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1.
Development ; 148(14)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34313318

RESUMO

Heterozygosity of ribosomal protein genes causes a variety of developmental abnormalities in humans, which are collectively known as ribosomopathies, yet the underlying mechanisms remain elusive. Here, we analyzed Drosophila Minute (M)/+ mutants, a group of mutants heterozygous for ribosomal protein genes that exhibit a characteristic thin-bristle phenotype. We found that, although M/+ flies develop essentially normal wings, simultaneous deletion of one copy of the Hippo pathway effector yki resulted in severe wing growth defects. These defects were caused by JNK-mediated cell death in the wing pouch via Eiger/TNF signaling. The JNK activation in M/+, yki/+ wing discs required the caspase Dronc, which is normally blocked by DIAP1. Notably, heterozygosity of yki reduced DIAP1 expression in the wing pouch, leading to elevation of Dronc activity. Dronc and JNK formed a positive-feedback loop that amplifies Dronc activation, leading to apoptosis. Our observations suggest a mechanism of robust tissue growth whereby tissues with reduced ribosomal protein prevent ectopic apoptosis via Yki activity.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Animais , Apoptose , Morte Celular , Regulação para Baixo , Drosophila/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Inibidoras de Apoptose/metabolismo , Proteínas Nucleares/genética , Transdução de Sinais , Transativadores/genética , Asas de Animais/anatomia & histologia , Asas de Animais/metabolismo
2.
Nat Commun ; 12(1): 2892, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001903

RESUMO

Flying insects have invaded all the aerial space on Earth and this astonishing radiation could not have been possible without a remarkable morphological diversification of their flight appendages. Here, we show that characteristic spatial expression profiles and levels of the Hox genes Antennapedia (Antp) and Ultrabithorax (Ubx) underlie the formation of two different flight organs in the fruit fly Drosophila melanogaster. We further demonstrate that flight appendage morphology is dependent on specific Hox doses. Interestingly, we find that wing morphology from evolutionary distant four-winged insect species is also associated with a differential expression of Antp and Ubx. We propose that variation in the spatial expression profile and dosage of Hox proteins is a major determinant of flight appendage diversification in Drosophila and possibly in other insect species during evolution.


Assuntos
Proteína do Homeodomínio de Antennapedia/genética , Proteínas de Drosophila/genética , Voo Animal , Proteínas de Homeodomínio/genética , Fatores de Transcrição/genética , Animais , Proteína do Homeodomínio de Antennapedia/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Dosagem de Genes , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/metabolismo , Asas de Animais/anatomia & histologia , Asas de Animais/metabolismo
3.
Nat Commun ; 12(1): 2159, 2021 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-33846330

RESUMO

N6-methyladenosine (m6A), the most abundant internal modification in eukaryotic mRNA, is installed by a multi-component writer complex; however, the exact roles of each component remain poorly understood. Here we show that a potential E3 ubiquitin ligase Hakai colocalizes and interacts with other m6A writer components, and Hakai mutants exhibit typical m6A pathway defects in Drosophila, such as lowered m6A levels in mRNA, aberrant Sxl alternative splicing, wing and behavior defects. Hakai, Vir, Fl(2)d and Flacc form a stable complex, and disruption of either Hakai, Vir or Fl(2)d led to the degradation of the other three components. Furthermore, MeRIP-seq indicates that the effective m6A modification is mostly distributed in 5' UTRs in Drosophila, in contrast to the mammalian system. Interestingly, we demonstrate that m6A modification is deposited onto the Sxl mRNA in a sex-specific fashion, which depends on the m6A writer. Together, our work not only advances the understanding of mechanism and regulation of the m6A writer complex, but also provides insights into how Sxl cooperate with the m6A pathway to control its own splicing.


