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1.
PLoS Genet ; 16(8): e1008942, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32764744

RESUMO

To remodel functional neuronal connectivity, neurons often alter dendrite arbors through elimination and subsequent regeneration of dendritic branches. However, the intrinsic mechanisms underlying this developmentally programmed dendrite regeneration and whether it shares common machinery with injury-induced regeneration remain largely unknown. Drosophila class IV dendrite arborization (C4da) sensory neurons regenerate adult-specific dendrites after eliminating larval dendrites during metamorphosis. Here we show that the microRNA miR-87 is a critical regulator of dendrite regeneration in Drosophila. miR-87 knockout impairs dendrite regeneration after developmentally-programmed pruning, whereas miR-87 overexpression in C4da neurons leads to precocious initiation of dendrite regeneration. Genetic analyses indicate that the transcriptional repressor Tramtrack69 (Ttk69) is a functional target for miR-87-mediated repression as ttk69 expression is increased in miR-87 knockout neurons and reducing ttk69 expression restores dendrite regeneration to mutants lacking miR-87 function. We further show that miR-87 is required for dendrite regeneration after acute injury in the larval stage, providing a mechanistic link between developmentally programmed and injury-induced dendrite regeneration. These findings thus indicate that miR-87 promotes dendrite regrowth during regeneration at least in part through suppressing Ttk69 in Drosophila sensory neurons and suggest that developmental and injury-induced dendrite regeneration share a common intrinsic mechanism to reactivate dendrite growth.


Assuntos
Proteínas de Drosophila/genética , Metamorfose Biológica/genética , MicroRNAs/genética , Regeneração Nervosa/genética , Proteínas Repressoras/genética , Animais , Dendritos/genética , Dendritos/fisiologia , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Larva/genética , Larva/crescimento & desenvolvimento , Células Receptoras Sensoriais/metabolismo
2.
PLoS One ; 15(4): e0231451, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32282855

RESUMO

Insect molting hormone (ecdysteroids) and juvenile hormone regulate molting and metamorphic events in a variety of insect species. Mealybugs undergo sexually dimorphic metamorphosis: males develop into winged adults through non-feeding, pupa-like stages called prepupa and pupa, while females emerge as neotenic wingless adults. We previously demonstrated, in the Japanese mealybug Planococcus kraunhiae (Kuwana), that the juvenile hormone titer is higher in males than in females at the end of the juvenile stage, which suggests that juvenile hormone may regulate male-specific adult morphogenesis. Here, we examined the involvement of ecdysteroids in sexually dimorphic metamorphosis. To estimate ecdysteroid titers, quantitative RT-PCR analyses of four Halloween genes encoding for cytochrome P450 monooxygenases in ecdysteroid biosynthesis, i.e., spook, disembodied, shadow and shade, were performed. Overall, their expression levels peaked before each nymphal molt. Transcript levels of spook, disembodied and shadow, genes that catalyze the steps in ecdysteroid biosynthesis in the prothoracic gland, were higher in males from the middle of the second nymphal instar to adult emergence. In contrast, the expression of shade, which was reported to be involved in the conversion of ecdysone into 20-hydroxyecdysone in peripheral tissues, was similar between males and females. These results suggest that ecdysteroid biosynthesis in the prothoracic gland is more active in males than in females, although the final conversion into 20-hydroxyecdysone occurs at similar levels in both sexes. Moreover, expression profiles of ecdysone response genes, ecdysone receptor and ecdysone-induced protein 75B, were also analyzed. Based on these expression profiles, we propose that the changes in ecdysteroid titer differ between males and females, and that high ecdysteroid titer is essential for directing male adult development.


Assuntos
Ecdisona/genética , Ecdisteroides/genética , Proteínas de Insetos/genética , Insetos/genética , Animais , Sistema Enzimático do Citocromo P-450/genética , Ecdisterona/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Insetos/crescimento & desenvolvimento , Hormônios Juvenis/genética , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Metamorfose Biológica/genética , Morfogênese/genética , Pupa/genética , Pupa/crescimento & desenvolvimento , Caracteres Sexuais , Asas de Animais/crescimento & desenvolvimento
3.
Gene ; 743: 144610, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32205235

