1
|
Zeng Z, Ni J, Huang Z, Tan Q. Expression and functional analysis of Fushi Tarazu transcription factor 1 (FTZ-F1) in the regulation of steroid hormones during the gonad development of Fujian Oyster, Crassostrea angulata. Comp Biochem Physiol A Mol Integr Physiol 2024; 295:111668. [PMID: 38797241 DOI: 10.1016/j.cbpa.2024.111668] [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: 04/29/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
Crassostrea angulata, a major shellfish cultivated in Southern China, has experienced a notable surge in commercial value in recent years. Understanding the molecular mechanisms governing their reproductive processes holds significant implications for advancing aquaculture practices. In this study, we cloned the orphan nuclear receptor gene, Fushi Tarazu transcription factor 1 (FTZ-F1), of C. angulata and investigated its functional role in the gonadal development. The full-length cDNA of FTZ-F1 spans 2357 bp and encodes a protein sequence of 530 amino acids. Notably, the amino acid sequence of FTZ-F1 in C. angulata shares remarkable similarity with its homologues in other species, particularly in the DNA-binding region (>90%) and ligand-binding region (>44%). In C. angulata, the highest expression level of FTZ-F1 was observed in the ovary, exhibiting more than a 200-fold increase during the maturation stage compared to the initiation stage (P < 0.001). Specifically, FTZ-F1 was mainly expressed in the follicular cells surrounding the oocytes of C. angulata. Upon inhibiting FTZ-F1 gene expression in C. angulata through RNA interference (RNAi), a substantial reduction in the expression of genes involved in the synthesis of sex steroids in the gonads, including 3β-HSD, Cyp17, and follistatin, was observed. In addition, estradiol (E2) and testosterone (T) levels also showed a decrease upon FTZ-F1 silencing, resulting in a delayed gonadal development. These results indicate that FTZ-F1 acts as a steroidogenic factor, participating in the synthesis and regulation of steroid hormones and thus playing an important role in the reproductive and endocrine systems within oysters.
Collapse
Affiliation(s)
- Zhen Zeng
- Xiamen Key Laboratory of Marine Medicinal Natural Products Resources, Xiamen Medical College, Xiamen 361023, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
| | - Jianbin Ni
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
| | - Zixia Huang
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Qianglai Tan
- Xiamen Key Laboratory of Marine Medicinal Natural Products Resources, Xiamen Medical College, Xiamen 361023, China.
| |
Collapse
|
2
|
Binti S, Edeen PT, Fay DS. Loss of the Na + /K + cation pump CATP-1 suppresses nekl -associated molting defects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.585189. [PMID: 38559007 PMCID: PMC10979969 DOI: 10.1101/2024.03.15.585189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The conserved C. elegans protein kinases NEKL-2 and NEKL-3 regulate multiple steps of membrane trafficking and are required for larval molting. Through a forward genetic screen we identified a loss-of-function mutation in catp-1 as a suppressor of molting defects in synthetically lethal nekl-2; nekl-3 double mutants. catp-1 is predicted to encode a membrane- associated P4-type ATPase involved in Na + -K + exchange. Moreover, a mutation predicted to abolish CATP-1 ion-pump activity also suppressed nekl-2; nekl-3 mutants. Endogenously tagged CATP-1 was primarily expressed in epidermal (hypodermal) cells within punctate structures located at or near the apical plasma membrane. Through whole genome sequencing, we identified two additional nekl-2; nekl-3 suppressor strains containing coding-altering mutations in catp-1 but found that neither mutation, when introduced into nekl-2; nekl-3 mutants using CRISPR methods, was sufficient to elicit robust suppression of molting defects. Our data also suggested that the two catp-1 isoforms, catp-1a and catp-1b , may in some contexts be functionally redundant. On the basis of previously published studies, we tested the hypothesis that loss of catp-1 may suppress nekl -associated defects by inducing partial entry into the dauer pathway. Contrary to expectations, however, we failed to obtain evidence that loss of catp-1 suppresses nekl-2; nekl-3 defects through a dauer-associated mechanism or that loss of catp-1 leads to entry into the pre-dauer L2d stage. As such, loss of catp-1 may suppress nekl- associated molting and membrane trafficking defects by altering electrochemical gradients within membrane-bound compartments.
Collapse
|
3
|
Nyaanga J, Andersen EC. Linkage mapping reveals loci that underlie differences in Caenorhabditis elegans growth. G3 GENES|GENOMES|GENETICS 2022; 12:6663991. [PMID: 35961034 PMCID: PMC9526057 DOI: 10.1093/g3journal/jkac207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/05/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Growth rate and body size are complex traits that contribute to the fitness of organisms. The identification of loci that underlie differences in these traits provides insights into the genetic contributions to development. Leveraging Caenorhabditis elegans as a tractable metazoan model for quantitative genetics, we can identify genomic regions that underlie differences in growth. We measured postembryonic growth of the laboratory-adapted wild-type strain (N2) and a wild strain from Hawaii (CB4856) and found differences in body size. Using linkage mapping, we identified three distinct quantitative trait loci (QTL) on chromosomes IV, V, and X that are associated with variation in body growth. We further examined these growth-associated quantitative trait loci using chromosome substitution strains and near-isogenic lines and validated the chromosome X quantitative trait loci. In addition, we generated a list of candidate genes for the chromosome X quantitative trait loci. These genes could potentially contribute to differences in animal growth and should be evaluated in subsequent studies. Our work reveals the genetic architecture underlying animal growth variation and highlights the genetic complexity of growth in Caenorhabditis elegans natural populations.
Collapse
Affiliation(s)
- Joy Nyaanga
- Department of Molecular Biosciences, Northwestern University , Evanston, IL 60208, USA
- Interdisciplinary Biological Sciences Program, Northwestern University , Evanston, IL 60208, USA
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University , Evanston, IL 60208, USA
| |
Collapse
|
4
|
Wu YZ, Jiang HS, Han HF, Li PH, Lu MR, Tsai IJ, Wu YC. C. elegans BLMP-1 controls apical epidermal cell morphology by repressing expression of mannosyltransferase bus-8 and molting signal mlt-8. Dev Biol 2022; 486:96-108. [DOI: 10.1016/j.ydbio.2022.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/17/2022] [Accepted: 03/29/2022] [Indexed: 11/26/2022]
|
5
|
Binti S, Melinda RV, Joseph BB, Edeen PT, Miller SD, Fay DS. A life cycle alteration can correct molting defects in Caenorhabditis elegans. Dev Biol 2022; 483:143-156. [PMID: 35038442 PMCID: PMC8867747 DOI: 10.1016/j.ydbio.2022.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/21/2021] [Accepted: 01/03/2022] [Indexed: 11/28/2022]
Abstract
Molting is a widespread feature in the development of many invertebrates, including nematodes and arthropods. In Caenorhabditis elegans, the highly conserved protein kinases NEKL-2/NEK8/9 and NEKL-3/NEK6/7 (NEKLs) promote molting through their involvement in the uptake and intracellular trafficking of epidermal cargos. We found that the relative requirements for NEKL-2 and NEKL-3 differed at different life-cycle stages and under different environmental conditions. Most notably, the transition from the second to the third larval stage (L2→L3 molt) required a higher level of NEKL function than during several other life stages or when animals had experienced starvation at the L1 stage. Specifically, larvae that entered the pre-dauer L2d stage could escape molting defects when transiting to the (non-dauer) L3 stage. Consistent with this, mutations that promote entry into L2d suppressed nekl-associated molting defects, whereas mutations that inhibit L2d entry reduced starvation-mediated suppression. We further showed that loss or reduction of NEKL functions led to defects in the transcription of cyclically expressed molting genes, many of which are under the control of systemic steroid hormone regulation. Moreover, the timing and severity of these transcriptional defects correlated closely with the strength of nekl alleles and with their stage of arrest. Interestingly, transit through L2d rescued nekl-associated expression defects in suppressed worms, providing an example of how life-cycle decisions can impact subsequent developmental events. Given that NEKLs are implicated in the uptake of sterols by the epidermis, we propose that loss of NEKLs leads to a physiological reduction in steroid-hormone signaling and consequent defects in the transcription of genes required for molting.
Collapse
Affiliation(s)
- Shaonil Binti
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA
| | - Rosa V Melinda
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA
| | - Braveen B Joseph
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA
| | - Phillip T Edeen
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA
| | - Sam D Miller
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA
| | - David S Fay
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, 82071, USA.
| |
Collapse
|
6
|
A 4D single-cell protein atlas of transcription factors delineates spatiotemporal patterning during embryogenesis. Nat Methods 2021; 18:893-902. [PMID: 34312566 DOI: 10.1038/s41592-021-01216-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/17/2021] [Indexed: 12/27/2022]
Abstract
Complex biological processes such as embryogenesis require precise coordination of cell differentiation programs across both space and time. Using protein-fusion fluorescent reporters and four-dimensional live imaging, we present a protein expression atlas of transcription factors (TFs) mapped onto developmental cell lineages during Caenorhabditis elegans embryogenesis, at single-cell resolution. This atlas reveals a spatiotemporal combinatorial code of TF expression, and a cascade of lineage-specific, tissue-specific and time-specific TFs that specify developmental states. The atlas uncovers regulators of embryogenesis, including an unexpected role of a skin specifier in neurogenesis and the critical function of an uncharacterized TF in convergent muscle differentiation. At the systems level, the atlas provides an opportunity to model cell state-fate relationships, revealing a lineage-dependent state diversity within functionally related cells and a winding trajectory of developmental state progression. Collectively, this single-cell protein atlas represents a valuable resource for elucidating metazoan embryogenesis at the molecular and systems levels.