Assuntos
Adenosina/análogos & derivados , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Regiões 5' não Traduzidas/genética , Adenosina/metabolismo , Processamento Alternativo/genética , Animais , Sequência de Bases , Comportamento Animal , Códon de Iniciação/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Feminino , Proteínas de Fluorescência Verde/metabolismo , Masculino , Metilação , Mutação/genética , Ligação Proteica , Subunidades Proteicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Caracteres Sexuais , Ubiquitina-Proteína Ligases/genética , Asas de Animais/metabolismo
4.
J Cell Biol ; 220(5)2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33734293

RESUMO

Cytonemes are specialized filopodia that mediate paracrine signaling in Drosophila and other animals. Studies using fluorescence confocal microscopy (CM) established their general paths, cell targets, and essential roles in signaling. To investigate details unresolvable by CM, we used high-pressure freezing and EM to visualize cytoneme structures, paths, contents, and contacts. We observed cytonemes previously seen by CM in the Drosophila wing imaginal disc system, including disc, tracheal air sac primordium (ASP), and myoblast cytonemes, and identified cytonemes extending into invaginations of target cells, and cytonemes connecting ASP cells and connecting myoblasts. Diameters of cytoneme shafts vary between repeating wide (206 ± 51.8 nm) and thin (55.9 ± 16.2 nm) segments. Actin, ribosomes, and membranous compartments are present throughout; rough ER and mitochondria are in wider proximal sections. These results reveal novel structural features of filopodia and provide a basis for understanding cytoneme cell biology and function.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Actinas/metabolismo , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Mioblastos/metabolismo , Pseudópodes/metabolismo , Transdução de Sinais/fisiologia , Asas de Animais/metabolismo
5.
Development ; 148(7)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33653875

RESUMO

Hedgehog (Hh) ligands orchestrate tissue patterning and growth by acting as morphogens, dictating different cellular responses depending on ligand concentration. Cellular sensitivity to Hh ligands is influenced by heterotrimeric G protein activity, which controls production of the second messenger 3',5'-cyclic adenosine monophosphate (cAMP). cAMP in turn activates Protein kinase A (PKA), which functions as an inhibitor and (uniquely in Drosophila) as an activator of Hh signalling. A few mammalian Gαi- and Gαs-coupled G protein-coupled receptors (GPCRs) have been shown to influence Sonic hedgehog (Shh) responses in this way. To determine whether this is a more-general phenomenon, we carried out an RNAi screen targeting GPCRs in Drosophila. RNAi-mediated depletion of more than 40% of GPCRs tested either decreased or increased Hh responsiveness in the developing Drosophila wing, closely matching the effects of Gαs and Gαi depletion, respectively. Genetic analysis indicated that the orphan GPCR Mthl5 lowers cAMP levels to attenuate Hh responsiveness. Our results identify Mthl5 as a new Hh signalling pathway modulator in Drosophila and suggest that many GPCRs may crosstalk with the Hh pathway in mammals.


Assuntos
Drosophila/metabolismo , Proteínas Hedgehog/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Animais , Animais Geneticamente Modificados , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Proteínas Hedgehog/genética , Proteínas Heterotriméricas de Ligação ao GTP/genética , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Masculino , Fenótipo , Receptores Acoplados a Proteínas G/genética , Asas de Animais/anatomia & histologia , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
6.
Dev Genes Evol ; 231(3-4): 85-93, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33774724

RESUMO

A polka-dotted fruit fly, Drosophila guttifera, has a unique pigmentation pattern on its wings and is used as a model for evo-devo studies exploring the mechanism of evolutionary gain of novel traits. In this species, a morphogen-encoding gene, wingless, is expressed in species-specific positions and induces a unique pigmentation pattern. To produce some of the pigmentation spots on wing veins, wingless is thought to be expressed in developing campaniform sensillum cells, but it was unknown which of the four cell types there express(es) wingless. Here we show that two of the cell types, dome cells and socket cells, express wingless, as indicated by in situ hybridization together with immunohistochemistry. This is a unique case in which non-neuronal SOP (sensory organ precursor) progeny cells produce Wingless as an inducer of pigmentation pattern formation. Our finding opens a path to clarifying the mechanism of evolutionary gain of a unique wingless expression pattern by analyzing gene regulation in dome cells and socket cells.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Pigmentação/genética , Proteína Wnt1/genética , Animais , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Sensilas/citologia , Sensilas/metabolismo , Asas de Animais/metabolismo , Proteína Wnt1/metabolismo
7.
Genetics ; 217(1): 1-9, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33683353