RESUMO

The American cockroach (Periplaneta americana), which is one of the most ancient insects in the world, is characterized by incomplete metamorphosis. So far, no one has studied the microRNA profile of P. americana and the changes in the expression of microRNAs on different developmental stages. In this study, we sequenced the small RNAs (sRNA) of four samples at four post-embryonic developmental stages. A total of 35 conserved known mature miRNAs and 134 novel mature miRNAs were identified. After differential expression analysis, we noticed there were more miRNA expressed differentially during early post-embryonic stages. We also found about one-third of known miRNAs were significantly dynamic. After a cross-species comparative analysis, we identified two miRNAs (miR-1000 and miR-932) that may be important for morphogenesis, olfactory, learning, and memory. In addition, unlike hetero-metabolous insects, miRNAs still played an important role in late post-embryonic stages in holo-metabolous insects. In conclusion, our results underline the significance of miRNA expression in post-embryonic developmental stages of the American cockroach and push forward the understanding of gene expression modulation by miRNAs in cockroach. This would also contribute to the study of gene expression regulation by miRNAs during metamorphosis development.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Metamorfose Biológica/genética , MicroRNAs/metabolismo , Periplaneta/fisiologia , Animais , Cognição , Feminino , Perfilação da Expressão Gênica , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , MicroRNAs/genética , MicroRNAs/isolamento & purificação , Análise de Sequência de RNA
4.
J Therm Biol ; 88: 102483, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32125973

RESUMO

The morphological and biological characteristics of ectothermic vertebrates are known to be strongly influenced by environmental conditions, particularly temperature. Epigenetic mechanisms such as DNA methylation have been reported to contribute to the phenotypic plasticity observed in vertebrates in response to environmental changes. Additionally, DNA methylation is a dynamic process that occurs throughout vertebrate ontogeny and it has been associated with the activation and silencing of gene expression during post-embryonic development and metamorphosis. In this study, we investigated genome-wide DNA methylation profiles during turbot metamorphosis, as well as the epigenetic effects of temperature on turbot post-embryonic development. Fish growth and rates of development were greatly affected by rearing temperature. Thus, turbot raised at ambient temperature (18 °C) achieved greater body weights and progressed through development more quickly than those reared at a colder temperature (14 °C). Genome-wide DNA methylation dynamics analyzed via a methylation-sensitive amplified polymorphism (MSAP) technique were not significantly different between animals reared within the two different thermal environments. Furthermore, comparisons between phenotypically similar fish revealed that genome-wide DNA methylation profiles do not necessarily correlate with specific developmental stages in turbot.


Assuntos
Metilação de DNA , Linguados/crescimento & desenvolvimento , Linguados/genética , Metamorfose Biológica/genética , Temperatura , Animais , Regulação da Expressão Gênica no Desenvolvimento , Genoma
5.
J Therm Biol ; 88: 102493, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32125981

RESUMO

Heat shock proteins (HSPs) greatly contribute to insect stress tolerance and enhance survival and adaptation in severe environmental conditions. To investigate the potential roles of HSPs in the spruce budworm, Choristoneura fumiferana (L.), an important native pest of forests in North America, we found eight ATP-dependent HSP transcripts (CfHSPs). Based on molecular characteristics, the identified HSP genes were classified into HSP70 and HSP90 families, and phylogenetic results showed that they had orthologues in other insects. The transcript levels of these HSPs were measured using RT-qPCR under normal and stressful conditions in the laboratory. Under normal conditions, three HSP genes were consistently expressed in all life stages, whereas expression of the other five genes was dependent on the developmental stage. In the larvae, most CfHSP transcripts displayed similar expression levels among different tissues. Under heat shock conditions, one HSP70 gene and one HSP90 gene were upregulated in all life stages. One HSP70 gene was upregulated after cold injury in the larval stage. With starvation, HSP gene expression exhibited complex expression patterns; most of them were downregulated. These results suggest that the ATP-dependent HSPs have multiple roles during normal development as well as under stressful conditions including heat, cold injury and starvation.


