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1.
Nat Commun ; 15(1): 5793, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987256

RESUMO

Temperature is a critical environmental cue that controls the development and lifespan of many animal species; however, mechanisms underlying low-temperature adaptation are poorly understood. Here, we describe cold-inducible diapause (CID), another type of diapause induced by low temperatures in Caenorhabditis elegans. A premature stop codon in heat shock factor 1 (hsf-1) triggers entry into CID at 9 °C, whereas wild-type animals enter CID at 4 °C. Furthermore, both wild-type and hsf-1(sy441) mutant animals undergoing CID can survive for weeks, and resume growth at 20 °C. Using epistasis analysis, we demonstrate that neural signalling pathways, namely tyraminergic and neuromedin U signalling, regulate entry into CID of the hsf-1 mutant. Overexpression of anti-ageing genes, such as hsf-1, XBP1/xbp-1, FOXO/daf-16, Nrf2/skn-1, and TFEB/hlh-30, also inhibits CID entry of the hsf-1 mutant. Based on these findings, we hypothesise that regulators of the hsf-1 mutant CID may impact longevity, and successfully isolate 16 long-lived mutants among 49 non-CID mutants via genetic screening. Furthermore, we demonstrate that the nonsense mutation of MED23/sur-2 prevents CID entry of the hsf-1(sy441) mutant and extends lifespan. Thus, CID is a powerful model to investigate neural networks involving cold acclimation and to explore new ageing mechanisms.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Temperatura Baixa , Proteínas de Ligação a DNA , Diapausa , Longevidade , Fatores de Transcrição , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Diapausa/genética , Diapausa/fisiologia , Longevidade/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Mutação , Transdução de Sinais , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/genética , Códon sem Sentido/genética , Neuropeptídeos/metabolismo , Neuropeptídeos/genética , Proteínas de Transporte , Fatores de Transcrição Hélice-Alça-Hélice Básicos
2.
Artigo em Inglês | MEDLINE | ID: mdl-38810773

RESUMO

Spotted stem borer, Chilo partellus, undergoes larval diapause (hibernation and aestivation), and depends on the food reserve accumulated during feeding stage for its survival. Lipids are the primary source of energy during diapause, and essential for different cellular, biochemical and physiological functions. However, there is no information on lipid and lipophilic compound contents during different stages of hibernation, aestivation and nondiapause in C. partellus. Thus, we compared the concentration and composition of lipids in pre-diapause, diapause and post-diapause stages of hibernation and aestivation with nondiapause stages of C. partellus. The studies revealed significant differences in total lipids and various lipophilic compounds during different stages of diapause as compared to nondiapause C. partellus. The total lipids were significantly lower during diapause stage of aestivation and hibernation as compared to nondiapause larvae. Further, the linoleic acid, Methyl 3-methoxytetradecanoate, and l-(+)-Ascorbic acid 2,6-dihexadecanoate were significantly lower, and oleic and palmitoleic acids greater during pre-diapause and diapause stages of hibernation and aestivation as compared to nondiapause larvae. The cholesterol content was significantly greater during pre-diapause stage of hibernation, and diapause and post-diapause stages of aestivation as compared to nondiapause stages. The unsaturation ratio was significantly higher in the pre-diapause and diapause stages and lower in post-diapause stage of aestivation than the hibernation and nondiapause states. This study provides insights on differential lipid profiles during different phases of diapause, which could be useful for further understanding biochemical and physiological cross-talk, and develop target-specific technologies for the management of C. partellus.


