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1.
J Zoo Wildl Med ; 50(4): 917-926, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31926524

RESUMO

Abnormal molting, including partial or incomplete molt, arrested molt cycle, or inappropriate frequency of molt, is a primary concern for the managed African penguin (Spheniscus demersus) population and is documented across institutions. To identify factors associated with increased odds of abnormal molts and characterize intervention opportunities, a comprehensive survey evaluating numerous husbandry and medical parameters was created. Survey results represent 45 North American African penguin holding facilities and 736 unique animals. Of these individuals, 135 (18.3%) demonstrated an abnormal molt over the 5-yr study period (2012-2017). Increased odds ratios for abnormal molt included biologic (age, sex, etc.), geographic (elevation, latitude), and husbandry (exhibit design, diet, etc.) variables. The mean age of affected animals was 15.2 yr (1-45 yr, n = 135) compared with 9.92 yr (4 mo-38 yr, n = 601) for unaffected animals. In addition, although statistically insignificant, males were overrepresented in the affected cohort compared with a near even distribution among unaffected animals. Identified factors with increased odds for abnormal molting included advanced age and facilities using freshwater pools. Normally molting penguins were more commonly found with saltwater pool access and natural lighting exposure. Anecdotal medical intervention attempts are discussed, although further research is needed to define their use. Of attempted interventions, subcutaneous 5.4-mg melatonin implants placed in anticipation of environmental molting cues showed the most promise at inducing catastrophic molt, with 14 of 17 (82.3%) of affected individuals molting normally following this treatment. Survey analysis indicated that abnormal molt is a complex, multifactorial process, and modifiable factors that may predispose animals to abnormally molt exist. Addressing these factors in future exhibit design may mitigate the prevalence of this condition. Despite these efforts, it is likely that medical interventions will be required to aid in the treatment of abnormal molting in this species.


Assuntos
Plumas , Muda/fisiologia , Spheniscidae , Animais , Animais de Zoológico , América do Norte
2.
Arch Virol ; 164(11): 2837-2841, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494776

RESUMO

Since January 2019, abnormal molting has been observed frequently in approximately 40-day-old Pekin ducks in China. To investigate the possible involvement of a virus, we tested the prevalence of duck circovirus (DuCV), goose hemorrhagic polyomavirus (GHPyV), and goose parvovirus (GPV) in 11 molt cases in two provinces. GPV was detected in all cases, particularly in all samples collected from the feather area. The complete genome sequences of three GPV strains were determined and found to have 52 nucleotide changes relative to GPVs associated with short beak and dwarfism syndrome of Pekin ducks. These data will enhance our understanding of GPV diversity and outcomes of GPV infection in Pekin ducks.


Assuntos
Patos/virologia , Gansos/virologia , Muda/fisiologia , Parvovirinae/isolamento & purificação , Doenças das Aves Domésticas/virologia , Animais , China/epidemiologia , Circovirus/genética , Circovirus/isolamento & purificação , Genoma Viral/genética , Parvovirinae/genética , Polyomavirus/genética , Polyomavirus/isolamento & purificação , Doenças das Aves Domésticas/epidemiologia
3.
PLoS Genet ; 15(8): e1008331, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31412019

RESUMO

Holometabolous insects stop feeding at the final larval instar stage and then undergo metamorphosis; however, the mechanism is unclear. In the present study, using the serious lepidopteran agricultural pest Helicoverpa armigera as a model, we revealed that 20-hydroxyecdysone (20E) binds to the dopamine receptor (DopEcR), a G protein-coupled receptor, to stop larval feeding and promote pupation. DopEcR was expressed in various tissues and its level increased during metamorphic molting under 20E regulation. The 20E titer was low during larval feeding stages and high during wandering stages. By contrast, the dopamine (DA) titer was high during larval feeding stages and low during the wandering stages. Injection of 20E or blocking dopamine receptors using the inhibitor flupentixol decreased larval food consumption and body weight. Knockdown of DopEcR repressed larval feeding, growth, and pupation. 20E, via DopEcR, promoted apoptosis; and DA, via DopEcR, induced cell proliferation. 20E opposed DA function by repressing DA-induced cell proliferation and AKT phosphorylation. 20E, via DopEcR, induced gene expression and a rapid increase in intracellular calcium ions and cAMP. 20E induced the interaction of DopEcR with G proteins αs and αq. 20E, via DopEcR, induced protein phosphorylation and binding of the EcRB1-USP1 transcription complex to the ecdysone response element. DopEcR could bind 20E inside the cell membrane or after being isolated from the cell membrane. Mutation of DopEcR decreased 20E binding levels and related cellular responses. 20E competed with DA to bind to DopEcR. The results of the present study suggested that 20E, via binding to DopEcR, arrests larval feeding and promotes pupation.


