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Marconi A, Vernaz G, Karunaratna A, Ngochera MJ, Durbin R, Santos ME. Genetic and Developmental Divergence in the Neural Crest Program between Cichlid Fish Species. Mol Biol Evol 2024; 41:msae217. [PMID: 39412298 PMCID: PMC11558072 DOI: 10.1093/molbev/msae217] [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: 06/06/2024] [Revised: 10/07/2024] [Accepted: 10/09/2024] [Indexed: 10/30/2024] Open
Abstract
Neural crest (NC) is a vertebrate-specific embryonic progenitor cell population at the basis of important vertebrate features such as the craniofacial skeleton and pigmentation patterns. Despite the wide-ranging variation of NC-derived traits across vertebrates, the contribution of NC to species diversification remains underexplored. Here, leveraging the adaptive diversity of African Great Lakes' cichlid species, we combined comparative transcriptomics and population genomics to investigate the evolution of the NC genetic program in the context of their morphological divergence. Our analysis revealed substantial differences in transcriptional landscapes across somitogenesis, an embryonic period coinciding with NC development and migration. This included dozens of genes with described functions in the vertebrate NC gene regulatory network, several of which showed signatures of positive selection. Among candidates showing between-species expression divergence, we focused on teleost-specific paralogs of the NC-specifier sox10 (sox10a and sox10b) as prime candidates to influence NC development. These genes, expressed in NC cells, displayed remarkable spatio-temporal variation in cichlids, suggesting their contribution to interspecific morphological differences, such as craniofacial structures and pigmentation. Finally, through CRISPR/Cas9 mutagenesis, we demonstrated the functional divergence between cichlid sox10 paralogs, with the acquisition of a novel skeletogenic function by sox10a. When compared with teleost models zebrafish and medaka, our findings reveal that sox10 duplication, although retained in most teleost lineages, had variable functional fates across their phylogeny. Altogether, our study suggests that NC-related processes-particularly those controlled by sox10s-are involved in generating morphological diversification between species and lays the groundwork for further investigations into the mechanisms underpinning vertebrate NC diversification.
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Affiliation(s)
| | - Grégoire Vernaz
- Zoological Institute, University of Basel, Basel, Switzerland
| | | | - Maxon J Ngochera
- Malawi Fisheries Department, Senga Bay Fisheries Research Center, P.O. Box 316, Salima, Malawi
| | - Richard Durbin
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - M Emília Santos
- Department of Zoology, University of Cambridge, Cambridge, UK
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2
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Jones AE, Maia A, Conway KW, Webb JF. The Silverjaw Minnow, Ericymba buccata: An Extraordinary Lateral Line System and its Contribution to Prey Detection. Integr Comp Biol 2024; 64:459-479. [PMID: 38992208 PMCID: PMC11406156 DOI: 10.1093/icb/icae111] [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: 12/04/2023] [Revised: 07/06/2024] [Accepted: 07/08/2024] [Indexed: 07/13/2024] Open
Abstract
Fishes use their mechanosensory lateral line (LL) system to detect local water flows in different behavioral contexts, including the detection of prey. The LL system is comprised of neuromast receptor organs on the skin (superficial neuromasts) and within bony canals (canal neuromasts). Most fishes have one cranial LL canal phenotype, but the silverjaw minnow (Ericymba buccata) has two: narrow canals dorsal and caudal to the eye and widened canals ventral to the eye and along the mandible. The ventrally directed widened LL canals have been hypothesized to be an adaptation for detection of their benthic prey. Multiple morphological methods were used to describe the narrow and widened canals and canal neuromasts in detail. The primary distribution of hundreds of superficial neuromasts and taste buds ventral to the eye and on the mandible (described here for the first time) suggests additional sensory investment for detecting flow and chemical stimuli emanating from benthic prey. The hypothesis that the LL system mediates prey localization was tested by measuring five parameters in behavioral trials in which the combination of sensory modalities available to fish was manipulated (four experimental treatments). Fish detected and localized prey regardless of available sensory modalities and they were able to detect prey in the dark in the absence of LL input (LL ablation with neomycin sulfate) revealing that chemoreception was sufficient to mediate benthic prey detection, localization, and consumption. However, elimination of LL input resulted in a change in the angle of approach to live (mobile) prey even when visual input was available, suggesting that mechanosensory input contributes to the successful detection and localization of prey. The results of this study demonstrate that the extraordinary LL canal system of the silverjaw minnow, in addition to the large number of superficial neuromasts, and the presence of numerous extraoral taste buds, likely represent adaptations for multimodal integration of sensory inputs contributing to foraging behavior in this species. The morphological and behavioral results of this study both suggest that this species would be an excellent model for future comparative structural and functional studies of sensory systems in fishes.
