1
|
Zhang Z, Luo J, Liu H, Wang S, An X, Li X, Wang W. Sonic hedgehog (shh) gene from Pseudopleuronectes yokohamae (Teleostei: Pleuronectidae): Molecular cloning, characterization, and expression profile during early embryonic, juvenile, and adult stages. JOURNAL OF FISH BIOLOGY 2024. [PMID: 38965864 DOI: 10.1111/jfb.15839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 05/04/2024] [Accepted: 05/23/2024] [Indexed: 07/06/2024]
Abstract
The hedgehog signaling pathway plays an important role in early development and growth of most vertebrates. Sonic hedgehog (shh) gene is a critical regulator of embryonic development in many species, including humans. However, it is not clear what roles shh can play in the development of fish. In this paper, shh gene was cloned from Pseudopleuronectes yokohamae. The full-length complementary DNA (cDNA) of P. yokohamae sonic hedgehog gene (Pyshh) comprises 3194 bp, with a 1317-bp open reading frame (ORF) that encodes a polypeptide of 438 amino acids with a typical HH-signal domain and Hint-N domain. The conserved sequences of the protein among species were predicted by using multiple sequence comparison. The phylogenetic tree construction showed that PySHH is clustered in a branch of Pleuronectidae. To explore the expression of Pyshh gene in various tissues of P. yokohamae, we used real-time fluorescence quantitative PCR technology to detect it. The results showed that Pyshh gene is widely distributed in various tissues of P. yokohamae juveniles, different tissues of adult males and females, and is particularly expressed in immune organs. The Pyshh gene expression was higher in the muscle and brain of juvenile fish, and higher in bone, gill, and skin of male fish than that of female fish, suggesting that Pyshh might be involved in the formation of immune organs of P. yokohamae. The expression of Pyshh gene significantly upregulated from the gastrula stage to the hatching stage. Western blotting of the expression levels of PySHH during different embryonic development stages revealed that PySHH levels increased gradually during development stages from oosperm stage to hatching stage. These results indicate that Pyshh is highly conserved among species and plays a critical role in the complex process of embryonic development. Its precise regulation is essential for the proper formation of many organs and tissues in the body, and disruptions in its function may have serious consequences for the formation of immune organs in fish.
Collapse
Affiliation(s)
- Zheng Zhang
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| | - Jun Luo
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian, China
- Dalian Sunasia Tourism Holding Co., LTD, Dalian, China
| | - Hui Liu
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| | - Shuai Wang
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| | - Xilin An
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| | - Xuejie Li
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| | - Wei Wang
- Key Laboratory of Applied Biology and Aquaculture of Northern Fishes in Liaoning Province, Dalian Ocean University, Dalian, China
| |
Collapse
|
2
|
Tetrault E, Aaronson B, Gilbert MC, Albertson RC. Foraging-induced craniofacial plasticity is associated with an early, robust and dynamic transcriptional response. Proc Biol Sci 2024; 291:20240215. [PMID: 38654651 PMCID: PMC11040245 DOI: 10.1098/rspb.2024.0215] [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: 02/12/2024] [Accepted: 03/19/2024] [Indexed: 04/26/2024] Open
Abstract
Phenotypic plasticity is the ability of a single genotype to vary its phenotype in response to the environment. Plasticity of the skeletal system in response to mechanical input is widely studied, but the timing of its transcriptional regulation is not well understood. Here, we used the cichlid feeding apparatus to examine the transcriptional dynamics of skeletal plasticity over time. Using three closely related species that vary in their ability to remodel bone and a panel of 11 genes, including well-studied skeletal differentiation markers and newly characterized environmentally sensitive genes, we examined plasticity at one, two, four and eight weeks following the onset of alternate foraging challenges. We found that the plastic species exhibited environment-specific bursts in gene expression beginning at one week, followed by a sharp decline in levels, while the species with more limited plasticity exhibited consistently low levels of gene expression. This trend held across nearly all genes, suggesting that it is a hallmark of the larger plasticity regulatory network. We conclude that plasticity of the cichlid feeding apparatus is not the result of slowly accumulating gene expression difference over time, but rather is stimulated by early bursts of environment-specific gene expression followed by a return to homeostatic levels.
Collapse
Affiliation(s)
- Emily Tetrault
- Molecular and Cell Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Ben Aaronson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Michelle C. Gilbert
- Department of Biology, Pennsylvania State University, State College, PA 16802, USA
| | - R. Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| |
Collapse
|
3
|
Xie M, Kaiser M, Gershtein Y, Schnyder D, Deviatiiarov R, Gazizova G, Shagimardanova E, Zikmund T, Kerckhofs G, Ivashkin E, Batkovskyte D, Newton PT, Andersson O, Fried K, Gusev O, Zeberg H, Kaiser J, Adameyko I, Chagin AS. The level of protein in the maternal murine diet modulates the facial appearance of the offspring via mTORC1 signaling. Nat Commun 2024; 15:2367. [PMID: 38531868 DOI: 10.1038/s41467-024-46030-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 02/09/2024] [Indexed: 03/28/2024] Open
Abstract
The development of craniofacial skeletal structures is fascinatingly complex and elucidation of the underlying mechanisms will not only provide novel scientific insights, but also help develop more effective clinical approaches to the treatment and/or prevention of the numerous congenital craniofacial malformations. To this end, we performed a genome-wide analysis of RNA transcription from non-coding regulatory elements by CAGE-sequencing of the facial mesenchyme of human embryos and cross-checked the active enhancers thus identified against genes, identified by GWAS for the normal range human facial appearance. Among the identified active cis-enhancers, several belonged to the components of the PI3/AKT/mTORC1/autophagy pathway. To assess the functional role of this pathway, we manipulated it both genetically and pharmacologically in mice and zebrafish. These experiments revealed that mTORC1 signaling modulates craniofacial shaping at the stage of skeletal mesenchymal condensations, with subsequent fine-tuning during clonal intercalation. This ability of mTORC1 pathway to modulate facial shaping, along with its evolutionary conservation and ability to sense external stimuli, in particular dietary amino acids, indicate that the mTORC1 pathway may play a role in facial phenotypic plasticity. Indeed, the level of protein in the diet of pregnant female mice influenced the activity of mTORC1 in fetal craniofacial structures and altered the size of skeletogenic clones, thus exerting an impact on the local geometry and craniofacial shaping. Overall, our findings indicate that the mTORC1 signaling pathway is involved in the effect of environmental conditions on the shaping of craniofacial structures.