Assuntos
Diapausa de Inseto , Larva , Mariposas , Animais , Diapausa de Inseto/fisiologia , Mariposas/fisiologia , Mariposas/crescimento & desenvolvimento , Larva/fisiologia , Larva/crescimento & desenvolvimento , Lipídeos/química , Hibernação/fisiologia , Metabolismo dos Lipídeos/fisiologia , Ácido Linoleico/metabolismo , Diapausa/fisiologia
3.
ISME J ; 18(1)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38767866

RESUMO

Host-microbe interactions underlie the development and fitness of many macroorganisms, including bees. Whereas many social bees benefit from vertically transmitted gut bacteria, current data suggests that solitary bees, which comprise the vast majority of species diversity within bees, lack a highly specialized gut microbiome. Here, we examine the composition and abundance of bacteria and fungi throughout the complete life cycle of the ground-nesting solitary bee Anthophora bomboides standfordiana. In contrast to expectations, immature bee stages maintain a distinct core microbiome consisting of Actinobacterial genera (Streptomyces, Nocardiodes) and the fungus Moniliella spathulata. Dormant (diapausing) larval bees hosted the most abundant and distinctive bacteria and fungi, attaining 33 and 52 times their initial copy number, respectively. We tested two adaptive hypotheses regarding microbial functions for diapausing bees. First, using isolated bacteria and fungi, we found that Streptomyces from brood cells inhibited the growth of multiple pathogenic filamentous fungi, suggesting a role in pathogen protection during overwintering, when bees face high pathogen pressure. Second, sugar alcohol composition changed in tandem with major changes in fungal abundance, suggesting links with bee cold tolerance or overwintering biology. We find that A. bomboides hosts a conserved core microbiome that may provide key fitness advantages through larval development and diapause, which raises the question of how this microbiome is maintained and faithfully transmitted between generations. Our results suggest that focus on microbiomes of mature or active insect developmental stages may overlook stage-specific symbionts and microbial fitness contributions during host dormancy.


Assuntos
Bactérias , Fungos , Simbiose , Animais , Abelhas/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Fungos/fisiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/crescimento & desenvolvimento , Larva/microbiologia , Microbioma Gastrointestinal , Estações do Ano , Interações entre Hospedeiro e Microrganismos , Diapausa/fisiologia
4.
Development ; 151(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38603796

RESUMO

Embryonic diapause is a special reproductive phenomenon in mammals that helps embryos to survive various harsh stresses. However, the mechanisms of embryonic diapause induced by the maternal environment is still unclear. Here, we uncovered that nutrient deficiency in uterine fluid was essential for the induction of mouse embryonic diapause, shown by a decreased concentration of arginine, leucine, isoleucine, lysine, glucose and lactate in the uterine fluid of mice suffering from maternal starvation or ovariectomy. Moreover, mouse blastocysts cultured in a medium with reduced levels of these six components could mimic diapaused blastocysts. Our mechanistic study indicated that amino acid starvation-dependent Gator1 activation and carbohydrate starvation-dependent Tsc2 activation inhibited mTORC1, leading to induction of embryonic diapause. Our study elucidates the essential environmental factors in diapause induction.


Assuntos
Diapausa , Nutrientes , Animais , Feminino , Camundongos , Blastocisto/metabolismo , Diapausa/fisiologia , Desenvolvimento Embrionário/fisiologia
5.
Development ; 150(20)2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37883062

RESUMO

Metabolism is crucial for development through supporting cell growth, energy production, establishing cell identity, developmental signaling and pattern formation. In many model systems, development occurs alongside metabolic transitions as cells differentiate and specialize in metabolism that supports new functions. Some cells exhibit metabolic flexibility to circumvent mutations or aberrant signaling, whereas other cell types require specific nutrients for developmental progress. Metabolic gradients and protein modifications enable pattern formation and cell communication. On an organism level, inadequate nutrients or stress can limit germ cell maturation, implantation and maturity through diapause, which slows metabolic activities until embryonic activation under improved environmental conditions.