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Affiliation(s)
- Aubree E Jones
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI 02881, USA
| | - Anabela Maia
- Department of Biology, Rhode Island College, 600 Mount Pleasant Avenue Providence, RI 02908, USA
| | - Kevin W Conway
- Department of Ecology and Conservation Biology, Texas A&M University, 534 John Kimbrough Blvd, College Station, TX 77843, USA
| | - Jacqueline F Webb
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI 02881, USA
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3
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Marconi A, Vernaz G, Karunaratna A, Ngochera MJ, Durbin R, Santos ME. Genetic and developmental divergence in the neural crest programme between cichlid fish species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.578004. [PMID: 38352436 PMCID: PMC10862805 DOI: 10.1101/2024.01.30.578004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Neural crest (NC) is a vertebrate-specific embryonic progenitor cell population at the basis of important vertebrate features such as the craniofacial skeleton and pigmentation patterns. Despite the wide-ranging variation of NC-derived traits across vertebrates, the contribution of NC to species diversification remains underexplored. Here, leveraging the adaptive diversity of African Great Lakes' cichlid species, we combined comparative transcriptomics and population genomics to investigate the evolution of the NC genetic programme in the context of their morphological divergence. Our analysis revealed substantial differences in transcriptional landscapes across somitogenesis, an embryonic period coinciding with NC development and migration. This included dozens of genes with described functions in the vertebrate NC gene regulatory network, several of which showed signatures of positive selection. Among candidates showing between-species expression divergence, we focused on teleost-specific paralogs of the NC-specifier sox10 (sox10a and sox10b) as prime candidates to influence NC development. These genes, expressed in NC cells, displayed remarkable spatio-temporal variation in cichlids, suggesting their contribution to inter-specific morphological differences. Finally, through CRISPR/Cas9 mutagenesis, we demonstrated the functional divergence between cichlid sox10 paralogs, with the acquisition of a novel skeletogenic function by sox10a. When compared to the teleost models zebrafish and medaka, our findings reveal that sox10 duplication, although retained in most teleost lineages, had variable functional fates across their phylogeny. Altogether, our study suggests that NC-related processes - particularly those controlled by sox10s - might be involved in generating morphological diversification between species and lays the groundwork for further investigations into mechanisms underpinning vertebrate NC diversification.
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Affiliation(s)
| | | | | | - Maxon J. Ngochera
- Senga Bay Fisheries Research Center, Malawi Fisheries Department, P.O. Box 316, Salima, Malawi
| | - Richard Durbin
- Department of Genetics, University of Cambridge, United Kingdom
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4
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Edgley DE, Carruthers M, Gabagambi NP, Saxon AD, Smith AM, Joyce DA, Vernaz G, Santos ME, Turner GF, Genner MJ. Lateral line system diversification during the early stages of ecological speciation in cichlid fish. BMC Ecol Evol 2024; 24:24. [PMID: 38378480 PMCID: PMC10877828 DOI: 10.1186/s12862-024-02214-5] [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: 09/15/2023] [Accepted: 02/09/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND The mechanosensory lateral line system is an important sensory modality in fishes, informing multiple behaviours related to survival including finding food and navigating in dark environments. Given its ecological importance, we may expect lateral line morphology to be under disruptive selection early in the ecological speciation process. Here we quantify the lateral line system morphology of two ecomorphs of the cichlid fish Astatotilapia calliptera in crater Lake Masoko that have diverged from common ancestry within the past 1,000 years. RESULTS Based on geometric morphometric analyses of CT scans, we show that the zooplanktivorous benthic ecomorph that dominates the deeper waters of the lake has large cranial lateral line canal pores, relative to those of the nearshore invertebrate-feeding littoral ecomorph found in the shallower waters. In contrast, fluorescence imaging revealed no evidence for divergence between ecomorphs in the number of either superficial or canal neuromasts. We illustrate the magnitude of the variation we observe in Lake Masoko A. calliptera in the context of the neighbouring Lake Malawi mega-radiation that comprises over 700 species. CONCLUSIONS These results provide the first evidence of divergence in this often-overlooked sensory modality in the early stages of ecological speciation, suggesting that it may have a role in the broader adaptive radiation process.