Assuntos
Ecdisterona/metabolismo , Proteínas de Insetos/metabolismo , Mariposas/fisiologia , Receptores Dopaminérgicos/metabolismo , Animais , Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Flupentixol/farmacologia , Técnicas de Silenciamento de Genes , Proteínas de Insetos/genética , Larva/efeitos dos fármacos , Larva/fisiologia , Muda/efeitos dos fármacos , Muda/fisiologia , Mariposas/efeitos dos fármacos , Interferência de RNA , Receptores Dopaminérgicos/genética , Células Sf9
4.
Artigo em Inglês | MEDLINE | ID: mdl-31454682

RESUMO

Heortia vitessoides Moore is a notorious defoliator of Aquilaria sinensis (Lour.) Gilg trees. Chitin deacetylases (CDAs) catalyze the N-deacetylation of chitin, which is a crucial process for chitin modification. Here, we identified and characterized HvCDA1 and HvCDA2 from H. vitessoides. HvCDA1 and HvCDA2 possess typical domain structures of CDAs and belong to the Group I CDAs. HvCDA1 and HvCDA2 were highly expressed before and after the larval-larval molt. In addition, both exhibited relatively high mRNA expression levels during the larval-pupal molt, the pupal stage, and the pupal-adult molt. HvCDA1 and HvCDA2 transcript expression levels were highest in the body wall and relatively high in the larval head. Significant increases in the HvCDA1 and HvCDA2 transcript expression levels were observed in the larvae upon exposure to 20-hydroxyecdysone. RNA interference-mediated HvCDA1 and HvCDA2 silencing significantly inhibited HvCDA1 and HvCDA2 expression, with abnormal or nonviable phenotypes being observed. Post injection survival rates of the larvae injected with dsHvCDA1 and dsHvCDA2 were 66.7% and 46.7% (larval-pupal) during development and 23.0% and 6.7% (pupal-adult), respectively. These rates were significantly lower than those of the control group insects. Our results suggest that HvCDA1 and HvCDA2 play important roles in the larval-pupal and pupal-adult transitions and represent potential targets for the management of H. vitessoides.


Assuntos
Amidoidrolases/metabolismo , Pupa/enzimologia , Amidoidrolases/genética , Animais , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/enzimologia , Muda/genética , Muda/fisiologia , Mariposas/enzimologia , Pupa/crescimento & desenvolvimento , Interferência de RNA
5.
Nat Commun ; 10(1): 2540, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182713

RESUMO

Global warming alters various avian phenological processes, including advanced reproduction and migration schedules. In birds, individual appearance is largely determined by plumage, influencing, for example, bird attractiveness, social status and camouflage. Juveniles of most passerine species replace their nest-grown plumage during the first months of life, a process that is called post-juvenile feather moult. Using data from ten natural history collections, we show that the extent of the post-juvenile moult has increased significantly over the last 212 years (1805-2016), a trend that is positively correlated with the temperature of the environment. Therefore, it seems that birds replaced more feathers under warmer conditions, causing juveniles to appear more similar to adult birds. Moreover, in several species, we describe a male-female switch in the extent of moult, with females currently replacing more feathers than males compared to the past. These results demonstrate different biological responses to climate warming by different phenotypes.


Assuntos
Aquecimento Global , Muda/fisiologia , Passeriformes/fisiologia , Animais , Plumas/anatomia & histologia , Plumas/crescimento & desenvolvimento , Feminino , Masculino , Passeriformes/anatomia & histologia , Passeriformes/crescimento & desenvolvimento , Caracteres Sexuais
6.
Arch Insect Biochem Physiol ; 101(4): e21561, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31218752