Assuntos
Resposta ao Choque Frio/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP90/genética , Resposta ao Choque Térmico/genética , Proteínas de Insetos/genética , Metamorfose Biológica/genética , Mariposas/genética , Inanição/genética , Trifosfato de Adenosina , Animais , Feminino , Larva , Masculino , Filogenia , Pupa , Transcriptoma , Zigoto
6.
Development ; 147(5)2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32051172

RESUMO

Neural remodeling is essential for the development of a functional nervous system and has been extensively studied in the metamorphosis of Drosophila Despite the crucial roles of glial cells in brain functions, including learning and behavior, little is known of how adult glial cells develop in the context of neural remodeling. Here, we show that the architecture of neuropil-glia in the adult Drosophila brain, which is composed of astrocyte-like glia (ALG) and ensheathing glia (EG), robustly develops from two different populations in the larva: the larval EG and glial cell missing-positive (gcm+ ) cells. Whereas gcm + cells proliferate and generate adult ALG and EG, larval EG dedifferentiate, proliferate and redifferentiate into the same glial subtypes. Each glial lineage occupies a certain brain area complementary to the other, and together they form the adult neuropil-glia architecture. Both lineages require the FGF receptor Heartless to proliferate, and the homeoprotein Prospero to differentiate into ALG. Lineage-specific inhibition of gliogenesis revealed that each lineage compensates for deficiency in the proliferation of the other. Together, the lineages ensure the robust development of adult neuropil-glia, thereby ensuring a functional brain.


Assuntos
Astrócitos/citologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Proteínas do Tecido Nervoso/metabolismo , Neurogênese/fisiologia , Neurópilo/citologia , Proteínas Nucleares/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Encéfalo/citologia , Encéfalo/embriologia , Linhagem da Célula/fisiologia , Proliferação de Células/fisiologia , Proteínas de Ligação a DNA/metabolismo , Drosophila melanogaster/metabolismo , Metamorfose Biológica/genética , Metamorfose Biológica/fisiologia , Neurogênese/genética
7.
Gen Comp Endocrinol ; 291: 113419, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32032606

RESUMO

Stress hormones, also known as glucocorticoids, are critical for survival at birth in mammals due at least in part to their importance in lung maturation. However, because air breathing is not always required for amphibian survival and because stress hormones have no known developmental impact except to modulate the developmental actions of thyroid hormone (TH), the requirement for stress hormone signaling during metamorphosis is not well understoodi. Here, we produced a glucocorticoid receptor knockout (GRKO) Xenopus line with a frameshift mutation in the first exon of the glucocorticoid receptor. Induction by exogenous corticosterone (CORT, the frog stress hormone) of the CORT response genes, klf9 (Krüppel-like factor 9, also regulated by TH) and ush1g (Usher's syndrome 1G), was completely abrogated in GRKO tadpoles. Surprisingly, GRKO tadpoles developed faster than wild-type tadpoles until forelimb emergence and then developed more slowly until their death at the climax of metamorphosis. Growth rate was not affected in GRKO tadpoles, but they achieved a smaller maximum size. Gene expression analysis of the TH response genes, thrb (TH receptor beta) and klf9 showed reduced expression in the tail at metamorphic climax consistent with the reduced development rate. These results indicate that glucocorticoid receptor is required for survival through metamorphosis and support dual roles for GR signaling in control of developmental rate.


Assuntos
Metamorfose Biológica , Receptores de Glucocorticoides/metabolismo , Xenopus/crescimento & desenvolvimento , Xenopus/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Cruzamento , Sistemas CRISPR-Cas/genética , Corticosterona/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Técnicas de Inativação de Genes , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Metamorfose Biológica/genética , Mutação/genética , Receptores de Glucocorticoides/química , Receptores de Glucocorticoides/genética , Hormônios Tireóideos/metabolismo
8.
Gen Comp Endocrinol ; 292: 113441, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32084349

RESUMO

In the intestine during metamorphosis of the frog Xenopus laevis, most of the larval epithelial cells are induced to undergo apoptosis by thyroid hormone (TH), and under continued TH action, the remaining epithelial cells dedifferentiate into stem cells (SCs), which then newly generate an adult epithelium analogous to the mammalian intestinal epithelium. Previously, we have shown that the precursors of the SCs that exist in the larval epithelium as differentiated absorptive cells specifically express receptor tyrosine kinase-like orphan receptor 2 (Ror2). By using Ror2 as a marker, we have immunohistochemically shown here that these SC precursors, but not the larval epithelial cells destined to die by apoptosis, express TH receptor α (TRα). Upon initiation of TH-dependent remodeling, TRα expression remains restricted to the SCs as well as proliferating adult epithelial primordia derived from them. As intestinal folds form, TRα expression becomes localized in the trough of the folds where the SCs reside. In contrast, TRß expression is transiently up-regulated in the entire intestine concomitantly with the increase of endogenous TH levels and is most highly expressed in the developing adult epithelial primordia. Moreover, we have shown here that global histone H4 acetylation is enhanced in the SC precursors and adult primordia including the SCs, while tri-methylation of histone H3 lysine 27 is lacking in those cells during metamorphosis. Our results strongly suggest distinct roles of TRα and TRß in the intestinal larval-to-adult remodeling, involving distinctive epigenetic modifications in the SC lineage.