Assuntos
Diapausa , Animais , Diapausa/fisiologia , Implantação do Embrião/genética , Transdução de Sinais , Metabolismo Energético
6.
J Comp Neurol ; 531(15): 1525-1549, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37493077

RESUMO

Insects from high latitudes spend the winter in a state of overwintering diapause, which is characterized by arrested reproduction, reduced food intake and metabolism, and increased life span. The main trigger to enter diapause is the decreasing day length in summer-autumn. It is thus assumed that the circadian clock acts as an internal sensor for measuring photoperiod and orchestrates appropriate seasonal changes in physiology and metabolism through various neurohormones. However, little is known about the neuronal organization of the circadian clock network and the neurosecretory system that controls diapause in high-latitude insects. We addressed this here by mapping the expression of clock proteins and neuropeptides/neurohormones in the high-latitude fly Drosophila littoralis. We found that the principal organization of both systems is similar to that in Drosophila melanogaster, but with some striking differences in neuropeptide expression levels and patterns. The small ventrolateral clock neurons that express pigment-dispersing factor (PDF) and short neuropeptide F (sNPF) and are most important for robust circadian rhythmicity in D. melanogaster virtually lack PDF and sNPF expression in D. littoralis. In contrast, dorsolateral clock neurons that express ion transport peptide in D. melanogaster additionally express allatostatin-C and appear suited to transfer day-length information to the neurosecretory system of D. littoralis. The lateral neurosecretory cells of D. littoralis contain more neuropeptides than D. melanogaster. Among them, the cells that coexpress corazonin, PDF, and diuretic hormone 44 appear most suited to control diapause. Our work sets the stage to investigate the roles of these diverse neuropeptides in regulating insect diapause.


Assuntos
Relógios Circadianos , Diapausa , Proteínas de Drosophila , Neuropeptídeos , Animais , Drosophila , Drosophila melanogaster/fisiologia , Proteínas CLOCK , Ritmo Circadiano/fisiologia , Diapausa/fisiologia , Relógios Circadianos/fisiologia , Neuropeptídeos/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
7.
eNeuro ; 10(7)2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37385728

RESUMO

The balance between the degeneration and regeneration of damaged neurons depends on intrinsic and environmental variables. In nematodes, neuronal degeneration can be reversed by intestinal GABA and lactate-producing bacteria, or by hibernation driven by food deprivation. However, it is not known whether these neuroprotective interventions share common pathways to drive regenerative outcomes. Using a well established neuronal degeneration model in the touch circuit of the bacterivore nematode Caenorhabditis elegans, we investigate the mechanistic commonalities between neuroprotection offered by the gut microbiota and hunger-induced diapause. Using transcriptomics approaches coupled to reverse genetics, we identify genes that are necessary for neuroprotection conferred by the microbiota. Some of these genes establish links between the microbiota and calcium homeostasis, diapause entry, and neuronal function and development. We find that extracellular calcium as well as mitochondrial MCU-1 and reticular SCA-1 calcium transporters are needed for neuroprotection by bacteria and by diapause entry. While the benefits exerted by neuroprotective bacteria require mitochondrial function, the diet itself does not affect mitochondrial size. In contrast, diapause increases both the number and length of mitochondria. These results suggest that metabolically induced neuronal protection may occur via multiple mechanisms.


Assuntos
Diapausa , Microbioma Gastrointestinal , Animais , Neuroproteção , Cálcio/metabolismo , Caenorhabditis elegans/fisiologia , Diapausa/fisiologia , Mitocôndrias/metabolismo
8.
Cells ; 11(19)2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36230891

RESUMO

Embryonic diapause is an enigmatic state of dormancy that interrupts the normally tight connection between developmental stages and time. This reproductive strategy and state of suspended development occurs in mice, bears, roe deer, and over 130 other mammals and favors the survival of newborns. Diapause arrests the embryo at the blastocyst stage, delaying the post-implantation development of the embryo. This months-long quiescence is reversible, in contrast to senescence that occurs in aging stem cells. Recent studies have revealed critical regulators of diapause. These findings are important since defects in the diapause state can cause a lack of regeneration and control of normal growth. Controlling this state may also have therapeutic applications since recent findings suggest that radiation and chemotherapy may lead some cancer cells to a protective diapause-like, reversible state. Interestingly, recent studies have shown the metabolic regulation of epigenetic modifications and the role of microRNAs in embryonic diapause. In this review, we discuss the molecular mechanism of diapause induction.


