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1.
Differentiation ; 137: 100765, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38522217

RESUMO

The acquisition of the post-mitotic state is crucial for the execution of many terminally differentiated cell behaviors during organismal development. However, the mechanisms that maintain the post-mitotic state in this context remain poorly understood. To gain insight into these mechanisms, we used the genetically and visually accessible model of C. elegans anchor cell (AC) invasion into the vulval epithelium. The AC is a terminally differentiated uterine cell that normally exits the cell cycle and enters a post-mitotic state before initiating contact between the uterus and vulva through a cell invasion event. Here, we set out to identify the set of negative cell cycle regulators that maintain the AC in this post-mitotic, invasive state. Our findings revealed a critical role for CKI-1 (p21CIP1/p27KIP1) in redundantly maintaining the post-mitotic state of the AC, as loss of CKI-1 in combination with other negative cell cycle regulators-including CKI-2 (p21CIP1/p27KIP1), LIN-35 (pRb/p107/p130), FZR-1 (Cdh1/Hct1), and LIN-23 (ß-TrCP)-resulted in proliferating ACs. Remarkably, time-lapse imaging revealed that these ACs retain their ability to invade. Upon examination of a node in the gene regulatory network controlling AC invasion, we determined that proliferating, invasive ACs do so by maintaining aspects of pro-invasive gene expression. We therefore report that the requirement for a post-mitotic state for invasive cell behavior can be bypassed following direct cell cycle perturbation.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Mitose , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Mitose/genética , Feminino , Ciclo Celular/genética , Vulva/citologia , Vulva/crescimento & desenvolvimento , Vulva/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular/genética , Movimento Celular/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo
2.
PLoS Biol ; 20(2): e3001549, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35196311

RESUMO

In this issue of PLOS Biology, Lattmann and colleagues report a new function for proteins of the DNA prereplication complex promoting the anchor cell to invade through the basement membrane and initiate vulval development in Caenorhabditis elegans.


Assuntos
Proteínas de Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cromossomos/metabolismo , Feminino , Vulva/crescimento & desenvolvimento , Vulva/metabolismo
3.
Development ; 149(1)2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34982813

RESUMO

During Caenorhabditis elegans vulval development, the uterine anchor cell (AC) first secretes an epidermal growth factor (EGF) to specify the vulval cell fates and then invades the underlying vulval epithelium. By doing so, the AC establishes direct contact with the invaginating primary vulF cells and attaches the developing uterus to the vulva. The signals involved and the exact sequence of events joining these two organs are not fully understood. Using a conditional let-23 EGF receptor (EGFR) allele along with novel microfluidic short- and long-term imaging methods, we discovered a specific function of the EGFR in the AC during vulval lumen morphogenesis. Tissue-specific inactivation of let-23 in the AC resulted in imprecise alignment of the AC with the primary vulval cells, delayed AC invasion and disorganized adherens junctions at the contact site forming between the AC and the dorsal vulF toroid. We propose that EGFR signaling, activated by a reciprocal EGF cue from the primary vulval cells, positions the AC at the vulval midline, guides it during invasion and assembles a cytoskeletal scaffold organizing the adherens junctions that connect the developing uterus to the dorsal vulF toroid. Thus, EGFR signaling in the AC ensures the precise alignment of the two developing organs.


Assuntos
Receptores ErbB/metabolismo , Morfogênese , Transdução de Sinais , Vulva/metabolismo , Junções Aderentes/metabolismo , Animais , Caenorhabditis elegans , Citoesqueleto/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Feminino , Vulva/citologia , Vulva/crescimento & desenvolvimento
4.
PLoS Comput Biol ; 17(6): e1009034, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34061834

RESUMO

Increasing interest has emerged in new mathematical approaches that simplify the study of complex differentiation processes by formalizing Waddington's landscape metaphor. However, a rational method to build these landscape models remains an open problem. Here we study vulval development in C. elegans by developing a framework based on Catastrophe Theory (CT) and approximate Bayesian computation (ABC) to build data-fitted landscape models. We first identify the candidate qualitative landscapes, and then use CT to build the simplest model consistent with the data, which we quantitatively fit using ABC. The resulting model suggests that the underlying mechanism is a quantifiable two-step decision controlled by EGF and Notch-Delta signals, where a non-vulval/vulval decision is followed by a bistable transition to the two vulval states. This new model fits a broad set of data and makes several novel predictions.