RESUMO

ß-N-acetylglucosaminidase (NAG) is a key enzyme in insect chitin metabolism and plays an important role in many physiological activities of insects. The HvNAG1 gene was identified from the Heortia vitessoides Moore (Lepidoptera: Crambidae) cDNA library and its expression patterns were determined using quantitative real-time polymerase chain reaction. The results indicated that HvNAG1 mRNA levels were high in the midgut and before molting, and 20E could induce its expression. Subsequently, the HvNAG1 gene was knocked down via RNA interference to identify its functions. We found that 3 µg of dsNAG1 resulted in optimal interference at 48 and 72 hr after injection, causing a decrease in NAG1 protein content, which resulted in abnormal or lethal phenotypes, and a sharp decrease in the survival rate. These results indicate that HvNAG1 plays a key role in the molting process of H. vitessoides. However, the silencing of HvNAG1 had no significant effect on the chitin metabolism-related genes tested in this study. Our present study provides a reference for further research on the utility of key genes involved in the chitin metabolic pathway in the insect molting process.


Assuntos
Acetilglucosaminidase/metabolismo , Regulação Enzimológica da Expressão Gênica , Muda/genética , Muda/fisiologia , Mariposas/genética , Mariposas/fisiologia , Acetilglucosaminidase/genética , Animais , Técnicas de Silenciamento de Genes , Mariposas/enzimologia
7.
Poult Sci ; 98(10): 4290-4300, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31180124

RESUMO

This study examined the effect of water-chilled perches on hen production and physiological responses to induced molt during elevated temperatures. A total of 288White Leghorns at 82 wk of age were housed in 36 cages of 6 banks. Each bank was assigned to 1 of 3 treatments: cooled perches, air perches, and no perches. The hens were subjected to 2 heat episodes during their first laying cycle at week 21 to 35 and week 73 to 80, respectively. The hens were subjected to a 28 D nonfasted molting regimen starting at 85 wk of age. Cyclic heat of 32°C (6:00 am to 6:00 pm) was applied daily during the molting period. After molt, hens were returned to a layer diet and housed under thermoneutral condition. Two birds per cage were monitored for BW change during molt. Egg production was recorded daily. Feed utilization was measured during molt at 86 and 88 wk of age. Egg weight and eggshell traits were examined at 84 wk (pre-molt) and post-molt at 92, 96, and 104 wk of age. Rectal temperature and blood samples were collected from 2 birds per cage at the end of molt. Blood samples were used for determining heterophil/lymphocyte ratio, corticosterone, and thyroid hormones. Plumage condition was examined at 22 wk post-molt. Compared to control and air perch hens, cooled perch hens had higher feed usage and greater BW loss, lower heterophil/lymphocyte ratios (P < 0.05) with no difference in thyroid hormones and corticosterone at the end of molt. Cooled perch hens also had higher egg production beginning at 98 wk of age (Ptreatment*age < 0.0001) than control hens and sometimes the air-perch hens. Cooled perch hens had higher rectal temperature than control but not air perch hens at end of molt. Moreover, cooled perch hens had better breast feather scores than air perch hens but worse vent plumage (P ≤ 0.05) than both control and air perch hens. These results indicate that the provision of cooled perches assists hens with better adaptation to stressors, such as induced molt plus heat exposure, resulting in improved post-molt egg production.


Assuntos
Criação de Animais Domésticos/métodos , Bem-Estar do Animal , Galinhas/fisiologia , Temperatura Baixa , Resposta ao Choque Térmico/fisiologia , Muda/fisiologia , Animais , Feminino , Abrigo para Animais , Distribuição Aleatória
8.
PLoS One ; 14(5): e0216565, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31067284

RESUMO

In many seabirds, individuals abstain from eating during the moult period. Penguins have an intense moult that lasts for weeks, during which they are confined to land. Despite the importance for survival, it is still unclear how the faecal microbiota of Antarctic penguins changes in response to the moult fast. Here, we investigated the faecal microbiota of chinstrap (Pygoscelis antarcticus) and gentoo penguins (Pygoscelis papua) on King George Island, Antarctica. The bacterial community compositions during the feeding and moulting stages were compared for both species using bacterial 16S rRNA gene amplicon on an Illumina MiSeq platform. Our results showed that the moult fast altered the bacterial community structures in both penguin species. Interestingly, the bacterial community composition shifted in the same direction in response to the moult fast but formed two distinct clusters that were specific to each penguin species. A significant increase in bacterial diversity was observed in gentoo penguins, whereas no such change was observed for chinstrap penguins. By analysing the contribution of the ecological processes that determine bacterial community assembly, we observed that processes regulating community turnover were considerably different between the feeding and moulting stages for each penguin. At the phylum level, the relative abundances of Fusobacteria, Firmicutes and Proteobacteria were dominant in chinstrap penguins, and no significant changes were detected in these phyla between the feeding and moulting periods. Our results suggest that moult fast-induced changes in the faecal microbiota occur in both species.