RESUMO

The eyespot patterns found on the wings of nymphalid butterflies are novel traits that originated first in hindwings and subsequently in forewings, suggesting that eyespot development might be dependent on Hox genes. Hindwings differ from forewings in the expression of Ultrabithorax (Ubx), but the function of this Hox gene in eyespot development as well as that of another Hox gene Antennapedia (Antp), expressed specifically in eyespots centers on both wings, are still unclear. We used CRISPR-Cas9 to target both genes in Bicyclus anynana butterflies. We show that Antp is essential for eyespot development on the forewings and for the differentiation of white centers and larger eyespots on hindwings, whereas Ubx is essential not only for the development of at least some hindwing eyespots but also for repressing the size of other eyespots. Additionally, Antp is essential for the development of silver scales in male wings. In summary, Antp and Ubx, in addition to their conserved roles in modifying serially homologous segments along the anterior-posterior axis of insects, have acquired a novel role in promoting the development of a new set of serial homologs, the eyespot patterns, in both forewings (Antp) and hindwings (Antp and Ubx) of B. anynana butterflies. We propose that the peculiar pattern of eyespot origins on hindwings first, followed by forewings, could be due to an initial co-option of Ubx into eyespot development followed by a later, partially redundant, co-option of Antp into the same network.


Assuntos
Borboletas/genética , Proteínas de Homeodomínio/genética , Proteínas de Insetos/genética , Pigmentação , Animais , Borboletas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Proteínas de Insetos/metabolismo , Masculino , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
8.
Elife ; 102021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33749594

RESUMO

In both vertebrates and invertebrates, generating a functional appendage requires interactions between ectoderm-derived epithelia and mesoderm-derived cells. To investigate such interactions, we used single-cell transcriptomics to generate a temporal cell atlas of the Drosophila wing disc from two developmental time points. Using these data, we visualized gene expression using a multilayered model of the wing disc and cataloged ligand-receptor pairs that could mediate signaling between epithelial cells and adult muscle precursors (AMPs). We found that localized expression of the fibroblast growth factor ligands, Thisbe and Pyramus, in the disc epithelium regulates the number and location of the AMPs. In addition, Hedgehog ligand from the epithelium activates a specific transcriptional program within adjacent AMP cells, defined by AMP-specific targets Neurotactin and midline, that is critical for proper formation of direct flight muscles. More generally, our annotated temporal cell atlas provides an organ-wide view of potential cell-cell interactions between epithelial and myogenic cells.


Assuntos
Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Discos Imaginais/crescimento & desenvolvimento , Transcriptoma , Animais , Epitélio/fisiologia , Discos Imaginais/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Mioblastos/fisiologia , Análise de Célula Única , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
9.
PLoS Biol ; 19(3): e3001111, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33657096

