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/02/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
The great diversity of color patterns observed among amphibians is largely explained by the differentiation of relatively few pigment cell types during development. Mexican axolotls present a variety of color phenotypes that span the continuum from leucistic to highly melanistic. The melanoid axolotl is a Mendelian variant characterized by large numbers of melanophores, proportionally fewer xanthophores, and no iridophores. Early studies of melanoid were influential in developing the single-origin hypothesis of pigment cell development, wherein it has been proposed that all three pigment cell types derive from a common progenitor cell, with pigment metabolites playing potential roles in directing the development of organelles that define different pigment cell types. Specifically, these studies identified xanthine dehydrogenase (XDH) activity as a mechanism for the permissive differentiation of melanophores at the expense of xanthophores and iridophores. We used bulked segregant RNA-Seq to screen the axolotl genome for melanoid candidate genes and identify the associated locus. Dissimilar frequencies of single-nucleotide polymorphisms were identified between pooled RNA samples of wild-type and melanoid siblings for a region on chromosome 14q. This region contains gephyrin (Gphn), an enzyme that catalyzes the synthesis of the molybdenum cofactor that is required for XDH activity, and leukocyte tyrosine kinase (Ltk), a cell surface signaling receptor that is required for iridophore differentiation in zebrafish. Wild-type Ltk crispants present similar pigment phenotypes to melanoid, strongly implicating Ltk as the melanoid locus. In concert with recent findings in zebrafish, our results support the idea of direct fate specification of pigment cells and, more generally, the single-origin hypothesis of pigment cell development.
Collapse
Affiliation(s)
- Mirindi Kabangu
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, and Ambystoma Genetic Stock Center, University of Kentucky, Lexington, KY 40536, USA
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Raissa Cecil
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, and Ambystoma Genetic Stock Center, University of Kentucky, Lexington, KY 40536, USA
| | | | | | - Jeramiah J. Smith
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Stephen R. Voss
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, and Ambystoma Genetic Stock Center, University of Kentucky, Lexington, KY 40536, USA
| |
Collapse
|
14
|
Mao L, Zhu Y, Yan J, Zhang L, Zhu S, An L, Meng Q, Zhang Z, Wang X. Full-length transcriptome sequencing analysis reveals differential skin color regulation in snakeheads fish Channa argus. AQUACULTURE AND FISHERIES 2023. [DOI: 10.1016/j.aaf.2022.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
15
|
Jahanbakhsh E, Milinkovitch MC. Modeling convergent scale-by-scale skin color patterning in multiple species of lizards. Curr Biol 2022; 32:5069-5082.e13. [PMID: 36379217 PMCID: PMC9763091 DOI: 10.1016/j.cub.2022.10.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/25/2022] [Accepted: 10/19/2022] [Indexed: 11/16/2022]
Abstract
Skin color patterning in vertebrates emerges at the macroscale from microscopic cell-cell interactions among chromatophores. Taking advantage of the convergent scale-by-scale skin color patterning dynamics in five divergent species of lizards, we quantify the respective efficiencies of stochastic (Lenz-Ising and cellular automata, sCA) and deterministic reaction-diffusion (RD) models to predict individual patterns and their statistical attributes. First, we show that all models capture the underlying microscopic system well enough to predict, with similar efficiencies, neighborhood statistics of adult patterns. Second, we show that RD robustly generates, in all species, a substantial gain in scale-by-scale predictability of individual adult patterns without the need to parametrize the system down to its many cellular and molecular variables. Third, using 3D numerical simulations and Lyapunov spectrum analyses, we quantitatively demonstrate that, given the non-linearity of the dynamical system, uncertainties in color measurements at the juvenile stage and in skin geometry variation explain most, if not all, of the residual unpredictability of adult individual scale-by-scale patterns. We suggest that the efficiency of RD is due to its intrinsic ability to exploit mesoscopic information such as continuous scale colors and the relations among growth, scales geometries, and the pattern length scale. Our results indicate that convergent evolution of CA patterning dynamics, leading to dissimilar macroscopic patterns in different species, is facilitated by their spontaneous emergence under a large range of RD parameters, as long as a Turing instability occurs in a skin domain with periodic thickness. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Ebrahim Jahanbakhsh
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, 1211 Geneva, Switzerland; SIB Swiss Institute of Bioinformatics, 1211 Geneva, Switzerland
| | - Michel C Milinkovitch
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, 1211 Geneva, Switzerland; SIB Swiss Institute of Bioinformatics, 1211 Geneva, Switzerland.
| |
Collapse
|
16
|
Recio P, Rodríguez-Ruiz G, López P, Martín J. Size-related changes and chemical basis of melanin-based body coloration in the amphisbaenian Trogonophis wiegmanni. AMPHIBIA-REPTILIA 2022. [DOI: 10.1163/15685381-bja10109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Melanin is a fundamental pigment in animal coloration as it is involved in many different adaptive functions such as signaling or thermoregulation. Two forms of melanin are known to produce different colors (eumelanin: black; pheomelanin: yellow or brown). Here, we explored whether there were intersexual differences and/or size-related changes in melanization of the amphisbaenian Trogonophis wiegmanni, a fossorial species with a characteristic black and yellow color pattern of scales. We found a clear effect of body length, but not of sex, on the levels of melanization, which was also dependent on the body region; the proportion of melanin-dependent blackish coloration increased with body length in the dorsum, but decreased with body length in the ventral belly area. We also studied the chemical basis of this coloration using Raman spectroscopy and found that eumelanin was present in both black and yellow scales, but pheomelanin was not found in yellow scales, suggesting that this yellow coloration is caused by the reduction of eumelanin or dispersion of melanosomes and/or perhaps by other pigments.
Collapse
Affiliation(s)
- Pablo Recio
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - Gonzalo Rodríguez-Ruiz
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - Pilar López
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - José Martín
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| |
Collapse
|
17
|
At the Intersection of Natural Structural Coloration and Bioengineering. Biomimetics (Basel) 2022; 7:biomimetics7020066. [PMID: 35645193 PMCID: PMC9149877 DOI: 10.3390/biomimetics7020066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 02/04/2023] Open
Abstract
Most of us get inspired by and interact with the world around us based on visual cues such as the colors and patterns that we see. In nature, coloration takes three primary forms: pigmentary coloration, structural coloration, and bioluminescence. Typically, pigmentary and structural coloration are used by animals and plants for their survival; however, few organisms are able to capture the nearly instantaneous and visually astounding display that cephalopods (e.g., octopi, squid, and cuttlefish) exhibit. Notably, the structural coloration of these cephalopods critically relies on a unique family of proteins known as reflectins. As a result, there is growing interest in characterizing the structure and function of such optically-active proteins (e.g., reflectins) and to leverage these materials across a broad range of disciplines, including bioengineering. In this review, I begin by briefly introducing pigmentary and structural coloration in animals and plants as well as highlighting the extraordinary appearance-changing capabilities of cephalopods. Next, I outline recent advances in the characterization and utilization of reflectins for photonic technologies and and discuss general strategies and limitations for the structural and optical characterization of proteins. Finally, I explore future directions of study for optically-active proteins and their potential applications. Altogether, this review aims to bring together an interdisciplinary group of researchers who can resolve the fundamental questions regarding the structure, function, and self-assembly of optically-active protein-based materials.
Collapse
|
18
|
Isolation of Chromatophores from Brown Trout (Salmo trutta) Skin. FISHES 2022. [DOI: 10.3390/fishes7020072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
As new techniques for single-cell analysis are evolving, there is a growing need for streamlined and flexible protocols for single-cell suspension preparation and single-cell isolation. Based on previous research on the model species zebrafish (Danio rerio), a novel protocol for the isolation of chromatophores from brown trout (Salmo trutta) skin was developed and specific gene expression in chromatophore types evaluated with qPCR. This is the first report on a protocol for the isolation of chromatophores from the skin of salmonids. The method is simple and fast (taking about 90 min), requires no special equipment and is in line with the high ethical standards required in animal research, as no animals need to be sacrificed. In addition, skin biopsies can be taken from the same fish at multiple time points, allowing monitoring of chromatophore differentiation and their involvement in the formation of pigmentation patterns. The protocol should be effective for the vast majority of salmonid species due to similarities in skin morphology.
