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Baccas M, Ganesan V, Leung A, Pineiro L, McKillop AN, Liu J. SEM-2/SoxC regulates multiple aspects of C. elegans postembryonic mesoderm development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.04.602042. [PMID: 39005444 PMCID: PMC11245110 DOI: 10.1101/2024.07.04.602042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Development of multicellular organisms requires well-orchestrated interplay between cell-intrinsic transcription factors and cell-cell signaling. One set of highly conserved transcription factors that plays diverse roles in development is the SoxC group. C. elegans contains a sole SoxC protein, SEM-2. SEM-2 is essential for embryonic development, and for specifying the sex myoblast (SM) fate in the postembryonic mesoderm, the M lineage. We have identified a novel partial loss-of-function sem-2 allele that has a proline to serine change in the C-terminal tail of the highly conserved DNA-binding domain. Detailed analyses of mutant animals harboring this point mutation uncovered new functions of SEM-2 in the M lineage. First, SEM-2 functions antagonistically with LET-381, the sole C. elegans FoxF/C forkhead transcription factor, to regulate dorsoventral patterning of the M lineage. Second, in addition to specifying the SM fate, SEM-2 is essential for the proliferation and diversification of the SM lineage. Finally, SEM-2 appears to directly regulate the expression of hlh-8, which encodes a basic helix-loop-helix Twist transcription factor and plays critical roles in proper patterning of the M lineage. Our data, along with previous studies, suggest an evolutionarily conserved relationship between SoxC and Twist proteins. Furthermore, our work identified new interactions in the gene regulatory network (GRN) underlying C. elegans postembryonic development and adds to the general understanding of the structure-function relationship of SoxC proteins.
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Affiliation(s)
- Marissa Baccas
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Vanathi Ganesan
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Amy Leung
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Lucas Pineiro
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | | | - Jun Liu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
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Liu J, Murray JI. Mechanisms of lineage specification in Caenorhabditis elegans. Genetics 2023; 225:iyad174. [PMID: 37847877 DOI: 10.1093/genetics/iyad174] [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: 08/26/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
The studies of cell fate and lineage specification are fundamental to our understanding of the development of multicellular organisms. Caenorhabditis elegans has been one of the premiere systems for studying cell fate specification mechanisms at single cell resolution, due to its transparent nature, the invariant cell lineage, and fixed number of somatic cells. We discuss the general themes and regulatory mechanisms that have emerged from these studies, with a focus on somatic lineages and cell fates. We next review the key factors and pathways that regulate the specification of discrete cells and lineages during embryogenesis and postembryonic development; we focus on transcription factors and include numerous lineage diagrams that depict the expression of key factors that specify embryonic founder cells and postembryonic blast cells, and the diverse somatic cell fates they generate. We end by discussing some future perspectives in cell and lineage specification.
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Affiliation(s)
- Jun Liu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - John Isaac Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Heinze SD, Berger S, Engleitner S, Daube M, Hajnal A. Prolonging somatic cell proliferation through constitutive hox gene expression in C. elegans. Nat Commun 2023; 14:6850. [PMID: 37891160 PMCID: PMC10611754 DOI: 10.1038/s41467-023-42644-1] [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: 05/04/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
hox genes encode a conserved family of homeodomain transcription factors that are essential to determine the identity of body segments during embryogenesis and maintain adult somatic stem cells competent to regenerate organs. In contrast to higher organisms, somatic cells in C. elegans irreversibly exit the cell cycle after completing their cell lineage and the adult soma cannot regenerate. Here, we show that hox gene expression levels in C. elegans determine the temporal competence of somatic cells to proliferate. Down-regulation of the central hox gene lin-39 in dividing vulval cells results in their premature cell cycle exit, whereas constitutive lin-39 expression causes precocious Pn.p cell and sex myoblast divisions and prolongs the proliferative phase of the vulval cells past their normal point of arrest. Furthermore, ectopic expression of hox genes in the quiescent anchor cell re-activates the cell cycle and induces proliferation until young adulthood. Thus, constitutive expression of a single hox transcription factor is sufficient to prolong somatic cell proliferation beyond the restriction imposed by the cell lineage. The down-regulation of hox gene expression in most somatic cells at the end of larval development may be one cause for the absence of cell proliferation in adult C. elegans.