Assuntos
Cervos , Diapausa , MicroRNAs , Neoplasias , Animais , Blastocisto/metabolismo , Diapausa/fisiologia , Desenvolvimento Embrionário/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias/genética , Neoplasias/metabolismo
9.
PLoS One ; 17(9): e0274076, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36112613

RESUMO

Genetic and environmental manipulations, such as dietary restriction, can improve both health span and lifespan in a wide range of organisms, including humans. Changes in nutrient intake trigger often overlapping metabolic pathways that can generate distinct or even opposite outputs depending on several factors, such as when dietary restriction occurs in the lifecycle of the organism or the nature of the changes in nutrients. Due to the complexity of metabolic pathways and the diversity in outputs, the underlying mechanisms regulating diet-associated pro-longevity are not yet well understood. Adult reproductive diapause (ARD) in the model organism Caenorhabditis elegans is a dietary restriction model that is associated with lengthened lifespan and reproductive potential. To explore the metabolic pathways regulating ARD in greater depth, we performed a candidate-based genetic screen analyzing select nutrient-sensing pathways to determine their contribution to the regulation of ARD. Focusing on the three phases of ARD (initiation, maintenance, and recovery), we found that ARD initiation is regulated by fatty acid metabolism, sirtuins, AMPK, and the O-linked N-acetyl glucosamine (O-GlcNAc) pathway. Although ARD maintenance was not significantly influenced by the nutrient sensors in our screen, we found that ARD recovery was modulated by energy sensing, stress response, insulin-like signaling, and the TOR pathway. Further investigation of downstream targets of NHR-49 suggest the transcription factor influences ARD initiation through the fatty acid ß-oxidation pathway. Consistent with these findings, our analysis revealed a change in levels of neutral lipids associated with ARD entry defects. Our findings identify conserved genetic pathways required for ARD entry and recovery and uncover genetic interactions that provide insight into the role of OGT and OGA.


Assuntos
Diapausa , Nutrientes , Transdução de Sinais , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Caenorhabditis elegans/metabolismo , Diapausa/genética , Diapausa/fisiologia , Ácidos Graxos/metabolismo , Glucosamina/metabolismo , Humanos , Insulinas/metabolismo , Lipídeos/química , Nutrientes/metabolismo , Nutrientes/farmacologia , Reprodução/genética , Reprodução/fisiologia , Transdução de Sinais/genética , Sirtuínas/genética , Sirtuínas/metabolismo , Fatores de Transcrição/metabolismo
10.
Dev Dyn ; 251(11): 1848-1861, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35766167

RESUMO

BACKGROUND: Temporary pools are variable environments with seasonal drought/flood phases. Annual killifish have adapted to life in temporary pools by producing embryos that undergo diapause to traverse the dry phase. To fill existing knowledge gaps about embryo diapause regulation and evolution in annual killifishes, we test the effect of maternal age, incubation temperature, and incubation medium on diapause induction and length in Millerichthys robustus, the only North American fish species that has evolved an annual life history. RESULTS: All embryos at extreme temperatures follow a defined developmental pathway: skipping diapause at 30°C, and entering diapause at 18°C, both regardless of maternal age, and incubation medium. However, maternal age, and incubation medium influenced whether diapause is entered, and time arrested in diapause for embryos incubated at 25°C. At 25°C, five-week-old, and 52-week-old females produced more embryos that entered diapause than 26-week-old females. Also, embryos incubated in aqueous medium skipped diapause more frequently at this intermediate temperature. CONCLUSIONS: Millerichthys developmental dynamics associated with maternal age under intermediate range of temperatures are likely adapted to the particular patterns of flood/drought in North American temporary pools. Millerichthys also exhibits developmental patterns largely comparable with other annual fishes, probably due to common seasonal patterns in temporary pools.