Assuntos
Caenorhabditis elegans/citologia , Modelos Biológicos , Animais , Teorema de Bayes , Diferenciação Celular , Fator de Crescimento Epidérmico/metabolismo , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Receptores Notch/metabolismo , Projetos de Pesquisa , Vulva/crescimento & desenvolvimento
5.
Methods Mol Biol ; 2262: 423-436, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33977493

RESUMO

Characterizing the consequences of mutated Ras/LET-60 on the development of the C. elegans vulva has provided critical insights into the role of Ras in normal animal development. Furthermore, double mutant analysis revealed the role of Ras relative to other components of growth factor signal transduction. Here we describe the combined use of principles of parallelism and epistasis to investigate the use of different Ras effectors, Raf and RalGEF > Ral, during the development of the vulva and other tissues. We additionally describe the use of these principles to delineate the function of the close Ras relative, RAP-1. The worm continues to lead the way in clarifying otherwise poorly understood functions of Ras during animal development.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Vulva/crescimento & desenvolvimento , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas rap1 de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Feminino , Transdução de Sinais , Vulva/metabolismo , Proteínas ral de Ligação ao GTP/genética , Proteínas rap1 de Ligação ao GTP/genética , Proteínas ras/genética
6.
Development ; 148(5)2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33526581

RESUMO

The evolutionarily conserved LIN-2 (CASK)/LIN-7 (Lin7A-C)/LIN-10 (APBA1) complex plays an important role in regulating spatial organization of membrane proteins and signaling components. In Caenorhabditiselegans, the complex is essential for the development of the vulva by promoting the localization of the sole Epidermal growth factor receptor (EGFR) ortholog LET-23 to the basolateral membrane of the vulva precursor cells where it can specify the vulval cell fate. To understand how the LIN-2/7/10 complex regulates receptor localization, we determined its expression and localization during vulva development. We found that LIN-7 colocalizes with LET-23 EGFR at the basolateral membrane, whereas the LIN-2/7/10 complex colocalizes with LET-23 EGFR at cytoplasmic punctae that mostly overlap with the Golgi. Furthermore, LIN-10 recruits LIN-2, which in turn recruits LIN-7. We demonstrate that the complex forms in vivo with a particularly strong interaction and colocalization between LIN-2 and LIN-7, consistent with them forming a subcomplex. Thus, the LIN-2/7/10 complex forms on the Golgi on which it likely targets LET-23 EGFR trafficking to the basolateral membrane rather than functioning as a tether.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Receptores ErbB/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Vulva/metabolismo , Animais , Animais Geneticamente Modificados/metabolismo , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Linhagem da Célula , Membrana Celular/metabolismo , Receptores ErbB/genética , Feminino , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Larva/metabolismo , Proteínas de Membrana/genética , Neurônios/metabolismo , Ligação Proteica , Células-Tronco/citologia , Células-Tronco/metabolismo , Vulva/citologia , Vulva/crescimento & desenvolvimento
7.
Development ; 147(24)2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33144396

