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D'Aniello S, Bertrand S, Escriva H. Amphioxus as a model to study the evolution of development in chordates. eLife 2023; 12:e87028. [PMID: 37721204 PMCID: PMC10506793 DOI: 10.7554/elife.87028] [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: 02/20/2023] [Accepted: 08/10/2023] [Indexed: 09/19/2023] Open
Abstract
Cephalochordates and tunicates represent the only two groups of invertebrate chordates, and extant cephalochordates - commonly known as amphioxus or lancelets - are considered the best proxy for the chordate ancestor, from which they split around 520 million years ago. Amphioxus has been an important organism in the fields of zoology and embryology since the 18th century, and the morphological and genomic simplicity of cephalochordates (compared to vertebrates) makes amphioxus an attractive model for studying chordate biology at the cellular and molecular levels. Here we describe the life cycle of amphioxus, and discuss the natural histories and habitats of the different species of amphioxus. We also describe their use as laboratory animal models, and discuss the techniques that have been developed to study different aspects of amphioxus.
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Affiliation(s)
- Salvatore D'Aniello
- Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton DohrnNapoliItaly
| | - Stephanie Bertrand
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire OcéanologiqueBanyuls-sur-MerFrance
| | - Hector Escriva
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire OcéanologiqueBanyuls-sur-MerFrance
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2
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Kostyuchenko RP, Amosov AV. Spatial Colinear but Broken Temporal Expression of Duplicated ParaHox Genes in Asexually Reproducing Annelids, Nais communis and Pristina longiseta. Genes (Basel) 2023; 14:1501. [PMID: 37510405 PMCID: PMC10379933 DOI: 10.3390/genes14071501] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023] Open
Abstract
ParaHox genes are key developmental regulators involved in the patterning of the digestive tract along the anteroposterior axis and the development of the nervous system. Most studies have focused on the function of these genes in embryogenesis, while their expression patterns in postembryonic development often remain unknown. In this study, we identified for the first time all ParaHox orthologs in two naidid oligochaetes, N. communis and P. longiseta, and described their expression patterns during normal growth and fission in these animals. We showed that Gsx and Cdx are presented by two paralogs, while Xlox is a single copy gene in both species. Using whole-mount in situ hybridization, we also found that orthologs, except for the Xlox gene, have similar activity patterns with minor differences in details, while the expression patterns of paralogs can differ significantly. However, all these genes are involved in axial patterning and/or in tissue remodeling during growth and asexual reproduction in naidids. Moreover, during paratomic fission, these genes are expressed with spatial colinearity but temporal colinearity is broken. The results of this study may be evidence of the functional diversification of duplicated genes and suggest involvement of the ParaHox genes in whole-body patterning during growth and asexual reproduction in annelids.
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Affiliation(s)
- Roman P Kostyuchenko
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia
| | - Artem V Amosov
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia
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3
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Clark E, Battistara M, Benton MA. A timer gene network is spatially regulated by the terminal system in the Drosophila embryo. eLife 2022; 11:e78902. [PMID: 36524728 PMCID: PMC10065802 DOI: 10.7554/elife.78902] [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: 03/23/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
In insect embryos, anteroposterior patterning is coordinated by the sequential expression of the 'timer' genes caudal, Dichaete, and odd-paired, whose expression dynamics correlate with the mode of segmentation. In Drosophila, the timer genes are expressed broadly across much of the blastoderm, which segments simultaneously, but their expression is delayed in a small 'tail' region, just anterior to the hindgut, which segments during germband extension. Specification of the tail and the hindgut depends on the terminal gap gene tailless, but beyond this the regulation of the timer genes is poorly understood. We used a combination of multiplexed imaging, mutant analysis, and gene network modelling to resolve the regulation of the timer genes, identifying 11 new regulatory interactions and clarifying the mechanism of posterior terminal patterning. We propose that a dynamic Tailless expression gradient modulates the intrinsic dynamics of a timer gene cross-regulatory module, delineating the tail region and delaying its developmental maturation.