Collapse
|
7
|
The FTZ-F1 gene encodes two functionally distinct nuclear receptor isoforms in the ectoparasitic copepod salmon louse (Lepeophtheirus salmonis). PLoS One 2021; 16:e0251575. [PMID: 34014986 PMCID: PMC8136749 DOI: 10.1371/journal.pone.0251575] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 04/29/2021] [Indexed: 01/21/2023] Open
Abstract
The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic crustacean that annually inflicts substantial losses to the aquaculture industry in the northern hemisphere and poses a threat to the wild populations of salmonids. The salmon louse life cycle consists of eight developmental stages each separated by a molt. Fushi Tarazu Factor-1 (FTZ-F1) is an ecdysteroid-regulated gene that encodes a member of the NR5A family of nuclear receptors that is shown to play a crucial regulatory role in molting in insects and nematodes. Characterization of an FTZ-F1 orthologue in the salmon louse gave two isoforms named αFTZ-F1 and βFTZ-F1, which are identical except for the presence of a unique N-terminal domain (A/B domain). A comparison suggest conservation of the FTZ-F1 gene structure among ecdysozoans, with the exception of nematodes, to produce isoforms with unique N-terminal domains through alternative transcription start and splicing. The two isoforms of the salmon louse FTZ-F1 were expressed in different amounts in the same tissues and showed a distinct cyclical expression pattern through the molting cycle with βFTZ-F1 being the highest expressed isoform. While RNA interference knockdown of βFTZ-F1 in nauplius larvae and in pre-adult males lead to molting arrest, knockdown of βFTZ-F1 in pre-adult II female lice caused disruption of oocyte maturation at the vitellogenic stage. No apparent phenotype could be observed in αFTZ-F1 knockdown larvae, or in their development to adults, and no genes were found to be differentially expressed in the nauplii larvae following αFTZ-F1 knockdown. βFTZ-F1 knockdown in nauplii larvae caused both down and upregulation of genes associated with proteolysis and chitin binding and affected a large number of genes which are in normal salmon louse development expressed in a cyclical pattern. This is the first description of FTZ-F1 gene function in copepod crustaceans and provides a foundation to expand the understanding of the molecular mechanisms of molting in the salmon louse and other copepods.
Collapse
|
8
|
Yuan H, Zhang W, Fu Y, Jiang S, Xiong Y, Zhai S, Gong Y, Qiao H, Fu H, Wu Y. MnFtz-f1 Is Required for Molting and Ovulation of the Oriental River Prawn Macrobrachium nipponense. Front Endocrinol (Lausanne) 2021; 12:798577. [PMID: 34987481 PMCID: PMC8721877 DOI: 10.3389/fendo.2021.798577] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/01/2021] [Indexed: 11/13/2022] Open
Abstract
Molting and ovulation are the basic processes responsible for the growth and reproduction of Macrobrachium nipponense; however, the molecular mechanisms of molting and ovulation in M. nipponense are poorly understood. The present study aimed to use MnFtz-f1 as the starting point to study the molting and ovulation phenomena in M. nipponense at the molecular level. The full-length MnFtz-f1 cDNA sequence was 2,198 base pairs (bp) in length with an open reading frame of 1,899 bp encoding 632 amino acids. Quantitative real-time PCR analysis showed that MnFtz-f1 was highly expressed in the ovary at the cleavage stage and on the fifth day after hatching. In vivo administration of 20-hydroxyecdysone (20E) showed that 20E effectively inhibited the expression of the MnFtz-f1 gene, and the silencing of the MnFtz-f1 gene reduced the content of 20E in the ovary. In situ hybridization (ISH) analysis revealed the localization of MnFtz-f1 in the ovary. Silencing of MnFtz-f1 by RNA interference (RNAi) resulted in significant inhibition of the expression of the vitellogenin (Vg), Spook, and Phantom genes, thus confirming that MnFtz-f1 had a mutual regulatory relationship with Vg, Spook, and Phantom. After RNAi, the molting frequency and ovulation number of M. nipponense decreased significantly, which demonstrated that MnFtz-f1 played a pivotal role in the process of molting and ovulation.
Collapse
Affiliation(s)
- Huwei Yuan
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yin Fu
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, China
| | - Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Shuhua Zhai
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yongsheng Gong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- *Correspondence: Hui Qiao, ; Hongtuo Fu,
| | - Hongtuo Fu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- *Correspondence: Hui Qiao, ; Hongtuo Fu,
| | - Yan Wu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| |
Collapse
|
9
|
Martinez MAQ, Kinney BA, Medwig-Kinney TN, Ashley G, Ragle JM, Johnson L, Aguilera J, Hammell CM, Ward JD, Matus DQ. Rapid Degradation of Caenorhabditis elegans Proteins at Single-Cell Resolution with a Synthetic Auxin. G3 (BETHESDA, MD.) 2020; 10:267-280. [PMID: 31727633 PMCID: PMC6945041 DOI: 10.1534/g3.119.400781] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/12/2019] [Indexed: 12/20/2022]
Abstract
As developmental biologists in the age of genome editing, we now have access to an ever-increasing array of tools to manipulate endogenous gene expression. The auxin-inducible degradation system allows for spatial and temporal control of protein degradation via a hormone-inducible Arabidopsis F-box protein, transport inhibitor response 1 (TIR1). In the presence of auxin, TIR1 serves as a substrate-recognition component of the E3 ubiquitin ligase complex SKP1-CUL1-F-box (SCF), ubiquitinating auxin-inducible degron (AID)-tagged proteins for proteasomal degradation. Here, we optimize the Caenorhabditis elegans AID system by utilizing 1-naphthaleneacetic acid (NAA), an indole-free synthetic analog of the natural auxin indole-3-acetic acid (IAA). We take advantage of the photostability of NAA to demonstrate via quantitative high-resolution microscopy that rapid degradation of target proteins can be detected in single cells within 30 min of exposure. Additionally, we show that NAA works robustly in both standard growth media and physiological buffer. We also demonstrate that K-NAA, the water-soluble, potassium salt of NAA, can be combined with microfluidics for targeted protein degradation in C. elegans larvae. We provide insight into how the AID system functions in C. elegans by determining that TIR1 depends on C. elegans SKR-1/2, CUL-1, and RBX-1 to degrade target proteins. Finally, we present highly penetrant defects from NAA-mediated degradation of the FTZ-F1 nuclear hormone receptor, NHR-25, during C. elegans uterine-vulval development. Together, this work improves our use and understanding of the AID system for dissecting gene function at the single-cell level during C. elegans development.
Collapse
Affiliation(s)
- Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794
| | - Brian A Kinney
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, and
| | - Taylor N Medwig-Kinney
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794
| | - Guinevere Ashley
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064
| | - James M Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064
| | - Londen Johnson
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064
| | - Joseph Aguilera
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064
| | | | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794,
| |
Collapse
|
10
|
Issigonis M, Newmark PA. From worm to germ: Germ cell development and regeneration in planarians. Curr Top Dev Biol 2019; 135:127-153. [DOI: 10.1016/bs.ctdb.2019.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
11
|
Zuo H, Yang L, Zheng J, Su Z, Weng S, He J, Xu X. A single C4 Zinc finger-containing protein from Litopenaeus vannamei involved in antibacterial responses. FISH & SHELLFISH IMMUNOLOGY 2018; 81:493-501. [PMID: 30064017 DOI: 10.1016/j.fsi.2018.07.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/18/2018] [Accepted: 07/27/2018] [Indexed: 06/08/2023]
Abstract
The Zinc finger domains (ZnFs), which contain finger-like protrusions stabilized by zinc ions and function to bind DNA, RNA, protein and lipid substrates, are ubiquitously present in a large number of proteins. In this study, a novel protein containing a single C4 type Znf domain (SZnf) was identified from Pacific white shrimp, Litopenaeus vannamei and its role in immunity was further investigated. The ZnF domain of SZnF but not other regions shared high homology with those of fushi tarazu-factor 1 (FTZ-F1) proteins. The SZnF protein was mainly localized in the cytoplasm and was also present in the nucleus at a small level. SZnF was high expressed in the scape and muscle tissues of healthy shrimp and its expression in gill and heptopancreas was strongly up-regulated during bacterial infection. Silencing of SZnf in vivo could strongly increase the susceptibility of shrimp to infection with Vibrio parahaemolyticus but not white spot syndrome virus (WSSV), suggesting that SZnf could be mainly involved in antibacterial responses. Both dual luciferase reporter assays and real-time PCR analysis demonstrated that SZnf could positively regulate the expression of various antimicrobial peptides in vitro and in vivo, which could be part of the mechanism underlying its antibacterial effects. In summary, the current study could help learn more about the function of ZnF-containing proteins and the regulatory mechanisms of immune responses against pathogen infection in crustaceans.
Collapse
Affiliation(s)
- Hongliang Zuo
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Linwei Yang
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jiefu Zheng
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Ziqi Su
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Shaoping Weng
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jianguo He
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China.
| | - Xiaopeng Xu
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China.
| |
Collapse
|
12
|
Metheetrairut C, Ahuja Y, Slack FJ. acn-1, a C. elegans homologue of ACE, genetically interacts with the let-7 microRNA and other heterochronic genes. Cell Cycle 2017; 16:1800-1809. [PMID: 28933985 DOI: 10.1080/15384101.2017.1344798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The heterochronic pathway in C. elegans controls the relative timing of cell fate decisions during post-embryonic development. It includes a network of microRNAs (miRNAs), such as let-7, and protein-coding genes, such as the stemness factors, LIN-28 and LIN-41. Here we identified the acn-1 gene, a homologue of mammalian angiotensin-converting enzyme (ACE), as a new suppressor of the stem cell developmental defects of let-7 mutants. Since acn-1 null mutants die during early larval development, we used RNAi to characterize the role of acn-1 in C. elegans seam cell development, and determined its interaction with heterochronic factors, including let-7 and its downstream interactors - lin-41, hbl-1, and apl-1. We demonstrate that although RNAi knockdown of acn-1 is insufficient to cause heterochronic defects on its own, loss of acn-1 suppresses the retarded phenotypes of let-7 mutants and enhances the precocious phenotypes of hbl-1, though not lin-41, mutants. Conversely, the pattern of acn-1 expression, which oscillates during larval development, is disrupted by lin-41 mutants but not by hbl-1 mutants. Finally, we show that acn-1(RNAi) enhances the let-7-suppressing phenotypes caused by loss of apl-1, a homologue of the Alzheimer's disease-causing amyloid precursor protein (APP), while significantly disrupting the expression of apl-1 during the L4 larval stage. In conclusion, acn-1 interacts with heterochronic genes and appears to function downstream of let-7 and its target genes, including lin-41 and apl-1.
Collapse
Affiliation(s)
- Chanatip Metheetrairut
- a Department of Molecular, Cellular, and Developmental Biology , Yale University , New Haven , CT , USA
| | - Yuri Ahuja
- a Department of Molecular, Cellular, and Developmental Biology , Yale University , New Haven , CT , USA
| | - Frank J Slack
- a Department of Molecular, Cellular, and Developmental Biology , Yale University , New Haven , CT , USA
| |
Collapse
|
13
|
Rashid S, MacNeil LT. Packing on the Pounds in Response to Bacterial Growth Conditions. Dev Cell 2017; 41:335-336. [PMID: 28535369 DOI: 10.1016/j.devcel.2017.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Reporting in Nature Cell Biology, Lin and Wang (2017) show that bacterial methyl metabolism impacts host mitochondrial dynamics and lipid storage in C. elegans. The authors propose a model whereby bacterial metabolic products regulate a nuclear hormone receptor that promotes lipid accumulation through expression of a secreted Hedgehog-like protein.