RESUMO

Development of the Drosophila wing-a paradigm of organ development-is governed by 2 morphogens, Decapentaplegic (Dpp, a BMP) and Wingless (Wg, a Wnt). Both proteins are produced by defined subpopulations of cells and spread outwards, forming gradients that control gene expression and cell pattern as a function of concentration. They also control growth, but how is unknown. Most studies have focused on Dpp and yielded disparate models in which cells throughout the wing grow at similar rates in response to the grade or temporal change in Dpp concentration or to the different amounts of Dpp "equalized" by molecular or mechanical feedbacks. In contrast, a model for Wg posits that growth is governed by a progressive expansion in morphogen range, via a mechanism in which a minimum threshold of Wg sustains the growth of cells within the wing and recruits surrounding "pre-wing" cells to grow and enter the wing. This mechanism depends on the capacity of Wg to fuel the autoregulation of vestigial (vg)-the selector gene that specifies the wing state-both to sustain vg expression in wing cells and by a feed-forward (FF) circuit of Fat (Ft)/Dachsous (Ds) protocadherin signaling to induce vg expression in neighboring pre-wing cells. Here, we have subjected Dpp to the same experimental tests used to elucidate the Wg model and find that it behaves indistinguishably. Hence, we posit that both morphogens act together, via a common mechanism, to control wing growth as a function of morphogen range.


Assuntos
Proteínas de Drosophila/genética , Asas de Animais/crescimento & desenvolvimento , Proteína Wnt1/genética , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Homeostase , Morfogênese , Proteínas Nucleares/metabolismo , Transdução de Sinais , Asas de Animais/metabolismo , Proteínas Wnt/metabolismo
10.
PLoS One ; 16(3): e0241729, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735177

RESUMO

Silver nanoparticles (AgNPs) are among the most widely synthesized and used nanoparticles (NPs). AgNPs have been traditionally synthesized from plant extracts, cobwebs, microorganisms, etc. However, their synthesis from wing extracts of common insect; Mang mao which is abundantly available in most of the Asian countries has not been explored yet. We report the synthesis of AgNPs from M. mao wings extract and its antioxidant and antimicrobial activity. The synthesized AgNPs were spherical, 40-60 nm in size and revealed strong absorption plasmon band around at 430 nm. Highly crystalline nature of these particles as determined by Energy-dispersive X-ray analysis and X-ray diffraction further confirmed the presence of AgNPs. Hydrodynamic size and zeta potential of AgNPs were observed to be 43.9 nm and -7.12 mV, respectively. Fourier-transform infrared spectroscopy analysis revealed the presence of characteristic amide proteins and aromatic functional groups. Thin-layer chromatography (TLC) and Gas chromatography-mass spectroscopy (GC-MS) analysis revealed the presence of fatty acids in the wings extract that may be responsible for biosynthesis and stabilization of AgNPs. Further, SDS-PAGE of the insect wing extract protein showed the molecular weight of 49 kDa. M. mao silver nanoparticles (MMAgNPs) exhibit strong antioxidant, broad-range antibacterial and antifungal activities, (66.8 to 87.0%), broad-range antibacterial and antifungal activities was found with maximum zone of inhibition against Staphylococcus aureus MTCC 96 (35±0.4 mm) and Fusarium oxysporum f. sp. ricini (86.6±0.4) which signifies their biomedical and agricultural potential.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Nanopartículas Metálicas/química , Prata/química , Asas de Animais/química , Animais , Anti-Infecciosos/farmacologia , Fusarium/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Insetos , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Asas de Animais/metabolismo
11.
Insect Biochem Mol Biol ; 131: 103551, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33556555

RESUMO

Matrix metalloproteinases (MMPs) are the major proteinases that process or degrade numerous extracellular matrix (ECM) components and are evolutionarily conserved from nematodes to humans. During molting in insects, the old cuticle is removed and replaced by a new counterpart. Although the regulatory mechanisms of hormones and nutrients in molting have been well studied, very little is known about the roles of ECM-modifying enzymes in this process. Here, we found that MMPs are necessary for imaginal molting of the American cockroach, Periplaneta americana. Inhibition of Mmp activity via inhibitor treatment led to the failure of eclosion and wing expansion. Five Mmps genes were identified from the P. americana genome, and PaMmp2 played the dominant roles during molting. Further microscopic investigations showed that newly formed adult cuticles were attenuated and that then chitin content was reduced upon Mmp inhibition. Transcriptomic analysis of the integument demonstrated that multiple signaling and metabolic pathways were changed. Microscopic investigation of the wings showed that epithelial cells were restrained together because they were incapable of degrading the ECM upon Mmp inhibition. Transcriptomic analysis of the wing identified dozens of possible genes functioned in wing expansion. This is the first study to show the essential roles of Mmps in the nymph-adult transition of hemimetabolous insects.