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Affiliation(s)
- Svenia D Heinze
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Simon Berger
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Institute for Chemical- and Bioengineering, ETH Zürich, Vladimir Prelog Weg 1, 8093, Zürich, Switzerland
| | - Stefanie Engleitner
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Michael Daube
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Alex Hajnal
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
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Mei X, Singson AW. The molecular underpinnings of fertility: Genetic approaches in Caenorhabditis elegans. ADVANCED GENETICS (HOBOKEN, N.J.) 2020; 2:e10034. [PMID: 34322672 PMCID: PMC8315475 DOI: 10.1002/ggn2.10034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The study of mutations that impact fertility has a catch-22. Fertility mutants are often lost since they cannot simply be propagated and maintained. This has hindered progress in understanding the genetics of fertility. In mice, several molecules are found to be required for the interactions between the sperm and egg, with JUNO and IZUMO1 being the only known receptor pair on the egg and sperm surface, respectively. In Caenorhabditis elegans, a total of 12 proteins on the sperm or oocyte have been identified to mediate gamete interactions. Majority of these genes were identified through mutants isolated from genetic screens. In this review, we summarize the several key screening strategies that led to the identification of fertility mutants in C. elegans and provide a perspective about future research using genetic approaches. Recently, advancements in new technologies such as high-throughput sequencing and Crispr-based genome editing tools have accelerated the molecular, cell biological, and mechanistic analysis of fertility genes. We review how these valuable tools advance our understanding of the molecular underpinnings of fertilization. We draw parallels of the molecular mechanisms of fertilization between worms and mammals and argue that our work in C. elegans complements fertility research in humans and other species.
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Affiliation(s)
- Xue Mei
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
| | - Andrew W. Singson
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
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Goh KY, Inoue T. A large transcribed enhancer region regulates C. elegans bed-3 and the development of egg laying muscles. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:519-533. [PMID: 29481869 DOI: 10.1016/j.bbagrm.2018.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 01/05/2023]
Abstract
Gene expression is regulated by the interaction of the RNA polymerase with various transcription factors at promoter and enhancer elements. Transcriptome analyses found that many non-protein-coding regions are transcribed to produce long non-coding RNAs and enhancer-associated RNAs. Production of these transcripts is associated with activation of nearby protein-coding genes, and at least in some cases, the transcripts themselves mediate this activation. Non-coding transcripts are also reported from large enhancers or clusters of enhancers. However, not much is known about the function of large transcribed enhancer regions during organismal development. Here we investigated a transcribed 10.6 kb intergenic region located upstream of the C. elegans bed-3 gene. We found that parts of this region exhibit tissue-specific promoter and enhancer activities. Deletion of the region disrupts egg laying, a phenotype also observed in bed-3 mutants, but with the severity correlating with the size of the deletion. This phenotype is not caused by overall reduction in bed-3 expression. Rather, deletions reduce bed-3 expression specifically in the mesoderm lineage. We found that bed-3 has a previously unknown function in the generation of sex myoblast (SM) cells from the M lineage, and deletions cause loss of SM cells leading to loss of vulval muscles required for egg laying. Furthermore, injection of dsRNA targeting non-coding transcripts from this region disrupted egg laying in the wild type but not in RNAi-defective mutants. Therefore, the region upstream of bed-3 is required for robust expression of bed-3 in a specific tissue, and non-coding transcripts may mediate this interaction.
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Affiliation(s)
- Kah Yee Goh
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597
| | - Takao Inoue
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597.