Collapse
Affiliation(s)
- Sabih Rashid
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Lesley T MacNeil
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada; Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON L8S 4K1, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4K1, Canada.
| |
Collapse
|
14
|
Lažetić V, Fay DS. Molting in C. elegans. WORM 2017; 6:e1330246. [PMID: 28702275 DOI: 10.1080/21624054.2017.1330246] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/01/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022]
Abstract
Molting is an essential developmental process for the majority of animal species on Earth. During the molting process, which is a specialized form of extracellular matrix (ECM) remodeling, the old apical ECM, or cuticle, is replaced with a new one. Many of the genes and pathways identified as important for molting in nematodes are highly conserved in vertebrates and include regulators and components of vesicular trafficking, steroid-hormone signaling, developmental timers, and hedgehog-like signaling. In this review, we discuss what is known about molting, with a focus on studies in Caenorhabditis elegans. We also describe the key structural elements of the cuticle that must be released, newly synthesized, or remodeled for proper molting to occur.
Collapse
Affiliation(s)
- Vladimir Lažetić
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, USA
| | - David S Fay
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, USA
| |
Collapse
|
15
|
Bodofsky S, Koitz F, Wightman B. CONSERVED AND EXAPTED FUNCTIONS OF NUCLEAR RECEPTORS IN ANIMAL DEVELOPMENT. NUCLEAR RECEPTOR RESEARCH 2017; 4:101305. [PMID: 29333434 PMCID: PMC5761748 DOI: 10.11131/2017/101305] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nuclear receptor gene family includes 18 members that are broadly conserved among multiple disparate animal phyla, indicating that they trace their evolutionary origins to the time at which animal life arose. Typical nuclear receptors contain two major domains: a DNA-binding domain and a C-terminal domain that may bind a lipophilic hormone. Many of these nuclear receptors play varied roles in animal development, including coordination of life cycle events and cellular differentiation. The well-studied genetic model systems of Drosophila, C. elegans, and mouse permit an evaluation of the extent to which nuclear receptor function in development is conserved or exapted (repurposed) over animal evolution. While there are some specific examples of conserved functions and pathways, there are many clear examples of exaptation. Overall, the evolutionary theme of exaptation appears to be favored over strict functional conservation. Despite strong conservation of DNA-binding domain sequences and activity, the nuclear receptors prove to be highly-flexible regulators of animal development.
Collapse
Affiliation(s)
- Shari Bodofsky
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Francine Koitz
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Bruce Wightman
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| |
Collapse
|
16
|
Xie QP, He X, Sui YN, Chen LL, Sun LN, Wang DS. Haploinsufficiency of SF-1 Causes Female to Male Sex Reversal in Nile Tilapia, Oreochromis niloticus. Endocrinology 2016; 157:2500-14. [PMID: 27046435 DOI: 10.1210/en.2015-2049] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Steroidogenic factor-1 (Sf-1) (officially designated nuclear receptor subfamily 5 group A member 1 [NR5A1]) is a master regulator of steroidogenesis and reproduction in mammals. However, its function remains unclear in nonmammalian vertebrates. In the present study, we used immunohistochemistry to detect expression of Sf-1 in the steroidogenic cells, the interstitial, granulosa, and theca cells of the ovary, and the Leydig cells of the testis, in Nile tilapia. Clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (Cas9) cleavage of sf-1 resulted in a high mutation rate in the F0 generation and a phenotype of gonadal dysgenesis and reduced steroidogenic cells in XX and XY fish. Sf-1 deficiency also resulted in decreased cytochrome P450, family 19, subfamily A, polypeptide 1a, forkhead box L2 expression, and serum estradiol-17β in XX fish. In XY fish, Sf-1 deficiency increased cytochrome P450, family 19, subfamily A, polypeptide 1a and forkhead box L2 expression but decreased cytochrome P450, family 11, subfamily B, polypeptide 2 expression and serum 11-ketotestosterone levels. 17α-methyltestosterone treatment successfully rescued the gonadal phenotype of Sf-1-deficient XY fish, as demonstrated by normal spermatogenesis and production of F1 mutants. In contrast, estradiol-17β treatment only partially rescued the gonadal phenotype of Sf-1-deficient XX fish, as demonstrated by the appearance of phase II oocytes. Furthermore, both sf-1(+/-) F1 XX and XY mutants developed as fertile males, although spermatogenesis was delayed and efferent duct formation was disordered. Our data suggest that Sf-1 is a major regulator of steroidogenesis and reproduction in fish, as it is in mammals. Sf-1 deficiency resulted in gonadal dysgenesis and feminization of XY gonads. However, unlike in mammals, Sf-1 deficiency also resulted in female to male sex reversal in 8.1% of F0 and 92.1% of sf-1(+/-) F1 in XX fish.
Collapse
Affiliation(s)
- Qing-Ping Xie
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| | - Xue He
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| | - Yi-Ning Sui
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| | - Li-Li Chen
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| | - Li-Na Sun
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| | - De-Shou Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, 400715 Chongqing, People's Republic of China
| |
Collapse
|
17
|
Ondrovics M, Gasser RB, Joachim A. Recent Advances in Elucidating Nematode Moulting - Prospects of Using Oesophagostomum dentatum as a Model. ADVANCES IN PARASITOLOGY 2015; 91:233-64. [PMID: 27015950 DOI: 10.1016/bs.apar.2015.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that understanding such processes could lead to new ways of treating and controlling parasitic diseases via the disruption of one or more biological pathways in the parasites. Progress in genomics, transcriptomics, proteomics and bioinformatics now provides unique opportunities to investigate the molecular basis of key developmental processes in parasitic nematodes. The porcine nodule worm, Oesophagostomum dentatum, represents a large order (Strongylida) of socioeconomically important nematodes, and provides a useful platform for exploring molecular developmental processes, particularly given that this nematode can be grown and maintained in culture in vitro for periods longer than most other nematodes of this order. In this article, we focus on the moulting process (ecdysis) in nematodes; review recent advances in our understanding of molecular aspects of moulting in O. dentatum achieved by using integrated proteomic-bioinformatic tools and discuss key implications and future prospects for research in this area, also with respect to developing new anti-nematode interventions and biotechnological outcomes.
Collapse
Affiliation(s)
- Martina Ondrovics
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| |
Collapse
|
18
|
DeLalio LJ, Dion SM, Bootes AM, Smith WA. Direct effects of hypoxia and nitric oxide on ecdysone secretion by insect prothoracic glands. JOURNAL OF INSECT PHYSIOLOGY 2015; 76:56-66. [PMID: 25747870 DOI: 10.1016/j.jinsphys.2015.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 02/19/2015] [Accepted: 02/22/2015] [Indexed: 06/04/2023]
Abstract
Insect molting and metamorphosis are controlled by the molt stimulating hormone ecdysone. A recent study suggests that reduced tissue oxygenation correlates with the size-sensing mechanism responsible for triggering molting. When reared in hypoxia, larvae of Manduca sexta and Drosophila melanogaster initiate molting at lower weights than do larvae reared in normoxia. Furthermore, in Drosophila, the signaling gas nitric oxide (NO) appears to be required for normal developmental timing. As observed in Drosophila, NO signaling targets the nuclear hormone receptor beta fushi tarazu transcription factor 1 (βFTZ-F1) through activation of Drosophila hormone receptor 3 (DHR3), two key regulators of ecdysone production and metamorphic tissue progression. We set out to directly examine the effects of hypoxia and NO on ecdysone secretion using prothoracic glands from feeding fifth (last) larval stage M. sexta. Our results indicate that in vitro treatment of prothoracic glands with hypoxia (2% oxygen) or the NO donor DETA-NONOate significantly inhibit ecdysone secretion. Protein markers of glandular activity were also in keeping with an initial inhibition, measured a decrease in phosphorylated ERK (extracellular signal regulated kinase) and an increase in non-phosphorylated 4EBP (eukaryotic initiation factor 4E binding protein). Additionally, gene expression levels of Manduca hormone receptor 3 (mhr3), βftz-f1, nitric oxide synthase (nos), and the PTTH receptor torso, were quantified using real-time PCR. NO treatment increased mhr3 expression and decreased nos expression. Hypoxia increased mhr3 transcription after 2 hr, but decreased transcription after 12 hr, with no effect on nos expression. Both NO and hypoxia had small effects on βftz-f1 expression, yet strongly increased torso transcription. Our results demonstrate that, in isolated prothoracic glands, hypoxia and NO signaling directly inhibit ecdysteroid secretion, but at the same time alter aspects of prothoracic gland function that may enhance secretory response.
Collapse
Affiliation(s)
- Leon J DeLalio
- Department of Biology, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Sara M Dion
- Department of Biology, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Abigail M Bootes
- Department of Biology, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Wendy A Smith
- Department of Biology, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA 02115, USA.
| |
Collapse
|
19
|
Rapid and precise engineering of the Caenorhabditis elegans genome with lethal mutation co-conversion and inactivation of NHEJ repair. Genetics 2014; 199:363-77. [PMID: 25491644 PMCID: PMC4317648 DOI: 10.1534/genetics.114.172361] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
As in other organisms, CRISPR/Cas9 methods provide a powerful approach for genome editing in the nematode Caenorhabditis elegans. Oligonucleotides are excellent repair templates for introducing substitutions and short insertions, as they are cost effective, require no cloning, and appear in other organisms to target changes by homologous recombination at DNA double-strand breaks (DSBs). Here, I describe a methodology in C. elegans to efficiently knock in epitope tags in 8–9 days, using a temperature-sensitive lethal mutation in the pha-1 gene as a co-conversion marker. I demonstrate that 60mer oligos with 29 bp of homology drive efficient knock-in of point mutations, and that disabling nonhomologous end joining by RNAi inactivation of the cku-80 gene significantly improves knock-in efficiency. Homology arms of 35–80 bp are sufficient for efficient editing and DSBs up to 54 bp away from the insertion site produced knock-ins. These findings will likely be applicable for a range of genome editing approaches in C. elegans, which will improve editing efficiency and minimize screening efforts.