RESUMO

Activation of a canonical EGFR-Ras-Raf-ERK cascade initiates patterning of multipotent vulval precursor cells (VPCs) of Caenorhabditis elegans We have previously shown that this pathway includes a negative-feedback component in which MPK-1/ERK activity targets the upstream kinase LIN-45/Raf for degradation by the SEL-10/FBXW7 E3 ubiquitin ligase. This regulation requires a Cdc4 phosphodegron (CPD) in LIN-45 that is conserved in BRAF. Here, we identify and characterize the minimal degron that encompasses the CPD and is sufficient for SEL-10-mediated, MPK-1-dependent protein degradation. A targeted screen of conserved protein kinase-encoding genes yielded gsk-3 (an ortholog of human GSK3B) and cdk-2 (a CDK2-related kinase) as required for LIN-45 degron-mediated turnover. Genetic analysis revealed that LIN-45 degradation is blocked at the second larval stage due to cell cycle quiescence, and that relief of this block during the third larval stage relies on activation of CDKs. Additionally, activation of MPK-1 provides spatial pattern to LIN-45 degradation but does not bypass the requirement for gsk-3 and cdk-2 This analysis supports a model whereby MPK-1/ERK, GSK-3/GSK3 and CDK-2/CDK2, along with SEL-10/FBXW7, constitute a regulatory network that exerts spatial and temporal control of LIN-45/Raf degradation during VPC patterning.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Quinase 3 da Glicogênio Sintase/genética , Vulva/crescimento & desenvolvimento , Quinases raf/genética , Animais , Caenorhabditis elegans/genética , Proteínas de Ciclo Celular/genética , Diferenciação Celular/genética , Retroalimentação Fisiológica , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Fosfotransferases/genética , Proteólise , Transdução de Sinais/genética , Ubiquitina-Proteína Ligases , Vulva/metabolismo
8.
Int J Mol Sci ; 21(20)2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076222

RESUMO

The C. elegans vulva is an excellent model for the study of developmental biology and cell-cell signaling. The developmental induction of vulval precursor cells (VPCs) to assume the 3°-3°-2°-1°-2°-3° patterning of cell fates occurs with 99.8% accuracy. During C. elegans vulval development, an EGF signal from the anchor cell initiates the activation of RasLET-60 > RafLIN-45 > MEKMEK-2 > ERKMPK-1 signaling cascade to induce the 1° cell. The presumptive 1° cell signals its two neighboring cells via NotchLIN-12 to develop 2° cells. In addition, RasLET-60 switches effectors to RalGEFRGL-1 > RalRAL-1 to promote 2° fate. Shin et al. (2019) showed that RalGEFRGL-1 is a dual-function protein in VPCs fate patterning. RalGEFRGL-1 functions as a scaffold for PDKPDK-1 > AktAKT-1/2 modulatory signaling to promote 1° fate in addition to propagating the RasLET-60 modulatory signal through RalRAL-1 to promote 2° fate. The deletion of RalGEFRGL-1 increases the frequency of VPC patterning errors 15-fold compared to the wild-type control. We speculate that RalGEFRGL-1 represents an "insulated switch", whereby the promotion of one signaling activity curtails the promotion of the opposing activity. This property might increase the impact of the switch on fidelity more than two separately encoded proteins could. Understanding how developmental fidelity is controlled will help us to better understand the origins of cancer and birth defects, which occur in part due to the misspecification of cell fates.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Linhagem da Célula , Feminino , Modelos Biológicos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Vulva/citologia , Vulva/crescimento & desenvolvimento , Vulva/metabolismo , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
9.
Development ; 147(14)2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32586974

RESUMO

Long-term survival of an animal species depends on development being robust to environmental variations and climate changes. We used C. elegans to study how mechanisms that sense environmental changes trigger adaptive responses that ensure animals develop properly. In water, the nervous system induces an adaptive response that reinforces vulval development through an unknown backup signal for vulval induction. This response involves the heterotrimeric G-protein EGL-30//Gαq acting in motor neurons. It also requires body-wall muscle, which is excited by EGL-30-stimulated synaptic transmission, suggesting a behavioral function of neurons induces backup signal production from muscle. We now report that increased acetylcholine during liquid growth activates an EGL-30-Rho pathway, distinct from the synaptic transmission pathway, that increases Wnt production from motor neurons. We also provide evidence that this neuronal Wnt contributes to EGL-30-stimulated vulval development, with muscle producing a parallel developmental signal. As diverse sensory modalities stimulate motor neurons via acetylcholine, this mechanism enables broad sensory perception to enhance Wnt-dependent development. Thus, sensory perception improves animal fitness by activating distinct neuronal functions that trigger adaptive changes in both behavior and developmental processes.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Neurônios/metabolismo , Proteínas Wnt/metabolismo , Acetilcolina/metabolismo , Citoesqueleto de Actina , Animais , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Fator de Crescimento Epidérmico/metabolismo , Feminino , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Genótipo , Mutagênese , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Transdução de Sinais , Transmissão Sináptica/genética , Vulva/crescimento & desenvolvimento , Vulva/metabolismo , Proteínas Wnt/genética
10.
PLoS Genet ; 16(6): e1008838, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544191