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Affiliation(s)
- Duncan E Edgley
- School of Biological Sciences, University of Bristol, Bristol, UK.
| | - Madeleine Carruthers
- School of Biological Sciences, University of Bristol, Bristol, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Nestory P Gabagambi
- Tanzania Fisheries Research Institute, Kyela Centre, P.O. Box 98, Kyela, Mbeya, Tanzania
| | - Andrew D Saxon
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Alan M Smith
- School of Natural Sciences, University of Hull, Hull, UK
| | - Domino A Joyce
- School of Natural Sciences, University of Hull, Hull, UK
| | - Grégoire Vernaz
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, UK
- Wellcome/Cancer Research UK, Gurdon Institute, University of Cambridge, Cambridge, UK
| | - M Emília Santos
- Department of Zoology, University of Cambridge, Cambridge, UK
| | | | - Martin J Genner
- School of Biological Sciences, University of Bristol, Bristol, UK.
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5
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Ehemann NR, Meyer A, Hulsey CD. Morphological description of spontaneous pelvic fin loss in a neotropical cichlid fish. J Morphol 2024; 285:e21663. [PMID: 38100744 DOI: 10.1002/jmor.21663] [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: 10/03/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 12/17/2023]
Abstract
Pelvic fins are a characteristic structure of the vertebrate Bauplan. Yet, pelvic fin loss has occurred repeatedly across a wide diversity of other lineages of tetrapods and at least 48 times in teleost fishes. This pelvic finless condition is often associated with other morphological features such as body elongation, loss of additional structures, and bilateral asymmetry. However, despite the remarkable diversity in the several thousand cichlid fish species, none of them are characterized by the complete absence of pelvic fins. Here, we examined the musculoskeletal structure and associated bilateral asymmetry in Midas cichlids (Amphilophus cf. citrinellus) that lost their pelvic fins spontaneously in the laboratory. Due to this apparent mutational loss of the pelvic girdle and fins, the external and internal anatomy are described in a series of "normal" Midas individuals and their pelvic finless sibling tankmates. First, other traits associated with teleost pelvic fin loss, the genetic basis of pelvic fin loss, and the potential for pleiotropic effects of these genes on other traits in teleosts were all reviewed. Using these traits as a guide, we investigated whether other morphological differences were associated with the pelvic girdle/fin loss. The mean values of the masses of muscle of the pectoral fin, fin ray numbers in the unpaired fins, and oral jaw tooth numbers did not differ between the two pelvic fin morphotypes. However, significant differences in meristic values of the paired traits assessed were observed for the same side of the body between morphotypes. Notably, bilateral asymmetry was found exclusively for the posterior lateral line scales. Finally, we found limited evidence of pleiotropic effects, such as lateral line scale numbers and fluctuating asymmetry between the Midas pelvic fin morphotypes. The fast and relatively isolated changes in the Midas cichlids suggest minor but interesting pleiotropic effects could accompany loss of cichlid pelvic fins.