Collapse
|
20
|
A lophotrochozoan-specific nuclear hormone receptor is required for reproductive system development in the planarian. Dev Biol 2014; 396:150-7. [PMID: 25278423 DOI: 10.1016/j.ydbio.2014.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/19/2014] [Accepted: 09/21/2014] [Indexed: 11/24/2022]
Abstract
Germ cells of sexually reproducing organisms receive an array of cues from somatic tissues that instruct developmental processes. Although the nature of these signals differs amongst organisms, the importance of germline-soma interactions is a common theme. Recently, peptide hormones from the nervous system have been shown to regulate germ cell development in the planarian Schmidtea mediterranea; thus, we sought to investigate a second class of hormones with a conserved role in reproduction, the lipophilic hormones. In order to study these signals, we identified a set of putative lipophilic hormone receptors, known as nuclear hormone receptors, and analyzed their functions in reproductive development. We found one gene, nhr-1, belonging to a small class of functionally uncharacterized lophotrochozoan-specific receptors, to be essential for the development of differentiated germ cells. Upon nhr-1 knockdown, germ cells in the testes and ovaries fail to mature, and remain as undifferentiated germline stem cells. Further analysis revealed that nhr-1 mRNA is expressed in the accessory reproductive organs and is required for their development, suggesting that this transcription factor functions cell non-autonomously in regulating germ cell development. Our studies identify a role for nuclear hormone receptors in planarian reproductive maturation and reinforce the significance of germline-soma interactions in sexual reproduction across metazoans.
Collapse
|
21
|
Xu C, Su Z. Identification of genes driving lineage divergence from single-cell gene expression data in C. elegans. Dev Biol 2014; 393:236-244. [PMID: 25050933 DOI: 10.1016/j.ydbio.2014.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 11/25/2022]
Abstract
The nematode Caenorhabditis elegans (C. elegans) is an ideal model organism to study the cell fate specification mechanisms during embryogenesis. It is generally believed that cell fate specification in C. elegans is mainly mediated by lineage-based mechanisms, where the specification paths are driven forward by a succession of asymmetric cell divisions. However, little is known about how each binary decision is made by gene regulatory programs. In this study, we endeavor to obtain a global understanding of cell lineage/fate divergence processes during the early embryogenesis of C. elegans. We reanalyzed the EPIC data set, which traced the expression level of reporter genes at single-cell resolution on a nearly continuous time scale up to the 350-cell stage in C. elegans embryos. We examined the expression patterns for a total of 131 genes from 287 embryos with high quality image recordings, among which 86 genes have replicate embryos. Our results reveal that during early embryogenesis, divergence between sister lineages could be largely explained by a few genes. We predicted genes driving lineage divergence and explored their expression patterns in sister lineages. Moreover, we found that divisions leading to fate divergence are associated with a large number of genes being differentially expressed between sister lineages. Interestingly, we found that the developmental paths of lineages could be differentiated by a small set of genes. Therefore, our results support the notion that the cell fate patterns in C. elegans are achieved through stepwise binary decisions punctuated by cell divisions. Our predicted genes driving lineage divergence provide good starting points for future detailed characterization of their roles in the embryogenesis in this important model organism.
Collapse
Affiliation(s)
- Chen Xu
- Department of Bioinformatics and Genomics, The University of North Carolina at Charlotte, 351 Bioinformatics Building, 9201 University City Blvd, Charlotte, NC 28223, USA.
| | - Zhengchang Su
- Department of Bioinformatics and Genomics, The University of North Carolina at Charlotte, 351 Bioinformatics Building, 9201 University City Blvd, Charlotte, NC 28223, USA.
| |
Collapse
|
22
|
Alexander AG, Marfil V, Li C. Use of Caenorhabditis elegans as a model to study Alzheimer's disease and other neurodegenerative diseases. Front Genet 2014; 5:279. [PMID: 25250042 PMCID: PMC4155875 DOI: 10.3389/fgene.2014.00279] [Citation(s) in RCA: 189] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/31/2014] [Indexed: 12/12/2022] Open
Abstract
Advances in research and technology has increased our quality of life, allowed us to combat diseases, and achieve increased longevity. Unfortunately, increased longevity is accompanied by a rise in the incidences of age-related diseases such as Alzheimer’s disease (AD). AD is the sixth leading cause of death, and one of the leading causes of dementia amongst the aged population in the USA. It is a progressive neurodegenerative disorder, characterized by the prevalence of extracellular Aβ plaques and intracellular neurofibrillary tangles, derived from the proteolysis of the amyloid precursor protein (APP) and the hyperphosphorylation of microtubule-associated protein tau, respectively. Despite years of extensive research, the molecular mechanisms that underlie the pathology of AD remain unclear. Model organisms, such as the nematode, Caenorhabditis elegans, present a complementary approach to addressing these questions. C. elegans has many advantages as a model system to study AD and other neurodegenerative diseases. Like their mammalian counterparts, they have complex biochemical pathways, most of which are conserved. Genes in which mutations are correlated with AD have counterparts in C. elegans, including an APP-related gene, apl-1, a tau homolog, ptl-1, and presenilin homologs, such as sel-12 and hop-1. Since the neuronal connectivity in C. elegans has already been established, C. elegans is also advantageous in modeling learning and memory impairments seen during AD. This article addresses the insights C. elegans provide in studying AD and other neurodegenerative diseases. Additionally, we explore the advantages and drawbacks associated with using this model.
Collapse
Affiliation(s)
- Adanna G Alexander
- Department of Biology, City College of New York New York, NY, USA ; Department of Biology, The Graduate Center, City University of New York New York, NY, USA
| | - Vanessa Marfil
- Department of Biology, City College of New York New York, NY, USA
| | - Chris Li
- Department of Biology, City College of New York New York, NY, USA ; Department of Biology, The Graduate Center, City University of New York New York, NY, USA
| |
Collapse
|
23
|
Li C, Wu W, Sang M, Liu X, Hu X, Yun X, Li B. Comparative RNA-sequencing analysis of mthl1 functions and signal transductions in Tribolium castaneum. Gene 2014; 547:310-8. [DOI: 10.1016/j.gene.2014.06.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/17/2014] [Accepted: 06/27/2014] [Indexed: 01/20/2023]
|
24
|
Nuclear receptors in nematode development: Natural experiments made by a phylum. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:224-37. [PMID: 24984201 DOI: 10.1016/j.bbagrm.2014.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 06/21/2014] [Accepted: 06/23/2014] [Indexed: 11/21/2022]
Abstract
The development of complex multicellular organisms is dependent on regulatory decisions that are necessary for the establishment of specific differentiation and metabolic cellular states. Nuclear receptors (NRs) form a large family of transcription factors that play critical roles in the regulation of development and metabolism of Metazoa. Based on their DNA binding and ligand binding domains, NRs are divided into eight NR subfamilies from which representatives of six subfamilies are present in both deuterostomes and protostomes indicating their early evolutionary origin. In some nematode species, especially in Caenorhabditis, the family of NRs expanded to a large number of genes strikingly exceeding the number of NR genes in vertebrates or insects. Nematode NRs, including the multiplied Caenorhabditis genes, show clear relation to vertebrate and insect homologues belonging to six of the eight main NR subfamilies. This review summarizes advances in research of nematode NRs and their developmental functions. Nematode NRs can reveal evolutionarily conserved mechanisms that regulate specific developmental and metabolic processes as well as new regulatory adaptations. They represent the results of a large number of natural experiments with structural and functional potential of NRs for the evolution of the phylum. The conserved and divergent character of nematode NRs adds a new dimension to our understanding of the general biology of regulation by NRs. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
Collapse
|
25
|
Defects in the C. elegans acyl-CoA synthase, acs-3, and nuclear hormone receptor, nhr-25, cause sensitivity to distinct, but overlapping stresses. PLoS One 2014; 9:e92552. [PMID: 24651852 PMCID: PMC3961378 DOI: 10.1371/journal.pone.0092552] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 02/25/2014] [Indexed: 12/13/2022] Open
Abstract
Metazoan transcription factors control distinct networks of genes in specific tissues, yet understanding how these networks are integrated into physiology, development, and homeostasis remains challenging. Inactivation of the nuclear hormone receptor nhr-25 ameliorates developmental and metabolic phenotypes associated with loss of function of an acyl-CoA synthetase gene, acs-3. ACS-3 activity prevents aberrantly high NHR-25 activity. Here, we investigated this relationship further by examining gene expression patterns following acs-3 and nhr-25 inactivation. Unexpectedly, we found that the acs-3 mutation or nhr-25 RNAi resulted in similar transcriptomes with enrichment in innate immunity and stress response gene expression. Mutants of either gene exhibited distinct sensitivities to pathogens and environmental stresses. Only nhr-25 was required for wild-type levels of resistance to the bacterial pathogen P. aeruginosa and only acs-3 was required for wild-type levels of resistance to osmotic stress and the oxidative stress generator, juglone. Inactivation of either acs-3 or nhr-25 compromised lifespan and resistance to the fungal pathogen D. coniospora. Double mutants exhibited more severe defects in the lifespan and P. aeruginosa assays, but were similar to the single mutants in other assays. Finally, acs-3 mutants displayed defects in their epidermal surface barrier, potentially accounting for the observed sensitivities. Together, these data indicate that inactivation of either acs-3 or nhr-25 causes stress sensitivity and increased expression of innate immunity/stress genes, most likely by different mechanisms. Elevated expression of these immune/stress genes appears to abrogate the transcriptional signatures relevant to metabolism and development.