RESUMO

Reactive oxygen species (ROS) are signalling molecules whose study in intact organisms has been hampered by their potential toxicity. This has prevented a full understanding of their role in organismal processes such as development, aging and disease. In Caenorhabditis elegans, the development of the vulva is regulated by a signalling cascade that includes LET-60ras (homologue of mammalian Ras), MPK-1 (ERK1/2) and LIN-1 (an ETS transcription factor). We show that both mitochondrial and cytoplasmic ROS act on a gain-of-function (gf) mutant of the LET-60ras protein through a redox-sensitive cysteine (C118) previously identified in mammals. We show that the prooxidant paraquat as well as isp-1, nuo-6 and sod-2 mutants, which increase mitochondrial ROS, inhibit the activity of LET-60rasgf on vulval development. In contrast, the antioxidant NAC and loss of sod-1, both of which decrease cytoplasmic H202, enhance the activity of LET-60rasgf. CRISPR replacement of C118 with a non-oxidizable serine (C118S) stimulates LET-60rasgf activity, whereas replacement of C118 with aspartate (C118D), which mimics a strongly oxidised cysteine, inhibits LET-60rasgf. These data strongly suggest that C118 is oxidized by cytoplasmic H202 generated from dismutation of mitochondrial and/or cytoplasmic superoxide, and that this oxidation inhibits LET-60ras. This contrasts with results in cultured mammalian cells where it is mostly nitric oxide, which is not found in worms, that oxidizes C118 and activates Ras. Interestingly, PQ, NAC and the C118S mutation do not act on the phosphorylation of MPK-1, suggesting that oxidation of LET-60ras acts on an as yet uncharacterized MPK-1-independent pathway. We also show that elevated cytoplasmic superoxide promotes vulva formation independently of C118 of LET-60ras and downstream of LIN-1. Finally, we uncover a role for the NADPH oxidases (BLI-3 and DUOX-2) and their redox-sensitive activator CED-10rac in stimulating vulva development. Thus, there are at least three genetically separable pathways by which ROS regulates vulval development.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Peróxidos/metabolismo , Vulva/crescimento & desenvolvimento , Proteínas ras/genética , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Feminino , Mutação com Ganho de Função , Genes de Helmintos/genética , Oxirredução , Oxirredutases/metabolismo , Peróxidos/análise , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo
11.
Development ; 147(11)2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32439759

RESUMO

The anchor cell (AC) in C. elegans secretes an epidermal growth factor (EGF) homolog that induces adjacent vulval precursor cells (VPCs) to differentiate. The EGF receptor in the nearest VPC sequesters the limiting EGF amounts released by the AC to prevent EGF from spreading to distal VPCs. Here, we show that not only EGFR localization in the VPCs but also EGF polarity in the AC is necessary for robust fate specification. The AC secretes EGF in a directional manner towards the nearest VPC. Loss of AC polarity causes signal spreading and, when combined with MAPK pathway hyperactivation, the ectopic induction of distal VPCs. In a screen for genes preventing distal VPC induction, we identified sra-9 and nlp-26 as genes specifically required for polarized EGF secretion. sra-9(lf) and nlp-26(lf) mutants exhibit errors in vulval fate specification, reduced precision in VPC to AC alignment and increased variability in MAPK activation. sra-9 encodes a seven-pass transmembrane receptor acting in the AC and nlp-26 a neuropeptide-like protein expressed in the VPCs. SRA-9 and NLP-26 may transduce a feedback signal to channel EGF secretion towards the nearest VPC.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Vulva/metabolismo , Animais , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/metabolismo , Sistemas CRISPR-Cas/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/genética , Fator de Crescimento Epidérmico/antagonistas & inibidores , Fator de Crescimento Epidérmico/genética , Receptores ErbB/metabolismo , Feminino , Edição de Genes , Larva/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutagênese , Netrinas/genética , Netrinas/metabolismo , Interferência de RNA , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismo , Vulva/citologia , Vulva/crescimento & desenvolvimento , Proteínas Ativadoras de ras GTPase/antagonistas & inibidores , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/metabolismo
12.
BMC Genet ; 21(1): 28, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32164558