Assuntos
Metaloproteinases da Matriz , Periplaneta , Asas de Animais , Animais , Quitina/metabolismo , Perfilação da Expressão Gênica , Genes de Insetos , Larva/metabolismo , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Metamorfose Biológica , Muda , Ninfa/metabolismo , Periplaneta/embriologia , Periplaneta/genética , Periplaneta/metabolismo , Periplaneta/fisiologia , Asas de Animais/embriologia , Asas de Animais/metabolismo
12.
EMBO Rep ; 22(4): e51861, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33629503

RESUMO

While the membrane potential of cells has been shown to be patterned in some tissues, specific roles for membrane potential in regulating signalling pathways that function during development are still being established. In the Drosophila wing imaginal disc, Hedgehog (Hh) from posterior cells activates a signalling pathway in anterior cells near the boundary which is necessary for boundary maintenance. Here, we show that membrane potential is patterned in the wing disc. Anterior cells near the boundary, where Hh signalling is most active, are more depolarized than posterior cells across the boundary. Elevated expression of the ENaC channel Ripped Pocket (Rpk), observed in these anterior cells, requires Hh. Antagonizing Rpk reduces depolarization and Hh signal transduction. Using genetic and optogenetic manipulations, in both the wing disc and the salivary gland, we show that membrane depolarization promotes membrane localization of Smoothened and augments Hh signalling, independently of Patched. Thus, membrane depolarization and Hh-dependent signalling mutually reinforce each other in cells immediately anterior to the compartment boundary.


Assuntos
Proteínas de Drosophila , Proteínas Hedgehog , Animais , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Proteínas Hedgehog/genética , Discos Imaginais/metabolismo , Potenciais da Membrana , Transdução de Sinais , Asas de Animais/metabolismo
13.
PLoS Genet ; 17(2): e1009312, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33561165

RESUMO

Wing polymorphism is an evolutionary feature found in a wide variety of insects, which offers a model system for studying the evolutionary significance of dispersal. In the wing-dimorphic planthopper Nilaparvata lugens, the insulin/insulin-like growth factor signaling (IIS) pathway acts as a 'master signal' that directs the development of either long-winged (LW) or short-winged (SW) morphs via regulation of the activity of Forkhead transcription factor subgroup O (NlFoxO). However, downstream effectors of the IIS-FoxO signaling cascade that mediate alternative wing morphs are unclear. Here we found that vestigial (Nlvg), a key wing-patterning gene, is selectively and temporally regulated by the IIS-FoxO signaling cascade during the wing-morph decision stage (fifth-instar stage). RNA interference (RNAi)-mediated silencing of Nlfoxo increase Nlvg expression in the fifth-instar stage (the last nymphal stage), thereby inducing LW development. Conversely, silencing of Nlvg can antagonize the effects of IIS activity on LW development, redirecting wing commitment from LW to the morph with intermediate wing size. In vitro and in vivo binding assays indicated that NlFoxO protein may suppress Nlvg expression by directly binding to the first intron region of the Nlvg locus. Our findings provide a first glimpse of the link connecting the IIS pathway to the wing-patterning network on the developmental plasticity of wings in insects, and help us understanding how phenotypic diversity is generated by the modification of a common set of pattern elements.