Collapse
|
26
|
Heffer A, Grubbs N, Mahaffey J, Pick L. The evolving role of the orphan nuclear receptor ftz-f1, a pair-rule segmentation gene. Evol Dev 2014; 15:406-17. [PMID: 24261442 DOI: 10.1111/ede.12050] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Segmentation is a critical developmental process that occurs by different mechanisms in diverse taxa. In insects, there are three common modes of embryogenesis-short-, intermediate-, and long-germ development-which differ in the number of segments specified at the blastoderm stage. While genes involved in segmentation have been extensively studied in the long-germ insect Drosophila melanogaster (Dm), it has been found that their expression and function in segmentation in short- and intermediate-germ insects often differ. Drosophila ftz-f1 encodes an orphan nuclear receptor that functions as a maternally expressed pair-rule segmentation gene, responsible for the formation of alternate body segments during Drosophila embryogenesis. Here we investigated the expression and function of ftz-f1 in the short-germ beetle, Tribolium castaneum (Tc). We found that Tc-ftz-f1 is expressed in stripes in Tribolium embryos. These stripes overlap alternate Tc-Engrailed (Tc-En) stripes, indicative of a pair-rule expression pattern. To test whether Tc-ftz-f1 has pair-rule function, we utilized embryonic RNAi, injecting double-stranded RNA corresponding to Tc-ftz-f1 coding or non-coding regions into early Tribolium embryos. Knockdown of Tc-ftz-f1 produced pair-rule segmentation defects, evidenced by loss of expression of alternate En stripes. In addition, a later role for Tc-ftz-f1 in cuticle formation was revealed. These results identify a new pair-rule gene in Tribolium and suggest that its role in segmentation may be shared among holometabolous insects. Interestingly, while Tc-ftz-f1 is expressed in pair-rule stripes, the gene is ubiquitously expressed in Drosophila embryos. Thus, the pair-rule function of ftz-f1 is conserved despite differences in expression patterns of ftz-f1 genes in different lineages. This suggests that ftz-f1 expression changed after the divergence of lineages leading to extant beetles and flies, likely due to differences in cis-regulatory sequences. We propose that the dependence of Dm-Ftz-F1 on interaction with the homeodomain protein Ftz which is expressed in stripes in Drosophila, loosened constraints on Dm-ftz-f1 expression, allowing for ubiquitous expression of this pair-rule gene in Drosophila.
Collapse
Affiliation(s)
- Alison Heffer
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
| | | | | | | |
Collapse
|
27
|
Ward JD, Bojanala N, Bernal T, Ashrafi K, Asahina M, Yamamoto KR. Sumoylated NHR-25/NR5A regulates cell fate during C. elegans vulval development. PLoS Genet 2013; 9:e1003992. [PMID: 24348269 PMCID: PMC3861103 DOI: 10.1371/journal.pgen.1003992] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 10/16/2013] [Indexed: 11/19/2022] Open
Abstract
Individual metazoan transcription factors (TFs) regulate distinct sets of genes depending on cell type and developmental or physiological context. The precise mechanisms by which regulatory information from ligands, genomic sequence elements, co-factors, and post-translational modifications are integrated by TFs remain challenging questions. Here, we examine how a single regulatory input, sumoylation, differentially modulates the activity of a conserved C. elegans nuclear hormone receptor, NHR-25, in different cell types. Through a combination of yeast two-hybrid analysis and in vitro biochemistry we identified the single C. elegans SUMO (SMO-1) as an NHR-25 interacting protein, and showed that NHR-25 is sumoylated on at least four lysines. Some of the sumoylation acceptor sites are in common with those of the NHR-25 mammalian orthologs SF-1 and LRH-1, demonstrating that sumoylation has been strongly conserved within the NR5A family. We showed that NHR-25 bound canonical SF-1 binding sequences to regulate transcription, and that NHR-25 activity was enhanced in vivo upon loss of sumoylation. Knockdown of smo-1 mimicked NHR-25 overexpression with respect to maintenance of the 3° cell fate in vulval precursor cells (VPCs) during development. Importantly, however, overexpression of unsumoylatable alleles of NHR-25 revealed that NHR-25 sumoylation is critical for maintaining 3° cell fate. Moreover, SUMO also conferred formation of a developmental time-dependent NHR-25 concentration gradient across the VPCs. That is, accumulation of GFP-tagged NHR-25 was uniform across VPCs at the beginning of development, but as cells began dividing, a smo-1-dependent NHR-25 gradient formed with highest levels in 1° fated VPCs, intermediate levels in 2° fated VPCs, and low levels in 3° fated VPCs. We conclude that sumoylation operates at multiple levels to affect NHR-25 activity in a highly coordinated spatial and temporal manner.
Collapse
Affiliation(s)
- Jordan D. Ward
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Nagagireesh Bojanala
- Institute of Parasitology, Biology Centre ASCR, Ceske Budejovice, Czech Republic
- University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Teresita Bernal
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Masako Asahina
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
- Institute of Parasitology, Biology Centre ASCR, Ceske Budejovice, Czech Republic
- University of South Bohemia, Ceske Budejovice, Czech Republic
- * E-mail: (MA); (KRY)
| | - Keith R. Yamamoto
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (MA); (KRY)
| |
Collapse
|
28
|
Shao J, He K, Wang H, Ho WS, Ren X, An X, Wong MK, Yan B, Xie D, Stamatoyannopoulos J, Zhao Z. Collaborative regulation of development but independent control of metabolism by two epidermis-specific transcription factors in Caenorhabditis elegans. J Biol Chem 2013; 288:33411-26. [PMID: 24097988 DOI: 10.1074/jbc.m113.487975] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cell fate specification is typically initiated by a master regulator, which is relayed by tissue-specific regulatory proteins (usually transcription factors) for further enforcement of cell identities, but how the factors are coordinated among each other to "finish up" the specification remains poorly understood. Caenorhabditis elegans epidermis specification is initiated by a master regulator, ELT-1, that activates its targets, NHR-25 and ELT-3, two epidermis-specific transcription factors that are important for development but not for initial specification of epidermis, thus providing a unique paradigm for illustrating how the tissue-specific regulatory proteins work together to enforce cell fate specification. Here we addressed the question through contrasting genome-wide in vivo binding targets between NHR-25 and ELT-3. We demonstrate that the two factors bind discrete but conserved DNA motifs, most of which remain in proximity, suggesting formation of a complex between the two. In agreement with this, gene ontology analysis of putative target genes suggested differential regulation of metabolism but coordinated control of epidermal development between the two factors, which is supported by quantitative analysis of expression of their specific or common targets in the presence or absence of either protein. Functional validation of a subset of the target genes showed both activating and inhibitory roles of NHR-25 and ELT-3 in regulating their targets. We further demonstrated differential control of specification of AB and C lineage-derived epidermis. The results allow us to assemble a comprehensive gene network underlying C. elegans epidermis development that is likely to be widely used across species and provides insights into how tissue-specific transcription factors coordinate with one another to enforce cell fate specification initiated by its master regulator.
Collapse
Affiliation(s)
- Jiaofang Shao
- From the Department of Biology, Hong Kong Baptist University, Hong Kong, China and
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Monsalve GC, Frand AR. Toward a unified model of developmental timing: A "molting" approach. WORM 2013; 1:221-30. [PMID: 24058853 PMCID: PMC3670223 DOI: 10.4161/worm.20874] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 05/24/2012] [Indexed: 02/06/2023]
Abstract
Animal development requires temporal coordination between recurrent processes and sequential events, but the underlying timing mechanisms are not yet understood. The molting cycle of C. elegans provides an ideal system to study this basic problem. We recently characterized LIN-42, which is related to the circadian clock protein PERIOD, as a key component of the developmental timer underlying rhythmic molting cycles. In this context, LIN-42 coordinates epithelial stem cell dynamics with progression of the molting cycle. Repeated actions of LIN-42 may enable the reprogramming of seam cell temporal fates, while stage-specific actions of LIN-42 and other heterochronic genes select fates appropriate for upcoming, rather than passing, life stages. Here, we discuss the possible configuration of the molting timer, which may include interconnected positive and negative regulatory loops among lin-42, conserved nuclear hormone receptors such as NHR-23 and -25, and the let-7 family of microRNAs. Physiological and environmental conditions may modulate the activities of particular components of this molting timer. Finding that LIN-42 regulates both a sleep-like behavioral state and epidermal stem cell dynamics further supports the model of functional conservation between LIN-42 and mammalian PERIOD proteins. The molting timer may therefore represent a primitive form of a central biological clock and provide a general paradigm for the integration of rhythmic and developmental processes.
Collapse
Affiliation(s)
- Gabriela C Monsalve
- Department of Biological Chemistry; David Geffen School of Medicine; University of California; Los Angeles, CA USA
| | | |
Collapse
|
30
|
Abstract
Hormones play a critical role in driving major stage transitions and developmental timing events in many species. In the nematode C. elegans the steroid hormone receptor, DAF-12, works at the confluence of pathways regulating developmental timing, stage specification, and longevity. DAF-12 couples environmental and physiologic signals to life history regulation, and it is embedded in a rich architecture governing diverse processes. Here, we highlight the molecular insights, extraordinary circuitry, and signaling pathways governing life stage transitions in the worm and how they have yielded fundamental insights into steroid regulation of biological time.
Collapse
Affiliation(s)
- Adam Antebi
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
| |
Collapse
|
31
|
|
32
|
Multiple cis-elements and trans-acting factors regulate dynamic spatio-temporal transcription of let-7 in Caenorhabditis elegans. Dev Biol 2012. [PMID: 23201578 DOI: 10.1016/j.ydbio.2012.11.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The let-7 microRNA (miRNA) is highly conserved across animal phyla and generally regulates cellular differentiation and developmental timing pathways. In Caenorhabditis elegans, the mature let-7 miRNA starts to accumulate in the last stages of larval development where it directs cellular differentiation programs required for adult fates. Here, we show that expression of the let-7 gene in C. elegans is under complex transcriptional control. The onset of let-7 transcription begins as early as the first larval stage in some tissues, and as late as the third larval stage in others, and is abrogated at the gravid adult stage. Transcription from two different start sites in the let-7 promoter oscillates during each larval stage. We show that transcription is regulated by two distinct cis-elements in the promoter of let-7, the previously described temporal regulatory element (TRE), and a novel element downstream of the TRE that we have named the let-7 transcription element (LTE). These elements play distinct and redundant roles in regulating let-7 expression in specific tissues. In the absence of the TRE and LTE, transcription of let-7 is undetectable and worms exhibit the lethal phenotype characteristic of let-7 null mutants. We also identify several genes that affect the transcription of let-7 generally and tissue-specifically. Overall, spatio-temporal regulation of let-7 transcription is orchestrated by multiple cis- and trans-acting factors to ensure appropriate expression of this essential miRNA during worm development.
Collapse
|
33
|
Melo JA, Ruvkun G. Inactivation of conserved C. elegans genes engages pathogen- and xenobiotic-associated defenses. Cell 2012; 149:452-66. [PMID: 22500807 DOI: 10.1016/j.cell.2012.02.050] [Citation(s) in RCA: 281] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 01/02/2012] [Accepted: 02/23/2012] [Indexed: 12/18/2022]
Abstract
The nematode C. elegans is attracted to nutritious bacteria and is repelled by pathogens and toxins. Here we show that RNAi and toxin-mediated disruption of core cellular activities, including translation, respiration, and protein turnover, stimulate behavioral avoidance of normally attractive bacteria. RNAi of these and other essential processes induces expression of detoxification and innate immune effectors, even in the absence of toxins or pathogens. Disruption of core processes in non-neuronal tissues was sufficient to stimulate aversion behavior, revealing a neuroendocrine axis of control that additionally required serotonergic and Jnk kinase signaling pathways. We propose that surveillance pathways overseeing core cellular activities allow animals to detect invading pathogens that deploy toxins and virulence factors to undermine vital host functions. Variation in cellular surveillance and endocrine pathways controlling behavior, detoxification, and immunity selected by past toxin or microbial interactions could underlie aberrant responses to foods, medicines, and microbes.