Assuntos
Ciprinodontiformes , Diapausa , Fundulidae , Animais , Feminino , Idade Materna , Sinais (Psicologia) , Diapausa/fisiologia , Ciprinodontiformes/fisiologia , América do Norte , Embrião não Mamífero
11.
Physiol Behav ; 249: 113749, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35202673

RESUMO

In this letter, I discuss the notion of dormancy that De Luca Jr. relies on to criticize the theory of homeostasis. In particular, I try to qualify the issues related to the fact that dormancy is not always a free behavior but is in most situations under the influence of environmental factors. To this end, I discuss diapause in arthropods, which can be obligatory (under the influence of endogenous commands) but which is in most cases facultative (under external command). I emphasize that the notion of stability of a dormant organism must be taken with caution. I briefly mention what the study of sleep in animals can contribute to the notion of homeostasis. Finally, I focus on the role of microbial symbionts and the notion of holobiont. Through this, I question the future of the notions of internal environment and homeostasis and I propose to revisit them in the context of the effects of species interactions on the physiology of organisms.


Assuntos
Diapausa , Simbiose , Animais , Diapausa/fisiologia , Homeostase
12.
Artigo em Inglês | MEDLINE | ID: mdl-35149343

RESUMO

Annual killifish could survive as diapaused embryos buried in soil during dry seasons. When the embryos in diapause III were incubated in water, the larvae could be hatched quickly. However, the mechanism of diapause and hatching of annual killifish was ambiguous. In the present study, Nothobranchius guentheri were used as the model to clarify the physiological mechanism of diapause and hatching of annual killifish. The results indicated that incubation with water could significantly enhance the heart rate and blood circulation of embryos. To clarify the molecular mechanism, the transcriptomic analysis was used to compare the embryos in diapause I, diapause III, and hatching period. The results showed that DNA replication-related genes, cell division cycle 45 and proliferating cell nuclear antigen were more highly expressed in diapause I compared to diapause III. In addition, the transcript levels of glucagon, glucokinase and phosphofructokinase were more abundantly detected in hatching period compared to diapause III, but insulin receptor and insulin-like growth factor-binding protein were lower. These results indicated glucose metabolism might play an important role in diapause and hatching of killifish. To further confirm this result, several reagents involved in glucose metabolism were used to incubate embryos in diapause III. The results displayed that glucose and glucagon could both shorten the hatching time of embryos. In contrast, 2-deoxy-d-glucose, metformin, and insulin could prolong the hatching time and reduce the hatching rate. The results further confirmed that glucose metabolism played an important role in the diapause and hatching of annual killifish.


Assuntos
Diapausa , Fundulidae , Adaptação Fisiológica/genética , Animais , Diapausa/fisiologia , Embrião não Mamífero/metabolismo , Glucagon/metabolismo , Glucose/metabolismo , Água/metabolismo
13.
Sci Rep ; 12(1): 2325, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35149738

RESUMO

Many parasites of seasonally available hosts must persist through times of the year when hosts are unavailable. In tropical environments, host availability is often linked to rainfall, and adaptations of parasites to dry periods remain understudied. The bird-parasitic fly Philornis downsi has invaded the Galapagos Islands and is causing high mortality of Darwin's finches and other bird species, and the mechanisms by which it was able to invade the islands are of great interest to conservationists. In the dry lowlands, this fly persists over a seven-month cool season when availability of hosts is very limited. We tested the hypothesis that adult flies could survive from one bird-breeding season until the next by using a pterin-based age-grading method to estimate the age of P. downsi captured during and between bird-breeding seasons. This study showed that significantly older flies were present towards the end of the cool season, with ~ 5% of captured females exhibiting estimated ages greater than seven months. However, younger flies also occurred during the cool season suggesting that some fly reproduction occurs when host availability is low. We discuss the possible ecological mechanisms that could allow for such a mixed strategy.