RESUMO

BACKGROUND: Reproductive performance is critical for efficient swine production. Recent results indicated that vulva size (VS) may be predictive of reproductive performance in sows. Study objectives were to estimate genetic parameters, identify genomic regions associated, and estimate genomic prediction accuracies (GPA) for VS traits. RESULTS: Heritability estimates of VS traits, vulva area (VA), height (VH), and width (VW) measurements, were moderately to highly heritable in Yorkshire, with 0.46 ± 0.10, 0.55 ± 0.10, 0.31 ± 0.09, respectively, whereas these estimates were low to moderate in Landrace, with 0.16 ± 0.09, 0.24 ± 0.11, and 0.08 ± 0.06, respectively. Genetic correlations within VS traits were very high for both breeds, with the lowest of 0.67 ± 0.29 for VH and VW for Landrace. Genome-wide association studies (GWAS) for Landrace, reveled genomic region associated with VS traits on Sus scrofa chromosome (SSC) 2 (154-157 Mb), 7 (107-110 Mb), 8 (4-6 Mb), and 10 (8-19 Mb). For Yorkshire, genomic regions on SSC 1 (87-91 and 282-287 Mb) and 5 (67 Mb) were identified. All regions explained at least 3.4% of the genetic variance. Accuracies of genomic prediction were moderate in Landrace, ranging from 0.30 (VH) to 0.61 (VA), and lower for Yorkshire, with 0.07 (VW) to 0.11 (VH). Between-breed and multi-breed genomic prediction accuracies were low. CONCLUSIONS: Our findings suggest that VS traits are heritable in Landrace and Yorkshire gilts. Genomic analyses show that major QTL control these traits, and they differ between breed. Genomic information can be used to increase genetic gains for these traits in gilts. Additional research must be done to validate the GWAS and genomic prediction results reported in our study.


Assuntos
Genômica , Reprodução/genética , Vulva/anatomia & histologia , Animais , Cruzamento , Feminino , Genoma , Fenótipo , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Sus scrofa/genética , Vulva/crescimento & desenvolvimento
13.
Mol Biol Evol ; 37(5): 1350-1361, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31960924

RESUMO

Comparative genomic sequence analysis has found that the genes for many chromatin-associated proteins are poorly conserved, but the biological consequences of these sequence changes are not understood. Here, we show that four genes identified for an Inappropriate Vulval cell Proliferation (ivp) phenotype in the nematode Caenorhabditis briggsae exhibit distinct functions and genetic interactions when compared with their orthologs in C. elegans. Specifically, we show that the four C. briggsae ivp genes encode the noncanonical histone HTZ-1/H2A.z and three nematode-specific proteins predicted to function in the nucleus. The mutants exhibit ectopic vulval precursor cell proliferation (the multivulva [Muv] phenotype) due to inappropriate expression of the lin-3/EGF gene, and RNAseq analysis suggests a broad role for these ivp genes in transcriptional repression. Importantly, although the C. briggsae phenotypes have parallels with those seen in the C. elegans synMuv system, except for the highly conserved HTZ-1/H2A.z, comparable mutations in C. elegans ivp orthologs do not exhibit synMuv gene interactions or phenotypes. These results demonstrate the evolutionary changes that can underlie conserved biological outputs and argue that proteins critical to repress inappropriate expression from the genome participate in a rapidly evolving functional landscape.