Assuntos
Proteína Forkhead Box O1/metabolismo , Hemípteros/metabolismo , Proteínas de Insetos/metabolismo , Somatomedinas/metabolismo , Asas de Animais/crescimento & desenvolvimento , Animais , Proteína Forkhead Box O1/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Técnicas de Inativação de Genes , Ontologia Genética , Inativação Gênica , Hemípteros/genética , Hemípteros/crescimento & desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas de Insetos/genética , Íntrons , Fenótipo , Ligação Proteica , Interferência de RNA , Somatomedinas/genética , Análise Espaço-Temporal , Asas de Animais/metabolismo
14.
Mol Cells ; 44(1): 13-25, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33510049

RESUMO

Apoptosis and compensatory proliferation, two intertwined cellular processes essential for both development and adult homeostasis, are often initiated by the mis-regulation of centrosomal proteins, damaged DNA, and defects in mitosis. Fly Anastral spindle 3 (Ana3) is a member of the pericentriolar matrix proteins and known as a key component of centriolar cohesion and basal body formation. We report here that ana3m19 is a suppressor of lethality induced by the overexpression of Sol narae (Sona), a metalloprotease in a disintegrin and metalloprotease with thrombospondin motif (ADAMTS) family. ana3m19 has a nonsense mutation that truncates the highly conserved carboxyl terminal region containing multiple Armadillo repeats. Lethality induced by Sona overexpression was completely rescued by knockdown of Ana3, and the small and malformed wing and hinge phenotype induced by the knockdown of Ana3 was also normalized by Sona overexpression, establishing a mutually positive genetic interaction between ana3 and sona. p35 inhibited apoptosis and rescued the small wing and hinge phenotype induced by knockdown of ana3. Furthermore, overexpression of Ana3 increased the survival rate of irradiated flies and reduced the number of dying cells, demonstrating that Ana3 actively promotes cell survival. Knockdown of Ana3 decreased the levels of both intra- and extracellular Sona in wing discs, while overexpression of Ana3 in S2 cells dramatically increased the levels of both cytoplasmic and exosomal Sona due to the stabilization of Sona in the lysosomal degradation pathway. We propose that one of the main functions of Ana3 is to stabilize Sona for cell survival and proliferation.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Metaloendopeptidases/metabolismo , Animais , Apoptose/genética , Sobrevivência Celular , Proteínas de Drosophila/genética , Epistasia Genética , Exossomos/metabolismo , Técnicas de Silenciamento de Genes , Metaloendopeptidases/genética , Mutação/genética , Estabilidade Proteica , Asas de Animais/metabolismo
15.
Science ; 371(6527): 396-400, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33479152

RESUMO

Sexual dimorphism in animals results from sex-biased gene expression patterns. These patterns are controlled by genetic sex determination hierarchies that establish the sex of an individual. Here we show that the male-biased wing expression pattern of the Drosophila biarmipes gene yellow, located on the X chromosome, is independent of the fly sex determination hierarchy. Instead, we find that a regulatory interaction between yellow alleles on homologous chromosomes (a process known as transvection) silences the activity of a yellow enhancer functioning in the wing. Therefore, this enhancer can be active in males (XY) but not in females (XX). This transvection-dependent enhancer silencing requires the yellow intron and the chromatin architecture protein Mod(mdg4). Our results suggest that transvection can contribute more generally to the sex-biased expression of X-linked genes.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Regulação da Expressão Gênica , Genes Ligados ao Cromossomo X , Caracteres Sexuais , Cromossomo X/genética , Alelos , Animais , Elementos Facilitadores Genéticos , Feminino , Masculino , Fatores Sexuais , Asas de Animais/metabolismo
16.
Proc Natl Acad Sci U S A ; 118(4)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33479178