Assuntos
Aves/parasitologia , Cruzamento , Interações Hospedeiro-Parasita , Muscidae/fisiologia , Envelhecimento , Animais , Aves/fisiologia , Diapausa/fisiologia , Equador , Feminino , Estágios do Ciclo de Vida , Masculino , Pupa , Estações do Ano
14.
Sci China Life Sci ; 64(12): 2153-2174, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34755252

RESUMO

Developmental diapause is a widespread strategy for animals to survive seasonal starvation and environmental harshness. Diapaused animals often ration body fat to generate a basal level of energy for enduring survival. How diapause and fat rationing are coupled, however, is poorly understood. The nematode Caenorhabditis elegans excretes pheromones to the environment to induce a diapause form called dauer larva. Through saturated forward genetic screens and CRISPR knockout, we found that dauer pheromones feed back to repress the transcription of ACOX-3, MAOC-1, DHS-28, DAF-22 (peroxisomal ß-oxidation enzymes dually involved in pheromone synthesis and fat burning), ALH-4 (aldehyde dehydrogenase for pheromone synthesis), PRX-10 and PRX-11 (peroxisome assembly and proliferation factors). Dysfunction of these pheromone enzymes and factors relieves the repression. Surprisingly, transcription is repressed not by pheromones excreted but by pheromones endogenous to each animal. The endogenous pheromones regulate the nuclear translocation of HNF4α family nuclear receptor NHR-79 and its co-receptor NHR-49, and, repress transcription through the two receptors. The feedback repression maintains pheromone homeostasis, increases fat storage, decreases fat burning, and prolongs dauer lifespan. Thus, the exocrine dauer pheromones possess an unexpected endocrine function to mediate a peroxisome-nucleus crosstalk, coupling dauer diapause to fat rationing.


Assuntos
Acil-CoA Oxidase/metabolismo , Caenorhabditis elegans/metabolismo , Ácidos Graxos/metabolismo , Fator 4 Nuclear de Hepatócito/metabolismo , Feromônios/metabolismo , Tecido Adiposo/metabolismo , Animais , Caenorhabditis elegans/genética , Diapausa/fisiologia , Homeostase/fisiologia , Larva , Oxirredução , Peroxissomos/metabolismo , Transcrição Gênica
15.
J Insect Sci ; 21(5)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34636890

RESUMO

Hexamerins are members of the hemocyanin superfamily and play essential roles in providing amino acids and energy for the nonfeeding stages of insects. In this study, we cloned and analyzed the expression patterns of four hexamerin genes (hex 70a, hex 70b, hex 70c, and hex 110) at different worker development stages and queen diapause statuses in the bumble bee, Bombus terrestris. The results of this study showed that hex 110 has the longest open reading frame (ORF; 3,297 bp) compared to the ORFs of hex 70a (2,034 bp), hex 70b (2,067 bp), and hex 70c (2,055 bp). The putative translation product of Hex 70a, Hex 70b, Hex70c, and Hex 110 has 677, 688, 684, and 1,098aa with predicted molecular mass of 81.13, 79.69, 81.58, and 119 kDa. In the development stages of workers, the expression levels of hex 70a, hex 70b, and hex 70c increased gradually from the larval stage and exhibited high expression levels at the pink eyed and brown eyed pupae stage, whereas hex 110 exhibited the highest expression level at the larval period. Four hexamerin genes were highly expressed at the prediapause status of queen (P < 0.05), and compared to the eclosion queen, the lowest upregulation was 3.7-fold, and the highest upregulation was 1,742-fold. The expression levels of hex 70b, hex 70c, and hex 110 at diapause were significantly higher than those at postdiapause (P < 0.05). In conclusion, hexamerins may play important roles in queen diapause and metamorphosis of larval and pupal stages.


Assuntos
Abelhas , Proteínas de Insetos/genética , Animais , Abelhas/genética , Abelhas/crescimento & desenvolvimento , Abelhas/fisiologia , Diapausa/genética , Diapausa/fisiologia , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Metamorfose Biológica/genética , Metamorfose Biológica/fisiologia , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/fisiologia
16.
Anim Reprod Sci ; 232: 106823, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34390943