Assuntos
Caenorhabditis/genética , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Animais , Caenorhabditis/crescimento & desenvolvimento , Caenorhabditis/metabolismo , Feminino , Histonas/metabolismo , Proteínas Nucleares/genética , Vulva/crescimento & desenvolvimento
14.
J Genet Genomics ; 47(11): 694-704, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33547005

RESUMO

Mitochondria are the central hub for many metabolic processes, including the citric acid cycle, oxidative phosphorylation, and fatty acid oxidation. Recent studies have identified a new mitochondrial protein family, Fam210, that regulates bone metabolism and red cell development in vertebrates. The model organism Caenorhabditis elegans has a Fam210 gene, y56a3a.22, but it lacks both bones and red blood cells. In this study, we report that Y56A3A.22 plays a crucial role in regulating mitochondrial protein homeostasis and reproduction. The nematode y56a3a.22 is expressed in various tissues, including the intestine, muscle, hypodermis, and germline, and its encoded protein is predominantly localized in mitochondria. y56a3a.22 deletion mutants are sterile owing to impaired oogenesis. Loss of Y56A3A.22 induced mitochondrial unfolded protein response (UPRmt), which is mediated through the ATFS-1-dependent pathway, in tissues such as the intestine, germline, hypodermis, and vulval muscle. We further show that infertility and UPRmt induces by Y56A3A.22 deficiency are not attributed to systemic iron deficiency. Together, our study reveals an important role of Y56A3A.22 in regulating mitochondrial protein homeostasis and oogenesis and provides a new genetic tool for exploring the mechanisms regulating mitochondrial metabolism and reproduction as well as the fundamental role of the Fam210 family.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Mitocôndrias/genética , Oogênese/genética , Fatores de Transcrição/genética , Resposta a Proteínas não Dobradas/genética , Animais , Osso e Ossos/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Eritrócitos/metabolismo , Feminino , Células Germinativas/crescimento & desenvolvimento , Células Germinativas/metabolismo , Humanos , Intestinos/crescimento & desenvolvimento , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Reprodução/genética , Transdução de Sinais/genética , Vulva/crescimento & desenvolvimento , Vulva/metabolismo
15.
PLoS Genet ; 15(5): e1008056, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31086367

RESUMO

The six C. elegans vulval precursor cells (VPCs) are induced to form the 3°-3°-2°-1°-2°-3° pattern of cell fates with high fidelity. In response to EGF signal, the LET-60/Ras-LIN-45/Raf-MEK-2/MEK-MPK-1/ERK canonical MAP kinase cascade is necessary to induce 1° fate and synthesis of DSL ligands for the lateral Notch signal. In turn, LIN-12/Notch receptor is necessary to induce neighboring cells to become 2°. We previously showed that, in response to graded EGF signal, the modulatory LET-60/Ras-RGL-1/RalGEF-RAL-1/Ral signal promotes 2° fate in support of LIN-12. In this study, we identify two key differences between RGL-1 and RAL-1. First, deletion of RGL-1 confers no overt developmental defects, while previous studies showed RAL-1 to be essential for viability and fertility. From this observation, we hypothesize that the essential functions of RAL-1 are independent of upstream activation. Second, RGL-1 plays opposing and genetically separable roles in VPC fate patterning. RGL-1 promotes 2° fate via canonical GEF-dependent activation of RAL-1. Conversely, RGL-1 promotes 1° fate via a non-canonical GEF-independent activity. Our genetic epistasis experiments are consistent with RGL-1 functioning in the modulatory 1°-promoting AGE-1/PI3-Kinase-PDK-1-AKT-1 cascade. Additionally, animals lacking RGL-1 experience 15-fold higher rates of VPC patterning errors compared to the wild type. Yet VPC patterning in RGL-1 deletion mutants is not more sensitive to environmental perturbations. We propose that RGL-1 functions to orchestrate opposing 1°- and 2°-promoting modulatory cascades to decrease developmental stochasticity. We speculate that such switches are broadly conserved but mostly masked by paralog redundancy or essential functions.