Collapse
Affiliation(s)
- Meng Xie
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institute, Flemingsberg, Sweden
- School of Psychological and Cognitive Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
| | - Markéta Kaiser
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Yaakov Gershtein
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Daniela Schnyder
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Ruslan Deviatiiarov
- Regulatory Genomics Research Center, Kazan Federal University, Kazan, Russia
- Endocrinology Research Center, Moscow, Russia
- Life Improvement by Future Technologies (LIFT) Center, Moscow, Russia
- Intractable Disease Research Center, Juntendo University, Tokyo, Japan
| | - Guzel Gazizova
- Regulatory Genomics Research Center, Kazan Federal University, Kazan, Russia
| | - Elena Shagimardanova
- Regulatory Genomics Research Center, Kazan Federal University, Kazan, Russia
- Life Improvement by Future Technologies (LIFT) Center, Moscow, Russia
| | - Tomáš Zikmund
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Greet Kerckhofs
- Biomechanics Lab, Institute of Mechanics, Materials, and Civil Engineering (iMMC), UCLouvain, Louvain-la-Neuve, Belgium
- Pole of Morphology, Institute of Experimental and Clinical Research (IREC), UCLouvain, Woluwe, Belgium
- Department of Materials Engineering, KU Leuven, Leuven, Belgium
- Prometheus, Division for Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Evgeny Ivashkin
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
- Department of Developmental and Comparative Physiology, N.K. Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Dominyka Batkovskyte
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Phillip T Newton
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
- Astrid Lindgren Children's hospital, Stockholm, Sweden
| | - Olov Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Kaj Fried
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Oleg Gusev
- Regulatory Genomics Research Center, Kazan Federal University, Kazan, Russia
- Endocrinology Research Center, Moscow, Russia
- Life Improvement by Future Technologies (LIFT) Center, Moscow, Russia
- Intractable Disease Research Center, Juntendo University, Tokyo, Japan
| | - Hugo Zeberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Jozef Kaiser
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Igor Adameyko
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria.
| | - Andrei S Chagin
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
| |
Collapse
|
4
|
Cao X, Deng S, Liu Q, Wu L, Zhuang X, Ding S. Important Role of the Ihh Signaling Pathway in Initiating Early Cranial Remodeling and Morphological Specialization in Cromileptes altivelis. Animals (Basel) 2023; 13:3840. [PMID: 38136878 PMCID: PMC10740873 DOI: 10.3390/ani13243840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
In this study, we identified the important contribution of frontal bone remodeling in shaping the 'sunken head and humpback' appearance in C. altivelis. Our investigation identified a developmental milestone at a total length of 5-6 cm, making the onset of its morphologic specialization in this species. A comparative analysis with closely related species reveals heightened activity in the frontal osteoblasts of the humpback grouper, potentially providing a physiological basis for its remodeling. Furthermore, our findings highlight that a significant upregulation in the expression levels of Ihhb, Ptch1, and Gli2a genes was seen in C. altivelis within the specified developmental stage, indicating an important involvement of the Ihhb-Ptch1-Gli2a signaling pathway in initiating the morphological specialization. We hypothesized that Ihh signaling could be attributed to shifts in mechanical stress, resulting from muscle traction on the frontal bone due to changes in swimming patterns during development. This study not only offers significant insights into unraveling the molecular mechanisms that govern phenotypic specialization and ecological adaptations in the humpback grouper but also serves as a valuable reference for studies on fishes with a controversial morphology and molecular phylogeny.