Assuntos
Fezes/microbiologia , Microbiota/genética , Muda/fisiologia , Spheniscidae/microbiologia , Spheniscidae/fisiologia , Animais , Regiões Antárticas , RNA Ribossômico 16S/genética , Spheniscidae/classificação
9.
J Insect Sci ; 19(2)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30953583

RESUMO

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is an important economic pest of maize (Zea mays L.) in North America and Europe. Previous efforts to formulate an artificial diet for western corn rootworm larvae highlighted an important role of corn root powder, which had a significant positive impact on several larval developmental traits. Unfortunately, this ingredient is not available for purchase. Toward the goal of developing an artificial diet for western corn rootworm larvae with all ingredients readily accessible, we conducted research to isolate essential growth factors for larval development from corn root powder to improve the performance of diet without corn root powder. For all experiments, multiple life history parameters (survival, weight, and molting) were recorded from 15-d diet bioassays. Corn roots may contain factors that assist in larval growth, but some of these factors were not fully extracted by methanol and remained in the extracted root. Methanolic extracts significantly increased molting to second instar, but did not significantly increase survival, dry weight, or molting to third instar, suggesting the primary corn root substituents affecting these factors cannot be extracted or other extraction methods may be required to extract the essential factors from corn roots. We showed that whole corn root powder was best when used in combination with all the other nutrient sources in the published western corn rootworm formulation. Corn root powder made from proprietary seed and Viking seed has similar value.


Assuntos
Ração Animal/análise , Besouros/crescimento & desenvolvimento , Zea mays/química , Animais , Besouros/fisiologia , Dieta , Larva/crescimento & desenvolvimento , Larva/fisiologia , Muda/fisiologia , Raízes de Plantas/química
10.
Int J Mol Sci ; 20(7)2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30987273

RESUMO

Chitin deacetylases (CDAs) are a group of enzymes involved in chitin metabolism in insects; they play a critical role in molting, pupation, and the modification of chitin. In this study, we identified several CDAs in the silkworm, Bombyx mori (BmCDA), and investigated the effect of various hormones on their expression in B. mori larvae and embryo cell lines (BmE). Eight genes encoding BmCDAs were identified in the silkworm genome. They showed different expression patterns in different tissues, and were classified into three types based on where they were expressed: the exoskeleton, digestive organs, and genital organs. Moreover, we found that some BmCDAs showed upregulated expression during the molting period, especially during the fourth molting period in larvae. We also verified that the expression of BmCDA1-6 was upregulated by treatment with 20-hydroxyecdysone not only in larvae, but also in BmE cells. Interestingly, juvenile hormone analog treatment also upregulated the expression of some BmCDAs. The overexpression of several transcription factors revealed that the POU transcription factor POUM2 may play a major role in the regulation of BmCDA expression. Finally, the silencing of BmCDA1 and BmCDA2 did not lead to abnormal phenotypes or death, but may have led to delays in silkworm pupation. These results provide important information about lepidopteran insects in terms of chitin deacetylases and the regulation of their expression.


Assuntos
Amidoidrolases/metabolismo , Bombyx/enzimologia , Bombyx/metabolismo , Estudo de Associação Genômica Ampla/métodos , Animais , Ecdisterona/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Muda/fisiologia
11.
Insect Biochem Mol Biol ; 108: 24-31, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30885802

RESUMO

Cuticle tanning occurs in insects immediately after hatching or molting. During this process, the cuticle becomes dark and rigid due to melanin deposition and protein crosslinking. In insects, different from mammals, melanin is synthesized mainly from dopamine, which is produced from DOPA by the enzyme DOPA decarboxylase. In this work, we report that the silencing of the RpAadc-2 gene, which encodes the putative Rhodnius prolixus DOPA decarboxylase enzyme, resulted in a reduction in nymph survival, with a high percentage of treated insects dying during the ecdysis process or in the expected ecdysis period. Those treated insects that could complete ecdysis presented a decrease in cuticle pigmentation and hardness after molting. In adult females, the knockdown of AADC-2 resulted in a reduction in the hatching of eggs; the nymphs that managed to hatch failed to tan the cuticle and were unable to feed. Despite the failure in cuticle tanning, knockdown of the AADC-2 did not increase the susceptibility to topically applied deltamethrin, a pyrethroid insecticide. Additionally, our results showed that the melanin synthesis pathway did not play a major role in the detoxification of the excess (potentially toxic) tyrosine from the diet, an essential trait for hematophagous arthropod survival after a blood meal.