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Affiliation(s)
| | - Axel Meyer
- Department of Biology, University of Konstanz, Konstanz, Germany
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6
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Webb JF. Structural and functional evolution of the mechanosensory lateral line system of fishesa). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3526-3542. [PMID: 38171014 PMCID: PMC10908562 DOI: 10.1121/10.0022565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 01/05/2024]
Abstract
The mechanosensory lateral line system is the flow sensing system present in all 34 000+ species of fishes. Its neuromast receptor organs, located on the skin or in bony canals on the head and tubed scales on the trunk, respond to the near field component of acoustic stimuli as well as short range, low frequency (0-200 Hz) water flows of biotic and abiotic origin. Here, I discuss the genesis of my research career and its focus on the structural and functional evolution of the lateral line system among a wide taxonomic range of fishes including those from different aquatic habitats (tropical lakes to coral reefs and the deep sea). I discuss the importance of investigating structure before function, using investigations in my laboratory that had unexpected outcomes, as well as the role of serendipity in the evolution of a career and in the nature of scientific discovery.
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Affiliation(s)
- Jacqueline F Webb
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA
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7
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Kundu S, De Alwis PS, Kim AR, Lee SR, Kang HE, Go Y, Gietbong FZ, Wibowo A, Kim HW. Mitogenomic Characterization of Cameroonian Endemic Coptodon camerunensis (Cichliformes: Cichlidae) and Matrilineal Phylogeny of Old-World Cichlids. Genes (Basel) 2023; 14:1591. [PMID: 37628642 PMCID: PMC10454717 DOI: 10.3390/genes14081591] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
The mitogenomic evolution of old-world cichlids is still largely incomplete in Western Africa. In this present study, the complete mitogenome of the Cameroon endemic cichlid, Coptodon camerunensis, was determined by next-generation sequencing. The mitogenome was 16,557 bp long and encoded with 37 genes (13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a control region). The C. camerunensis mitogenome is AT-biased (52.63%), as exhibited in its congener, Coptodon zillii (52.76% and 53.04%). The majority of PCGs start with an ATG initiation codon, except COI, which starts with a GTG codon and five PCGs and ends with the TAA termination codon and except seven PCGs with an incomplete termination codon. In C. camerunensis mitogenome, most tRNAs showed classical cloverleaf secondary structures, except tRNA-serine with a lack of DHU stem. Comparative analyses of the conserved blocks of two Coptodonini species control regions revealed that the CSB-II block was longer than other blocks and contained highly variable sites. Using 13 concatenated PCGs, the mitogenome-based Bayesian phylogeny easily distinguished all the examined old-world cichlids. Except for Oreochromini and Coptodinini tribe members, the majority of the taxa exhibited monophyletic clustering within their respective lineages. C. camerunensis clustered closely with Heterotilapia buttikoferi (tribe Heterotilapiini) and had paraphyletic clustering with its congener, C. zillii. The Oreochromini species also displayed paraphyletic grouping, and the genus Oreochromis showed a close relationship with Coptodinini and Heterotilapiini species. In addition, illustrating the known distribution patterns of old-world cichlids, the present study is congruent with the previous hypothesis and proclaims that prehistoric geological evolution plays a key role in the hydroclimate of the African continent during Mesozoic, which simultaneously disperses and/or colonizes cichlids in different ichthyological provinces and Rift Lake systems in Africa. The present study suggests that further mitogenomes of cichlid species are required, especially from western Africa, to understand their unique evolution and adaptation.
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Affiliation(s)
- Shantanu Kundu
- Department of Marine Biology, Pukyong National University, Busan 48513, Republic of Korea; (S.K.); (P.S.D.A.)
| | - Piyumi S. De Alwis
- Department of Marine Biology, Pukyong National University, Busan 48513, Republic of Korea; (S.K.); (P.S.D.A.)
| | - Ah Ran Kim
- Marine Integrated Biomedical Technology Center, National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (A.R.K.); (S.R.L.)
| | - Soo Rin Lee
- Marine Integrated Biomedical Technology Center, National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (A.R.K.); (S.R.L.)
| | - Hye-Eun Kang
- Institute of Marine Life Science, Pukyong National University, Busan 48513, Republic of Korea;
| | - Yunji Go
- Industry 4.0 Convergence Bionics Engineering, Pukyong National University, Busan 48513, Republic of Korea;
| | | | - Arif Wibowo
- Research Center for Conservation of Marine and Inland Water Resources, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia;
| | - Hyun-Woo Kim
- Department of Marine Biology, Pukyong National University, Busan 48513, Republic of Korea; (S.K.); (P.S.D.A.)