Collapse
Affiliation(s)
- Xiaoying Cao
- State Key Laboratory of Marine Environment Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Shunyun Deng
- State Key Laboratory of Marine Environment Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Quanyin Liu
- State Key Laboratory of Marine Environment Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Lisheng Wu
- State Key Laboratory of Marine Environment Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Xuan Zhuang
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Shaoxiong Ding
- State Key Laboratory of Marine Environment Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| |
Collapse
|
5
|
McWhinnie K, Negi D, Tanner KE, Parsons KJ. Functional trait plasticity diverges between sexes in African cichlids: A contribution toward ecological sexual dimorphism? Ecol Evol 2023; 13:e10702. [PMID: 38034329 PMCID: PMC10682861 DOI: 10.1002/ece3.10702] [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: 11/09/2022] [Revised: 08/02/2023] [Accepted: 08/17/2023] [Indexed: 12/02/2023] Open
Abstract
Phenotypic plasticity enables development to produce multiple phenotypes in response to environmental conditions. Plasticity driven variation has been suggested to play a key role in adaptive divergence, and plasticity itself can evolve. However, the interaction of plasticity with the multiple levels involved with adaptive divergence is less understood. For example, sexual dimorphism can contribute adaptive variation through ecological sexual dimorphism (ESD), but the contribution of plasticity to this phenomenon is unknown. Therefore, to determine the potential contribution of plasticity to ESD, we used the adaptive radiation of Malawi cichlids. Two mouthbrooding species (Labeotropheus fuelleborni and Tropheops "Red Cheek") with differences in foraging tactics underwent foraging experiments using benthic and limnetic treatments while accounting for sex. Plasticity in craniofacial shape and three functionally important traits were measured. Plasticity was shown, but without any sex-based differences in shape. However, for mechanical advantage traits of the mandible sex by diet interactions were found. This suggests that ESD, may be influenced by phenotypic plasticity that diverges between sexes. Given the involvement of the mandible in parental care in cichlids this may indicate that sexual divergence in plasticity may trade-off against maternal care tactics.
Collapse
Affiliation(s)
- Kirsty McWhinnie
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Deepti Negi
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - K. Elizabeth Tanner
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
- School of Engineering and Materials ScienceQueen Mary University of LondonLondonUK
| | - Kevin J. Parsons
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| |
Collapse
|
6
|
Palominos MF, Muhl V, Richards EJ, Miller CT, Martin CH. Jaw size variation is associated with a novel craniofacial function for galanin receptor 2 in an adaptive radiation of pupfishes. Proc Biol Sci 2023; 290:20231686. [PMID: 37876194 PMCID: PMC10598438 DOI: 10.1098/rspb.2023.1686] [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: 07/28/2023] [Accepted: 10/02/2023] [Indexed: 10/26/2023] Open
Abstract
Understanding the genetic basis of novel adaptations in new species is a fundamental question in biology. Here we demonstrate a new role for galr2 in vertebrate craniofacial development using an adaptive radiation of trophic specialist pupfishes endemic to San Salvador Island, Bahamas. We confirmed the loss of a putative Sry transcription factor binding site upstream of galr2 in scale-eating pupfish and found significant spatial differences in galr2 expression among pupfish species in Meckel's cartilage using in situ hybridization chain reaction (HCR). We then experimentally demonstrated a novel role for Galr2 in craniofacial development by exposing embryos to Garl2-inhibiting drugs. Galr2-inhibition reduced Meckel's cartilage length and increased chondrocyte density in both trophic specialists but not in the generalist genetic background. We propose a mechanism for jaw elongation in scale-eaters based on the reduced expression of galr2 due to the loss of a putative Sry binding site. Fewer Galr2 receptors in the scale-eater Meckel's cartilage may result in their enlarged jaw lengths as adults by limiting opportunities for a circulating Galr2 agonist to bind to these receptors during development. Our findings illustrate the growing utility of linking candidate adaptive SNPs in non-model systems with highly divergent phenotypes to novel vertebrate gene functions.
Collapse
Affiliation(s)
- M. Fernanda Palominos
- Department of Integrative Biology, University of California, 3101 Valley Life Sciences Building, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Vanessa Muhl
- Department of Integrative Biology, University of California, 3101 Valley Life Sciences Building, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Emilie J. Richards
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN, USA
| | - Craig T. Miller
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA
| | - Christopher H. Martin
- Department of Integrative Biology, University of California, 3101 Valley Life Sciences Building, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| |
Collapse
|
7
|
Palominos MF, Muhl V, Richards EJ, Miller CT, Martin CH. Jaw size variation is associated with a novel craniofacial function for galanin receptor 2 in an adaptive radiation of pupfishes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.02.543513. [PMID: 37333213 PMCID: PMC10274624 DOI: 10.1101/2023.06.02.543513] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Understanding the genetic basis of novel adaptations in new species is a fundamental question in biology that also provides an opportunity to uncover new genes and regulatory networks with potential clinical relevance. Here we demonstrate a new role for galr2 in vertebrate craniofacial development using an adaptive radiation of trophic specialist pupfishes endemic to San Salvador Island in the Bahamas. We confirmed the loss of a putative Sry transcription factor binding site in the upstream region of galr2 in scale-eating pupfish and found significant spatial differences in galr2 expression among pupfish species in Meckel's cartilage and premaxilla using in situ hybridization chain reaction (HCR). We then experimentally demonstrated a novel function for Galr2 in craniofacial development and jaw elongation by exposing embryos to drugs that inhibit Galr2 activity. Galr2-inhibition reduced Meckel's cartilage length and increased chondrocyte density in both trophic specialists but not in the generalist genetic background. We propose a mechanism for jaw elongation in scale-eaters based on the reduced expression of galr2 due to the loss of a putative Sry binding site. Fewer Galr2 receptors in the scale-eater Meckel's cartilage may result in their enlarged jaw lengths as adults by limiting opportunities for a postulated Galr2 agonist to bind to these receptors during development. Our findings illustrate the growing utility of linking candidate adaptive SNPs in non-model systems with highly divergent phenotypes to novel vertebrate gene functions.