Collapse
|
19
|
Kuhar F, Terzzoli L, Nouhra E, Robledo G, Mercker M. Pattern formation features might explain homoplasy: fertile surfaces in higher fungi as an example. Theory Biosci 2022; 141:1-11. [PMID: 35174438 DOI: 10.1007/s12064-022-00363-z] [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: 03/20/2021] [Accepted: 01/20/2022] [Indexed: 11/25/2022]
Abstract
Fungi show a high degree of morphological convergence. Regarded for a long time as an obstacle for phylogenetic studies, homoplasy has also been proposed as a source of information about underlying morphogenetic patterning mechanisms. The "local-activation and long-range inhibition principle" (LALIP), underlying the famous reaction-diffusion model proposed by Alan Turing in 1952, appears to be one of the universal phenomena that can explain the ontogenetic origin of seriate patterns in living organisms. Reproductive structures of fungi in the class Agaricomycetes show a highly periodic structure resulting in, for example, poroid, odontoid, lamellate or labyrinthic hymenophores. In this paper, we claim that self-organized patterns might underlie the basic ontogenetic processes of these structures. Simulations based on LALIP-driven models and covering a wide range of parameters show an absolute mutual correspondence with the morphospace explored by extant agaricomycetes. This could not only explain geometric particularities but could also account for the limited possibilities displayed by hymenial configurations, thus making homoplasy a direct consequence of the limited morphospace resulting from the proposed patterning dynamics.
Collapse
Affiliation(s)
- Francisco Kuhar
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Universidad Nacional de Córdoba, Av. Vélez Sársfield 1611 CC. 4955000, Córdoba, Argentina.
| | - Leticia Terzzoli
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Universidad Nacional de Córdoba, Av. Vélez Sársfield 1611 CC. 4955000, Córdoba, Argentina
| | - Eduardo Nouhra
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Universidad Nacional de Córdoba, Av. Vélez Sársfield 1611 CC. 4955000, Córdoba, Argentina
| | - Gerardo Robledo
- Facultad de Ciencias Agropecuarias BioTecA3 - Centro de Biotecnología Aplicada Al Agro Y Alimentos, Universidad Nacionel de Córdoba, Ing. Agr. Félix Aldo Marrone 746, CC509 - CP 5000, Córdoba, Argentina.,CONICET, Consejo Nacional de Investigaciones Científicas Y Técnicas, Godoy Cruz 2290, (C1425FQB), CABA, Argentina
| | - Moritz Mercker
- Institute of Applied Mathematics (IAM), Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| |
Collapse
|
20
|
Goldenberg J, Bisschop K, D'Alba L, Shawkey MD. The link between body size, colouration and thermoregulation and their integration into ecogeographical rules: a critical appraisal in light of climate change. OIKOS 2022. [DOI: 10.1111/oik.09152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Jonathan Goldenberg
- Evolution and Optics of Nanostructures group, Dept of Biology, Ghent Univ. Ghent Belgium
| | - Karen Bisschop
- Inst. for Biodiversity and Ecosystem Dynamics, Univ. of Amsterdam Amsterdam the Netherlands
- Laboratory of Aquatic Biology, Dept of Biology, KU Leuven KULAK Kortrijk Belgium
| | - Liliana D'Alba
- Evolution and Optics of Nanostructures group, Dept of Biology, Ghent Univ. Ghent Belgium
| | - Matthew D. Shawkey
- Evolution and Optics of Nanostructures group, Dept of Biology, Ghent Univ. Ghent Belgium
| |
Collapse
|
21
|
Sheng J, Guan L, Sheng B, Geng S, Wu D, Hu B, Li Z, Le S, Hong Y. Analysis of pigment cell composition, pigment content, tyrosinase content and activity of three kinds of loaches Misgurnus anguillicaudatus from Poyang Lake. JOURNAL OF FISH BIOLOGY 2022; 100:366-377. [PMID: 34751443 DOI: 10.1111/jfb.14945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 09/28/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Pigment cell composition, pigment content, tyrosinase content and activity analysis were investigated on three kinds of loaches Misgurnus anguillicaudatus: big blackspot loaches (BBL), small blackspot loaches (SBL) and non-blackspot loaches (NBL), from Poyang Lake. Results showed that there were three types of skin pigment cells, namely melanophores, xanthophores and iridophores. Melanophores in dorsum were more than those in abdomen. Melanophore cytosomes in BBL were larger than those in SBL and NBL, and melanosomes were the largest in stage four. The melanophores in dorsal skin of SBL or NBL were small cell bodies, spindle-like and in chain distribution. There was an extremely significant difference in melanin content in BBL between the dorsum and abdomen (P < 0.01). There were no significant differences in melanin abdominal content, lutein and carotenoid contents among three kinds of loaches (P > 0.05). In dorsal skin, tyrosinase content was the highest in BBL, and it was significantly lower in NBL than in BBL and SBL (P < 0.01). This study reveals the differences in pigment and tyrosinase content in three kinds of loaches and provides a theoretical basis for further study of the mechanism of black spot formation.
Collapse
Affiliation(s)
- Junqing Sheng
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Le Guan
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Bin Sheng
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Shiyu Geng
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Di Wu
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Beijuan Hu
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Zhixiong Li
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| | - Shunlong Le
- Jiayu Agriculture Development Company Limited, Fuzhou, China
| | - Yijiang Hong
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China
| |
Collapse
|
22
|
Konow C, Dolnik M, Epstein IR. Insights from chemical systems into Turing-type morphogenesis. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20200269. [PMID: 34743602 DOI: 10.1098/rsta.2020.0269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In 1952, Alan Turing proposed a theory showing how morphogenesis could occur from a simple two morphogen reaction-diffusion system [Turing, A. M. (1952) Phil. Trans. R. Soc. Lond. A 237, 37-72. (doi:10.1098/rstb.1952.0012)]. While the model is simple, it has found diverse applications in fields such as biology, ecology, behavioural science, mathematics and chemistry. Chemistry in particular has made significant contributions to the study of Turing-type morphogenesis, providing multiple reproducible experimental methods to both predict and study new behaviours and dynamics generated in reaction-diffusion systems. In this review, we highlight the historical role chemistry has played in the study of the Turing mechanism, summarize the numerous insights chemical systems have yielded into both the dynamics and the morphological behaviour of Turing patterns, and suggest future directions for chemical studies into Turing-type morphogenesis. This article is part of the theme issue 'Recent progress and open frontiers in Turing's theory of morphogenesis'.
Collapse
Affiliation(s)
- C Konow
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA
| | - M Dolnik
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA
| | - I R Epstein
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA
| |
Collapse
|
23
|
Genetic basis of orange spot formation in the guppy (Poecilia reticulata). BMC Ecol Evol 2021; 21:211. [PMID: 34823475 PMCID: PMC8613973 DOI: 10.1186/s12862-021-01942-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/17/2021] [Indexed: 12/13/2022] Open
Abstract
Background To understand the evolutionary significance of female mate choice for colorful male ornamentation, the underlying regulatory mechanisms of such ornamentation must be understood for examining how the ornaments are associated with “male qualities” that increase the fitness or sexual attractiveness of offspring. In the guppy (Poecilia reticulata), an established model system for research on sexual selection, females prefer males possessing larger and more highly saturated orange spots as potential mates. Although previous studies have identified some chromosome regions and genes associated with orange spot formation, the regulation and involvement of these genetic elements in orange spot formation have not been elucidated. In this study, the expression patterns of genes specific to orange spots and certain color developmental stages were investigated using RNA-seq to reveal the genetic basis of orange spot formation. Results Comparing the gene expression levels of male guppy skin with orange spots (orange skin) with those without any color spots (dull skin) from the same individuals identified 1102 differentially expressed genes (DEGs), including 630 upregulated genes and 472 downregulated genes in the orange skin. Additionally, the gene expression levels of the whole trunk skin were compared among the three developmental stages and 2247 genes were identified as DEGs according to color development. These analyses indicated that secondary differentiation of xanthophores may affect orange spot formation. Conclusions The results suggested that orange spots might be formed by secondary differentiation, rather than de novo generation, of xanthophores, which is induced by Csf1 and thyroid hormone signaling pathways. Furthermore, we suggested candidate genes associated with the areas and saturation levels of orange spots, which are both believed to be important for female mate choice and independently regulated. This study provides insights into the genetic and cellular regulatory mechanisms underlying orange spot formation, which would help to elucidate how these processes are evolutionarily maintained as ornamental traits relevant to sexual selection. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01942-2.
Collapse
|
24
|
Jang HS, Chen Y, Ge J, Wilkening AN, Hou Y, Lee HJ, Choi YR, Lowdon RF, Xing X, Li D, Kaufman CK, Johnson SL, Wang T. Epigenetic dynamics shaping melanophore and iridophore cell fate in zebrafish. Genome Biol 2021; 22:282. [PMID: 34607603 PMCID: PMC8489059 DOI: 10.1186/s13059-021-02493-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 09/09/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Zebrafish pigment cell differentiation provides an attractive model for studying cell fate progression as a neural crest progenitor engenders diverse cell types, including two morphologically distinct pigment cells: black melanophores and reflective iridophores. Nontrivial classical genetic and transcriptomic approaches have revealed essential molecular mechanisms and gene regulatory circuits that drive neural crest-derived cell fate decisions. However, how the epigenetic landscape contributes to pigment cell differentiation, especially in the context of iridophore cell fate, is poorly understood. RESULTS We chart the global changes in the epigenetic landscape, including DNA methylation and chromatin accessibility, during neural crest differentiation into melanophores and iridophores to identify epigenetic determinants shaping cell type-specific gene expression. Motif enrichment in the epigenetically dynamic regions reveals putative transcription factors that might be responsible for driving pigment cell identity. Through this effort, in the relatively uncharacterized iridophores, we validate alx4a as a necessary and sufficient transcription factor for iridophore differentiation and present evidence on alx4a's potential regulatory role in guanine synthesis pathway. CONCLUSIONS Pigment cell fate is marked by substantial DNA demethylation events coupled with dynamic chromatin accessibility to potentiate gene regulation through cis-regulatory control. Here, we provide a multi-omic resource for neural crest differentiation into melanophores and iridophores. This work led to the discovery and validation of iridophore-specific alx4a transcription factor.