RESUMO

Mink embryonic diapause occurs when embryos, at the blastocyst stage, enter a state of a reversible arrest in development and metabolism. Some ovarian factors are required because ovariectomy leads to prevention of implantation in mink. Mechanisms regulating this process, however, remain largely unknown. To explore ovarian modifications associated with emergence of embryonic diapause in mink, there was comparison of transcriptomes after embryonic activation to when there was embryonic diapause using RNA-sequencing. A library of 655 differentially expressed genes (DEGs) of all assembled 33,656 genes was generated. Among these, 558 genes were annotated with 106 genes being expressed to a greater extent in ovaries during embryonic diapause, whereas 452 genes were more abundantly expressed in ovaries after embryonic activation. The major categories of genes with differential transcript abundances include metabolic pathways, metabolism of tryptophan, tyrosine and vitamin B6, oxidoreductase activity, calcium signaling pathway, steroid biosynthesis and lysosome. The APOE and APOA1 hub genes identified through the protein-protein interaction (PPI) analysis have important functions in cholesterol transport and steroidogenesis. Transcript abundances associated with 39 genes were investigated using RT-qPCR procedures to confirm RNA-sequencing data. Of 29 mRNA transcripts, 26 were validated using RNA-sequencing, whereas three of ten indistinguishable genes determined using RNA-sequencing were confirmed. Most of these verified DEGs are involved in the prolactin signaling pathway, formation of functional corpora lutea, and steroid synthesis, suggesting these biological processes are implicated in embryonic reactivation. Overall, results provide new insights into ovarian signaling at the time of emergence of the blastocyst from diapause in mink.


Assuntos
Diapausa/fisiologia , Embrião de Mamíferos/fisiologia , Vison/fisiologia , Ovário/fisiologia , Animais , Implantação do Embrião/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Gravidez , Mapas de Interação de Proteínas
17.
Insect Biochem Mol Biol ; 136: 103623, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34246764

RESUMO

Aphids were the first animals described as photoperiodic due to their seasonal switch from viviparous parthenogenesis to sexual reproduction (cyclical parthenogenesis) caused by the shortening of the photoperiod in autumn. This switch produces a single sexual generation of oviparous females and males that mate and lay diapausing cold-resistant eggs that can overcome the unfavourable environmental conditions typical of winter in temperate regions. Previous studies have hinted at a possible implication of two insulin-like peptides (ILP1 and ILP4) in the aphid seasonal response, changing their expression levels between different photoperiodic conditions. Moreover, in situ localization of their transcripts in particular neurosecretory cells (NSCs) in the aphid brain supported the idea that these neuropeptides could correspond to the formerly called virginoparin, an uncharacterized factor originally proposed to be transported directly to the aphid embryos to promote their development as parthenogenetic individuals. To further investigate the fate of these ILPs, we raised a specific antiserum against one of them (ILP4) and mapped this neuropeptide by immunohistochemistry (IHC) in Acyrthosiphon pisum and Megoura viciae aphids. Coincident with in situ localization, our results show that ILP4 is synthesized in two groups (one in each brain hemisphere) of four neurosecretory cells in the pars intercerebralis (NSC group I) and then it is transported outside the brain to the corpora cardiaca. From there, three nerves (two laterals and one medial) transport it to the abdomen. Although no precise site of release has been found, the terminations of these nerves near the germaria would be compatible with the proposal of a direct connection between group I of NSCs and the reproductive system by localized release. In addition, we detected some collateral arborizations originating from the eight NSCs going to the pars lateralis, where clock neurons and some photoreceptors have been previously localized, suggesting a possible communication between the circadian and photoperiodic systems.


Assuntos
Afídeos , Hormônios de Inseto/metabolismo , Insulina/metabolismo , Oligopeptídeos/metabolismo , Fotoperíodo , Ácido Pirrolidonocarboxílico/análogos & derivados , Animais , Afídeos/metabolismo , Afídeos/fisiologia , Encéfalo/metabolismo , Relógios Circadianos/fisiologia , Diapausa/fisiologia , Imuno-Histoquímica , Proteínas de Insetos/metabolismo , Neuropeptídeos/metabolismo , Partenogênese/fisiologia , Peptídeos/metabolismo , Ácido Pirrolidonocarboxílico/metabolismo , Reprodução/fisiologia
18.
Biomolecules ; 11(5)2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062764