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Affiliation(s)
- Erik Clark
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Margherita Battistara
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
| | - Matthew A Benton
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Developmental Biology Unit, EMBLHeidelbergGermany
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4
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Ma P, Liu X, Xu Z, Liu H, Ding X, Huang Z, Shi C, Liang L, Xu L, Li X, Li G, He Y, Ding Z, Chai C, Wang H, Qiu J, Zhu J, Wang X, Ding P, Zhou S, Yuan Y, Wu W, Wan C, Yan Y, Zhou Y, Zhou QJ, Wang GD, Zhang Q, Xu X, Li G, Zhang S, Mao B, Chen D. Joint profiling of gene expression and chromatin accessibility during amphioxus development at single-cell resolution. Cell Rep 2022; 39:110979. [PMID: 35732129 DOI: 10.1016/j.celrep.2022.110979] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 03/21/2022] [Accepted: 05/27/2022] [Indexed: 11/03/2022] Open
Abstract
Vertebrate evolution was accompanied by two rounds of whole-genome duplication followed by functional divergence in terms of regulatory circuits and gene expression patterns. As a basal and slow-evolving chordate species, amphioxus is an ideal paradigm for exploring the origin and evolution of vertebrates. Single-cell sequencing has been widely used to construct the developmental cell atlas of several representative species of vertebrates (human, mouse, zebrafish, and frog) and tunicates (sea squirts). Here, we perform single-nucleus RNA sequencing (snRNA-seq) and single-cell assay for transposase accessible chromatin sequencing (scATAC-seq) for different stages of amphioxus (covering embryogenesis and adult tissues). With the datasets generated, we constructed a developmental tree for amphioxus cell fate commitment and lineage specification and characterize the underlying key regulators and genetic regulatory networks. The data are publicly available on the online platform AmphioxusAtlas.
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Affiliation(s)
- Pengcheng Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Xingyan Liu
- Academy of Mathematics and Systems Science, Chinese Academy of Science, Beijing 100190, China; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zaoxu Xu
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huimin Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, Fujian 361102, China
| | - Xiangning Ding
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Huang
- Fujian Key Laboratory of Special Marine Bio-resources Sustainable Utilization, College of Life Sciences, Fujian Normal University, Fuzhou, 350117 Fujian, China; Fuzhou Institute of Oceanography, Minjiang University, Fuzhou 350108, China; Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Minjiang University, Fuzhou 350108, China
| | - Chenggang Shi
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, Fujian 361102, China
| | - Langchao Liang
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luohao Xu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Xiaolu Li
- Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, China
| | - Guimei Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Yuqi He
- Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, China
| | - Zhaoli Ding
- Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, China
| | - Chaochao Chai
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haoyu Wang
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiaying Qiu
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiacheng Zhu
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | | | - Peiwen Ding
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Si Zhou
- BGI-Shenzhen, Shenzhen 518083, China
| | | | - Wendi Wu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Cen Wan
- Fujian Key Laboratory of Special Marine Bio-resources Sustainable Utilization, College of Life Sciences, Fujian Normal University, Fuzhou, 350117 Fujian, China
| | - Yanan Yan
- Fujian Key Laboratory of Special Marine Bio-resources Sustainable Utilization, College of Life Sciences, Fujian Normal University, Fuzhou, 350117 Fujian, China
| | - Yitao Zhou
- Fujian Key Laboratory of Special Marine Bio-resources Sustainable Utilization, College of Life Sciences, Fujian Normal University, Fuzhou, 350117 Fujian, China
| | - Qi-Jun Zhou
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Guo-Dong Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
| | - Qiujin Zhang
- Fujian Key Laboratory of Special Marine Bio-resources Sustainable Utilization, College of Life Sciences, Fujian Normal University, Fuzhou, 350117 Fujian, China.
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China.
| | - Guang Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, Fujian 361102, China.
| | - Shihua Zhang
- Academy of Mathematics and Systems Science, Chinese Academy of Science, Beijing 100190, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China; Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou 310024, China.
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China.