Collapse
Affiliation(s)
- Hyo Sik Jang
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
- Present address: Department of Epigenetics, Van Andel Institute, Grand Rapids, MI USA
| | - Yujie Chen
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Jiaxin Ge
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Alicia N. Wilkening
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Yiran Hou
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Hyung Joo Lee
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - You Rim Choi
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Rebecca F. Lowdon
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Xiaoyun Xing
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Daofeng Li
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
| | - Charles K. Kaufman
- Department of Medicine, Division of Medical Oncology, and Department of Developmental Biology, Washington University in Saint Louis, St. Louis, MO USA
| | - Stephen L. Johnson
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
| | - Ting Wang
- Department of Genetics, Washington University School of Medicine, St Louis, MO USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO USA
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO USA
| |
Collapse
|
25
|
Katz SR, Yakovlev MA, Vanselow DJ, Ding Y, Lin AY, Parkinson DY, Wang Y, Canfield VA, Ang KC, Cheng KC. Whole-organism 3D quantitative characterization of zebrafish melanin by silver deposition micro-CT. eLife 2021; 10:68920. [PMID: 34528510 PMCID: PMC8445617 DOI: 10.7554/elife.68920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/19/2021] [Indexed: 01/10/2023] Open
Abstract
We previously described X-ray histotomography, a high-resolution, non-destructive form of X-ray microtomography (micro-CT) imaging customized for three-dimensional (3D), digital histology, allowing quantitative, volumetric tissue and organismal phenotyping (Ding et al., 2019). Here, we have combined micro-CT with a novel application of ionic silver staining to characterize melanin distribution in whole zebrafish larvae. The resulting images enabled whole-body, computational analyses of regional melanin content and morphology. Normalized micro-CT reconstructions of silver-stained fish consistently reproduced pigment patterns seen by light microscopy, and further allowed direct quantitative comparisons of melanin content across wild-type and mutant samples, including subtle phenotypes not previously noticed. Silver staining of melanin for micro-CT provides proof-of-principle for whole-body, 3D computational phenomic analysis of a specific cell type at cellular resolution, with potential applications in other model organisms and melanocytic neoplasms. Advances such as this in whole-organism, high-resolution phenotyping provide superior context for studying the phenotypic effects of genetic, disease, and environmental variables.
Collapse
Affiliation(s)
- Spencer R Katz
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States.,Medical Scientist Training Program, Penn State College of Medicine, Hershey, United States
| | - Maksim A Yakovlev
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States
| | - Daniel J Vanselow
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States
| | - Yifu Ding
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States.,Medical Scientist Training Program, Penn State College of Medicine, Hershey, United States
| | - Alex Y Lin
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States
| | | | - Yuxin Wang
- Mobile Imaging Innovations, Inc, Palatine, United States
| | - Victor A Canfield
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States
| | - Khai C Ang
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States.,Zebrafish Functional Genomics Core, Penn State College of Medicine, Hershey, United States
| | - Keith C Cheng
- Division of Experimental Pathology, Department of Pathology, Pennsylvania State University College of Medicine, Hershey, United States.,The Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, United States.,Zebrafish Functional Genomics Core, Penn State College of Medicine, Hershey, United States
| |
Collapse
|
26
|
McCluskey BM, Liang Y, Lewis VM, Patterson LB, Parichy DM. Pigment pattern morphospace of Danio fishes: evolutionary diversification and mutational effects. Biol Open 2021; 10:271991. [PMID: 34463758 PMCID: PMC8487636 DOI: 10.1242/bio.058814] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/13/2021] [Indexed: 11/29/2022] Open
Abstract
Molecular and cellular mechanisms underlying variation in adult form remain largely unknown. Adult pigment patterns of fishes in the genus Danio, which includes zebrafish, Danio rerio, consist of horizontal stripes, vertical bars, spots and uniform patterns, and provide an outstanding opportunity to identify causes of species level variation in a neural crest derived trait. Understanding pigment pattern variation requires quantitative approaches to assess phenotypes, yet such methods have been mostly lacking for pigment patterns. We introduce metrics derived from information theory that describe patterns and pattern variation in Danio fishes. We find that these metrics used singly and in multivariate combinations are suitable for distinguishing general pattern types, and can reveal even subtle phenotypic differences attributable to mutations. Our study provides new tools for analyzing pigment pattern in Danio and potentially other groups, and sets the stage for future analyses of pattern morphospace and its mechanistic underpinnings. Summary: A multidimensional morphospace for pigment patterns yields quantitative insights into the evolution and genetics of diverse pigment patterns across zebrafish and related species.
Collapse
Affiliation(s)
| | - Yipeng Liang
- Department of Biology, University of Virginia, Charlottesville, USA
| | - Victor M Lewis
- Department of Biology, University of Virginia, Charlottesville, USA
| | | | - David M Parichy
- Department of Biology, University of Virginia, Charlottesville, USA.,Biology Department, Rhode Island College, Providence, USA.,Department of Cell Biology, University of Virginia, Charlottesville, USA
| |
Collapse
|
27
|
Eom DS, Patterson LB, Bostic RR, Parichy DM. Immunoglobulin superfamily receptor Junctional adhesion molecule 3 (Jam3) requirement for melanophore survival and patterning during formation of zebrafish stripes. Dev Biol 2021; 476:314-327. [PMID: 33933422 PMCID: PMC10069301 DOI: 10.1016/j.ydbio.2021.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/03/2021] [Accepted: 04/22/2021] [Indexed: 12/14/2022]
Abstract
Adhesive interactions are essential for tissue patterning and morphogenesis yet difficult to study owing to functional redundancies across genes and gene families. A useful system in which to dissect roles for cell adhesion and adhesion-dependent signaling is the pattern formed by pigment cells in skin of adult zebrafish, in which stripes represent the arrangement of neural crest derived melanophores, cells homologous to melanocytes. In a forward genetic screen for adult pattern defects, we isolated the pissarro (psr) mutant, having a variegated phenotype of spots, as well as defects in adult fin and lens. We show that psr corresponds to junctional adhesion protein 3b (jam3b) encoding a zebrafish orthologue of the two immunoglobulin-like domain receptor JAM3 (JAM-C), known for roles in adhesion and signaling in other developing tissues, and for promoting metastatic behavior of human and murine melanoma cells. We found that zebrafish jam3b is expressed post-embryonically in a variety of cells including melanophores, and that jam3b mutants have defects in melanophore survival. Jam3b supported aggregation of cells in vitro and was required autonomously by melanophores for an adherent phenotype in vivo. Genetic analyses further indicated both overlapping and non-overlapping functions with the related receptor, Immunoglobulin superfamily 11 (Igsf11) and Kit receptor tyrosine kinase. These findings suggest a model for Jam3b function in zebrafish melanophores and hint at the complexity of adhesive interactions underlying pattern formation.
Collapse
Affiliation(s)
- Dae Seok Eom
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
| | | | - Raegan R Bostic
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - David M Parichy
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Department of Cell Biology, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
28
|
Gerwin J, Urban S, Meyer A, Kratochwil CF. Of bars and stripes: A Malawi cichlid hybrid cross provides insights into genetic modularity and evolution of modifier loci underlying colour pattern diversification. Mol Ecol 2021; 30:4789-4803. [PMID: 34322938 DOI: 10.1111/mec.16097] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/13/2021] [Accepted: 07/23/2021] [Indexed: 11/25/2022]
Abstract
Understanding the origins of phenotypic diversity among closely related species remains an important largely unsolved question in evolutionary biology. With over 800 species, Lake Malawi haplochromine cichlid fishes are a prominent example of extremely fast evolution of diversity including variation in colouration. Previously, a single major effect gene, agrp2 (asip2b), has been linked to evolutionary losses and gains of horizontal stripe patterns in cichlids, but it remains unknown what causes more fine-scale variation in the number and continuity of the stripes. Also, the genetic basis of the most common colour pattern in African cichlids, vertical bars, and potential interactions between the two colour patterns remain unknown. Based on a hybrid cross of the horizontally striped Lake Malawi cichlid Pseudotropheus cyaneorhabdos and the vertically barred species Chindongo demasoni we investigated the genetic basis of both colour patterns. The distribution of phenotypes in the F2 generation of the cross indicates that horizontal stripes and vertical bars are independently inherited patterns that are caused by two sets of genetic modules. While horizontal stripes are largely controlled by few major effect loci, vertical bars are a highly polygenic trait. Horizontal stripes show substantial variation in the F2 generation that, interestingly, resemble naturally occurring phenotypes found in other Lake Malawi cichlid species. Quantitative trait loci (QTL) mapping of this cross reveals known (agrp2) and unknown loci underlying horizontal stripe patterns. These findings provide novel insights into the incremental fine-tuning of an adaptive trait that diversified through the evolution of additional modifier loci.