Collapse
Affiliation(s)
- M Fernanda Palominos
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| | - Vanessa Muhl
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| | - Emilie J Richards
- Department of Ecology, Evolution, and Behavior, University of Minnesota
| | - Craig T Miller
- Department of Molecular & Cell Biology, University of California, Berkeley
| | - Christopher H Martin
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| |
Collapse
|
8
|
Packard M, Gilbert MC, Tetrault E, Albertson RC. Zebrafish crocc2 mutants exhibit divergent craniofacial shape, misregulated variability, and aberrant cartilage morphogenesis. Dev Dyn 2023; 252:1026-1045. [PMID: 37032317 PMCID: PMC10524572 DOI: 10.1002/dvdy.591] [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: 11/07/2022] [Revised: 03/21/2023] [Accepted: 03/29/2023] [Indexed: 04/11/2023] Open
Abstract
BACKGROUND Phenotypic variation is of paramount importance in development, evolution, and human health; however, the molecular mechanisms that influence organ shape and shape variability are not well understood. During craniofacial development, the behavior of skeletal precursors is regulated by both biochemical and environmental inputs, and the primary cilia play critical roles in transducing both types of signals. Here, we examine a gene that encodes a key constituent of the ciliary rootlets, crocc2, and its role in cartilage morphogenesis in larval zebrafish. RESULTS Geometric morphometric analysis of crocc2 mutants revealed altered craniofacial shapes and expanded variation. At the cellular level, we observed altered chondrocyte shapes and planar cell polarity across multiple stages in crocc2 mutants. Notably, cellular defects were specific to areas that experience direct mechanical input. Cartilage cell number, apoptosis, and bone patterning were not affected in crocc2 mutants. CONCLUSIONS Whereas "regulatory" genes are widely implicated in patterning the craniofacial skeleton, genes that encode "structural" aspects of the cell are increasingly implicated in shaping the face. Our results add crocc2 to this list, and demonstrate that it affects craniofacial geometry and canalizes phenotypic variation. We propose that it does so via mechanosensing, possibly through the ciliary rootlet. If true, this would implicate a new organelle in skeletal development and evolution.
Collapse
Affiliation(s)
- Mary Packard
- Department of Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Michelle C. Gilbert
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, U.S.A
- Current address, Department of Biology, Penn State University, University Park, PA 16802, U.S.A
| | - Emily Tetrault
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - R. Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
| |
Collapse
|
9
|
Tetrault E, Swenson J, Aaronson B, Marcho C, Albertson RC. The transcriptional state and chromatin landscape of cichlid jaw shape variation across species and environments. Mol Ecol 2023; 32:3922-3941. [PMID: 37160741 PMCID: PMC10524807 DOI: 10.1111/mec.16975] [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: 11/30/2022] [Revised: 04/17/2023] [Accepted: 04/24/2023] [Indexed: 05/11/2023]
Abstract
Adaptive phenotypes are shaped by a combination of genetic and environmental forces, but how they interact remains poorly understood. Here, we utilize the cichlid oral jaw apparatus to better understand these gene-by-environment effects. First, we employed RNA-seq in bony and ligamentous tissues important for jaw opening to identify differentially expressed genes between species and across foraging environments. We used two Lake Malawi species adapted to different foraging habitats along the pelagic-benthic ecomorphological axis. Our foraging treatments were designed to force animals to employ either suction or biting/scraping, which broadly mimic pelagic or benthic modes of feeding. We found a large number of differentially expressed genes between species, and while we identified relatively few differences between environments, species differences were far more pronounced when they were challenged with a pelagic versus benthic foraging mode. Expression data carried the signature of genetic assimilation, and implicated cell cycle regulation in shaping the jaw across species and environments. Next, we repeated the foraging experiment and performed ATAC-seq procedures on nuclei harvested from the same tissues. Cross-referencing results from both analyses revealed subsets of genes that were both differentially expressed and differentially accessible. This reduced dataset implicated notable candidate genes including the Hedgehog effector, KIAA0586 and the ETS transcription factor, etv4, which connects environmental stress and craniofacial morphogenesis. Taken together, these data provide novel insights into the epigenetic, genetic and cellular bases of species- and environment-specific bone shapes.
Collapse
Affiliation(s)
- Emily Tetrault
- Graduate Program in Molecular and Cell Biology, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - John Swenson
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - Ben Aaronson
- Biology Department, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - Chelsea Marcho
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - R. Craig Albertson
- Biology Department, University of Massachusetts, Amherst MA, 01003, U.S.A
| |
Collapse
|
10
|
Ducos B, Bensimon D, Scerbo P. Vertebrate Cell Differentiation, Evolution, and Diseases: The Vertebrate-Specific Developmental Potential Guardians VENTX/ NANOG and POU5/ OCT4 Enter the Stage. Cells 2022; 11:cells11152299. [PMID: 35892595 PMCID: PMC9331430 DOI: 10.3390/cells11152299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/09/2022] [Accepted: 07/13/2022] [Indexed: 01/02/2023] Open
Abstract
During vertebrate development, embryonic cells pass through a continuum of transitory pluripotent states that precede multi-lineage commitment and morphogenesis. Such states are referred to as “refractory/naïve” and “competent/formative” pluripotency. The molecular mechanisms maintaining refractory pluripotency or driving the transition to competent pluripotency, as well as the cues regulating multi-lineage commitment, are evolutionarily conserved. Vertebrate-specific “Developmental Potential Guardians” (vsDPGs; i.e., VENTX/NANOG, POU5/OCT4), together with MEK1 (MAP2K1), coordinate the pluripotency continuum, competence for multi-lineage commitment and morphogenesis in vivo. During neurulation, vsDPGs empower ectodermal cells of the neuro-epithelial border (NEB) with multipotency and ectomesenchyme potential through an “endogenous reprogramming” process, giving rise to the neural crest cells (NCCs). Furthermore, vsDPGs are expressed in undifferentiated-bipotent neuro-mesodermal progenitor cells (NMPs), which participate in posterior axis elongation and growth. Finally, vsDPGs are involved in carcinogenesis, whereby they confer selective advantage to cancer stem cells (CSCs) and therapeutic resistance. Intriguingly, the heterogenous distribution of vsDPGs in these cell types impact on cellular potential and features. Here, we summarize the findings about the role of vsDPGs during vertebrate development and their selective advantage in evolution. Our aim to present a holistic view regarding vsDPGs as facilitators of both cell plasticity/adaptability and morphological innovation/variation. Moreover, vsDPGs may also be at the heart of carcinogenesis by allowing malignant cells to escape from physiological constraints and surveillance mechanisms.