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Shen Q, Shi H, Tian C, Ghai V, Liu J. The C. elegans Spalt-like protein SEM-4 functions through the SoxC transcription factor SEM-2 to promote a proliferative blast cell fate in the postembryonic mesoderm. Dev Biol 2017; 429:335-342. [PMID: 28614700 DOI: 10.1016/j.ydbio.2017.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/09/2017] [Accepted: 06/09/2017] [Indexed: 11/29/2022]
Abstract
Proper development of a multicellular organism relies on well-coordinated regulation of cell fate specification, cell proliferation and cell differentiation. The C. elegans postembryonic mesoderm provides a useful system for uncovering factors involved in these processes and for further dissecting their regulatory relationships. The single Spalt-like zinc finger containing protein SEM-4/SALL is known to be involved in specifying the proliferative sex myoblast (SM) fate. We have found that SEM-4/SALL is sufficient to promote the SM fate and that it does so in a cell autonomous manner. We further showed that SEM-4/SALL acts through the SoxC transcription factor SEM-2 to promote the SM fate. SEM-2 is known to promote the SM fate by inhibiting the expression of two BWM-specifying transcription factors. In light of recent findings in mammals showing that Sall4, one of the mammalian homologs of SEM-4, contributes to pluripotency regulation by inhibiting differentiation, our work suggests that the function of SEM-4/SALL proteins in regulating pluripotency versus differentiation appears to be evolutionarily conserved.
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Affiliation(s)
- Qinfang Shen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Herong Shi
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Chenxi Tian
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Vikas Ghai
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Jun Liu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States.
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Vidal B, Santella A, Serrano-Saiz E, Bao Z, Chuang CF, Hobert O. C. elegans SoxB genes are dispensable for embryonic neurogenesis but required for terminal differentiation of specific neuron types. Development 2015; 142:2464-77. [PMID: 26153233 DOI: 10.1242/dev.125740] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 05/28/2015] [Indexed: 12/31/2022]
Abstract
Neurogenesis involves deeply conserved patterning molecules, such as the proneural basic helix-loop-helix transcription factors. Sox proteins and specifically members of the SoxB and SoxC groups are another class of conserved transcription factors with an important role in neuronal fate commitment and differentiation in various species. In this study, we examine the expression of all five Sox genes of the nematode C. elegans and analyze the effect of null mutant alleles of all members of the SoxB and SoxC groups on nervous system development. Surprisingly, we find that, unlike in other systems, neither of the two C. elegans SoxB genes sox-2 (SoxB1) and sox-3 (SoxB2), nor the sole C. elegans SoxC gene sem-2, is broadly expressed throughout the embryonic or adult nervous system and that all three genes are mostly dispensable for embryonic neurogenesis. Instead, sox-2 is required to maintain the developmental potential of blast cells that are generated in the embryo but divide only postembryonically to give rise to differentiated neuronal cell types. Moreover, sox-2 and sox-3 have selective roles in the terminal differentiation of specific neuronal cell types. Our findings suggest that the common themes of SoxB gene function across phylogeny lie in specifying developmental potential and, later on, in selectively controlling terminal differentiation programs of specific neuron types, but not in broadly controlling neurogenesis.