Collapse
Affiliation(s)
- Justine A Melo
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | |
Collapse
|
34
|
Wiese M, Antebi A, Zheng H. Regulation of neuronal APL-1 expression by cholesterol starvation. PLoS One 2012; 7:e32038. [PMID: 22363792 PMCID: PMC3283687 DOI: 10.1371/journal.pone.0032038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/18/2012] [Indexed: 12/04/2022] Open
Abstract
Background Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the deposition of β-amyloid plaques composed primarily of the amyloid-β peptide, a cleavage product of amyloid precursor protein (APP). While mutations in APP lead to the development of Familial Alzheimer's Disease (FAD), sporadic AD has only one clear genetic modifier: the ε4 allele of the apolipoprotein E (ApoE) gene. Cholesterol starvation in Caenorhabditis elegans leads to molting and arrest phenotypes similar to loss-of-function mutants of the APP ortholog, apl-1 (amyloid precursor-like protein 1), and lrp-1 (lipoprotein receptor-related protein 1), suggesting a potential interaction between apl-1 and cholesterol metabolism. Methodology/Principal Findings Previously, we found that RNAi knock-down of apl-1 leads to aldicarb hypersensitivity, indicating a defect in synaptic function. Here we find the same defect is recapitulated during lrp-1 knock-down and by cholesterol starvation. A cholesterol-free diet or loss of lrp-1 directly affects APL-1 levels as both lead to loss of APL-1::GFP fluorescence in neurons. However, loss of cholesterol does not affect global transcription or protein levels as seen by qPCR and Western blot. Conclusions Our results show that cholesterol and lrp-1 are involved in the regulation of synaptic transmission, similar to apl-1. Both are able to modulate APL-1 protein levels in neurons, however cholesterol changes do not affect global apl-1 transcription or APL-1 protein indicating the changes are specific to neurons. Thus, regulation of synaptic transmission and molting by LRP-1 and cholesterol may be mediated by their ability to control APL-1 neuronal protein expression.
Collapse
Affiliation(s)
- Mary Wiese
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Adam Antebi
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Max Planck Institute for Biology of Ageing, Köln, Germany
- * E-mail: (AA); (HZ)
| | - Hui Zheng
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail: (AA); (HZ)
| |
Collapse
|
35
|
Monsalve GC, Van Buskirk C, Frand AR. LIN-42/PERIOD controls cyclical and developmental progression of C. elegans molts. Curr Biol 2011; 21:2033-45. [PMID: 22137474 DOI: 10.1016/j.cub.2011.10.054] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 10/07/2011] [Accepted: 10/31/2011] [Indexed: 01/06/2023]
Abstract
BACKGROUND Biological timing mechanisms that integrate cyclical and successive processes are not well understood. C. elegans molting cycles involve rhythmic cellular and animal behaviors linked to the periodic reconstruction of cuticles. Molts are coordinated with successive transitions in the temporal fates of epidermal blast cells, which are programmed by genes in the heterochronic regulatory network. It was known that juveniles molt at regular 8-10 hr intervals, but the anticipated pacemaker had not been characterized. RESULTS We find that inactivation of the heterochronic gene lin-42a, which is related to the core circadian clock gene PERIOD (PER), results in arrhythmic molts and continuously abnormal epidermal stem cell dynamics. The oscillatory expression of lin-42a in the epidermis peaks during the molts. Further, forced expression of lin-42a leads to anachronistic larval molts and lethargy in adults. CONCLUSIONS Our results suggest that rising and falling levels of LIN-42A allow the start and completion, respectively, of larval molts. We propose that LIN-42A and affiliated factors regulate molting cycles in much the same way that PER-based oscillators drive rhythmic behaviors and metabolic processes in mature mammals. Further, the combination of reiterative and stage-specific functions of LIN-42 may coordinate periodic molts with successive development of the epidermis.
Collapse
Affiliation(s)
- Gabriela C Monsalve
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
36
|
Harris DT, Horvitz HR. MAB-10/NAB acts with LIN-29/EGR to regulate terminal differentiation and the transition from larva to adult in C. elegans. Development 2011; 138:4051-62. [PMID: 21862562 DOI: 10.1242/dev.065417] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Caenorhabditis elegans, a well-defined pathway of heterochronic genes ensures the proper timing of stage-specific developmental events. During the final larval stage, an upregulation of the let-7 microRNA indirectly activates the terminal differentiation factor and central regulator of the larval-to-adult transition, LIN-29, via the downregulation of the let-7 target genes lin-41 and hbl-1. Here, we identify a new heterochronic gene, mab-10, and show that mab-10 encodes a NAB (NGFI-A-binding protein) transcriptional co-factor. MAB-10 acts with LIN-29 to control the expression of genes required to regulate a subset of differentiation events during the larval-to-adult transition, and we show that the NAB-interaction domain of LIN-29 is conserved in Kruppel-family EGR (early growth response) proteins. In mammals, EGR proteins control the differentiation of multiple cell lineages, and EGR-1 acts with NAB proteins to initiate menarche by regulating the transcription of the luteinizing hormone β subunit. Genome-wide association studies of humans and various studies of mouse recently have implicated the mammalian homologs of the C. elegans heterochronic gene lin-28 in regulating cellular differentiation and the timing of menarche. Our work suggests that human homologs of multiple C. elegans heterochronic genes might act in an evolutionarily conserved pathway to promote cellular differentiation and the onset of puberty.
Collapse
Affiliation(s)
- David T Harris
- Howard Hughes Medical Institute, Department of Biology, 68-425, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | | |
Collapse
|
37
|
Nelson MD, Zhou E, Kiontke K, Fradin H, Maldonado G, Martin D, Shah K, Fitch DHA. A bow-tie genetic architecture for morphogenesis suggested by a genome-wide RNAi screen in Caenorhabditis elegans. PLoS Genet 2011; 7:e1002010. [PMID: 21408209 PMCID: PMC3048373 DOI: 10.1371/journal.pgen.1002010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 01/04/2011] [Indexed: 11/19/2022] Open
Abstract
During animal development, cellular morphogenesis plays a fundamental role in determining the shape and function of tissues and organs. Identifying the components that regulate and drive morphogenesis is thus a major goal of developmental biology. The four-celled tip of the Caenorhabditis elegans male tail is a simple but powerful model for studying the mechanism of morphogenesis and its spatiotemporal regulation. Here, through a genome-wide post-embryonic RNAi-feeding screen, we identified 212 components that regulate or participate in male tail tip morphogenesis. We constructed a working hypothesis for a gene regulatory network of tail tip morphogenesis. We found regulatory roles for the posterior Hox genes nob-1 and php-3, the TGF-β pathway, nuclear hormone receptors (e.g. nhr-25), the heterochronic gene blmp-1, and the GATA transcription factors egl-18 and elt-6. The majority of the pathways converge at dmd-3 and mab-3. In addition, nhr-25 and dmd-3/mab-3 regulate each others' expression, thus placing these three genes at the center of a complex regulatory network. We also show that dmd-3 and mab-3 negatively regulate other signaling pathways and affect downstream cellular processes such as vesicular trafficking (e.g. arl-1, rme-8) and rearrangement of the cytoskeleton (e.g. cdc-42, nmy-1, and nmy-2). Based on these data, we suggest that male tail tip morphogenesis is governed by a gene regulatory network with a bow-tie architecture. Morphogenesis is a process in which cells change their shape and position to give rise to mature structures. Elucidation of the molecular basis of morphogenesis and its regulation would be a major step towards understanding organ formation and functionality. We focus on a powerful model for morphogenesis, the four-celled tail tip of the C. elegans male, which undergoes morphogenesis during the last larval stage. To comprehensively determine the components that regulate and execute male tail tip morphogenesis, we performed a genome-wide RNAi screen. We identified 212 genes that encode proteins with roles in fundamental processes like endocytosis, vesicular trafficking, cell–cell communication, and cytoskeletal organization. We determined the interactions among several of these genes to reconstruct a first draft of the genetic network underlying tail tip morphogenesis. The structure of this network is consistent with the "bow-tie architecture" that has been proposed to be universal and confers evolvability and robustness to biological systems. Bow-tie networks have a conserved core which is linked to numerous input and output components. Many components of the network underlying tail tip morphogenesis in C. elegans are conserved all the way to humans. Thus, understanding tail tip morphogenesis will inform us about morphogenesis in other organisms.
Collapse
Affiliation(s)
- Matthew D. Nelson
- Department of Biology, New York University, New York, New York, United States of America
| | - Elinor Zhou
- Department of Biology, New York University, New York, New York, United States of America
| | - Karin Kiontke
- Department of Biology, New York University, New York, New York, United States of America
| | - Hélène Fradin
- Department of Biology, New York University, New York, New York, United States of America
| | - Grayson Maldonado
- Department of Biology, New York University, New York, New York, United States of America
| | - Daniel Martin
- Department of Biology, New York University, New York, New York, United States of America
| | - Khushbu Shah
- Department of Biology, New York University, New York, New York, United States of America
| | - David H. A. Fitch
- Department of Biology, New York University, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
38
|
Mullaney BC, Blind RD, Lemieux GA, Perez CL, Elle IC, Faergeman NJ, Van Gilst MR, Ingraham HA, Ashrafi K. Regulation of C. elegans fat uptake and storage by acyl-CoA synthase-3 is dependent on NR5A family nuclear hormone receptor nhr-25. Cell Metab 2010; 12:398-410. [PMID: 20889131 PMCID: PMC2992884 DOI: 10.1016/j.cmet.2010.08.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 04/28/2010] [Accepted: 06/23/2010] [Indexed: 01/09/2023]
Abstract
Acyl-CoA synthases are important for lipid synthesis and breakdown, generation of signaling molecules, and lipid modification of proteins, highlighting the challenge of understanding metabolic pathways within intact organisms. From a C. elegans mutagenesis screen, we found that loss of ACS-3, a long-chain acyl-CoA synthase, causes enhanced intestinal lipid uptake, de novo fat synthesis, and accumulation of enlarged, neutral lipid-rich intestinal depots. Here, we show that ACS-3 functions in seam cells, epidermal cells anatomically distinct from sites of fat uptake and storage, and that acs-3 mutant phenotypes require the nuclear hormone receptor NHR-25, a key regulator of C. elegans molting. Our findings suggest that ACS-3-derived long-chain fatty acyl-CoAs, perhaps incorporated into complex ligands such as phosphoinositides, modulate NHR-25 function, which in turn regulates an endocrine program of lipid uptake and synthesis. These results reveal a link between acyl-CoA synthase function and an NR5A family nuclear receptor in C. elegans.