- Marine Integrated Biomedical Technology Center, National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (A.R.K.); (S.R.L.)
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8
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Santos ME, Lopes JF, Kratochwil CF. East African cichlid fishes. EvoDevo 2023; 14:1. [PMID: 36604760 PMCID: PMC9814215 DOI: 10.1186/s13227-022-00205-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/29/2022] [Indexed: 01/06/2023] Open
Abstract
Cichlid fishes are a very diverse and species-rich family of teleost fishes that inhabit lakes and rivers of India, Africa, and South and Central America. Research has largely focused on East African cichlids of the Rift Lakes Tanganyika, Malawi, and Victoria that constitute the biodiversity hotspots of cichlid fishes. Here, we give an overview of the study system, research questions, and methodologies. Research on cichlid fishes spans many disciplines including ecology, evolution, physiology, genetics, development, and behavioral biology. In this review, we focus on a range of organismal traits, including coloration phenotypes, trophic adaptations, appendages like fins and scales, sensory systems, sex, brains, and behaviors. Moreover, we discuss studies on cichlid phylogenies, plasticity, and general evolutionary patterns, ranging from convergence to speciation rates and the proximate and ultimate mechanisms underlying these processes. From a methodological viewpoint, the last decade has brought great advances in cichlid fish research, particularly through the advent of affordable deep sequencing and advances in genetic manipulations. The ability to integrate across traits and research disciplines, ranging from developmental biology to ecology and evolution, makes cichlid fishes a fascinating research system.
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Affiliation(s)
- M Emília Santos
- Department of Zoology, University of Cambridge, Cambridge, UK.
| | - João F Lopes
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
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Scott E, Edgley DE, Smith A, Joyce DA, Genner MJ, Ioannou CC, Hauert S. Lateral line morphology, sensory perception and collective behaviour in African cichlid fish. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221478. [PMID: 36704254 PMCID: PMC9874273 DOI: 10.1098/rsos.221478] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/14/2022] [Indexed: 06/18/2023]
Abstract
The lateral line system of fishes provides cues for collective behaviour, such as shoaling, but it remains unclear how anatomical lateral line variation leads to behavioural differences among species. Here we studied associations between lateral line morphology and collective behaviour using two morphologically divergent species and their second-generation hybrids. We identify collective behaviours associated with variation in canal and superficial lateral line morphology, with closer proximities to neighbouring fish associated with larger canal pore sizes and fewer superficial neuromasts. A mechanistic understanding of the observed associations was provided by hydrodynamic modelling of an artificial lateral line sensor, which showed that simulated canal-based neuromasts were less susceptible to saturation during unidirectional movement than simulated superficial neuromasts, while increasing the canal pore size of the simulated lateral line sensor elevated sensitivity to vortices shed by neighbouring fish. Our results propose a mechanism behind lateral line flow sensing during collective behaviour in fishes.