Collapse
Affiliation(s)
- Jan Gerwin
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Sabine Urban
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Axel Meyer
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Claudius F Kratochwil
- Department of Biology, University of Konstanz, Konstanz, Germany.,Institute of Biotechnology, HiLIFE, Helsinki, Finland
| |
Collapse
|
29
|
Guo L, Bloom J, Sykes S, Huang E, Kashif Z, Pham E, Ho K, Alcaraz A, Xiao XG, Duarte-Vogel S, Kruglyak L. Genetics of white color and iridophoroma in "Lemon Frost" leopard geckos. PLoS Genet 2021; 17:e1009580. [PMID: 34166378 PMCID: PMC8224956 DOI: 10.1371/journal.pgen.1009580] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/04/2021] [Indexed: 12/16/2022] Open
Abstract
The squamates (lizards and snakes) are close relatives of birds and mammals, with more than 10,000 described species that display extensive variation in a number of important biological traits, including coloration, venom production, and regeneration. Due to a lack of genomic tools, few genetic studies in squamates have been carried out. The leopard gecko, Eublepharis macularius, is a popular companion animal, and displays a variety of coloration patterns. We took advantage of a large breeding colony and used linkage analysis, synteny, and homozygosity mapping to investigate a spontaneous semi-dominant mutation, “Lemon Frost”, that produces white coloration and causes skin tumors (iridophoroma). We localized the mutation to a single locus which contains a strong candidate gene, SPINT1, a tumor suppressor implicated in human skin cutaneous melanoma (SKCM) and over-proliferation of epithelial cells in mice and zebrafish. Our work establishes the leopard gecko as a tractable genetic system and suggests that a tumor suppressor in melanocytes in humans can also suppress tumor development in iridophores in lizards. The squamates (lizards and snakes) comprise a diverse group of reptiles, with more than 10,000 described species that display extensive variation in a number of important biological traits, including coloration. In this manuscript, we used quantitative genetics and genomics to map the mutation underlying white coloration in the Lemon Frost morph of the common leopard gecko, Eublepharis macularius. Lemon Frost geckos have increased white body coloration with brightened yellow and orange areas. This morph also displays a high incidence of iridophoroma, a tumor of white-colored cells. We obtained phenotype information and DNA samples from geckos in a large breeding colony and used genome sequencing and genetic linkage analysis to localize the Lemon Frost mutation to a single locus. This locus contains a strong candidate gene, SPINT1, a tumor suppressor implicated in human skin cutaneous melanoma. Together with other recent advances, our work brings reptiles into the modern genetics era.
Collapse
Affiliation(s)
- Longhua Guo
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
- * E-mail: (LG); (LK)
| | - Joshua Bloom
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
| | - Steve Sykes
- Geckos Etc. Herpetoculture, Rocklin, California, United States of America
| | - Elaine Huang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, United States of America
| | - Zain Kashif
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
| | - Elise Pham
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
| | - Katarina Ho
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
| | - Ana Alcaraz
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, California, United States of America
| | - Xinshu Grace Xiao
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, United States of America
| | - Sandra Duarte-Vogel
- Division of Laboratory Animal Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Leonid Kruglyak
- Department of Human Genetics, Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, California, United States of America
- * E-mail: (LG); (LK)
| |
Collapse
|
30
|
Klann M, Mercader M, Carlu L, Hayashi K, Reimer JD, Laudet V. Variation on a theme: pigmentation variants and mutants of anemonefish. EvoDevo 2021; 12:8. [PMID: 34147131 PMCID: PMC8214269 DOI: 10.1186/s13227-021-00178-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/02/2021] [Indexed: 11/10/2022] Open
Abstract
Pigmentation patterning systems are of great interest to understand how changes in developmental mechanisms can lead to a wide variety of patterns. These patterns are often conspicuous, but their origins remain elusive for many marine fish species. Dismantling a biological system allows a better understanding of the required components and the deciphering of how such complex systems are established and function. Valuable information can be obtained from detailed analyses and comparisons of pigmentation patterns of mutants and/or variants from normal patterns. Anemonefishes have been popular marine fish in aquaculture for many years, which has led to the isolation of several mutant lines, and in particular color alterations, that have become very popular in the pet trade. Additionally, scattered information about naturally occurring aberrant anemonefish is available on various websites and image platforms. In this review, the available information on anemonefish color pattern alterations has been gathered and compiled in order to characterize and compare different mutations. With the global picture of anemonefish mutants and variants emerging from this, such as presence or absence of certain phenotypes, information on the patterning system itself can be gained.
Collapse
Affiliation(s)
- Marleen Klann
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Manon Mercader
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Lilian Carlu
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Kina Hayashi
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Molecular Invertebrate Systematics and Ecology Lab, Graduate School of the Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
| | - James Davis Reimer
- Molecular Invertebrate Systematics and Ecology Lab, Graduate School of the Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
- Tropical Biosphere Research Center, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
| | - Vincent Laudet
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
- Marine Research Station, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, 23-10, Dah-Uen Rd, Jiau Shi, I-Lan 262, I-Lan, Taiwan.
| |
Collapse
|
31
|
Wang C, Lu B, Li T, Liang G, Xu M, Liu X, Tao W, Zhou L, Kocher TD, Wang D. Nile Tilapia: A Model for Studying Teleost Color Patterns. J Hered 2021; 112:469-484. [PMID: 34027978 DOI: 10.1093/jhered/esab018] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 04/08/2021] [Indexed: 11/12/2022] Open
Abstract
The diverse color patterns of cichlid fishes play an important role in mate choice and speciation. Here we develop the Nile tilapia (Oreochromis niloticus) as a model system for studying the developmental genetics of cichlid color patterns. We identified 4 types of pigment cells: melanophores, xanthophores, iridophores and erythrophores, and characterized their first appearance in wild-type fish. We mutated 25 genes involved in melanogenesis, pteridine metabolism, and the carotenoid absorption and cleavage pathways. Among the 25 mutated genes, 13 genes had a phenotype in both the F0 and F2 generations. None of F1 heterozygotes had phenotype. By comparing the color pattern of our mutants with that of red tilapia (Oreochromis spp), a natural mutant produced during hybridization of tilapia species, we found that the pigmentation of the body and eye is controlled by different genes. Previously studied genes like mitf, kita/kitlga, pmel, tyrb, hps4, gch2, csf1ra, pax7b, and bco2b were proved to be of great significance for color patterning in tilapia. Our results suggested that tilapia, a fish with 4 types of pigment cells and a vertically barred wild-type color pattern, together with various natural and artificially induced color gene mutants, can serve as an excellent model system for study color patterning in vertebrates.
Collapse
Affiliation(s)
- Chenxu Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Baoyue Lu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Tao Li
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Guangyuan Liang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Mengmeng Xu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Xingyong Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Wenjing Tao
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Linyan Zhou
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Thomas D Kocher
- the Department of Biology, University of Maryland, College Park, MD
| | - Deshou Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| |
Collapse
|
32
|
Influence of survival, promotion, and growth on pattern formation in zebrafish skin. Sci Rep 2021; 11:9864. [PMID: 33972585 PMCID: PMC8110552 DOI: 10.1038/s41598-021-89116-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/14/2021] [Indexed: 11/24/2022] Open
Abstract
The coloring of zebrafish skin is often used as a model system to study biological pattern formation. However, the small number and lack of movement of chromatophores defies traditional Turing-type pattern generating mechanisms. Recent models invoke discrete short-range competition and long-range promotion between different pigment cells as an alternative to a reaction-diffusion scheme. In this work, we propose a lattice-based “Survival model,” which is inspired by recent experimental findings on the nature of long-range chromatophore interactions. The Survival model produces stationary patterns with diffuse stripes and undergoes a Turing instability. We also examine the effect that domain growth, ubiquitous in biological systems, has on the patterns in both the Survival model and an earlier “Promotion” model. In both cases, domain growth alone is capable of orienting Turing patterns above a threshold wavelength and can reorient the stripes in ablated cells, though the wavelength for which the patterns orient is much larger for the Survival model. While the Survival model is a simplified representation of the multifaceted interactions between pigment cells, it reveals complex organizational behavior and may help to guide future studies.