RESUMO

Regulation of microtubule stability is crucial for the maintenance of cell structure and function. While the acetylation of α-tubulin lysine 40 by acetylase has been implicated in the regulation of microtubule stability, the in vivo functions of N-terminal acetyltransferases (NATs) involved in the acetylation of N-terminal amino acids are not well known. Here, we identify an N-terminal acetyltransferase, Mnat9, that regulates cell signaling and microtubule stability in Drosophila Loss of Mnat9 causes severe developmental defects in multiple tissues. In the wing imaginal disc, Mnat9 RNAi leads to the ectopic activation of c-Jun N-terminal kinase (JNK) signaling and apoptotic cell death. These defects are suppressed by reducing the level of JNK signaling. Overexpression of Mnat9 can also inhibit JNK signaling. Mnat9 colocalizes with mitotic spindles, and its loss results in various spindle defects during mitosis in the syncytial embryo. Furthermore, overexpression of Mnat9 enhances microtubule stability. Mnat9 is physically associated with microtubules and shows a catalytic activity in acetylating N-terminal peptides of α- and ß-tubulin in vitro. Cell death and tissue loss in Mnat9-depleted wing discs are restored by reducing the severing protein Spastin, suggesting that Mnat9 protects microtubules from its severing activity. Remarkably, Mnat9 mutated in the acetyl-CoA binding site is as functional as its wild-type form. We also find that human NAT9 can rescue Mnat9 RNAi phenotypes in flies, indicating their functional conservation. Taken together, we propose that Mnat9 is required for microtubule stability and regulation of JNK signaling to promote cell survival in developing Drosophila organs.


Assuntos
Drosophila melanogaster/genética , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Acetiltransferases N-Terminal/genética , Animais , Apoptose/genética , Drosophila melanogaster/crescimento & desenvolvimento , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Discos Imaginais/crescimento & desenvolvimento , Discos Imaginais/metabolismo , Microtúbulos/genética , Mitose/genética , Transdução de Sinais/genética , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
17.
PLoS Genet ; 17(1): e1009300, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33507966

RESUMO

Highly reproducible tissue development is achieved by robust, time-dependent coordination of cell proliferation and cell death. To study the mechanisms underlying robust tissue growth, we analyzed the developmental process of wing imaginal discs in Drosophila Minute mutants, a series of heterozygous mutants for a ribosomal protein gene. Minute animals show significant developmental delay during the larval period but develop into essentially normal flies, suggesting there exists a mechanism ensuring robust tissue growth during abnormally prolonged developmental time. Surprisingly, we found that both cell death and compensatory cell proliferation were dramatically increased in developing wing pouches of Minute animals. Blocking the cell-turnover by inhibiting cell death resulted in morphological defects, indicating the essential role of cell-turnover in Minute wing morphogenesis. Our analyses showed that Minute wing discs elevate Wg expression and JNK-mediated Dilp8 expression that causes developmental delay, both of which are necessary for the induction of cell-turnover. Furthermore, forced increase in Wg expression together with developmental delay caused by ecdysone depletion induced cell-turnover in the wing pouches of non-Minute animals. Our findings suggest a novel paradigm for robust coordination of tissue growth by cell-turnover, which is induced when developmental time axis is distorted.


Assuntos
Proteínas de Drosophila/genética , Discos Imaginais/crescimento & desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas Ribossômicas/genética , Proteína Wnt1/genética , Animais , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Ecdisona/genética , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Discos Imaginais/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Metamorfose Biológica/genética , Organogênese/genética , Transdução de Sinais/genética , Fatores de Transcrição/genética , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
18.
Nat Cell Biol ; 23(2): 127-135, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33495632

RESUMO

Ribosomes are multicomponent molecular machines that synthesize all of the proteins of living cells. Most of the genes that encode the protein components of ribosomes are therefore essential. A reduction in gene dosage is often viable albeit deleterious and is associated with human syndromes, which are collectively known as ribosomopathies1-3. The cell biological basis of these pathologies has remained unclear. Here, we model human ribosomopathies in Drosophila and find widespread apoptosis and cellular stress in the resulting animals. This is not caused by insufficient protein synthesis, as reasonably expected. Instead, ribosomal protein deficiency elicits proteotoxic stress, which we suggest is caused by the accumulation of misfolded proteins that overwhelm the protein degradation machinery. We find that dampening the integrated stress response4 or autophagy increases the harm inflicted by ribosomal protein deficiency, suggesting that these activities could be cytoprotective. Inhibition of TOR activity-which decreases ribosomal protein production, slows down protein synthesis and stimulates autophagy5-reduces proteotoxic stress in our ribosomopathy model. Interventions that stimulate autophagy, combined with means of boosting protein quality control, could form the basis of a therapeutic strategy for this class of diseases.