Assuntos
Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Intestinos/crescimento & desenvolvimento , Metamorfose Biológica/genética , Receptores dos Hormônios Tireóideos/metabolismo , Células-Tronco/citologia , Xenopus laevis/genética , Acetilação , Animais , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Histonas/metabolismo , Larva/metabolismo , Metilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores dos Hormônios Tireóideos/genética , Células-Tronco/metabolismo , Fatores de Tempo , Xenopus laevis/metabolismo
9.
Sci Rep ; 10(1): 2577, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054934

RESUMO

As a stage of life cycle, larval settlement and metamorphosis are critical processes for persistence of many marine invertebrate populations. Bacterial biofilms (BFs) could induce larval settlement and metamorphosis. Pseudoalteromonas, a widely distributed genus of marine bacteria, showed inductive effects on several invertebrates. However, how Pseudoalteromonas BFs induce settlement and metamorphosis of Mytilus coruscus remains unclear. Pseudoalteromonas marina BFs with the highest inducing activity were further investigated to define inductive cues. Surface-bound products of P. marina BFs could induce larval settlement and metamorphosis. P. marina BFs treated with formalin, antibiotics, ultraviolet irradiation, heat and ethanol significantly reduced inductive effects and cell survival rates. The confocal laser scanning microscopy and the biovolume analysis showed the dominance of α-polysaccharides on P. marina BFs. Treatment of BFs with amylases, proteases and lipase led to the decrease of inducing activity, suggesting that inductive cues of P. marina BFs may comprise of molecular domains of polysaccharides, proteins, and lipids. Finding inductive cues of BFs could put forward further studies about the mechanism of larval settlement and metamorphosis of marine invertebrates.


Assuntos
Biofilmes/crescimento & desenvolvimento , Metamorfose Biológica/genética , Mytilus/microbiologia , Pseudoalteromonas/genética , Animais , Larva/crescimento & desenvolvimento , Larva/microbiologia , Estágios do Ciclo de Vida/genética , Mytilus/genética , Mytilus/crescimento & desenvolvimento , Pseudoalteromonas/crescimento & desenvolvimento
10.
BMC Genomics ; 21(1): 171, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075574

RESUMO

BACKGROUND: Lepidoptera is one group of the largest plant-feeding insects and Spodoptera litura (Lepidoptera: Noctuidae) is one of the most serious agricultural pests in Asia countries. An interesting and unique phenomenon for gonad development of Lepidoptera is the testicular fusion. Two separated testes fused into a single one during the larva-to-pupa metamorphosis, which is believed to contribute to sperm production and the prevalence in field. To study the molecular mechanism of the testicular fusion, RNA sequencing (RNA-seq) experiments of the testes from 4-day-old sixth instar larvae (L6D4) (before fusion), 6-day-old sixth instar larvae (L6D6, prepupae) (on fusing) and 4-day-old pupae (P4D) (after fusion) of S. litura were performed. RESULTS: RNA-seq data of the testes showed that totally 12,339 transcripts were expressed at L6D4, L6D6 and P4D stages. A large number of differentially expressed genes (DEGs) were up-regulated from L6D4 to L6D6, and then more genes were down-regulated from L6D6 to P4D. The DEGs mainly belongs to the genes related to the 20E signal transduction pathway, transcription factors, chitin metabolism related enzymes, the families of cytoskeleton proteins, extracellular matrix (ECM) components, ECM-related protein, its receptor integrins and ECM-remodeling enzymes. The expression levels of these genes that were up-regulated significantly during the testicular fusion were verified by qRT-PCR. The matrix metalloproteinases (MMPs) were found to be the main enzymes related to the ECM degradation and contribute to the testicular fusion. The testis was not able to fuse if MMPs inhibitor GM6001 was injected into the 5th abdomen region at L6D6 early stage. CONCLUSIONS: The transcriptome and DEGs analysis of the testes at L6D4, L6D6 and P4D stages provided genes expression information related to the testicular fusion in S. litura. These results indicated that cytoskeleton proteins, ECM-integrin interaction genes and ECM-related proteins were involved in cell migration, adhesion and fusion during the testicular fusion. The ECM degradation enzymes MMPs probably play a critical role in the fusion of testis.