Collapse
|
33
|
Galipot P, Damerval C, Jabbour F. The seven ways eukaryotes produce repeated colour motifs on external tissues. Biol Rev Camb Philos Soc 2021; 96:1676-1693. [PMID: 33955646 DOI: 10.1111/brv.12720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 02/03/2023]
Abstract
The external tissues of numerous eukaryote species show repeated colour patterns, usually characterized by units that are present at least twice on the body. These dotted, striped or more complex phenotypes carry out crucial biological functions, such as partner recognition, aposematism or camouflage. Very diverse mechanisms explaining the formation of repeated colour patterns in eukaryotes have been identified and described, and it is timely to review this field from an evolutionary and developmental biology perspective. We propose a novel classification consisting of seven families of primary mechanisms: Turing(-like), cellular automaton, multi-induction, physical cracking, random, neuromuscular and printing. In addition, we report six pattern modifiers, acting synergistically with these primary mechanisms to enhance the spectrum of repeated colour patterns. We discuss the limitations of our classification in light of currently unexplored extant diversity. As repeated colour patterns require both the production of a repetitive structure and colouration, we also discuss the nature of the links between these two processes. A more complete understanding of the formation of repeated colour patterns in eukaryotes will require (i) a deeper exploration of biological diversity, tackling the issue of pattern elaboration during the development of non-model taxa, and (ii) exploring some of the most promising ways to discover new families of mechanisms. Good starting points include evaluating the role of mechanisms known to produce non-repeated colour patterns and that of mechanisms responsible for repeated spatial patterns lacking colouration.
Collapse
Affiliation(s)
- Pierre Galipot
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP39, Paris, 75005, France.,Génétique Quantitative et Evolution-Le Moulon, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, Gif-sur-Yvette, 91190, France
| | - Catherine Damerval
- Génétique Quantitative et Evolution-Le Moulon, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, Gif-sur-Yvette, 91190, France
| | - Florian Jabbour
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP39, Paris, 75005, France
| |
Collapse
|
34
|
A complex genetic architecture in zebrafish relatives Danio quagga and D. kyathit underlies development of stripes and spots. PLoS Genet 2021; 17:e1009364. [PMID: 33901178 PMCID: PMC8102007 DOI: 10.1371/journal.pgen.1009364] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/06/2021] [Accepted: 04/08/2021] [Indexed: 02/07/2023] Open
Abstract
Vertebrate pigmentation is a fundamentally important, multifaceted phenotype. Zebrafish, Danio rerio, has been a valuable model for understanding genetics and development of pigment pattern formation due to its genetic and experimental tractability, advantages that are shared across several Danio species having a striking array of pigment patterns. Here, we use the sister species D. quagga and D. kyathit, with stripes and spots, respectively, to understand how natural genetic variation impacts phenotypes at cellular and organismal levels. We first show that D. quagga and D. kyathit phenotypes resemble those of wild-type D. rerio and several single locus mutants of D. rerio, respectively, in a morphospace defined by pattern variation along dorsoventral and anteroposterior axes. We then identify differences in patterning at the cellular level between D. quagga and D. kyathit by repeated daily imaging during pattern development and quantitative comparisons of adult phenotypes, revealing that patterns are similar initially but diverge ontogenetically. To assess the genetic architecture of these differences, we employ reduced-representation sequencing of second-generation hybrids. Despite the similarity of D. quagga to D. rerio, and D. kyathit to some D. rerio mutants, our analyses reveal a complex genetic basis for differences between D. quagga and D. kyathit, with several quantitative trait loci contributing to variation in overall pattern and cellular phenotypes, epistatic interactions between loci, and abundant segregating variation within species. Our findings provide a window into the evolutionary genetics of pattern-forming mechanisms in Danio and highlight the complexity of differences that can arise even between sister species. Further studies of natural genetic diversity underlying pattern variation in D. quagga and D. kyathit should provide insights complementary to those from zebrafish mutant phenotypes and more distant species comparisons. Pigment patterns of fishes are diverse and function in a wide range of behaviors. Common pattern themes include stripes and spots, exemplified by the closely related minnows Danio quagga and D. kyathit, respectively. We show that these patterns arise late in development owing to alterations in the development and arrangements of pigment cells. In the closely related model organism zebrafish (D. rerio) single genes can switch the pattern from stripes to spots. Yet, we show that pattern differences between D. quagga and D. kyathit have a more complex genetic basis, depending on multiple genes and interactions between these genes. Our findings illustrate the importance of characterizing naturally occurring genetic variants, in addition to laboratory induced mutations, for a more complete understanding of pigment pattern development and evolution.
Collapse
|
35
|
Fofonjka A, Milinkovitch MC. Reaction-diffusion in a growing 3D domain of skin scales generates a discrete cellular automaton. Nat Commun 2021; 12:2433. [PMID: 33893277 PMCID: PMC8065134 DOI: 10.1038/s41467-021-22525-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 03/11/2021] [Indexed: 11/09/2022] Open
Abstract
We previously showed that the adult ocellated lizard skin colour pattern is effectively generated by a stochastic cellular automaton (CA) of skin scales. We additionally suggested that the canonical continuous 2D reaction-diffusion (RD) process of colour pattern development is transformed into this discrete CA by reduced diffusion coefficients at the borders of scales (justified by the corresponding thinning of the skin). Here, we use RD numerical simulations in 3D on realistic lizard skin geometries and demonstrate that skin thickness variation on its own is sufficient to cause scale-by-scale coloration and CA dynamics during RD patterning. In addition, we show that this phenomenon is robust to RD model variation. Finally, using dimensionality-reduction approaches on large networks of skin scales, we show that animal growth affects the scale-colour flipping dynamics by causing a substantial decrease of the relative length scale of the labyrinthine colour pattern of the lizard skin.
Collapse
Affiliation(s)
- Anamarija Fofonjka
- Laboratory of Artificial & Natural Evolution (LANE), Dept. of Genetics & Evolution, University of Geneva, Geneva, Switzerland.,SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Michel C Milinkovitch
- Laboratory of Artificial & Natural Evolution (LANE), Dept. of Genetics & Evolution, University of Geneva, Geneva, Switzerland. .,SIB Swiss Institute of Bioinformatics, Geneva, Switzerland.
| |
Collapse
|
36
|
P-Glycoprotein Inhibitor Tariquidar Plays an Important Regulatory Role in Pigmentation in Larval Zebrafish. Cells 2021; 10:cells10030690. [PMID: 33804686 PMCID: PMC8003715 DOI: 10.3390/cells10030690] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/17/2022] Open
Abstract
Zebrafish has emerged as a powerful model in studies dealing with pigment development and pathobiology of pigment diseases. Due to its conserved pigment pattern with established genetic background, the zebrafish is used for screening of active compounds influencing melanophore, iridophore, and xanthophore development and differentiation. In our study, zebrafish embryos and larvae were used to investigate the influence of third-generation noncompetitive P-glycoprotein inhibitor, tariquidar (TQR), on pigmentation, including phenotype effects and changes in gene expression of chosen chromatophore differentiation markers. Five-day exposure to increasing TQR concentrations (1 µM, 10 µM, and 50 µM) resulted in a dose-dependent augmentation of the area covered with melanophores but a reduction in the area covered by iridophores. The observations were performed in three distinct regions-the eye, dorsal head, and tail. Moreover, TQR enhanced melanophore renewal after depigmentation caused by 0.2 mM 1-phenyl-2-thiourea (PTU) treatment. qPCR analysis performed in 56-h post-fertilization (hpf) embryos demonstrated differential expression patterns of genes related to pigment development and differentiation. The most substantial findings include those indicating that TQR had no significant influence on leukocyte tyrosine kinase, GTP cyclohydrolase 2, tyrosinase-related protein 1, and forkhead box D3, however, markedly upregulated tyrosinase, dopachrome tautomerase and melanocyte inducing transcription factor, and downregulated purine nucleoside phosphorylase 4a. The present study suggests that TQR is an agent with multidirectional properties toward pigment cell formation and distribution in the zebrafish larvae and therefore points to the involvement of P-glycoprotein in this process.