Assuntos
Dopa Descarboxilase/fisiologia , Proteínas de Insetos/fisiologia , Tegumento Comum/fisiologia , Rhodnius/enzimologia , Rhodnius/crescimento & desenvolvimento , Animais , Dopa Descarboxilase/farmacologia , Feminino , Inativação Metabólica , Proteínas de Insetos/farmacologia , Inseticidas , Melaninas/metabolismo , Muda/fisiologia , Nitrilos , Pigmentação/fisiologia , Piretrinas , Reprodução , Rhodnius/genética , Tirosina/metabolismo
12.
Genes Genomics ; 41(5): 515-528, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30767169

RESUMO

BACKGROUND: Molting is a critical developmental process for crustaceans, during which the claw muscles undergo periodic atrophy and restoration. But the mechanism underlying this special muscle reshuffle around ecdysis is not yet thoroughly understood. OBJECTIVE: To investigate the molecular mechanism underlying the muscle's reshuffle over the molting cycle of Chinese mitten crab Eriocheir sinensis. METHODS: The Illumina high-throughput sequencing technique were used to sequence the transcriptome of the whole claw muscles from Chinese mitten crab Eriocheir sinensis in three molting stages (inter-molt C stage, pre-molt D3-4 and post-molt A-B stage); the de novo assembly, annotation and functional evaluation of the contigs were performed with bioinformatics tools. RESULTS: Totally 129,149 unigenes, 128,190 CDS, 33,770 SSRs and a large number of SNP sites were obtained, and 3700 and 12,771 differentially expressed genes (DEGs) were identified respectively in A-B and D3-4 stage compared with that in C stage. The identified DEGs were enriched to 746 and 1 408 GO terms respectively in A-B and D3-4 stage compared with C stage (p ≤ 0.05). KEGG pathway analysis showed that the DEGs were significantly enriched in 14 and 11 pathways in A-B vs C comparison and D3-4 vs C comparison (p ≤ 0.05), respectively. These DEGs are involved in several biological processes critical for the animal's growth and development, such as gene expression, protein synthesis, muscle development, new cuticle reconstruction, oxidation-reduction process and glycolytic process. CONCLUSION: The data generated in this study is the first transcriptomic resource from the muscles of Chinese mitten crab, which would facilitate to characterize key molecular processes underlying crab muscle's growth and development during the molting cycles.


Assuntos
Braquiúros/genética , Muda/genética , Animais , China , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Muda/fisiologia , Músculo Esquelético/fisiologia , Transcriptoma/genética
13.
J Insect Physiol ; 113: 42-48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30682338

RESUMO

Peritrophic membrane (PM) is a chitin and protein-containing extracellular matrix that lines the midgut in most insect species, functioning as a barrier to exogenous toxins and pathogens. Midgut chitin deacetylases (CDAs) are chitin-modifying enzymes known to alter the mechanical property and permeability of PM. However, biochemical properties and specific roles of these enzymes remain elusive. In this study, the midgut-expressed CDAs (BmCDA6, BmCDA7 and BmCDA8) from Bombyx mori were cloned, recombinantly expressed and purified and their enzymatic activities toward PM chitin were determined. Of the three enzymes, BmCDA7 exhibited the highest activity (0.284 µmol/min/µmol), while BmCDA8 showed lower activity of 0.061 µmol/min/µmol. BmCDA6 was inactive towards PM chitin. Gene expression patterns indicated that although all three CDA genes were specifically expressed in the anterior midgut, they differed in their temporal expression patterns. BmCDA6 was expressed almost exclusively at the mid-molt stage, the stage when the PM was thick and with multiple chitin layers. Unlike BmCDA6, high expression levels of BmCDA7 and BmCDA8 were observed only at the feeding stage, the stage when the PM is thin and with fewer chitin layers. The different gene expression patterns and biochemical characteristics provide new information about the functional specialization among BmCDA6, BmCDA7 and BmCDA8 proteins.