Collapse
Affiliation(s)
- Brendan C Mullaney
- Graduate Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; UCSF Diabetes Center, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Raymond D Blind
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - George A Lemieux
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carissa L Perez
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Ida C Elle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Nils J Faergeman
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Marc R Van Gilst
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Holly A Ingraham
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; UCSF Diabetes Center, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
39
|
Hada K, Asahina M, Hasegawa H, Kanaho Y, Slack FJ, Niwa R. The nuclear receptor gene nhr-25 plays multiple roles in the Caenorhabditis elegans heterochronic gene network to control the larva-to-adult transition. Dev Biol 2010; 344:1100-9. [PMID: 20678979 DOI: 10.1016/j.ydbio.2010.05.508] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 05/16/2010] [Accepted: 05/24/2010] [Indexed: 11/20/2022]
Abstract
Developmental timing in the nematode Caenorhabditis elegans is controlled by heterochronic genes, mutations in which cause changes in the relative timing of developmental events. One of the heterochronic genes, let-7, encodes a microRNA that is highly evolutionarily conserved, suggesting that similar genetic pathways control developmental timing across phyla. Here we report that the nuclear receptor nhr-25, which belongs to the evolutionarily conserved fushi tarazu-factor 1/nuclear receptor NR5A subfamily, interacts with heterochronic genes that regulate the larva-to-adult transition in C. elegans. We identified nhr-25 as a regulator of apl-1, a homolog of the Alzheimer's amyloid precursor protein-like gene that is downstream of let-7 family microRNAs. NHR-25 controls not only apl-1 expression but also regulates developmental progression in the larva-to-adult transition. NHR-25 negatively regulates the expression of the adult-specific collagen gene col-19 in lateral epidermal seam cells. In contrast, NHR-25 positively regulates the larva-to-adult transition for other timed events in seam cells, such as cell fusion, cell division and alae formation. The genetic relationships between nhr-25 and other heterochronic genes are strikingly varied among several adult developmental events. We propose that nhr-25 has multiple roles in both promoting and inhibiting the C. elegans heterochronic gene pathway controlling adult differentiation programs.
Collapse
Affiliation(s)
- Kazumasa Hada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | | | | | | | | | | |
Collapse
|
40
|
Meli VS, Osuna B, Ruvkun G, Frand AR. MLT-10 defines a family of DUF644 and proline-rich repeat proteins involved in the molting cycle of Caenorhabditis elegans. Mol Biol Cell 2010; 21:1648-61. [PMID: 20335506 PMCID: PMC2869372 DOI: 10.1091/mbc.e08-07-0708] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Molting of nematodes involves the synthesis and removal of a collagen-rich exoskeleton. We describe Caenorhabditis elegans MLT-10, which defines a large family of DUF644 and proline-rich repeat proteins. We show that MLT-10 is released from the epidermis during molting and that MLT-10 is involved in renewal of the exoskeleton and development of the epidermis. The molting cycle of nematodes involves the periodic synthesis and removal of a collagen-rich exoskeleton, but the underlying molecular mechanisms are not well understood. Here, we describe the mlt-10 gene of Caenorhabditis elegans, which emerged from a genetic screen for molting-defective mutants sensitized by low cholesterol. MLT-10 defines a large family of nematode-specific proteins comprised of DUF644 and tandem P-X2-L-(S/T)-P repeats. Conserved nuclear hormone receptors promote expression of the mlt-10 gene in the hypodermis whenever the exoskeleton is remade. Further, a MLT-10::mCherry fusion protein is released from the hypodermis to the surrounding matrices and fluids during molting. The fusion protein is also detected in strands near the surface of animals. Both loss-of-function and gain-of-function mutations of mlt-10 impede the removal of old cuticles. However, the substitution mutation mlt-10(mg364), which disrupts the proline-rich repeats, causes the most severe phenotype. Mutations of mlt-10 are also associated with abnormalities in the exoskeleton and improper development of the epidermis. Thus, mlt-10 encodes a secreted protein involved in three distinct but interconnected aspects of the molting cycle. We propose that the molting cycle of C. elegans involves the dynamic assembly and disassembly of MLT-10 and possibly the paralogs of MLT-10.
Collapse
Affiliation(s)
- Vijaykumar S Meli
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA
| | | | | | | |
Collapse
|
41
|
Molecular evidence for a functional ecdysone signaling system in Brugia malayi. PLoS Negl Trop Dis 2010; 4:e625. [PMID: 20231890 PMCID: PMC2834746 DOI: 10.1371/journal.pntd.0000625] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 01/22/2010] [Indexed: 11/20/2022] Open
Abstract
Background Filarial nematodes, including Brugia malayi, the causative agent of lymphatic filariasis, undergo molting in both arthropod and mammalian hosts to complete their life cycles. An understanding of how these parasites cross developmental checkpoints may reveal potential targets for intervention. Pharmacological evidence suggests that ecdysteroids play a role in parasitic nematode molting and fertility although their specific function remains unknown. In insects, ecdysone triggers molting through the activation of the ecdysone receptor: a heterodimer of EcR (ecdysone receptor) and USP (Ultraspiracle). Methods and Findings We report the cloning and characterization of a B. malayi EcR homologue (Bma-EcR). Bma-EcR dimerizes with insect and nematode USP/RXRs and binds to DNA encoding a canonical ecdysone response element (EcRE). In support of the existence of an active ecdysone receptor in Brugia we also cloned a Brugia rxr (retinoid X receptor) homolog (Bma-RXR) and demonstrate that Bma-EcR and Bma-RXR interact to form an active heterodimer using a mammalian two-hybrid activation assay. The Bma-EcR ligand-binding domain (LBD) exhibits ligand-dependent transactivation via a GAL4 fusion protein combined with a chimeric RXR in mammalian cells treated with Ponasterone-A or a synthetic ecdysone agonist. Furthermore, we demonstrate specific up-regulation of reporter gene activity in transgenic B. malayi embryos transfected with a luciferase construct controlled by an EcRE engineered in a B. malayi promoter, in the presence of 20-hydroxy-ecdysone. Conclusions Our study identifies and characterizes the two components (Bma-EcR and Bma-RXR) necessary for constituting a functional ecdysteroid receptor in B. malayi. Importantly, the ligand binding domain of BmaEcR is shown to be capable of responding to ecdysteroid ligands, and conversely, ecdysteroids can activate transcription of genes downstream of an EcRE in live B. malayi embryos. These results together confirm that an ecdysone signaling system operates in B. malayi and strongly suggest that Bma-EcR plays a central role in it. Furthermore, our study proposes that existing compounds targeting the insect ecdysone signaling pathway should be considered as potential pharmacological agents against filarial parasites. Filarial parasites such as Brugia malayi and Onchocerca volvulus are the causative agents of the tropical diseases lymphatic filariasis and onchocerciasis, which infect 150 million people, mainly in Africa and Southeast Asia. Filarial nematodes have a complex life cycle that involves transmission and development within both mammalian and insect hosts. The successful completion of the life cycle includes four molts, two of which are triggered upon transmission from one host to the other, human and mosquito, respectively. Elucidation of the molecular mechanisms involved in the molting processes in filarial nematodes may yield a new set of targets for drug intervention. In insects and other arthropods molting transitions are regulated by the steroid hormone ecdysone that interacts with a specialized hormone receptor composed of two different proteins belonging to the family of nuclear receptors. We have cloned from B. malayi two members of the nuclear receptor family that show many sequence and biochemical properties consistent with the ecdysone receptor of insects. This finding represents the first report of a functional ecdysone receptor homolog in nematodes. We have also established a transgenic hormone induction assay in B. malayi that can be used to discover ecdysone responsive genes and potentially lead to screening assays for active compounds for pharmaceutical development.
Collapse
|
42
|
Kato M, Sternberg PW. The C. elegans tailless/Tlx homolog nhr-67 regulates a stage-specific program of linker cell migration in male gonadogenesis. Development 2009; 136:3907-15. [PMID: 19906858 DOI: 10.1242/dev.035477] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cell migration is a common event during organogenesis, yet little is known about how migration is temporally coordinated with organ development. We are investigating stage-specific programs of cell migration using the linker cell (LC), a migratory cell crucial for male gonadogenesis of C. elegans. During the L3 and L4 larval stages of wild-type males, the LC undergoes changes in its position along the migratory route, in transcriptional regulation of the unc-5 netrin receptor and zmp-1 zinc matrix metalloprotease, and in cell morphology. We have identified the tailless homolog nhr-67 as a cell-autonomous, stage-specific regulator of timing in LC migration programs. In nhr-67-deficient animals, each of the L3 and L4 stage changes is either severely delayed or never occurs, yet LC development before the early L3 stage or after the mid-L4 stage occurs with normal timing. We propose that there is a basal migration program utilized throughout LC migration that is modified by stage-specific regulators such as nhr-67.
Collapse
Affiliation(s)
- Mihoko Kato
- HHMI and Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA
| | | |
Collapse
|
43
|
Hajduskova M, Jindra M, Herman MA, Asahina M. The nuclear receptor NHR-25 cooperates with the Wnt/beta-catenin asymmetry pathway to control differentiation of the T seam cell in C. elegans. J Cell Sci 2009; 122:3051-60. [PMID: 19654209 DOI: 10.1242/jcs.052373] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Asymmetric cell divisions produce new cell types during animal development. Studies in Caenorhabditis elegans have identified major signal-transduction pathways that determine the polarity of cell divisions. How these relatively few conserved pathways interact and what modulates them to ensure the diversity of multiple tissue types is an open question. The Wnt/beta-catenin asymmetry pathway governs polarity of the epidermal T seam cell in the C. elegans tail. Here, we show that the asymmetry of T-seam-cell division and morphogenesis of the male sensory rays require NHR-25, an evolutionarily conserved nuclear receptor. NHR-25 ensures the neural fate of the T-seam-cell descendants in cooperation with the Wnt/beta-catenin asymmetry pathway. Loss of NHR-25 enhances the impact of mutated nuclear effectors of this pathway, POP-1 (TCF) and SYS-1 (beta-catenin), on T-seam-cell polarity, whereas it suppresses the effect of the same mutations on asymmetric division of the somatic gonad precursor cells. Therefore, NHR-25 can either synergize with or antagonize the Wnt/beta-catenin asymmetry pathway depending on the tissue context. Our findings define NHR-25 as a versatile modulator of Wnt/beta-catenin-dependent cell-fate decisions.