Collapse
|
37
|
Owen JP, Kelsh RN. A suitable anaesthetic protocol for metamorphic zebrafish. PLoS One 2021; 16:e0246504. [PMID: 33667238 PMCID: PMC7935316 DOI: 10.1371/journal.pone.0246504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 02/01/2023] Open
Abstract
Zebrafish are frequently used as a means to investigate development. These studies increasingly require repeated anaesthesia of zebrafish during juvenile (i.e. metamorphic) stages. The effects of anaesthesia during this time remain poorly studied. The aim of this study was to develop a reliable method that can be used for frequently repeated anaesthesia during juvenile stages. Initially, we assessed different concentrations of MS-222, the most commonly used fish anaesthetic, for 30 minute anaesthesia with recovery. We showed that suitable MS-222 doses could be identified for the smallest (7mm) and largest (20mm) fish. However, we found that juvenile fish within a specific metamorphic window (sized between 8-16 mm) were vulnerable to MS-222 and no standard concentration of MS-222 provided reliable anaesthesia under these conditions. Hence we focussed our efforts on identifying a protocol for these stages. We tested six different published anaesthesia protocols P1-P6 where P1, P2 corresponds to 0.01% MS-222, P3, P4: 0.085% 2-phenoxyethanol and P5, P6: 0.00025%/0.0050% Propofol/Lidocaine. In protocols P1, P3, P5 fish were maintained by immersion, whilst in P2, P4 and P6: fish were maintained on an anaesthetic-doused cotton-pad. We assessed reliable anaesthesia using 10 fish for 10 minutes, with full recovery. Our data allowed us to eliminate two of these protocols as unsuitable for short term anaesthesia with recovery of juvenile fish. Extending these studies to explore repeated anaesthesia at 4 day intervals for 20 days under the remaining four protocols, we showed that P1 and P4 were both suitable for repeated anaesthesia, and that P4 was most suitable for imaging. We confirmed that P4 remained suitable when the frequency of anaesthesia was increased to every 2 days. We conclude that this protocol provides a refinement to the current protocol for repeated anaesthesia with recovery of juvenile zebrafish in the vulnerable metamorphic window.
Collapse
Affiliation(s)
- Jennifer P. Owen
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Robert N. Kelsh
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| |
Collapse
|
38
|
Duran-Nebreda S, Pla J, Vidiella B, Piñero J, Conde-Pueyo N, Solé R. Synthetic Lateral Inhibition in Periodic Pattern Forming Microbial Colonies. ACS Synth Biol 2021; 10:277-285. [PMID: 33449631 PMCID: PMC8486170 DOI: 10.1021/acssynbio.0c00318] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Multicellular entities are characterized by intricate spatial patterns, intimately related to the functions they perform. These patterns are often created from isotropic embryonic structures, without external information cues guiding the symmetry breaking process. Mature biological structures also display characteristic scales with repeating distributions of signals or chemical species across space. Many candidate patterning modules have been used to explain processes during development and typically include a set of interacting and diffusing chemicals or agents known as morphogens. Great effort has been put forward to better understand the conditions in which pattern-forming processes can occur in the biological domain. However, evidence and practical knowledge allowing us to engineer symmetry-breaking is still lacking. Here we follow a different approach by designing a synthetic gene circuit in E. coli that implements a local activation long-range inhibition mechanism. The synthetic gene network implements an artificial differentiation process that changes the physicochemical properties of the agents. Using both experimental results and modeling, we show that the proposed system is capable of symmetry-breaking leading to regular spatial patterns during colony growth. Studying how these patterns emerge is fundamental to further our understanding of the evolution of biocomplexity and the role played by self-organization. The artificial system studied here and the engineering perspective on embryogenic processes can help validate developmental theories and identify universal properties underpinning biological pattern formation, with special interest for the area of synthetic developmental biology.
Collapse
Affiliation(s)
- Salva Duran-Nebreda
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
- Evolution of Technology Lab, Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
| | - Jordi Pla
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Blai Vidiella
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Jordi Piñero
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Nuria Conde-Pueyo
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Ricard Solé
- Institut de Biologia Evolutiva (CSIC-UPF), 08003 Barcelona, Spain
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra, 08003 Barcelona, Spain
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501, United States
| |
Collapse
|
39
|
Vissio PG, Darias MJ, Di Yorio MP, Pérez Sirkin DI, Delgadin TH. Fish skin pigmentation in aquaculture: The influence of rearing conditions and its neuroendocrine regulation. Gen Comp Endocrinol 2021; 301:113662. [PMID: 33220300 DOI: 10.1016/j.ygcen.2020.113662] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/05/2020] [Accepted: 11/12/2020] [Indexed: 12/14/2022]
Abstract
Skin pigmentation pattern is a species-specific characteristic that depends on the number and the spatial combination of several types of chromatophores. This feature can change during life, for example in the metamorphosis or reproductive cycle, or as a response to biotic and/or abiotic environmental cues (nutrition, UV incidence, surrounding luminosity, and social interactions). Fish skin pigmentation is one of the most important quality criteria dictating the market value of both aquaculture and ornamental species because it serves as an external signal to infer its welfare and the culture conditions used. For that reason, several studies have been conducted aiming to understand the mechanisms underlying fish pigmentation as well as the influence exerted by rearing conditions. In this context, the present review focuses on the current knowledge on endocrine regulation of fish pigmentation as well as on the aquaculture conditions affecting skin coloration. Available information on Iberoamerican fish species cultured is presented.
Collapse
Affiliation(s)
- Paula G Vissio
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental. Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Buenos Aires, Argentina.
| | - Maria J Darias
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - María P Di Yorio
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental. Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Buenos Aires, Argentina
| | - Daniela I Pérez Sirkin
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental. Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Buenos Aires, Argentina
| | - Tomás H Delgadin
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental. Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET, Buenos Aires, Argentina
| |
Collapse
|
40
|
Usui Y, Watanabe M. Role of the Connexin C-terminus in skin pattern formation of Zebrafish. BBA ADVANCES 2021; 1:100006. [PMID: 37082017 PMCID: PMC10074918 DOI: 10.1016/j.bbadva.2021.100006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Background Zebrafish display a striped skin pattern on their body; two types of connexins, namely, Connexin39.4 (Cx39.4) and Connexin41.8 (Cx41.8), are involved in stripe pattern formation. Herein, we investigated the role of the C-terminal (CT) domains of Cx39.4 and Cx41.8 in vivo and in vitro. Methods To investigate the role of CT domains in vivo, we established transgenic zebrafish lines expressing the CT-domain-modified connexin series in pigmented cells and observed skin patterns in fish. To investigate the role of the CT domains in vitro, we expressed the CT-domain modified connexin series in Neuro-2a (N2a) cells and calculated the plaque formation frequency. Results The overexpression of Cx39.4 lacking a CT domain produced skin patterns similar to that produced by full-length Cx39.4 in the cx39.4 -/- mutant and in cx39.4 and cx41.8 double-knockout mutant zebrafish. Fluorescence-protein-fused CT-domain-modified Cx39.4 formed gap junction plaques between N2a cells. The overexpression of CT-truncated Cx41.8 rescued the mutant phenotype in the cx41.8 -/- mutant but did not function in the double knockout zebrafish. Fluorescence-protein-fused CT-truncated Cx41.8 hardly formed plaques between N2a cells without Cx39.4 but formed gap junction plaques when co-expressed with Cx39.4. Conclusions The CT domain of Cx39.4 is not required for protein function, at least in the pigment cells of zebrafish. However, the need for the CT domain of Cx41.8 depends on Cx39.4 expression. General significance These results provide evidence for the interactions between Cx39.4 and Cx41.8 in pigment cells of zebrafish and suggest that at least one connexin must have a CT domain.
Collapse
|
41
|
Gur D, Bain EJ, Johnson KR, Aman AJ, Pasoili HA, Flynn JD, Allen MC, Deheyn DD, Lee JC, Lippincott-Schwartz J, Parichy DM. In situ differentiation of iridophore crystallotypes underlies zebrafish stripe patterning. Nat Commun 2020; 11:6391. [PMID: 33319779 PMCID: PMC7738553 DOI: 10.1038/s41467-020-20088-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
Skin color patterns are ubiquitous in nature, impact social behavior, predator avoidance, and protection from ultraviolet irradiation. A leading model system for vertebrate skin patterning is the zebrafish; its alternating blue stripes and yellow interstripes depend on light-reflecting cells called iridophores. It was suggested that the zebrafish’s color pattern arises from a single type of iridophore migrating differentially to stripes and interstripes. However, here we find that iridophores do not migrate between stripes and interstripes but instead differentiate and proliferate in-place, based on their micro-environment. RNA-sequencing analysis further reveals that stripe and interstripe iridophores have different transcriptomic states, while cryogenic-scanning-electron-microscopy and micro-X-ray diffraction identify different crystal-arrays architectures, indicating that stripe and interstripe iridophores are different cell types. Based on these results, we present an alternative model of skin patterning in zebrafish in which distinct iridophore crystallotypes containing specialized, physiologically responsive, organelles arise in stripe and interstripe by in-situ differentiation. The skin of zebrafish is patterned by alternating blue stripes and yellow interstripes which arises from guanine crystal-containing cells called iridophores that reflect light. Here the authors track iridophores and see that they do not migrate between stripes and interstripes, but instead differentiate and proliferate in place based on their micro-environment.