RESUMO

The mechanistic target of rapamycin (mTOR) is a central regulator of cellular homeostasis that integrates environmental and nutrient signals to control cell growth and survival. Over the past two decades, extensive studies of mTOR have implicated the importance of this protein complex in regulating a broad range of metabolic functions, as well as its role in the progression of various human diseases. Recently, mTOR has emerged as a key signaling molecule in regulating animal entry into a hypometabolic state as a survival strategy in response to environmental stress. Here, we review current knowledge of the role that mTOR plays in contributing to natural hypometabolic states such as hibernation, estivation, hypoxia/anoxia tolerance, and dauer diapause. Studies across a diverse range of animal species reveal that mTOR exhibits unique regulatory patterns in an environmental stressor-dependent manner. We discuss how key signaling proteins within the mTOR signaling pathways are regulated in different animal models of stress, and describe how each of these regulations uniquely contribute to promoting animal survival in a hypometabolic state.


Assuntos
Estresse Fisiológico/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Ciclo Celular , Proliferação de Células , Diapausa/fisiologia , Estivação/fisiologia , Hibernação/fisiologia , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Transdução de Sinais/fisiologia
19.
PLoS One ; 16(6): e0251820, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086690

RESUMO

Diapause is a reversible developmental arrest faced by many organisms in harsh environments. Annual killifish present this mechanism in three possible stages of development. Killifish are freshwater teleosts from Africa and America that live in ephemeral ponds, which dry up in the dry season. The juvenile and adult populations die, and the embryos remain buried in the bottom mud until the next rainy season. Thus, species survival is entirely embryo-dependent, and they are perhaps the most remarkable extremophile organisms among vertebrates. The aim of the present study was to gather information about embryonic diapauses with the use of a "shotgun" proteomics approach in diapause III and prehatching Austrolebias charrua embryos. Our results provide insight into the molecular mechanisms of diapause III. Data are available via ProteomeXchange with identifier PXD025196. We detected a diapause-dependent change in a large group of proteins involved in different functions, such as metabolic pathways and stress tolerance, as well as proteins related to DNA repair and epigenetic modifications. Furthermore, we observed a diapause-associated switch in cytoskeletal proteins. This first glance into global protein expression differences between prehatching and diapause III could provide clues regarding the induction/maintenance of this developmental arrest in A. charrua embryos. There appears to be no single mechanism underlying diapause and the present data expand our knowledge of the molecular basis of diapause regulation. This information will be useful for future comparative approaches among different diapauses in annual killifish and/or other organisms that experience developmental arrest.


Assuntos
Ciprinodontiformes/metabolismo , Ciprinodontiformes/fisiologia , Diapausa/fisiologia , Embrião não Mamífero/metabolismo , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário/fisiologia , Adaptação Fisiológica/fisiologia , África , Animais , Proteômica/métodos , Estações do Ano
20.
Artigo em Inglês | MEDLINE | ID: mdl-33862219

RESUMO

Throughout diapause in mosquitoes, stress resistance and subsequent prolonged lifespan are a few important features of diapause that are crucial for overwintering success. In the mosquito Culex pipiens, we suggest that oxidoreductin-like protein is involved with these diapause characteristics for overwintering survival. Expression of oxidor was more than two-fold higher in early stage diapausing females compared to their non-diapausing counterparts. Suppression of the gene that encodes oxidoreductin-like protein by RNAi significantly increased the proportion of degenerating follicles in early-stage adult diapausing females. Inhibition of oxidor also significantly reduced the survivability of diapausing females which indicates that this protein plays a key role in protecting multiple tissues during early diapause.


Assuntos
Culex/fisiologia , Culicidae/fisiologia , Diapausa/fisiologia , Folículo Ovariano/fisiologia , Oxirredutases/metabolismo , Animais , Feminino , Humanos , Proteínas de Insetos/genética , Folículo Ovariano/metabolismo , Estresse Oxidativo , Filogenia , Interferência de RNA , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano
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