Assuntos
Caenorhabditis elegans/genética , Fator de Crescimento Epidérmico/genética , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/genética , Vulva/metabolismo , Animais , Padronização Corporal/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Epistasia Genética , Feminino , Fertilidade/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismo , Vulva/citologia , Vulva/crescimento & desenvolvimento , Quinases raf/genética , Quinases raf/metabolismo , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
16.
Life Sci Alliance ; 2(2)2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30910805

RESUMO

The juvenile-to-adult (J/A) transition, or puberty, is a period of extensive changes of animal body morphology and function. The onset of puberty is genetically controlled, and the let-7 miRNA temporally regulates J/A transition events in nematodes and mammals. Here, we uncover the targets and downstream pathways through which Caenorhabditis elegans let-7 controls male and female sexual organ morphogenesis and skin progenitor cell fates. We find that let-7 directs all three processes by silencing a single target, the post-transcriptional regulator lin-41 In turn, the RNA-binding protein LIN41/TRIM71 regulates these processes by silencing only four target mRNAs. Thus, by silencing LIN41, let-7 activates LIN-29a and MAB-10 (an early growth response-type transcription factor and its NAB1/2-orthologous cofactor, respectively) to terminate progenitor cell self-renewal and to promote vulval integrity. By contrast, let-7 promotes development of the male sexual organ by up-regulating DMD-3 and MAB-3, two Doublesex/MAB-3 domain-containing transcription factors. Our results provide mechanistic insight into how a linear chain of post-transcriptional regulators diverges in the control of a small set of transcriptional regulators to achieve a coordinated J/A transition.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , MicroRNAs/genética , Maturidade Sexual/genética , Fatores de Transcrição/genética , Alelos , Animais , Animais Geneticamente Modificados , Proteína 9 Associada à CRISPR/genética , Proteínas de Ligação a DNA/genética , Feminino , Masculino , Fenótipo , Transativadores/genética , Transgenes , Vulva/crescimento & desenvolvimento
17.
Genetics ; 211(4): 1315-1330, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30700527

RESUMO

Genetic screens in the nematode Caenorhabditis elegans identified the EGF/Ras and Notch pathways as central for vulval precursor cell fate patterning. Schematically, the anchor cell secretes EGF, inducing the P6.p cell to a primary (1°) vulval fate; P6.p in turn induces its neighbors to a secondary (2°) fate through Delta-Notch signaling and represses Ras signaling. In the nematode Oscheius tipulae, the anchor cell successively induces 2° then 1° vulval fates. Here, we report on the molecular identification of mutations affecting vulval induction in O. tipulae A single Induction Vulvaless mutation was found, which we identify as a cis-regulatory deletion in a tissue-specific enhancer of the O. tipulae lin-3 homolog, confirmed by clustered regularly interspaced short palindromic repeats/Cas9 mutation. In contrast to this predictable Vulvaless mutation, mutations resulting in an excess of 2° fates unexpectedly correspond to the plexin/semaphorin pathway. Hyperinduction of P4.p and P8.p in these mutants likely results from mispositioning of these cells due to a lack of contact inhibition. The third signaling pathway found by forward genetics in O. tipulae is the Wnt pathway; a decrease in Wnt pathway activity results in loss of vulval precursor competence and induction, and 1° fate miscentering on P5.p. Our results suggest that the EGF and Wnt pathways have qualitatively similar activities in vulval induction in C. elegans and O. tipulae, albeit with quantitative differences in the effects of mutation. Thus, the derived induction process in C. elegans with an early induction of the 1° fate appeared during evolution, after the recruitment of the EGF pathway for vulval induction.