Collapse
Affiliation(s)
- Bertrand Ducos
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- High Throughput qPCR Core Facility, ENS, PSL, 46 rue d’Ulm, 75005 Paris, France
- Correspondence: (B.D.); (D.B.); (P.S.)
| | - David Bensimon
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90094, USA
- Correspondence: (B.D.); (D.B.); (P.S.)
| | - Pierluigi Scerbo
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- Correspondence: (B.D.); (D.B.); (P.S.)
| |
Collapse
|
11
|
McWhinnie K, Gibson J, Gislason M, Tanner E, Windmill J, Albertson RC, Parsons K. Assessing the Levels of Functional Adaptation: Finite Element Analysis Reveals Species, Hybrid, and Sexual Variation in the Biomechanics of African Cichlid Mandibles. Evol Biol 2022. [DOI: 10.1007/s11692-022-09566-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractTo understand how adaptive divergence emerges it is essential to examine the function of phenotypic traits along a continuum. For vertebrates, the mandible provides a key link with foraging and other important activities which has made it highly relevant for investigations of biomechanical change. Variation in mandible shape is known to correspond with ecology but its function is often only investigated between distinct species. However, for such divergence to occur and be maintained selection likely draws from many sources of biomechanical variation. African cichlids represent an exemplar model for understanding how such processes unfold with mandible variation existing between species, sexes, and is likely generated in nature by the potential for hybridization. We explored such mandible variation through a finite element modelling approach and predicted that hybrids and females would have reduced functional capabilities, the former in line with disruptive selection and the latter due to potential trade-offs incurred by maternal mouthbrooding in Malawian haplochromines. We revealed evidence of structural adaptations between Tropheops ‘Red Cheek’ and Labeotrophues fuelleborni that impacted the dispersion of mechanical stress in ways that matched the foraging of these species. Also, hybrids showed higher stresses relative to both species across the mandible. Sexual dimorphism in stress handling was evident despite minor differences in shape with males showing enhanced load resistance. However, in hybrids it appeared that males were disadvantaged relative to females, and displayed asymmetry in load handling. Together, these results show evidence of species and sex based biomechanical variation, that could be targeted by divergent selection.
Collapse
|
12
|
Diamond KM, Rolfe SM, Kwon RY, Maga AM. Computational anatomy and geometric shape analysis enables analysis of complex craniofacial phenotypes in zebrafish. Biol Open 2022; 11:274056. [PMID: 35072203 PMCID: PMC8864294 DOI: 10.1242/bio.058948] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/11/2022] [Indexed: 11/20/2022] Open
Abstract
Due to the complexity of fish skulls, previous attempts to classify craniofacial phenotypes have relied on qualitative features or sparce 2D landmarks. In this work we aim to identify previously unknown 3D craniofacial phenotypes with a semiautomated pipeline in adult zebrafish mutants. We first estimate a synthetic ‘normative’ zebrafish template using microCT scans from a sample pool of wildtype animals using the Advanced Normalization Tools (ANTs). We apply a computational anatomy (CA) approach to quantify the phenotype of zebrafish with disruptions in bmp1a, a gene implicated in later skeletal development and whose human ortholog when disrupted is associated with Osteogenesis Imperfecta. Compared to controls, the bmp1a fish have larger otoliths, larger normalized centroid sizes, and exhibit shape differences concentrated around the operculum, anterior frontal, and posterior parietal bones. Moreover, bmp1a fish differ in the degree of asymmetry. Our CA approach offers a potential pipeline for high-throughput screening of complex fish craniofacial shape to discover novel phenotypes for which traditional landmarks are too sparce to detect. The current pipeline successfully identifies areas of variation in zebrafish mutants, which are an important model system for testing genome to phenome relationships in the study of development, evolution, and human diseases.