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5
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Ozernyuk ND, Isaeva VV. Early Stages of Animal Mesoderm Evolution. Russ J Dev Biol 2022. [DOI: 10.1134/s1062360422020096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Holland LZ, Holland ND. The invertebrate chordate amphioxus gives clues to vertebrate origins. Curr Top Dev Biol 2022; 147:563-594. [PMID: 35337463 DOI: 10.1016/bs.ctdb.2021.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Amphioxus (cepholochordates) have long been used to infer how the vertebrates evolved from their invertebrate ancestors. However, some of the body part homologies between amphioxus and vertebrates have been controversial. This is not surprising as the amphioxus and vertebrate lineages separated half a billion years ago-plenty of time for independent loss and independent gain of features. The development of new techniques in the late 20th and early 21st centuries including transmission electron microscopy and serial blockface scanning electron microscopy in combination with in situ hybridization and immunocytochemistry to reveal spatio-temporal patterns of gene expression and gene products have greatly strengthened inference of some homologies (like those between regions of the central nervous system), although others (like nephridia) still need further support. These major advances in establishing homologies between amphioxus and vertebrates, together with strong support from comparative genomics, have firmly established amphioxus as a stand-in or model for the ancestral vertebrate.
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Affiliation(s)
- Linda Z Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States.
| | - Nicholas D Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States
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Stevens SJC, Stumpel CTRM, Diderich KEM, van Slegtenhorst MA, Abbott MA, Manning C, Balciuniene J, Pyle LC, Leonard J, Murrell JR, van de Putte R, van Rooij IALM, Hoischen A, Lasko P, Brunner HG. The broader phenotypic spectrum of congenital caudal abnormalities associated with mutations in the caudal type homeobox 2 gene. Clin Genet 2021; 101:183-189. [PMID: 34671974 PMCID: PMC9153267 DOI: 10.1111/cge.14076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/28/2022]
Abstract
The caudal type homeobox 2 (CDX2) gene encodes a developmental regulator involved in caudal body patterning. Only three pathogenic variants in human CDX2 have been described, in patients with persistent cloaca, sirenomelia and/or renal and anogenital malformations. We identified five patients with de novo or inherited pathogenic variants in CDX2 with clinical phenotypes that partially overlap with previous cases, that is, imperforate anus and renal, urogenital and limb abnormalities. However, additional clinical features were seen including vertebral agenesis and we describe considerable phenotypic variability, even in unrelated patients with the same recurrent p.(Arg237His) variant. We propose CDX2 variants as rare genetic cause for a multiple congenital anomaly syndrome that can include features of caudal regression syndrome and VACTERL. A causative role is further substantiated by the relationship between CDX2 and other proteins encoded by genes that were previously linked to caudal abnormalities in humans, for example, TBXT (sacral agenesis and other vertebral segmentation defects) and CDX1 (anorectal malformations). Our findings confirm the essential role of CDX2 in caudal morphogenesis and formation of cloacal derivatives in humans, which to date has only been well characterized in animals.
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Affiliation(s)
- Servi J C Stevens
- Department of Clinical Genetics, Maastricht University Medical Centre and GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands
| | - Constance T R M Stumpel
- Department of Clinical Genetics, Maastricht University Medical Centre and GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands
| | - Karin E M Diderich
- Department of Clinical Genetics, Erasmus Medical Centre, Rotterdam, the Netherlands
| | | | - Mary-Alice Abbott
- Department of Pediatrics, University of Massachusetts Medical School-Baystate, Springfield, Massachusetts, USA
| | - Courtney Manning
- Department of Pediatrics, University of Massachusetts Medical School-Baystate, Springfield, Massachusetts, USA
| | - Jorune Balciuniene
- Division of Human Genetics and the Roberts Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Louise C Pyle
- Division of Human Genetics and the Roberts Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jacqueline Leonard
- Division of Human Genetics and the Roberts Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jill R Murrell
- Division of Human Genetics and the Roberts Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Romy van de Putte
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Iris A L M van Rooij
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alexander Hoischen
- Department of Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Paul Lasko
- Department of Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands.,Department of Biology, McGill University, Montréal, Québec, Canada
| | - Han G Brunner
- Department of Clinical Genetics, Maastricht University Medical Centre and GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands.,Department of Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
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8
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Zou J, Wu X, Shi C, Zhong Y, Zhang L, Yan Q, Su L, Li G. A Potential Method for Rapid Screening of Amphioxus Founder Harboring Germline Mutation and Transgene. Front Cell Dev Biol 2021; 9:702290. [PMID: 34458263 PMCID: PMC8387717 DOI: 10.3389/fcell.2021.702290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
Amphioxus is a promising model organism for understanding the origin and evolution of vertebrates due to its basal phylogenetic position among chordates. We here compared the mutation efficacy and mutation type of tail tips and gametes of amphioxus founders injected with Cas9 protein and six different sgRNAs targeting five distinct genes, and revealed a strong correlation for mutation efficacy and a mild correlation for mutation type among the two tissues. In addition, we also observed a positive relationship between gene insertions observed in tail tips and gametes of amphioxus founders injected with Tol2 transposase and two different transgenic constructs. Finally, we showed that amphioxus larvae which had their tail tips cut at the 3-4 gill-slit stage were able to recover within 6 days and developed a normal number of gonads at the adult stage, and that F0 larvae carry similar mutation efficacy and type in the posterior end to that in the tail tips after their metamorphosis. Together, these findings suggest a great potential for obtaining valid amphioxus founders with desired mutations and transgenes at as early as the early larval stage, which will certainly speed up the generation of amphioxus mutants and transgenes and make it more cost- and labor-effective.