Assuntos
Fator de Crescimento Epidérmico/metabolismo , Proteínas de Helminto/genética , Nematoides/genética , Semaforinas/genética , Vulva/crescimento & desenvolvimento , Via de Sinalização Wnt , Animais , Fator de Crescimento Epidérmico/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Helminto/metabolismo , Mutação , Nematoides/crescimento & desenvolvimento , Nematoides/metabolismo , Semaforinas/metabolismo , Vulva/metabolismo
18.
Sci Rep ; 8(1): 16736, 2018 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-30425296

RESUMO

AP endonuclease deficiency causes cell death and embryonic lethality in mammals. However, the physiological roles of AP endonucleases in multicellular organisms remain unclear, especially after embryogenesis. Here, we report novel physiological roles of the AP endonuclease EXO-3 from larval to adult stages in Caenorhabditis elegans, and elucidated the mechanism of the observed phenotypes due to EXO-3 deficiency. The exo-3 mutants exhibited developmental delay, whereas the apn-1 mutants did not. The delay depended on the DNA glycosylase NTH-1 and checkpoint kinase CHK-2. The exo-3 mutants had further developmental delay when treated with AP site-generating agents such as methyl methane sulfonate and sodium bisulfite. The further delay due to sodium bisulfite was dependent on the DNA glycosylase UNG-1. The exo-3 mutants also demonstrated an increase in dut-1 (RNAi)-induced abnormal vulval organogenesis protruding vulva (Pvl), whereas the apn-1 mutants did not. The increase in Pvl was dependent on UNG-1 and CHK-2. Methyl viologen, ndx-1 (RNAi) and ndx-2 (RNAi) enhanced the incidence of Pvl among exo-3 mutants only when combined with dut-1 (RNAi). This further increase in Pvl incidence was independent of NTH-1. These results indicate that EXO-3 prevents developmental delay and Pvl in C. elegans, which are induced via DNA glycosylase-initiated checkpoint activation.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/crescimento & desenvolvimento , DNA Glicosilases/metabolismo , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/deficiência , Mutação , Organogênese/genética , Vulva/anormalidades , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Quinase do Ponto de Checagem 2/metabolismo , Dano ao DNA , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/genética , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Fenótipo , Vulva/crescimento & desenvolvimento
19.
Genetics ; 210(4): 1339-1354, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30257933

RESUMO

The notoriety of the small GTPase Ras as the most mutated oncoprotein has led to a well-characterized signaling network largely conserved across metazoans. Yet the role of its close relative Rap1 (Ras Proximal), which shares 100% identity between their core effector binding sequences, remains unclear. A long-standing controversy in the field is whether Rap1 also functions to activate the canonical Ras effector, the S/T kinase Raf. We used the developmentally simpler Caenorhabditis elegans, which lacks the extensive paralog redundancy of vertebrates, to examine the role of RAP-1 in two distinct LET-60/Ras-dependent cell fate patterning events: induction of 1° vulval precursor cell (VPC) fate and of the excretory duct cell. Fluorescence-tagged endogenous RAP-1 is localized to plasma membranes and is expressed ubiquitously, with even expression levels across the VPCs. RAP-1 and its activating GEF PXF-1 function cell autonomously and are necessary for maximal induction of 1° VPCs. Critically, mutationally activated endogenous RAP-1 is sufficient both to induce ectopic 1°s and duplicate excretory duct cells. Like endogenous RAP-1, before induction GFP expression from the pxf-1 promoter is uniform across VPCs. However, unlike endogenous RAP-1, after induction GFP expression is increased in presumptive 1°s and decreased in presumptive 2°s. We conclude that RAP-1 is a positive regulator that promotes Ras-dependent inductive fate decisions. We hypothesize that PXF-1 activation of RAP-1 serves as a minor parallel input into the major LET-60/Ras signal through LIN-45/Raf.


Assuntos
Padronização Corporal/genética , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas ras/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Diferenciação Celular/genética , Linhagem da Célula/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Mutação , Transdução de Sinais/genética , Vulva/crescimento & desenvolvimento , Quinases raf/genética
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