Collapse
Affiliation(s)
- Martina Hajduskova
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | | | | | | |
Collapse
|
44
|
Cruz J, Nieva C, Mané-Padrós D, Martín D, Bellés X. Nuclear receptor BgFTZ-F1 regulates molting and the timing of ecdysteroid production during nymphal development in the hemimetabolous insectBlattella germanica. Dev Dyn 2008; 237:3179-91. [DOI: 10.1002/dvdy.21728] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
45
|
Hao L, Mukherjee K, Liegeois S, Baillie D, Labouesse M, Bürglin TR. The hedgehog-related gene qua-1 is required for molting in Caenorhabditis elegans. Dev Dyn 2007; 235:1469-81. [PMID: 16502424 DOI: 10.1002/dvdy.20721] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Caenorhabditis elegans genome encodes ten proteins that share similarity with Hedgehog through the C-terminal Hint/Hog domain. While most genes are members of larger gene families, qua-1 is a single copy gene. Here we show that orthologs of qua-1 exist in many nematodes, including Brugia malayi, which shared a common ancestor with C. elegans about 300 million years ago. The QUA-1 proteins contain an N-terminal domain, the Qua domain, that is highly conserved, but whose molecular function is not known. We have studied the expression pattern of qua-1 in C. elegans using a qua-1::GFP transcriptional fusion. qua-1 is mainly expressed in hyp1 to hyp11 hypodermal cells, but not in seam cells. It is also expressed in intestinal and rectal cells, sensilla support cells, and the P cell lineage in L1. The expression of qua-1::GFP undergoes cyclical changes during development in phase with the molting cycle. It accumulates prior to molting and disappears between molts. Disruption of the qua-1 gene function through an internal deletion that causes a frame shift with premature stop in the middle of the gene results in strong lethality. The animals arrest in the early larval stages due to defects in molting. Electron microscopy reveals double cuticles due to defective ecdysis, but no obvious defects are seen in the hypodermis. Qua domain-only::GFP and full-length QUA-1::GFP fusion constructs are secreted and associated with the overlying cuticle, but only QUA-1::GFP rescues the mutant phenotype. Our results suggest that both the Hint/Hog domain and Qua domain are critically required for the function of QUA-1.
Collapse
Affiliation(s)
- Limin Hao
- Department of Biosciences and Nutrition, and Center for Genomics and Bioinformatics, Karolinska Institutet, Huddinge, Sweden
| | | | | | | | | | | |
Collapse
|
46
|
Lu C, Wu W, Niles EG, LoVerde PT. Identification and characterization of a novel fushi tarazu factor 1 (FTZ-F1) nuclear receptor in Schistosoma mansoni. Mol Biochem Parasitol 2006; 150:25-36. [PMID: 16870276 DOI: 10.1016/j.molbiopara.2006.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Revised: 06/05/2006] [Accepted: 06/08/2006] [Indexed: 11/15/2022]
Abstract
Fushi-tarazu factor-1 (FTZ-F1) is an orphan nuclear receptor involved in gene regulation of various developmental processes and physiological activities. We identified a new member of ftz-f1 gene in Schistosoma mansoni, termed Smftz-f1alpha. The Smftz-f1alpha gene has a complex structure with 15 exons interrupted by 14 introns. It encodes an unusually long SmFTZ-F1alpha protein of 1892 amino acids containing all the modular domains found in nuclear receptors. The DNA-binding domain (DBD) of SmFTZ-F1alpha is conserved and most similar to those of human and mouse FTZ-F1 orthologues, exhibiting a 76% identity. The ligand-binding domain (LBD) is less conserved than the DBD; it shares more diverse identity scores in different regions ranging from 23% to 42% in region II and 28% to 72% in region III. A conserved activation function-2 (AF-2) sequence is present in the SmFTZ-F1alpha LBD. This protein also contains a long hinge region (1027 aa) and an F region (220 aa) at the carboxyl end. Phylogenetic analysis suggests that SmFTZ-F1alpha is the orthologue of Drosophila FTZ-F1alpha and vertebrate NR5 members. Western blot analysis of a schistosome extract identified two proteins, one with a size (206 kDa) predicted by the SmFTZ-F1alpha cDNA sequence and a smaller component of 120 kDa. Smftz-f1alpha is expressed throughout the schistosome life cycle with the highest expression in the egg stage. SmFTZ-F1alpha mRNA is widely distributed in adult worms but does not appear in vitelline cells of female worms. SmFTZ-F1alpha localizes to a variety of tissues but is most abundant in the testis of the male and the ovary of female worms. Our results suggest that SmFTZ-F1alpha plays a role in regulating schistosome development and sexual differentiation similar to other FTZ-F1 family members.
Collapse
Affiliation(s)
- Changxue Lu
- Department of Microbiology and Immunology, School of Medicine and Biomedical Research, State University of New York, Buffalo, NY 14214, USA
| | | | | | | |
Collapse
|
47
|
Hayes GD, Frand AR, Ruvkun G. The mir-84 and let-7 paralogous microRNA genes of Caenorhabditis elegans direct the cessation of molting via the conserved nuclear hormone receptors NHR-23 and NHR-25. Development 2006; 133:4631-41. [PMID: 17065234 DOI: 10.1242/dev.02655] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The let-7 microRNA (miRNA) gene of Caenorhabditis elegans controls the timing of developmental events. let-7 is conserved throughout bilaterian phylogeny and has multiple paralogs. Here, we show that the paralog mir-84 acts synergistically with let-7 to promote terminal differentiation of the hypodermis and the cessation of molting in C. elegans. Loss of mir-84 exacerbates phenotypes caused by mutations in let-7, whereas increased expression of mir-84 suppresses a let-7 null allele. Adults with reduced levels of mir-84 and let-7 express genes characteristic of larval molting as they initiate a supernumerary molt. mir-84 and let-7 promote exit from the molting cycle by regulating targets in the heterochronic pathway and also nhr-23 and nhr-25, genes encoding conserved nuclear hormone receptors essential for larval molting. The synergistic action of miRNA paralogs in development may be a general feature of the diversified miRNA gene family.
Collapse
Affiliation(s)
- Gabriel D Hayes
- Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | |
Collapse
|
48
|
Asahina M, Valenta T, Silhankova M, Korinek V, Jindra M. Crosstalk between a nuclear receptor and beta-catenin signaling decides cell fates in the C. elegans somatic gonad. Dev Cell 2006; 11:203-11. [PMID: 16890160 DOI: 10.1016/j.devcel.2006.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 05/18/2006] [Accepted: 06/06/2006] [Indexed: 01/07/2023]
Abstract
beta-Catenin signaling determines the proximal-distal axis of the C. elegans gonad by promoting distal fate in asymmetrically dividing somatic gonad precursor cells (SGPs). Impaired function of the Wnt effector POP-1/TCF, its coactivator SYS-1/beta-catenin, and of upstream components including beta-catenin WRM-1 causes all SGP daughters to adopt the proximal fate. Consequently, no distal tip cells (DTCs) that would lead differentiation of gonad arms form in the affected hermaphrodites. Here, we show that deficiency of the nuclear receptor NHR-25 has the opposite effect: extra DTCs develop instead of proximal cells. NHR-25 knockdown restores DTC formation and fertility in pop-1 and sys-1 mutants, suggesting that a balance between NHR-25 and beta-catenin pathway activities is required to establish both proximal and distal fates. This balance relies on direct crossregulation between NHR-25 and the distinct beta-catenin proteins WRM-1 and SYS-1. The nuclear receptor-beta-catenin interaction may be an ancient mechanism of cell-fate decision.
Collapse
Affiliation(s)
- Masako Asahina
- Biology Center, Czech Academy of Sciences, University of South Bohemia, Budweis 37005, Czech Republic.
| | | | | | | | | |
Collapse
|
49
|
Schmidt AW, Doert T, Goutal S, Gruner M, Mende F, Kurzchalia TV, Knölker HJ. Regio- and Stereospecific Synthesis of Cholesterol Derivatives and Their Hormonal Activity inCaenorhabditis elegans. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600394] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
50
|
Brozová E, Simecková K, Kostrouch Z, Rall JE, Kostrouchová M. NHR-40, a Caenorhabditis elegans supplementary nuclear receptor, regulates embryonic and early larval development. Mech Dev 2006; 123:689-701. [PMID: 16920335 DOI: 10.1016/j.mod.2006.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 06/22/2006] [Accepted: 06/26/2006] [Indexed: 11/21/2022]
Abstract
Nuclear hormone receptors (NHRs) are important regulators of development and metabolism in animal species. They are characterized by the ability to regulate gene expression in response to the binding of small hydrophobic molecules, hormones, metabolites, and xenobiotics. The Caenorhabditis elegans genome contains 284 sequences that share homology to vertebrate and insect NHRs, a surprisingly large number compared with other species. The majority of C. elegans NHRs are nematode-specific and are referred to as supplementary nuclear receptors (supnrs) that are thought to have originated by duplications of an ancient homolog of vertebrate HNF4. Here, we report on the function of NHR-40, a member of a subgroup of 18 Caenorhabditis elegans supnrs that share DNA-binding domain sequence CNGCKT. NHR-40 is expressed from at least two promoters, generates at least three transcripts, and is detectable in pharyngeal, body wall, and sex muscles as well as in a subset of neurons. The downregulation of nhr-40 by RNAi, or a mutant with an intronic region deletion, results in late embryonic and early larval arrest with defects in elongation and morphogenesis. The nhr-40 loss of function phenotype includes irregular development of body wall muscle cells and impaired movement and coordination resembling neuromuscular affection. NHR-40 joins the list of C. elegans NHRs that regulate development and suggests that members of extensive nematode supnr family have acquired varied and novel functions during evolution.
Collapse
Affiliation(s)
- Eva Brozová
- Laboratory of Molecular Biology and Genetics, Institute of Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, Ke Karlovu 2, CZ 128 01 Prague 2, Czech Republic
| | | | | | | | | |
Collapse
|