Collapse
Affiliation(s)
- Kelly M. Diamond
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Sara M. Rolfe
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Friday Harbor Marine Laboratories, University of Washington, San Juan, WA, USA
| | - Ronald Y. Kwon
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - A. Murat Maga
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Division of Craniofacial Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| |
Collapse
|
13
|
Roman-Trufero M, Dillon N. The UBE2D ubiquitin conjugating enzymes: Potential regulatory hubs in development, disease and evolution. Front Cell Dev Biol 2022; 10:1058751. [PMID: 36578786 PMCID: PMC9790923 DOI: 10.3389/fcell.2022.1058751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
Ubiquitination of cellular proteins plays critical roles in key signalling pathways and in the regulation of protein turnover in eukaryotic cells. E2 ubiquitin conjugating enzymes function as essential intermediates in ubiquitination reactions by acting as ubiquitin donors for the E3 ubiquitin ligase enzymes that confer substrate specificity. The members of the UBE2D family of E2 enzymes are involved in regulating signalling cascades through ubiquitination of target proteins that include receptor tyrosine kinases (RTKs) and components of the Hedgehog, TGFβ and NFκB pathways. UBE2D enzymes also function in transcriptional control by acting as donors for ubiquitination of histone tails by the Polycomb protein Ring1B and the DNA methylation regulator UHRF1 as well as having roles in DNA repair and regulation of the level of the tumour suppressor p53. Here we review the functional roles and mechanisms of regulation of the UBE2D proteins including recent evidence that regulation of the level of UBE2D3 is critical for controlling ubiquitination of specific targets during development. Cellular levels of UBE2D3 have been shown to be regulated by phosphorylation, which affects folding of the protein, reducing its stability. Specific variations in the otherwise highly conserved UBE2D3 protein sequence in amniotes and in a subgroup of teleost fishes, the Acanthomorpha, suggest that the enzyme has had important roles during vertebrate evolution.
Collapse
Affiliation(s)
- Monica Roman-Trufero
- Centre for Haematology, Department of Immunology and Inflammation, Imperial College, Hammersmith Hospital Campus, London, United Kingdom
| | - Niall Dillon
- MRC London Institute of Medical Sciences, Imperial College, Hammersmith Hospital Campus, London, United Kingdom
| |
Collapse
|
14
|
Gilbert MC, Tetrault E, Packard M, Navon D, Albertson RC. Ciliary Rootlet Coiled-Coil 2 (crocc2) Is Associated with Evolutionary Divergence and Plasticity of Cichlid Jaw Shape. Mol Biol Evol 2021; 38:3078-3092. [PMID: 33720362 PMCID: PMC8321518 DOI: 10.1093/molbev/msab071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cichlid fishes exhibit rapid, extensive, and replicative adaptive radiation in feeding morphology. Plasticity of the cichlid jaw has also been well documented, and this combination of iterative evolution and developmental plasticity has led to the proposition that the cichlid feeding apparatus represents a morphological "flexible stem." Under this scenario, the fixation of environmentally sensitive genetic variation drives evolutionary divergence along a phenotypic axis established by the initial plastic response. Thus, if plasticity is predictable then so too should be the evolutionary response. We set out to explore these ideas at the molecular level by identifying genes that underlie both the evolution and plasticity of the cichlid jaw. As a first step, we fine-mapped an environment-specific quantitative trait loci for lower jaw shape in cichlids, and identified a nonsynonymous mutation in the ciliary rootlet coiled-coil 2 (crocc2), which encodes a major structural component of the primary cilium. Given that primary cilia play key roles in skeletal mechanosensing, we reasoned that this gene may confer its effects by regulating the sensitivity of bone to respond to mechanical input. Using both cichlids and zebrafish, we confirmed this prediction through a series of experiments targeting multiple levels of biological organization. Taken together, our results implicate crocc2 as a novel mediator of bone formation, plasticity, and evolution.
Collapse
Affiliation(s)
- Michelle C Gilbert
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, USA
| | - Emily Tetrault
- Graduate Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Mary Packard
- Department of Biology, University of Massachusetts, Amherst, MA, USA
| | - Dina Navon
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, USA
| | - R Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA, USA
| |
Collapse
|
15
|
Fischer C, Koblmüller S, Börger C, Michelitsch G, Trajanoski S, Schlötterer C, Guelly C, Thallinger GG, Sturmbauer C. Genome sequences of Tropheus moorii and Petrochromis trewavasae, two eco-morphologically divergent cichlid fishes endemic to Lake Tanganyika. Sci Rep 2021; 11:4309. [PMID: 33619328 PMCID: PMC7900123 DOI: 10.1038/s41598-021-81030-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 12/28/2020] [Indexed: 01/01/2023] Open
Abstract
With more than 1000 species, East African cichlid fishes represent the fastest and most species-rich vertebrate radiation known, providing an ideal model to tackle molecular mechanisms underlying recurrent adaptive diversification. We add high-quality genome reconstructions for two phylogenetic key species of a lineage that diverged about ~ 3-9 million years ago (mya), representing the earliest split of the so-called modern haplochromines that seeded additional radiations such as those in Lake Malawi and Victoria. Along with the annotated genomes we analysed discriminating genomic features of the study species, each representing an extreme trophic morphology, one being an algae browser and the other an algae grazer. The genomes of Tropheus moorii (TM) and Petrochromis trewavasae (PT) comprise 911 and 918 Mbp with 40,300 and 39,600 predicted genes, respectively. Our DNA sequence data are based on 5 and 6 individuals of TM and PT, and the transcriptomic sequences of one individual per species and sex, respectively. Concerning variation, on average we observed 1 variant per 220 bp (interspecific), and 1 variant per 2540 bp (PT vs PT)/1561 bp (TM vs TM) (intraspecific). GO enrichment analysis of gene regions affected by variants revealed several candidates which may influence phenotype modifications related to facial and jaw morphology, such as genes belonging to the Hedgehog pathway (SHH, SMO, WNT9A) and the BMP and GLI families.