Assuntos
Metaloproteinases da Matriz/fisiologia , Metamorfose Biológica/genética , Spodoptera/genética , Testículo/metabolismo , Transcriptoma , Animais , Matriz Extracelular/enzimologia , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/fisiologia , Larva/genética , Masculino , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Pupa/genética , Análise de Sequência de RNA , Spodoptera/enzimologia , Spodoptera/crescimento & desenvolvimento , Testículo/enzimologia , Testículo/crescimento & desenvolvimento
11.
Development ; 147(6)2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32094114

RESUMO

How temporal cues combine with spatial inputs to control gene expression during development is poorly understood. Here, we test the hypothesis that the Drosophila transcription factor E93 controls temporal gene expression by regulating chromatin accessibility. Precocious expression of E93 early in wing development reveals that it can simultaneously activate and deactivate different target enhancers. Notably, the precocious patterns of enhancer activity resemble the wild-type patterns that occur later in development, suggesting that expression of E93 alters the competence of enhancers to respond to spatial cues. Genomic profiling reveals that precocious E93 expression is sufficient to regulate chromatin accessibility at a subset of its targets. These accessibility changes mimic those that normally occur later in development, indicating that precocious E93 accelerates the wild-type developmental program. Further, we find that target enhancers that do not respond to precocious E93 in early wings become responsive after a developmental transition, suggesting that parallel temporal pathways work alongside E93. These findings support a model wherein E93 expression functions as an instructive cue that defines a broad window of developmental time through control of chromatin accessibility.


Assuntos
Cromatina/metabolismo , Proteínas de Drosophila/genética , Desenvolvimento Embrionário/genética , Elementos Facilitadores Genéticos/fisiologia , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Cromatina/química , Montagem e Desmontagem da Cromatina/fisiologia , Drosophila/embriologia , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Metamorfose Biológica/genética , Ligação Proteica , Fatores de Transcrição/genética , Asas de Animais/embriologia , Asas de Animais/metabolismo
12.
Biofouling ; 35(9): 986-996, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31724449

RESUMO

Metamorphosis is crucial in the life-cycle transition between the larval and juvenile stages of marine invertebrates. Although a number of agonists and antagonists of the adrenergic receptor (AR) are known to regulate larval metamorphosis in Mytilus coruscus (Mc), the molecular basis of the modulation of larval metamorphosis by the AR gene in this species remains elusive. Herein, the role of the AR gene in M. coruscus larval metamorphosis using the RNA interference technique was examined. The Mcα2AR transcript was observed to be present during the entire process of larval development and its level in the post-larvae was significantly increased compared to that in the pediveligers. Mcα2AR-knockdown resulted in a substantial reduction in the abundance of the Mcα2AR transcript and significantly inhibited the metamorphosis of M. coruscus larvae. These findings provide new insights into the molecular basis of modulation of larval metamorphosis in M. coruscus by the AR gene.


Assuntos
Larva/fisiologia , Metamorfose Biológica/genética , Mytilus/fisiologia , Receptores Adrenérgicos alfa 2/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , Larva/genética , Mytilus/genética , Interferência de RNA , RNA Interferente Pequeno/genética
13.
Am Nat ; 194(6): 854-864, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31738099

RESUMO

Genome size varies widely among organisms and is known to affect vertebrate development, morphology, and physiology. In amphibians, genome size is hypothesized to contribute to loss of late-forming structures, although this hypothesis has mainly been discussed in salamanders. Here we estimated genome size for 22 anuran species and combined this novel data set with existing genome size data for an additional 234 anuran species to determine whether larger genome size is associated with loss of a late-forming anuran sensory structure, the tympanic middle ear. We established that genome size is negatively correlated with development rate across 90 anuran species and found that genome size evolution is correlated with evolutionary loss of the middle ear bone (columella) among 241 species (224 eared and 17 earless). We further tested whether the development of the tympanic middle ear could be constrained by large cell sizes and small body sizes during key stages of tympanic middle ear development (metamorphosis). Together, our evidence suggests that larger genomes, slower development rate, and smaller body sizes at metamorphosis may contribute to the loss of the anuran tympanic middle ear. We conclude that increases in anuran genome size, although less drastic than those in salamanders, may affect development of late-forming traits.