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Affiliation(s)
- Elliott Scott
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, UK
| | - Duncan E. Edgley
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Alan Smith
- Department of Biological and Marine Sciences, University of Hull, Hull HU6 7RX, UK
| | - Domino A. Joyce
- Department of Biological and Marine Sciences, University of Hull, Hull HU6 7RX, UK
| | - Martin J. Genner
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | | | - Sabine Hauert
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, UK
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10
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Clark B, Elkin J, Marconi A, Turner GF, Smith AM, Joyce D, Miska EA, Juntti SA, Santos ME. Oca2 targeting using CRISPR/Cas9 in the Malawi cichlid Astatotilapia calliptera. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220077. [PMID: 35601449 PMCID: PMC9019512 DOI: 10.1098/rsos.220077] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/22/2022] [Indexed: 05/03/2023]
Abstract
Identifying genetic loci underlying trait variation provides insights into the mechanisms of diversification, but demonstrating causality and characterizing the role of genetic loci requires testing candidate gene function, often in non-model species. Here we establish CRISPR/Cas9 editing in Astatotilapia calliptera, a generalist cichlid of the remarkably diverse Lake Malawi radiation. By targeting the gene oca2 required for melanin synthesis in other vertebrate species, we show efficient editing and germline transmission. Gene edits include indels in the coding region, probably a result of non-homologous end joining, and a large deletion in the 3' untranslated region due to homology-directed repair. We find that oca2 knock-out A. calliptera lack melanin, which may be useful for developmental imaging in embryos and studying colour pattern formation in adults. As A. calliptera resembles the presumed generalist ancestor of the Lake Malawi cichlids radiation, establishing genome editing in this species will facilitate investigating speciation, adaptation and trait diversification in this textbook radiation.
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Affiliation(s)
- Bethan Clark
- Department of Zoology, University of Cambridge, UK
| | - Joel Elkin
- Department of Zoology, University of Cambridge, UK
| | | | - George F. Turner
- School of Natural Sciences, Bangor University, Gwynedd LL57 2TH, UK
| | - Alan M. Smith
- Department of Biological and Marine Sciences, University of Hull, UK
| | - Domino Joyce
- Department of Biological and Marine Sciences, University of Hull, UK
| | - Eric A. Miska
- Department of Genetics, University of Cambridge, UK
- Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
- Wellcome Sanger Institute, Wellcome Trust Genome Campus, Cambridge, UK
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11
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Aragona M, Porcino C, Guerrera MC, Montalbano G, Levanti M, Abbate F, Laurà R, Germanà A. Localization of Neurotrophin Specific Trk Receptors in Mechanosensory Systems of Killifish ( Nothobranchius guentheri). Int J Mol Sci 2021; 22:10411. [PMID: 34638748 PMCID: PMC8508645 DOI: 10.3390/ijms221910411] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 12/25/2022] Open
Abstract
Neurotrophins (NTs) and their signal-transducing Trk receptors play a crucial role in the development and maintenance of specific neuronal subpopulations in nervous and sensory systems. NTs are supposed to regulate two sensory systems in fish, the inner ear and the lateral line system (LLS). The latter is one of the major mechanosensory systems in fish. Considering that annual fishes of the genus Nothobranchius, with their short life expectancy, have become a suitable model for aging studies and that the occurrence and distribution of neurotrophin Trk receptors have never been investigated in the inner ear and LLS of killifish (Nothobranchius guentheri), our study aimed to investigate the localization of neurotrophin-specific Trk receptors in mechanosensory systems of N. guentheri. For histological and immunohistochemical analysis, adult specimens of N. guentheri were processed using antibodies against Trk receptors and S100 protein. An intense immunoreaction for TrkA and TrkC was found in the sensory cells of the inner ear as well as in the hair cells of LLS. Moreover, also the neurons localized in the acoustic ganglia displayed a specific immunoreaction for all Trk receptors (TrkA, B, and C) analyzed. Taken together, our results demonstrate, for the first time, that neurotrophins and their specific receptors could play a pivotal role in the biology of the sensory cells of the inner ear and LLS of N. guentheri and might also be involved in the hair cells regeneration process in normal and aged conditions.
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Affiliation(s)
| | | | | | | | | | | | | | - Antonino Germanà
- Zebrafish Neuromorphology Laboratory, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (M.L.); (F.A.); (R.L.)