Assuntos
Amidoidrolases/genética , Bombyx/genética , Sistema Digestório/enzimologia , Proteínas de Insetos/genética , Amidoidrolases/química , Amidoidrolases/metabolismo , Sequência de Aminoácidos , Animais , Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Quitina/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Muda/fisiologia , Alinhamento de Sequência
14.
Arch Insect Biochem Physiol ; 100(4): e21535, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30672604

RESUMO

Previously, we showed that inhibition of the activity of fatty acid desaturases (Desat) perturbs signalling of the developmental timing hormone ecdysone in the fruit fly Drosophila melanogaster. To understand the impact of this effect on cuticle differentiation, a process regulated by ecdysone, we analysed the cuticle of D. melanogaster larvae fed with the Desat inhibitor CA10556. In these larvae, the expression of most of the key cuticle genes is normal or slightly elevated at day one of CA10556 feeding. As an exception, expression of twdlM coding for a yet uncharacterised cuticle protein is completely suppressed. The cuticle of these larvae appears to be normal at the morphological level. However, these animals are sensitive to desiccation, a trait that according to our data, among others, may be associated with reduced TwdlM amounts. At day two of CA10556 feeding, expression of most of the cuticle genes tested including twdlM is suppressed. Expression of cpr47Eb coding for a chitin-binding protein is, by contrast, highly elevated suggesting that Cpr47Eb participates at a specific compensation program. Overall, the cuticle of these larvae is thinner than the cuticle of control larvae. Taken together, lipid desaturation is necessary for a coordinated deployment of a normal cuticle differentiation program.


Assuntos
Drosophila melanogaster/crescimento & desenvolvimento , Inibidores Enzimáticos/farmacologia , Ácidos Graxos Dessaturases/antagonistas & inibidores , Ácidos Graxos/metabolismo , Animais , Drosophila melanogaster/efeitos dos fármacos , Inibidores Enzimáticos/química , Ácidos Graxos/química , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Umidade , Muda/efeitos dos fármacos , Muda/fisiologia
15.
J Steroid Biochem Mol Biol ; 185: 172-183, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30157455

RESUMO

Arthropods have long been utilized as models to explore molecular function, and the findings derived from them can be applied throughout metazoa, including as a basis for medical research. This has led to the adoption of many representative insect models beyond Drosophila, as each lends its own unique perspective to questions in endocrinology and genetics. However, non-insect arthropods are yet to be realised for the potential insight they may provide in such studies. The Crustacea are among the most ancient arthropods from which insects descended, comprising a huge variety of life histories and ecological roles. Of the events in a typical crustacean development, metamorphosis is perhaps the most ubiquitous, challenging and highly studied. Despite this, our knowledge of the endocrinology which underpins metamorphosis is rudimentary at best; although several key molecules have been identified and studied in depth, the link between them is quite nebulous and leans heavily on well-explored insect models, which diverged from the Pancrustacea over 450 million years ago. As omics technologies become increasingly accessible, they bring the prospect of explorative molecular research which will allow us to uncover components and pathways unique to crustaceans. This review reconciles known components of crustacean metamorphosis and reflects on our findings in insects to outline a future search space, with focus given to the ecdysone cascade. To expand our knowledge of this ubiquitous endocrine system not only aids in our understanding of crustacean metamorphosis, but also provides a deeper insight into the adaptive capacity of arthropods throughout evolution.


Assuntos
Crustáceos/fisiologia , Ecdisona/metabolismo , Sistema Endócrino/fisiologia , Insetos/fisiologia , Muda/fisiologia , Animais , Modelos Animais
16.
Biol Rev Camb Philos Soc ; 94(2): 700-720, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30334341