Collapse
Affiliation(s)
- C Fischer
- Institute of Biology, University of Graz, Graz, Austria
- Institute of Biomedical Informatics, Graz University of Technology, Graz, Austria
| | - S Koblmüller
- Institute of Biology, University of Graz, Graz, Austria
| | - C Börger
- Institute of Biology, University of Graz, Graz, Austria
| | - G Michelitsch
- Center for Medical Research, Medical University of Graz, Graz, Austria
| | - S Trajanoski
- Center for Medical Research, Medical University of Graz, Graz, Austria
| | - C Schlötterer
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
| | - C Guelly
- Center for Medical Research, Medical University of Graz, Graz, Austria
| | - G G Thallinger
- Institute of Biomedical Informatics, Graz University of Technology, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - C Sturmbauer
- Institute of Biology, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| |
Collapse
|
16
|
Navon D, Hatini P, Zogbaum L, Albertson RC. The genetic basis of coordinated plasticity across functional units in a Lake Malawi cichlid mapping population. Evolution 2021; 75:672-687. [PMID: 33438760 DOI: 10.1111/evo.14157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 12/15/2020] [Accepted: 12/22/2020] [Indexed: 11/28/2022]
Abstract
Adaptive radiations are often stereotypical, as populations repeatedly specialize along conserved environmental axes. Phenotypic plasticity may be similarly stereotypical, as individuals respond to environmental cues. These parallel patterns of variation, which are often consistent across traits, have led researchers to propose that plasticity can facilitate predictable patterns of evolution along environmental gradients. This "flexible stem" model of evolution raises questions about the genetic nature of plasticity, including how complex is the genetic basis for plasticity? Is plasticity across traits mediated by many distinct loci, or few "global" regulators? To address these questions, we reared a hybrid cichlid mapping population on alternate diet regimes mimicking an important environmental axis. We show that plasticity across an array of ecologically relevant traits is generally morphologically integrated, such that traits respond in a coordinated manner, especially those with overlapping function. Our genetic data are more ambiguous. While our mapping experiment provides little evidence for global genetic regulators of plasticity, these data do contain a genetic signal for the integration of plasticity across traits. Overall, our data suggest a compromise between genetic modularity, whereby plasticity may evolve independently across traits, and low level but widespread genetic integration, establishing the potential for plasticity to experience coordinated evolution.
Collapse
Affiliation(s)
- Dina Navon
- Graduate Program in Organismal & Evolutionary Biology, University of Massachusetts Amherst, Amherst, Massachusetts, 01003.,Rutgers University Human Genetics Institute, Piscataway, New Jersey, 08854
| | - Paul Hatini
- Department of Biology, Morrill Science Center, University of Massachusetts Amherst, Amherst, Massachusetts, 01003
| | - Lily Zogbaum
- Biology Department, Swarthmore College, Swarthmore, Pennsylvania, 19081
| | - R Craig Albertson
- Graduate Program in Organismal & Evolutionary Biology, University of Massachusetts Amherst, Amherst, Massachusetts, 01003.,Department of Biology, Morrill Science Center, University of Massachusetts Amherst, Amherst, Massachusetts, 01003
| |
Collapse
|
17
|
Zogbaum L, Friend PG, Albertson RC. Plasticity and genetic basis of cichlid gill arch anatomy reveal novel roles for Hedgehog signaling. Mol Ecol 2021; 30:761-774. [PMID: 33278044 DOI: 10.1111/mec.15766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 01/10/2023]
Abstract
Teleost gill arches are exquisitely evolved to maximize foraging efficiency, and include structures for the capture, filtering, and processing of prey. While both plasticity and a genetic basis for gill arch traits have been noted, the relative contributions of genetics and the environment in shaping these structures remains poorly understood. East African cichlids are particularly useful in this line of study due to their highly diverse and plastic feeding apparatus. Here we explore the gene-by-environmental effects on cichlid GRs by rearing pure bred species and their F3 hybrids in different foraging environments. We find that anatomical differences between species are dependent on the environment. The genetic architecture of these traits is also largely distinct between foraging environments. We did, however, note a few genomic "hotspots" where multiple traits map to a common region. One of these, for GR number across multiple arches, maps to the ptch1 locus, a key component of the Hedgehog (Hh) pathway that has previously been implicated in cichlid oral jaw shape and plasticity. Since Hh signalling has not previously been implicated in GR development, we explored functional roles for this pathway. Using a small molecule inhibitor in cichlids, as well as zebrafish transgenic systems, we demonstrate that Hh levels negatively regulate GR number, and are both necessary and sufficient to maintain plasticity in this trait. In all these data underscore the critical importance of the environment in determining the relationship between genotype and phenotype, and provide a molecular inroad to better understand the origins of variation in this important foraging-related trait.
Collapse
Affiliation(s)
| | | | - R Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA, USA
| |
Collapse
|
18
|
Bonnet X, Brischoux F, Briand M, Shine R. Plasticity matches phenotype to local conditions despite genetic homogeneity across 13 snake populations. Proc Biol Sci 2021; 288:20202916. [PMID: 33499786 DOI: 10.1098/rspb.2020.2916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In a widespread species, a matching of phenotypic traits to local environmental optima is generally attributed to site-specific adaptation. However, the same matching can occur via adaptive plasticity, without requiring genetic differences among populations. Adult sea kraits (Laticauda saintgironsi) are highly philopatric to small islands, but the entire population within the Neo-Caledonian Lagoon is genetically homogeneous because females migrate to the mainland to lay their eggs at communal sites; recruits disperse before settling, mixing up alleles. Consequently, any matching between local environments (e.g. prey sizes) and snake phenotypes (e.g. body sizes and relative jaw sizes (RJSs)) must be achieved via phenotypic plasticity rather than spatial heterogeneity in gene frequencies. We sampled 13 snake colonies spread along an approximately 200 km northwest-southeast gradient (n > 4500 individuals) to measure two morphological features that affect maximum ingestible prey size in gape-limited predators: body size and RJS. As proxies of habitat quality (HQ), we used protection status, fishing pressure and lagoon characteristics (lagoon width and distance of islands to the barrier reef). In both sexes, spatial variation in body sizes and RJSs was linked to HQ; albeit in different ways, consistent with sex-based divergences in foraging ecology. Strong spatial divergence in morphology among snake colonies, despite genetic homogeneity, supports the idea that phenotypic plasticity can facilitate speciation by creating multiple phenotypically distinct subpopulations shaped by their environment.