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Affiliation(s)
- Jiaqi Zou
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Xiaotong Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Chenggang Shi
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Yanhong Zhong
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Lei Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Qiuning Yan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Liuru Su
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Guang Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
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Xing C, Pan R, Hu G, Liu X, Wang Y, Li G. Pitx controls amphioxus asymmetric morphogenesis by promoting left-side development and repressing right-side formation. BMC Biol 2021; 19:166. [PMID: 34416880 PMCID: PMC8377849 DOI: 10.1186/s12915-021-01095-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022] Open
Abstract
Background Left-right (LR) asymmetry is an essential feature of bilateral animals. Studies in vertebrates show that LR asymmetry formation comprises three major steps: symmetry breaking, asymmetric gene expression, and LR morphogenesis. Although much progress has been made in the first two events, mechanisms underlying asymmetric morphogenesis remain largely unknown due to the complex developmental processes deployed by vertebrate organs. Results We here addressed this question by studying Pitx gene function in the basal chordate amphioxus whose asymmetric organogenesis, unlike that in vertebrates, occurs essentially in situ and does not rely on cell migration. Pitx null mutation in amphioxus causes loss of all left-sided organs and incomplete ectopic formation of all right-sided organs on the left side, whereas Pitx partial loss-of-function leads to milder phenotypes with only some LR organs lost or ectopically formed. At the N1 to N3 stages, Pitx expression is gradually expanded from the dorsal anterior domain to surrounding regions. This leads to activation of genes like Lhx3 and/or Prop1 and Pit, which are essential for left-side organs, and downregulation of genes like Hex and/or Nkx2.1 and FoxE4, which are required for right-side organs to form ectopically on the left side. In Pitx mutants, the left-side expressed genes are not activated, while the right-side genes fail to decrease expression on the left side. In contrast, in embryos overexpressing Pitx genes, the left-side genes are induced ectopically on the right side, and the right-side genes are inhibited. Several Pitx binding sites are identified in the upstream sequences of the left-side and right-side genes which are essential for activation of the former and repression of the latter by Pitx. Conclusions Our results demonstrate that (1) Pitx is a major (although not the only) determinant of asymmetric morphogenesis in amphioxus, (2) the development of different LR organs have distinct requirements for Pitx activity, and (3) Pitx controls amphioxus LR morphogenesis probably through inducing left-side organs and inhibiting right-side organs directly. These findings show much more dependence of LR organogenesis on Pitx in amphioxus than in vertebrates. They also provide insight into the molecular developmental mechanism of some vertebrate LR organs like the lungs and atria, since they show a right-isomerism phenotype in Pitx2 knockout mice like right-sided organs in Pitx mutant amphioxus. Our results also explain why some organs like the adenohypophysis are asymmetrically located in amphioxus but symmetrically positioned in vertebrates. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01095-0.
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Affiliation(s)
- Chaofan Xing
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China
| | - Rongrong Pan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China
| | - Guangwei Hu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China.,Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xian Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China
| | - Yiquan Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China
| | - Guang Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, 361102, Fujian, China.
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