RESUMO

Although feathers are the unifying characteristic of all birds, our understanding of the causes, mechanisms, patterns and consequences of the feather moult process lags behind that of other major avian life-history phenomena such as reproduction and long-distance migration. Migration, which evolved in many species of the temperate and arctic zones, requires high energy expenditure to endure long-distance journeys. About a third of Western-Palearctic passerines perform long-distance migrations of thousands of kilometres each year using various morphological, physiological, biomechanical, behavioural and life-history adaptations. The need to include the largely non-overlapping breeding, long-distance migration and feather moult processes within the annual cycle imposes a substantial constraint on the time over which the moult process can take place. Here, we review four feather-moult-related adaptations which, likely due to time constraints, evolved among long-distance Western-Palearctic migrants: (i) increased moult speed; (ii) increased overlap between moult and breeding or migration; (iii) decreased extent of plumage moult; and (iv) moult of part or all of the plumage during the over-wintering period in the tropics rather than in the breeding areas. We suggest that long-distance migration shaped the evolution of moult strategies and increased the diversity of these strategies among migratory passerines. In contrast to this variation, all resident passerines in the Western Palearctic moult immediately after breeding by renewing the entire plumage of adults and in some species also juveniles, while in other species juvenile moult is partial. We identify important gaps in our current understanding of the moult process that should be addressed in the future. Notably, previous studies suggested that the ancestral moult strategy is a post-breeding summer moult in the Western Palearctic breeding areas and that moult during the winter evolved due to the scheduling of long-distance migration immediately after breeding. We offer an alternative hypothesis based on the notion of southern ancestry, proposing that the ancestral moult strategy was a complete moult during the 'northern winter' in the Afro-tropical region in these species, for both adults and juveniles. An important aspect of the observed variation in moult strategies relates to their control mechanisms and we suggest that there is insufficient knowledge regarding the physiological mechanisms that are involved, and whether they are genetically fixed or shaped by environmental factors. Finally, research effort is needed on how global climate changes may influence avian annual routines by altering the scheduling of major processes such as long-distance migration and feather moult.


Assuntos
Migração Animal/fisiologia , Muda/fisiologia , Passeriformes/fisiologia , Fatores Etários , Análise de Variância , Animais , Evolução Biológica , Cruzamento , Clima , Plumas/crescimento & desenvolvimento , Feminino , Masculino , Estações do Ano , Fatores Sexuais , Fatores de Tempo
17.
Insect Biochem Mol Biol ; 104: 91-105, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30278207

RESUMO

Anopheles gambiae devotes over 2% of its protein coding genes to its 298 structural cuticular proteins (CPs). This paper provides new LC-MS/MS data on two adult structures, proboscises and palps, as well as three larval samples - 4th instar larvae, just their terminal segment, and a preparation enriched in their tracheae. These data were combined with our previously published results of proteins from five other adult structures, whole adults, and two preparations chosen for their relatively clean cuticle, the larval head capsules left behind after ecdysis and the pupal cuticles left behind after adult eclosion. Peptides from 28 CPs were recovered in all adult structures; 24 CPs were identified for the first time, 6 of these were members of the TWDL family. Most newly identified proteins came from the larval sources. Based solely on peptide recovery, from our data and from other investigators, most available on VectorBase, there were only 4 CPs that were restricted to a single adult structure. More were restricted to a single metamorphic stage, 14 in larvae, 0 in pupae and 32 in adults. Expression data from our earlier RT-qPCR studies reduces these numbers. Charting restriction of CPs to stage or structure is a step forward in establishing their specific roles.


Assuntos
Anopheles/metabolismo , Proteínas de Insetos/metabolismo , Muda/fisiologia , Proteômica , Animais , Anopheles/anatomia & histologia , Larva/anatomia & histologia , Larva/metabolismo , Pupa/anatomia & histologia , Pupa/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-30308304

RESUMO

Feed intake and body weight are drastically altered in penguins during peri-molting period, and molting is known to affect the nutritional status of vitamin A and E. Although vitamin D status is not known in penguins during peri-molting period, vitamin D intake is supposed to be remarkably altered. The objective of the present study was to clarify the alterations in plasma 25-hydroxyvitamin D (25(OH)D) concentration, the most reliable biomarker for assessing vitamin D status, and vitamin D intake during peri-molting period. Blood samples were collected from seven adult male African penguins (Spheniscus demersus) in the control period, pre-molting period, early-molting period, and late-molting period. The dietary content of vitamin D and calcium (Ca) were higher than that of the estimated requirements. Feed intake increased in the pre-molting period and drastically decreased during the molting periods. Body weight increased in the pre-molting period, followed by the loss of weight towards the end of the experiment. Although vitamin D and Ca intakes decreased during the molting periods, plasma 25(OH)D concentration increased during the molting periods and the increase in plasma Ca concentration was also observed in the late-molting period. These results suggest that the reduction in body fat induced by reducing feed intake stimulated the release of vitamin D from body fat, which increased plasma 25(OH)D and Ca concentrations in molting penguins. Penguins are unlikely to suffer from typical hypervitaminosis D even during molting and vitamin D toxicity is not a realistic problem in penguins because of the short duration of molting.