Collapse
Affiliation(s)
- Dvir Gur
- HHMI Janelia Research Campus, Ashburn, VA, USA.,National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Emily J Bain
- Department of Biology, University of Virginia, Charlottesville, VA, USA.,Department of Biology and Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorder and Stroke, NIH, Bethesda, MD, USA
| | - Andy J Aman
- Department of Biology, University of Virginia, Charlottesville, VA, USA.,Department of Biology and Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | | | - Jessica D Flynn
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Michael C Allen
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Dimitri D Deheyn
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Jennifer C Lee
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | | | - David M Parichy
- Department of Biology, University of Virginia, Charlottesville, VA, USA. .,Department of Biology and Department of Cell Biology, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
42
|
Podobnik M, Frohnhöfer HG, Dooley CM, Eskova A, Nüsslein-Volhard C, Irion U. Evolution of the potassium channel gene Kcnj13 underlies colour pattern diversification in Danio fish. Nat Commun 2020; 11:6230. [PMID: 33277491 PMCID: PMC7718271 DOI: 10.1038/s41467-020-20021-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 11/06/2020] [Indexed: 12/20/2022] Open
Abstract
The genetic basis of morphological variation provides a major topic in evolutionary developmental biology. Fish of the genus Danio display colour patterns ranging from horizontal stripes, to vertical bars or spots. Stripe formation in zebrafish, Danio rerio, is a self-organizing process based on cell-contact mediated interactions between three types of chromatophores with a leading role of iridophores. Here we investigate genes known to regulate chromatophore interactions in zebrafish that might have evolved to produce a pattern of vertical bars in its sibling species, Danio aesculapii. Mutant D. aesculapii indicate a lower complexity in chromatophore interactions and a minor role of iridophores in patterning. Reciprocal hemizygosity tests identify the potassium channel gene obelix/Kcnj13 as evolved between the two species. Complementation tests suggest evolutionary change through divergence in Kcnj13 function in two additional Danio species. Thus, our results point towards repeated and independent evolution of this gene during colour pattern diversification.
Collapse
Affiliation(s)
- Marco Podobnik
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany
| | - Hans Georg Frohnhöfer
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany
| | - Christopher M Dooley
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany
- Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Anastasia Eskova
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany
- IBM Research and Development, Schönaicher Straße 220, 71032, Böblingen, Germany
| | | | - Uwe Irion
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany.
| |
Collapse
|
43
|
Hamied A, Alnedawy Q, Correia A, Hacker C, Ramsdale M, Hashimoto H, Kudoh T. Identification and Characterization of Highly Fluorescent Pigment Cells in Embryos of the Arabian Killifish ( Aphanius Dispar). iScience 2020; 23:101674. [PMID: 33145484 PMCID: PMC7593555 DOI: 10.1016/j.isci.2020.101674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/15/2020] [Accepted: 10/09/2020] [Indexed: 11/26/2022] Open
Abstract
The Arabian killifish, Aphanius dispar, is a small tropical teleost fish living in wide range of habitats in sea water and fresh water in the Middle East. Here, we report extraordinary fluorescent pigment cells in the Arabian killifish embryo. These cells appear brown in transmitted light, yellowish white in reflected light, and as strong fluorescence in GFP and RFP filters. TEM and confocal microscopy analyses show the fluorescence emanates from leucosome-like pigment organelles. The cells express the gene encoding GTP cyclohydrolase (gch), a marker for leucophores and xanthophore. Gene knockdown and knockout of gch using morpholino or CRISPR-Cas9 induced loss of fluorescence in these embryos, indicating a crucial role of the enzyme and the associated pterine biosynthesis pathway in the generation of the fluorescence. We concluded that these cells are a highly fluorescent subtype of leucophores and have named them as fluoroleucophores. Arabian killifish embryos possess extremely fluorescent pigment cells The fluorescent pigment cells show characteristics in common with leucophores Gene knockout of GTP cyclohydrolase removes fluorescence from the pigment cells The novel pigment cells are termed fluoroleucophores
Collapse
Affiliation(s)
- Atyaf Hamied
- Biosciences, University of Exeter, Exeter, EX4 4QD, UK
| | | | - Ana Correia
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK
| | | | - Mark Ramsdale
- Biosciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Hisashi Hashimoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
| | | |
Collapse
|
44
|
Molecular Plasticity in Animal Pigmentation: Emerging Processes Underlying Color Changes. Integr Comp Biol 2020; 60:1531-1543. [DOI: 10.1093/icb/icaa142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Synopsis
Animal coloration has been rigorously studied and has provided morphological implications for fitness with influences over social behavior, predator–prey interactions, and sexual selection. In vertebrates, its study has developed our understanding across diverse fields ranging from behavior to molecular biology. In the search for underlying molecular mechanisms, many have taken advantage of pedigree-based and genome-wide association screens to reveal the genetic architecture responsible for pattern variation that occurs in early development. However, genetic differences do not provide a full picture of the dynamic changes in coloration that are most prevalent across vertebrates at the molecular level. Changes in coloration that occur in adulthood via phenotypic plasticity rely on various social, visual, and dietary cues independent of genetic variation. Here, I will review the contributions of pigment cell biology to animal color changes and recent studies describing their molecular underpinnings and function. In this regard, conserved epigenetic processes such as DNA methylation play a role in lending plasticity to gene regulation as it relates to chromatophore function. Lastly, I will present African cichlids as emerging models for the study of pigmentation and molecular plasticity for animal color changes. I posit that these processes, in a dialog with environmental stimuli, are important regulators of variation and the selective advantages that accompany a change in coloration for vertebrate animals.
Collapse
|
45
|
Zhou A, Xie S, Feng Y, Sun D, Liu S, Sun Z, Li M, Zhang C, Zou J. Insights Into the Albinism Mechanism for Two Distinct Color Morphs of Northern Snakehead, Channa argus Through Histological and Transcriptome Analyses. Front Genet 2020; 11:830. [PMID: 33193565 PMCID: PMC7530302 DOI: 10.3389/fgene.2020.00830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022] Open
Abstract
The great northern snakehead (Channa argus) is one of the most important economic and conservational fish in China. In this study, the melanocytes in the skin of two distinct color morphs C. argus were investigated and compared through employment of the microscopic analysis, hematoxylin and eosin (H&E) and Masson Fontana staining. Our results demonstrated the uneven distribution of melanocytes with extremely low density and most of them were in the state of aging or death. Meanwhile, there was no obvious pigment layer and melanocytes distribution pattern found in the albino-type (AT), while the melanocytes were evenly distributed with abundance in the bicolor-type (BT). The transcriptome analysis through Illumina HiSeq sequencing showed that a total of 34.93 Gb Clean Data was obtained, and Q30 base percentage reached 92.66%. The BT and AT northern snakeheads transcriptome data included a total of 56,039,701 and 60,410,063 clean reads (n = 3), respectively. In gene expression analyses, the sample correlation coefficients (r) were ranged between 0.92 and 1.00; the contribution of PC1 and PC2 were 50.25 and 13.73% by using PCA cluster analysis, the total number of DEGs were 1024 (559 up-regulated and 465 down-regulated), and the number of annotated DEGs was 767 (COG 172, KEGG 262, GO 288, SwissProt 548, Pfam 579 and NR 765). Additionally, 46,363 ± 873 and 44,947 ± 392 single nucleotide polymorphisms (SNPs) were compiled via genetic structure analysis, respectively. Ten key pigment-related genes were screened using qRT-PCR. And all of them revealed extremely higher expression levels in the skin of BT than those of AT. This is the first study to analyze the mechanism of albino characteristics of Channa via histology and transcriptomics, and also provide the oretical and practical support for the protection and development of germplasm resources for C. argus.
Collapse
Affiliation(s)
- Aiguo Zhou
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Shaolin Xie
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Yongyong Feng
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Di Sun
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Shulin Liu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Zhuolin Sun
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Mingzhi Li
- Independent Researcher, Guangzhou, China
| | - Chaonan Zhang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Jixing Zou
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| |
Collapse
|
46
|
Eom DS. Airinemes: thin cellular protrusions mediate long-distance signalling guided by macrophages. Open Biol 2020; 10:200039. [PMID: 32810422 PMCID: PMC7479939 DOI: 10.1098/rsob.200039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Understanding the mechanisms of cell-to-cell communication is one of the fundamental questions in biology and medicine. In particular, long-range signalling where cells communicate over several cell diameters is vital during development and homeostasis. The major morphogens, their receptors and intracellular signalling cascades have largely been identified; however, there is a gap in our knowledge of how such signalling factors are propagated over a long distance. In addition to the diffusion-based propagation model, new modalities of disseminating signalling molecules have been identified. It has been shown that cells can communicate with direct contact through long, thin cellular protrusions between signal sending and receiving cells at a distance. Recent studies have revealed a type of cellular protrusion termed 'airinemes' in zebrafish pigment cell types. They share similarities with previously reported cellular protrusions; however, they also exhibit distinct morphology and features. Airinemes are indispensable for pigment pattern development by mediating long-distance Delta-Notch signalling between different pigment cell types. Notably, airineme-mediated signalling is dependent on skin-resident macrophages. Key findings of airineme-mediated intercellular signalling in pattern development, their interplay with macrophages and their implications for the understanding of cellular protrusion-mediated intercellular communication will be discussed.