Assuntos
Anuros/crescimento & desenvolvimento , Anuros/genética , Tamanho do Genoma , Animais , Anuros/anatomia & histologia , Evolução Biológica , Tamanho Corporal , Orelha Média/anatomia & histologia , Orelha Média/crescimento & desenvolvimento , Metamorfose Biológica/genética
14.
J Insect Sci ; 19(5)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31612946

RESUMO

Insect hormones regulate metamorphosis including that leading to sexual dimorphism. Using RNA-Seq, we discovered that the second-instar male larva (SM) of the white wax insect, Ericerus pela, have 5,968 and 8,620 differentially expressed transcripts compared with the second-instar female larva (SF) and the first-instar male larva (FM), respectively. The expression levels of genes involved in the apoptosis of old tissues and the reconstruction of new ones in the SM significantly enhanced, while the SF mainly has enhanced expression levels of anabolic genes such as chitin. We predicted that the second-instar larvae are the developmental origin of sexual dimorphic metamorphosis. Meanwhile, in the juvenile hormone (JH) metabolic pathway, CYP15A1 and JH esterase (JHE) are differentially expressed; and in the 20-hydroxyecdysone (20E) metabolic pathway, CYP307A1, CYP314A1, and CYP18A1 are differentially expressed. In the SM, the expression levels of CYP307A1 and CYP314A1 are significantly increased, whereas the expression level of CYP18A1 is significantly decreased; in the SF, the expression levels of the above genes are opposite to that of the SM. Expression trends of RNA-seq is consistent with the expression level of qRT-PCR, and seven of them are highly correlated (R ≥ 0.610) and four are moderately correlated (0.588 ≥ R ≥ 0.542).


Assuntos
Regulação da Expressão Gênica/fisiologia , Hemípteros/genética , Proteínas de Insetos/genética , Hormônios Juvenis/genética , Metamorfose Biológica/genética , Animais , Feminino , Hemípteros/crescimento & desenvolvimento , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Masculino , Ninfa/genética , Ninfa/crescimento & desenvolvimento
15.
Am Nat ; 194(3): 356-366, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31553218

RESUMO

Whenever genetically correlated traits experience antagonistic selection, an adaptive response in one trait can lead to a maladaptive response in the correlated trait. This is a form of genome-level conflict that can have important evolutionary consequences by impeding organisms from reaching their adaptive optima. Antagonistic selection should be pervasive in organisms with complex life histories because larval and adult life stages specialize in dramatically different environments. Since individuals express larval and adult morphologies from a single genome, genomic conflict across ontogenetic stages should also be prevalent. Using wood frogs as a study system, we measured natural selection on larval and postmetamorphic life stages and estimated genetic correlations among traits. Alternative life stages experienced a mix of both antagonistic and congruent viability selection. The integration between traits changed over the course of metamorphosis, reducing genetic correlations that cause conflict. Our results provide novel experimental evidence that metamorphosis can alleviate genomic conflict by partitioning life-history stages into modules that can more readily respond to selection. These results highlight the adaptive potential of metamorphosis as a means to avoid ecological specialization trade-offs. Moreover, they provide insights into the prevalence and evolutionary maintenance of complex life cycles.


Assuntos
Metamorfose Biológica/genética , Ranidae/crescimento & desenvolvimento , Ranidae/genética , Seleção Genética , Animais , Besouros , Colubridae , Feminino , Genoma , Larva/genética , Larva/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Masculino , Comportamento Predatório
16.
PLoS One ; 14(9): e0222261, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31525738