Assuntos
Muda/fisiologia , Spheniscidae/sangue , Vitamina D/análogos & derivados , Animais , Cálcio/administração & dosagem , Dieta , Masculino , Vitamina D/administração & dosagem , Vitamina D/sangue
19.
Insect Biochem Mol Biol ; 104: 39-49, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30543984

RESUMO

Fibroin modulator binding protein-1 (FMBP-1) is a novel DNA-binding protein containing a conserved score and three amino acid peptide repeat (STPR) domain. The roles of factors containing STPR domain are less known. Although multiple transcription factors are involved in the transcriptional regulation of silk protein genes during the development of silkworm, the mechanism of transcriptional repression of silk protein genes during molting remains unclear. Here, we found that FMBP-1 expression was contrary to that of fibroin heavy chain (fib-H) during the fourth molting period of Bombyx mori. FMBP-1 repressed fib-H promoter activity by directly binding to the -130 element in the fib-H promoter region. We also identified two proteins, Bmsage and Bmdimm, that interacted with FMBP-1 in the posterior silk gland of silkworm larvae, and further verified these interactions by far western blotting and microscale thermophoresis in vitro, as well as co-immunoprecipitation and bimolecular fluorescence complementation at the cellular level. The luciferase reporter assay showed that the interaction between FMBP-1 and Bmdimm antagonized the activation of Bmdimm on fib-H transcription, but did not affect FMBP-1-mediated transcriptional repression on fib-H gene. Therefore, we proposed the following mechanism of fib-H transcriptional repression by FMBP-1 during the molting of silkworm larvae: 1) FMBP-1 directly binds to the -130 element in the fib-H promoter to repress fib-H transcription; 2) FMBP-1 interacts with Bmdimm to antagonize the activation of Bmdimm on fib-H transcription. Our findings promote a better understanding of fib-H transcriptional regulation and provide novel insights into the transcriptional repression of fib-H by FMBP-1 and basic helix-loop-helix factors Bmdimm during the molting of silkworm larvae. Our study also provides valuable information regarding the biological function of factors containing STPR domain.


Assuntos
Bombyx/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fibroínas/biossíntese , Proteínas de Insetos/metabolismo , Muda/fisiologia , Regiões Promotoras Genéticas/fisiologia , Transcrição Genética/fisiologia , Animais , Bombyx/genética , Proteínas de Ligação a DNA/genética , Fibroínas/genética , Regulação da Expressão Gênica/fisiologia , Proteínas de Insetos/genética
20.
Int J Biol Macromol ; 125: 588-595, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30513306

RESUMO

Insect cuticle is a composite made of chitin filaments embedded in a proteinaceous matrix, consisting mainly of structural cuticular proteins. In the present study, an endocuticle structural glycoprotein gene, LmAbd-9, was characterized based on the Locusta migratoria transcriptome. LmAbd-9 encodes a glycoprotein with a chitin binding domain 4, belonging to RR-1 subclass of the CPR family, which has two potential O-linked glycosylation sites (S115 and T137) at which glycosylation modification may occur. LmAbd-9 was highly expressed in the integument and showed periodic expression during molting. The expression levels of LmAbd-9 were significantly down-regulated after injection with 20-hydroxyecdysone (20E) for 6, 12, and 24 h, whereas it was upregulated after double-stranded RNA-mediated RNA interference of the 20E receptor gene LmEcR and LmFTZ-F1beta at day 2 of fifth instar nymphs for 48 h. After injection of dsLmAbd-9 on day 2 of fifth instar nymphs, the insects could normally molt to adults and showed no macroscopic phenotype; however, the cuticle of the adults was thinner, and there were significantly fewer endocuticular lamellae than in the control. Thus, LmAbd-9 that negatively regulated by the 20E signaling pathway was involved in the formation of the endocuticle in L. migratoria.


Assuntos
Glicoproteínas/genética , Proteínas de Insetos/genética , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/genética , Muda/genética , Animais , Quitina/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Ecdisterona/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , Glicosilação/efeitos dos fármacos , Locusta migratoria/efeitos dos fármacos , Muda/efeitos dos fármacos , Muda/fisiologia , Ninfa/efeitos dos fármacos , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Interferência de RNA/efeitos dos fármacos , RNA de Cadeia Dupla/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
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