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Affiliation(s)
- Berta Vidal
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, NY 10032, USA
| | - Anthony Santella
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Esther Serrano-Saiz
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, NY 10032, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Oliver Hobert
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, NY 10032, USA
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Minor PJ, He TF, Sohn CH, Asthagiri AR, Sternberg PW. FGF signaling regulates Wnt ligand expression to control vulval cell lineage polarity in C. elegans. Development 2013; 140:3882-91. [PMID: 23946444 DOI: 10.1242/dev.095687] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The interpretation of extracellular cues leading to the polarization of intracellular components and asymmetric cell divisions is a fundamental part of metazoan organogenesis. The Caenorhabditis elegans vulva, with its invariant cell lineage and interaction of multiple cell signaling pathways, provides an excellent model for the study of cell polarity within an organized epithelial tissue. Here, we show that the fibroblast growth factor (FGF) pathway acts in concert with the Frizzled homolog LIN-17 to influence the localization of SYS-1, a component of the Wnt/β-catenin asymmetry pathway, indirectly through the regulation of cwn-1. The source of the FGF ligand is the primary vulval precursor cell (VPC) P6.p, which controls the orientation of the neighboring secondary VPC P7.p by signaling through the sex myoblasts (SMs), activating the FGF pathway. The Wnt CWN-1 is expressed in the posterior body wall muscle of the worm as well as in the SMs, making it the only Wnt expressed on the posterior and anterior sides of P7.p at the time of the polarity decision. Both sources of cwn-1 act instructively to influence P7.p polarity in the direction of the highest Wnt signal. Using single molecule fluorescence in situ hybridization, we show that the FGF pathway regulates the expression of cwn-1 in the SMs. These results demonstrate an interaction between FGF and Wnt in C. elegans development and vulval cell lineage polarity, and highlight the promiscuous nature of Wnts and the importance of Wnt gradient directionality within C. elegans.
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Affiliation(s)
- Paul J Minor
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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The role of SRY-related HMG box transcription factor 4 (SOX4) in tumorigenesis and metastasis: friend or foe? Oncogene 2012; 32:3397-409. [PMID: 23246969 DOI: 10.1038/onc.2012.506] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/18/2012] [Accepted: 09/18/2012] [Indexed: 12/29/2022]
Abstract
Development and progression of cancer are mediated by alterations in transcriptional networks, resulting in a disturbed balance between the activity of oncogenes and tumor suppressor genes. Transcription factors have the capacity to regulate global transcriptional profiles, and are consequently often found to be deregulated in their expression and function during tumorigenesis. Sex-determining region Y-related high-mobility-group box transcription factor 4 (SOX4) is a member of the group C subfamily of the SOX transcription factors and has a critical role during embryogenesis, where its expression is widespread and controls the development of numerous tissues. SOX4 expression is elevated in a wide variety of tumors, including leukemia, colorectal cancer, lung cancer and breast cancer, suggesting a fundamental role in the development of these malignancies. In many cancers, deregulated expression of this developmental factor has been correlated with increased cancer cell proliferation, cell survival, inhibition of apoptosis and tumor progression through the induction of an epithelial-to-mesenchymal transition and metastasis. However, in a limited subset of tumors, SOX4 has also been reported to act as a tumor suppressor. These opposing roles suggest that the outcome of SOX4 activation depends on the cellular context and the tumor origin. Indeed, SOX4 expression, transcriptional activity and target gene specificity can be controlled by signaling pathways, including the transforming growth factor-β and the WNT pathway, as well as at the post-translational level through regulation of protein stability and interaction with specific cofactors, such as TCF, syntenin-1 and p53. Here, we provide an overview of our current knowledge concerning the role of SOX4 in tumor development and progression.
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Krause M, Liu J. Somatic muscle specification during embryonic and post-embryonic development in the nematode C. elegans. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2011; 1:203-14. [PMID: 23801436 DOI: 10.1002/wdev.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Myogenesis has proved to be a powerful paradigm for understanding cell fate specification and differentiation in many model organisms. Studies of somatic bodywall muscle (BWM) development in Caenorhabditis elegans allow us to define, with single cell resolution, the distinct hierarchies of transcriptional regulators needed for myogenesis throughout development. Although all 95 BWM cells appear uniform after differentiation, there are several different regulatory cascades employed embryonically and post-embryonically. These, in turn, are integrated into multiple extrinsic cell signaling events. The convergence of these different pathways on the key nodal point, that is the activation of the core muscle module, commits individual cells to myogenesis. Comparisons of myogenesis between C. elegans and other model systems provide insights into the evolution of contractile cell types, demonstrating the conservation of regulatory schemes for muscles throughout the animal kingdom.
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Affiliation(s)
- Michael Krause
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA.
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