RESUMO

Condition indices aim to evaluate the physiological status of fish larvae by estimating both the level of starvation and potential of survival. Histological indices reveal direct effects of starvation whereas biochemical indices such as lipid classes or RNA:DNA ratios are used as proxies of condition, giving information on the amount of energy reserves and growth rate, respectively. We combined these three indices to evaluate ontogenetic variations of growth performance, lipid dynamics and nutritional condition of plaice larvae caught in the field during winter 2017 in the eastern English Channel and the Southern Bight of the North Sea. RNA:DNA ratios showed that larvae at the beginning of metamorphosis (stage 4) had a lower growth rate than younger individuals (stages 2 and 3). A significant increase in the proportion of triglycerides also occurred at stage 4, indicating energy storage. Histological indices indicated that most of the larvae were in good condition, even younger ones with low lipid reserves. There was, however, an increase in the proportion of healthy individuals over ontogeny, especially with respect to liver vacuoles which were larger and more numerous for stage 4 larvae. Combined together, these condition indices revealed the ontogenetic shift in the energy allocation strategy of plaice larvae. Young larvae (stages 2 and 3) primarily allocate energy towards somatic growth. The decrease in growth performance for stage 4 was not related to poor condition, but linked to a higher proportion of energy stored as lipids. Since the quantity of lipid reserves is particularly important for plaice larvae to withstand starvation during metamorphosis, this could be considered as a second critical period after the one of exogenous feeding for larval survival and recruitment success.


Assuntos
Metabolismo Energético/fisiologia , Linguado/fisiologia , Larva/fisiologia , Animais , DNA/genética , Metabolismo Energético/genética , Linguado/genética , Variação Genética/genética , Larva/genética , Lipídeos/genética , Fígado/fisiologia , Metamorfose Biológica/genética , Mar do Norte , RNA/genética , Inanição/genética , Inanição/fisiopatologia
17.
Ecotoxicol Environ Saf ; 183: 109461, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31377519

RESUMO

The present work investigated the changes in DNA methylation pattern of Tenebrio molitor mitochondria genome at different development stages, which was fed with polyurethane foam as a sole diet. Polyurethane foam could influence the global methylation levels in mitochondria DNA of Tenebrio molitor. Different leves of 5-methylcytosine appeared at CpG and non-CpG sites of Tenebrio molitor mtDNA while they were fed with polyurethane foam: 10 CpG and 49 non-CpG sites at larval stage, 4 CpG and 31 non-CpG sites at pupa stage, 7 CpG and 56 non-CpG sites at adult stage in general. Moreover, we observed the decreased levels of ATP generation with the mitochondria DNA methylation variation. The results demonstrated that mitochondria DNA gene could be methylated in response to environmental pollutants to modulate stage-specific functions. Moreover, mtDNA methylation of polyurethane-foam-feeding Tenebrio molitor existed discrepancy in the developmental stage. The tentative methylation mechanism of mtDNA might be that polyurethane foam induced oxidative stress and increased the permeability of mitochondrial membranes, which resulted in transmethylase entry into mitochondria.


Assuntos
DNA Mitocondrial/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Epigênese Genética/efeitos dos fármacos , Metamorfose Biológica/efeitos dos fármacos , Poliuretanos/toxicidade , Tenebrio/efeitos dos fármacos , 5-Metilcitosina/metabolismo , Animais , Metilação de DNA/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Metamorfose Biológica/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Pupa/efeitos dos fármacos , Pupa/genética , Tenebrio/genética , Tenebrio/crescimento & desenvolvimento
18.
Insect Biochem Mol Biol ; 112: 103206, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31425850

RESUMO

Wings are an indispensable structure in many insects for their foraging, courtship, escape from predators, and migration. Cuticular proteins are major components of the insect cuticle and wings, but there is limited information on how cuticular proteins may play an essential role in wing morphogenesis. We identified a wing-specific cuticular protein, LmACP7, which belongs to the RR-2 subfamily of CPR chitin-binding proteins in the migratory locust. LmACP7 was initially produced in epidermal cells and subsequently migrated to the exocuticle at the pre-ecdysial stage in adult wings. Depletion of LmACP7 transcripts by RNA interference markedly reduced its protein amounts, which consequently led to abnormal wing morphogenesis. The deformed wings were curved, wrinkled, and failed to fully expand. We further demonstrated that the deformation was caused by both severe damage of the endocuticle and death of the epidermal cells in the wings. Based on these data, we propose that LmACP7 not only serves as an essential structural protein in the wing but is also required for the integrity of wing epithelial cells. LmACP7 contributes to production of the wing endocuticle and to the morphogenesis of functional wings in the migratory locust.