Collapse
Affiliation(s)
- Xavier Bonnet
- CEBC, UMR 7372 CNRS and University of La Rochelle, 79360 Villiers en Bois, France
| | - François Brischoux
- CEBC, UMR 7372 CNRS and University of La Rochelle, 79360 Villiers en Bois, France
| | | | - Richard Shine
- Department of Biological Sciences, Macquarie University, New South Wales 2109, Australia
| |
Collapse
|
19
|
Conith AJ, Hope SA, Chhouk BH, Albertson RC. Weak genetic signal for phenotypic integration implicates developmental processes as major regulators of trait covariation. Mol Ecol 2021; 30:464-480. [PMID: 33231336 PMCID: PMC8811731 DOI: 10.1111/mec.15748] [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: 04/15/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022]
Abstract
Phenotypic integration is an important metric that describes the degree of covariation among traits in a population, and is hypothesized to arise due to selection for shared functional processes. Our ability to identify the genetic and/or developmental underpinnings of integration is marred by temporally overlapping cell-, tissue- and structure-level processes that serve to continually 'overwrite' the structure of covariation among traits through ontogeny. Here, we examine whether traits that are integrated at the phenotypic level also exhibit a shared genetic basis (e.g. pleiotropy). We micro-CT scanned two hard tissue traits, and two soft tissue traits (mandible, pectoral girdle, atrium and ventricle, respectively) from an F5 hybrid population of Lake Malawi cichlids, and used geometric morphometrics to extract 3D shape information from each trait. Given the large degree of asymmetric variation that may reflect developmental instability, we separated symmetric from asymmetric components of shape variation. We then performed quantitative trait loci (QTL) analysis to determine the degree of genetic overlap between shapes. While we found ubiquitous associations among traits at the phenotypic level, except for a handful of notable exceptions, our QTL analysis revealed few overlapping genetic regions. Taken together, this indicates developmental interactions can play a large role in determining the degree of phenotypic integration among traits, and likely obfuscate the genotype to phenotype map, limiting our ability to gain a comprehensive picture of the genetic contributors responsible for phenotypic divergence.
Collapse
Affiliation(s)
- Andrew J. Conith
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01002
| | - Sylvie A. Hope
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01002
| | - Brian H Chhouk
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01002
| | - R. Craig Albertson
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01002
| |
Collapse
|
20
|
Hedgehog signaling is necessary and sufficient to mediate craniofacial plasticity in teleosts. Proc Natl Acad Sci U S A 2020; 117:19321-19327. [PMID: 32719137 PMCID: PMC7431006 DOI: 10.1073/pnas.1921856117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Phenotypic plasticity has emerged as an important concept in evolutionary biology. It is thought to contribute to an organism’s ability to adapt to environmental change within a single generation, which may facilitate survival and increase fitness. Furthermore, plasticity has the potential to bias the direction and/or speed of evolution by changing patterns of phenotypic variation and exposing new genetic variation to selection (i.e., flexible stem evolution). Our understanding of this important phenomenon is incomplete owing to limited knowledge of the molecular underpinnings of reaction norm evolution. Using the teleost feeding apparatus as a model, we explore this open question and show that the Hh signaling pathway underlies the ability of this structure to respond plastically to alternate feeding regimes. Phenotypic plasticity, the ability of a single genotype to produce multiple phenotypes under different environmental conditions, is critical for the origins and maintenance of biodiversity; however, the genetic mechanisms underlying plasticity as well as how variation in those mechanisms can drive evolutionary change remain poorly understood. Here, we examine the cichlid feeding apparatus, an icon of both prodigious evolutionary divergence and adaptive phenotypic plasticity. We first provide a tissue-level mechanism for plasticity in craniofacial shape by measuring rates of bone deposition within functionally salient elements of the feeding apparatus in fishes forced to employ alternate foraging modes. We show that levels and patterns of phenotypic plasticity are distinct among closely related cichlid species, underscoring the evolutionary potential of this trait. Next, we demonstrate that hedgehog (Hh) signaling, which has been implicated in the evolutionary divergence of cichlid feeding architecture, is associated with environmentally induced rates of bone deposition. Finally, to demonstrate that Hh levels are the cause of the plastic response and not simply the consequence of producing more bone, we use transgenic zebrafish in which Hh levels could be experimentally manipulated under different foraging conditions. Notably, we find that the ability to modulate bone deposition rates in different environments is dampened when Hh levels are reduced, whereas the sensitivity of bone deposition to different mechanical demands increases with elevated Hh levels. These data advance a mechanistic understanding of phenotypic plasticity in the teleost feeding apparatus and in doing so contribute key insights into the origins of adaptive morphological radiations.
Collapse
|