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12
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Lloyd E, Chhouk B, Conith AJ, Keene AC, Albertson RC. Diversity in rest-activity patterns among Lake Malawi cichlid fishes suggests a novel axis of habitat partitioning. J Exp Biol 2021; 224:238727. [PMID: 33658242 PMCID: PMC8077532 DOI: 10.1242/jeb.242186] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/11/2021] [Indexed: 12/04/2022]
Abstract
Animals display remarkable diversity in rest and activity patterns that are regulated by endogenous foraging strategies, social behaviors and predator avoidance. Alteration in the circadian timing of activity or the duration of rest–wake cycles provide a central mechanism for animals to exploit novel niches. The diversity of the >3000 cichlid species throughout the world provides a unique opportunity to examine variation in locomotor activity and rest. Lake Malawi alone is home to over 500 species of cichlids that display divergent behaviors and inhabit well-defined niches throughout the lake. These species are presumed to be diurnal, though this has never been tested systematically. Here, we measured locomotor activity across the circadian cycle in 11 Lake Malawi cichlid species. We documented surprising variability in the circadian time of locomotor activity and the duration of rest. In particular, we identified a single species, Tropheops sp. ‘red cheek’, that is nocturnal. Nocturnal behavior was maintained when fish were provided shelter, but not under constant darkness, suggesting that it results from acute response to light rather than an endogenous circadian rhythm. Finally, we showed that nocturnality is associated with increased eye size after correcting for evolutionary history, suggesting a link between visual processing and nighttime activity. Together, these findings identify diversity of locomotor behavior in Lake Malawi cichlids and provide a system for investigating the molecular and neural basis underlying variation in nocturnal activity. Summary: Cichlids show a remarkable diversity in morphology and behavior. Cichlid species exhibit differences in strength and polarity of activity rhythms, revealing a new axis of habitat partitioning.
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Affiliation(s)
- Evan Lloyd
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33401, USA
| | - Brian Chhouk
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Andrew J Conith
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alex C Keene
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33401, USA
| | - R Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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Rizzato PP, Pospisilova A, Hilton EJ, Bockmann FA. Ontogeny and homology of cranial bones associated with lateral-line canals of the Senegal Bichir, Polypterus senegalus (Actinopterygii: Cladistii: Polypteriformes), with a discussion on the formation of lateral-line canal bones in fishes. J Anat 2020; 237:439-467. [PMID: 32285471 DOI: 10.1111/joa.13202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 03/13/2020] [Accepted: 03/19/2020] [Indexed: 12/17/2022] Open
Abstract
The association between lateral-line canals and skull bones in fishes has been the subject of several studies and raised a series of controversies, particularly with regard to the hypothesized role of lateral-line organs (i.e. neuromasts) in osteogenesis and the consequences for hypotheses of homology of the bones associated with lateral-line canals. Polypteridae, a group of freshwater fishes that occupies a key phylogenetic position as the most basal extant lineage of ray-finned fishes (Actinopterygii), provides an interesting model for the study of the relationships between lateral-line canals and skull bones. We describe the development of bones associated with lateral-line canals in the Senegal Bichir, Polypterus senegalus, and use these data to re-address previous hypotheses of homology of skull bones of polypterids. We demonstrate that the lateral-line canals constitute a separate component of the dermatocranium that may interact with a membranodermal component, thereby forming compound bones in the adult. Differences in the interactions between these components determine the characteristics of the development of each independent bone in the skull of adult P. senegalus. Our results shed light on long-standing controversies about the identity of skull bones such as the rostral, preopercle, and sphenotic in Polypteridae, and suggest the presence of an ancestral two-component pattern of formation of bones associated with lateral-line canals in bony fishes. These findings reveal the need to re-address previous hypotheses of homology of bones associated with lateral-line canals in different groups of bony fishes, especially fossil taxa.
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Affiliation(s)
- Pedro P Rizzato
- Laboratório de Ictiologia de Ribeirão Preto (LIRP), Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil.,Programa de Pós-Graduação em Biologia Comparada, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Anna Pospisilova
- Department of Zoology, Charles University, Prague, Czech Republic
| | - Eric J Hilton
- Department of Fisheries Science, Virginia Institute of Marine Sciences, William & Mary, Gloucester Point, VA, USA
| | - Flávio A Bockmann
- Laboratório de Ictiologia de Ribeirão Preto (LIRP), Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil.,Programa de Pós-Graduação em Biologia Comparada, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
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