Assuntos
Proteínas de Insetos/genética , Locusta migratoria/genética , Asas de Animais/crescimento & desenvolvimento , Animais , Quitina/metabolismo , Células Epidérmicas/metabolismo , Proteínas de Insetos/metabolismo , Locusta migratoria/crescimento & desenvolvimento , Metamorfose Biológica/genética , Morfogênese/genética , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Interferência de RNA , Asas de Animais/anormalidades
19.
BMC Genomics ; 20(1): 531, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253104

RESUMO

BACKGROUND: The Crustacea are an evolutionarily diverse taxon which underpins marine food webs and contributes significantly to the global economy. However, our knowledge of crustacean endocrinology and development is far behind that of terrestrial arthropods. Here we present a unique insight into the molecular pathways coordinating crustacean metamorphosis, by reconciling nuclear receptor (NR) gene activity from a 12-stage, 3-replicate transcriptome in the ornate spiny lobster (Panulirus ornatus) during larval development. RESULTS: We annotated 18 distinct nuclear receptor genes, including three novel NRs which are upregulated prior to metamorphosis and have hence been named the "molt-associated receptors" (MARs). We also demonstrate the ecdysone-responsive expression of several known molt-related NRs including ecdysone receptor, fushi-tarazu-F1 and E75. Phylogenetic analysis of the curated NR family confirmed gene annotations and suggested that the MARs are a recent addition to the crustacean superfamily, occurring across the Malacostraca from the Stomatopoda to the Decapoda. The ligand-binding domain of these receptors appears to be less conserved than that of typical group-1 NRs. Expression data from two other crustacean species was utilized to examine MAR expression. The Y-organ of the tropical land crab showed a decline in expression of all MARs from intermolt to post-molt. Tissue distributions showed gonad-enriched expression in the Eastern rock lobster and antennal gland-enriched expression in the tropical land crab, although expression was evident across most tissues. CONCLUSION: By mining transcriptome data, we have curated an extensive list of NR genes expressed during the metamorphic molts of P. ornatus, including three novel crustacean NRs which appear to play a role in the molting process. Divergence of the E-region of these new receptors indicates that they may have adopted a function that is unconventional for NRs. Based on expression patterns, we can confirm that a number of NRs play a role in the ecdysone cassette which regulates molting in crustaceans. This study describes in detail the molecular events surrounding crustacean molting and metamorphosis by taking advantage of the distinctive life history unique to achelatan crustaceans.


Assuntos
Perfilação da Expressão Gênica , Metamorfose Biológica/genética , Palinuridae/crescimento & desenvolvimento , Palinuridae/genética , Receptores Citoplasmáticos e Nucleares/genética , Animais , Muda/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie
20.
RNA Biol ; 16(10): 1386-1400, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31195914

RESUMO

Metamorphosis is an intricate developmental process in which large-scale remodelling of mRNA and microRNA (miRNA) profiles leads to orchestrated tissue remodelling and organogenesis. Whether, which, and how, ribonucleases (RNases) are involved in the RNA profile remodelling during metamorphosis remain unknown. Human Regnase-1 (also known as MCPIP1 and Zc3h12a) RNase remodels RNA profile by cleaving specific RNAs and is a crucial modulator of immune-inflammatory and cellular defence. Here, we studied Drosophila CG10889, which we named Drosophila Regnase-1, an ortholog of human Regnase-1. The larva-to-adult metamorphosis in Drosophila includes two major transitions, larva-to-pupa and pupa-to-adult. regnase-1 knockout flies developed until the pupa stage but could not complete pupa-to-adult transition, dying in puparium case. Regnase-1 RNase activity is required for completion of pupa-to-adult transition as transgenic expression of wild-type Drosophila Regnase-1, but not the RNase catalytic-dead mutants, rescued the pupa-to-adult transition in regnase-1 knockout. High-throughput RNA sequencing revealed that regnase-1 knockout flies fail to remodel mRNA and miRNA profiles during the larva-to-pupa transition. Thus, we uncovered the roles of Drosophila Regnase-1 in the larva-to-adult metamorphosis and large-scale remodelling of mRNA and miRNA profiles during this metamorphosis process.


Assuntos
Drosophila/fisiologia , Metamorfose Biológica/genética , MicroRNAs/genética , RNA Mensageiro/genética , Ribonucleases/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Sequência de Bases , Catálise , Expressão Gênica , Hidrólise , Larva , Mutação , Ribonucleases/genética
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