Assuntos
Mutação/genética , Proteínas/toxicidade , Ribossomos/genética , Ribossomos/patologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Alelos , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Células HEK293 , Heterozigoto , Humanos , Discos Imaginais/efeitos dos fármacos , Discos Imaginais/metabolismo , Agregados Proteicos/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Proteômica , Proteínas Ribossômicas/biossíntese , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Asas de Animais/efeitos dos fármacos , Asas de Animais/metabolismo
19.
FEBS J ; 288(1): 99-110, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32307851

RESUMO

How evolutionary novelties have arisen is one of the central questions in evolutionary biology. Preexisting gene regulatory networks or signaling pathways have been shown to be co-opted for building novel traits in several organisms. However, the structure of entire gene regulatory networks and evolutionary events of gene co-option for emergence of a novel trait are poorly understood. In this study, to explore the genetic and molecular bases of the novel wing pigmentation pattern of a polka-dotted fruit fly (Drosophila guttifera), we performed de novo genome sequencing and transcriptome analyses. As a result, we comprehensively identified the genes associated with the pigmentation pattern. Furthermore, we revealed that 151 of these associated genes were positively or negatively regulated by wingless, a master regulator of wing pigmentation. Genes for neural development, Wnt signaling, Dpp signaling, and effectors (such as enzymes) for melanin pigmentation were included among these 151 genes. None of the known regulatory genes that regulate pigmentation pattern formation in other fruit fly species were included. Our results suggest that the novel pigmentation pattern of a polka-dotted fruit fly might have emerged through multistep co-options of multiple gene regulatory networks, signaling pathways, and effector genes, rather than recruitment of one large gene circuit.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Neurogênese/genética , Pigmentação/genética , Transcriptoma , Asas de Animais/metabolismo , Proteína Wnt1/genética , Animais , Evolução Biológica , Drosophila/crescimento & desenvolvimento , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Melaninas/genética , Melaninas/metabolismo , Sistema Nervoso/citologia , Sistema Nervoso/crescimento & desenvolvimento , Sistema Nervoso/metabolismo , Fenótipo , Transdução de Sinais , Asas de Animais/crescimento & desenvolvimento , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteína Wnt1/metabolismo
20.
EMBO J ; 40(3): e104895, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33320356

RESUMO

The Hippo signaling pathway is a major regulator of organ growth, which controls the activity of the transcription coactivator Yorkie (Yki) in Drosophila and its homolog YAP in mammals. Both Yki and YAP proteins exist as alternatively spliced isoforms containing either one or two WW domains. The biological importance of this conserved alternative splicing event is unknown. Here, we identify the splicing factor B52 as a regulator of yki alternative splicing in Drosophila and show that B52 modulates growth in part through modulation of yki alternative splicing. Yki isoforms differ by their transcriptional activity as well as their ability to bind and bridge PPxY motifs-containing partners, and can compete in vivo. Strikingly, flies in which yki alternative splicing has been abrogated, thus expressing only Yki2 isoform, exhibit fluctuating wing asymmetry, a signal of developmental instability. Our results identify yki alternative splicing as a new level of modulation of the Hippo pathway, that is required for growth equilibration during development. This study provides the first demonstration that the process of alternative splicing contributes to developmental robustness.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fatores de Processamento de RNA/metabolismo , Transativadores/genética , Transativadores/metabolismo , Processamento Alternativo , Animais , Linhagem Celular , Proteínas de Drosophila/química , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Proteínas Nucleares/química , Ligação Proteica , Domínios Proteicos , Fatores de Processamento de RNA/genética , Análise de Sequência de RNA , Transativadores/química , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
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