Collapse
Affiliation(s)
- Dae Seok Eom
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA
| |
Collapse
|
47
|
Wu M, Chen X, Cui K, Li H, Jiang Y. Pigmentation formation and expression analysis of tyrosinase in Siniperca chuatsi. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:1279-1293. [PMID: 32185567 DOI: 10.1007/s10695-020-00788-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/04/2020] [Indexed: 06/10/2023]
Abstract
Animal pigmentation primarily depends on the presence and mixing ratio of chromatophores, functioning in animal survival and communication. For the benthic and carnivorous Siniperca chuatsi, pigmentation pattern is key to concealment and predation. In this study, the formation, distribution, and main pattern of chromatophores were observed in the embryos, larvae, skins, and visceral tissues from S. chuatsi. Melanophores were firstly visualized in the yolk sac at segmentation stage, and then they were migrated to the whole body and further clustered into the black stripes, bands, and patches. In adult S. chuatsi, the head, black band, and body side skins mainly contained melanophores, showing as deep or light black. The abdomen skin mainly contained iridophores, showing as silvery. In the eye, the pigment layers were located in the epithelial layers of iris and retina and shown as black. Then, the pigmentation-related gene, tyrosinase gene from S. chuatsi (Sc-tyr) was analyzed by bioinformatics and quantitative methods. The Sc-tyr gene encoded a protein with 540 amino acids (Sc-TYR). The Sc-TYR contained two copper ion binding sites, which were coordinated by six conserved histidines (H182, H205, H214, H366, H370, H393) and necessary for catalytic activity. The Sc-TYR was well conserved compared with TYR of various species with higher degree of sequence similarity with other fishes (77.6-98.3%). The qRT-PCR test showed that the Sc-tyr mRNA reached the peak value at segmentation stage in the embryo development, the black skins displayed a higher expression level than that in silvery skin, and the eye had the highest expression level compared with other tissues. Further research on enzyme activity showed that the expression patterns of tyrosinase activity were similar to that of the Sc-tyr mRNA. Comparing with the results of molecular and phenotype, it was found that the temporal and spatial distributions of tyrosinase corresponded well with changes in pigmentation patterns and the intensity of skin melanization. This study initially explored the pigmentation formation and tyrosinase expression, which served as a foundation for further insight into the genetics mechanism of body color formation in S. chuatsi.
Collapse
Affiliation(s)
- Minglin Wu
- Fisheries Research Institute, Anhui Academy of Agricultural Sciences, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
- Anhui Province Key Laboratory of Aquaculture & Stock Enhancement, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
| | - Xiaowu Chen
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), Shanghai, 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai, 201306, China
- Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai, 201306, China
| | - Kai Cui
- Fisheries Research Institute, Anhui Academy of Agricultural Sciences, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China.
- Anhui Province Key Laboratory of Aquaculture & Stock Enhancement, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China.
| | - Haiyang Li
- Fisheries Research Institute, Anhui Academy of Agricultural Sciences, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
- Anhui Province Key Laboratory of Aquaculture & Stock Enhancement, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
| | - Yangyang Jiang
- Fisheries Research Institute, Anhui Academy of Agricultural Sciences, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
- Anhui Province Key Laboratory of Aquaculture & Stock Enhancement, NO.40 South Nongke Road, Luyang District, Hefei, 230031, Anhui, China
| |
Collapse
|
48
|
Owen JP, Kelsh RN, Yates CA. A quantitative modelling approach to zebrafish pigment pattern formation. eLife 2020; 9:52998. [PMID: 32716296 PMCID: PMC7384860 DOI: 10.7554/elife.52998] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 06/21/2020] [Indexed: 12/14/2022] Open
Abstract
Pattern formation is a key aspect of development. Adult zebrafish exhibit a striking striped pattern generated through the self-organisation of three different chromatophores. Numerous investigations have revealed a multitude of individual cell-cell interactions important for this self-organisation, but it has remained unclear whether these known biological rules were sufficient to explain pattern formation. To test this, we present an individual-based mathematical model incorporating all the important cell-types and known interactions. The model qualitatively and quantitatively reproduces wild type and mutant pigment pattern development. We use it to resolve a number of outstanding biological uncertainties, including the roles of domain growth and the initial iridophore stripe, and to generate hypotheses about the functions of leopard. We conclude that our rule-set is sufficient to recapitulate wild-type and mutant patterns. Our work now leads the way for further in silico exploration of the developmental and evolutionary implications of this pigment patterning system.
Collapse
Affiliation(s)
- Jennifer P Owen
- Department of Biology and Biochemistry and Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, United Kingdom
| | - Robert N Kelsh
- Department of Biology and Biochemistry and Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, United Kingdom
| | - Christian A Yates
- Department of Biology and Biochemistry and Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, United Kingdom
| |
Collapse
|
49
|
Scarabotti P, Govezensky T, Bolcatto P, Barrio RA. Universal model for the skin colouration patterns of neotropical catfishes of the genus Pseudoplatystoma. Sci Rep 2020; 10:12445. [PMID: 32709921 PMCID: PMC7381642 DOI: 10.1038/s41598-020-68700-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/23/2020] [Indexed: 11/29/2022] Open
Abstract
Fish skin colouration has been widely studied because it involves a variety of processes that are important to the broad field of the developmental biology. Mathematical modelling of fish skin patterning first predicted the existence of morphogens and helped to elucidate the mechanisms of pattern formation. The catfishes of the genus Pseudoplatystoma offer a good biological study model, since its species exhibit the most spectacular and amazing variations of colour patterns on the skin. They present labyrinths, closed loops (or cells), alternate spots and stripes, only spots and combinations of these. We have extended a well known mathematical model to study the skin of Pseudoplatystoma. The basic model is a two component, non-linear reaction diffusion system that presents a richness of bifurcations. The extended model assumes that there are two interacting cell/tissue layers in which morphogens diffuse and interact giving rise to the skin colouration pattern. We have found that by varying only two parameters we are able to accurately reproduce the distinct patterns found in all species of Pseudoplatystoma. The histological analysis of skin samples of two species of this genus, with different patterns, revealed differences on the disposition of the colouration cells that are consistent with our theoretical predictions.
Collapse
Affiliation(s)
- Pablo Scarabotti
- Instituto Nacional de Limnología, UNL, CONICET, FHUC, Ruta 168 Km 0, Ciudad Universitaria, S3001XAI, Santa Fe, Argentina.
| | - Tzipe Govezensky
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, CD.MX., Mexico
| | - Pablo Bolcatto
- Instituto de Matemática Aplicada del Litoral, UNL, CONICET, FHUC, IMAL, Colectora Ruta Nac. 168 km 0, Paraje El Pozo, S3007ABA, Santa Fe, Argentina
| | - Rafael A Barrio
- Instituto de Física, U.N.A.M., Apdo. Postal 20-36, 01000, CD.MX., Mexico
| |
Collapse
|
50
|
Cornwall Scoones J, Banerjee DS, Banerjee S. Size-Regulated Symmetry Breaking in Reaction-Diffusion Models of Developmental Transitions. Cells 2020; 9:E1646. [PMID: 32659915 PMCID: PMC7407810 DOI: 10.3390/cells9071646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/26/2022] Open
Abstract
The development of multicellular organisms proceeds through a series of morphogenetic and cell-state transitions, transforming homogeneous zygotes into complex adults by a process of self-organisation. Many of these transitions are achieved by spontaneous symmetry breaking mechanisms, allowing cells and tissues to acquire pattern and polarity by virtue of local interactions without an upstream supply of information. The combined work of theory and experiment has elucidated how these systems break symmetry during developmental transitions. Given that such transitions are multiple and their temporal ordering is crucial, an equally important question is how these developmental transitions are coordinated in time. Using a minimal mass-conserved substrate-depletion model for symmetry breaking as our case study, we elucidate mechanisms by which cells and tissues can couple reaction-diffusion-driven symmetry breaking to the timing of developmental transitions, arguing that the dependence of patterning mode on system size may be a generic principle by which developing organisms measure time. By analysing different regimes of our model, simulated on growing domains, we elaborate three distinct behaviours, allowing for clock-, timer- or switch-like dynamics. Relating these behaviours to experimentally documented case studies of developmental timing, we provide a minimal conceptual framework to interrogate how developing organisms coordinate developmental transitions.
Collapse
Affiliation(s)
- Jake Cornwall Scoones
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA;
| | - Deb Sankar Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA;
| | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA;
| |
Collapse
|