Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.819
Filtrar
1.
Gene ; 809: 146002, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34648919

RESUMO

We aimed to explain the reason and function of the successive expression of ecdysone-responsive transcription factors (ERTFs) and related cuticular protein (CP) genes during transformation from larva to pupa. The regulation of the expression of CP genes by ERTFs was examined by in vitro wing disc culture and reporter assay using a gene gun transduction system. Two CP genes that showed expression peaks at different stages-BmorCPG12 at W3L and BmorCPH2 at P0 stage-were selected and examined. Reporter constructs conveying putative BHR3, ßFTZ-F1, BHR39, and E74A binding sites of BmorCPG12 and BmorCPH2 showed promoter activity when introduced into wing discs. In the present study, we showed the functioning of the putative BHR3 and E74A binding sites, together with putative ßFTZ-F1 binding sites, on the activation of CP genes, and different ERTF binding sites functioned in one CP gene. From these, we conclude that BHR3, ßFTZ-F1, and E74A that are successively expressed bring about the successive expression of CP genes, resulting in insect metamorphosis. In addition to this, reporter constructs conveying putative BHR39 binding sites of BmorCPG12 and BmorCPH2 showed negative regulation.


Assuntos
Bombyx/genética , Ecdisona/metabolismo , Proteínas de Insetos/genética , Metamorfose Biológica/genética , Fatores de Transcrição/genética , Animais , Sítios de Ligação , Bombyx/fisiologia , Ecdisona/genética , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteínas de Insetos/metabolismo , Larva/genética , Mutagênese Sítio-Dirigida , Pupa/genética , Fatores de Transcrição/metabolismo , Asas de Animais/crescimento & desenvolvimento
2.
Dev Biol ; 481: 104-115, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34648816

RESUMO

Pulses of the steroid hormone ecdysone act through transcriptional cascades to direct the major developmental transitions during the Drosophila life cycle. These include the prepupal ecdysone pulse, which occurs 10 â€‹hours after pupariation and triggers the onset of adult morphogenesis and larval tissue destruction. E93 encodes a transcription factor that is specifically induced by the prepupal pulse of ecdysone, supporting a model proposed by earlier work that it specifies the onset of adult development. Although a number of studies have addressed these functions for E93, little is known about its roles in the salivary gland where the E93 locus was originally identified. Here we show that E93 is required for development through late pupal stages, with mutants displaying defects in adult differentiation and no detectable effect on the destruction of larval salivary glands. RNA-seq analysis demonstrates that E93 regulates genes involved in development and morphogenesis in the salivary glands, but has little effect on cell death gene expression. We also show that E93 is required to direct the proper timing of ecdysone-regulated gene expression in salivary glands, and that it suppresses earlier transcriptional programs that occur during larval and prepupal stages. These studies support the model that the stage-specific induction of E93 in late prepupae provides a critical signal that defines the end of larval development and the onset of adult differentiation.


Assuntos
Proteínas de Drosophila/metabolismo , Ecdisona/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Metamorfose Biológica/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Ecdisona/metabolismo , Larva , Fatores de Transcrição/genética
3.
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
4.
Biofouling ; 37(8): 911-921, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34620016

RESUMO

The molecular mechanism underlying modulation of metamorphosis of the bivalve Mytilus coruscus by bacteria remains unclear. Here, the functional role of the thioesterase gene tesA of the bacterium Pseudoalteromonas marina in larval metamorphosis was examined. The aim was to determine whether inactivation of the tesA gene altered the biofilm-inducing capacity, bacterial cell motility, biopolymers, or the intracellular c-di-GMP levels. Complete inactivation of tesA increased the c-di-GMP content in P. marina, accompanied by a reduced fatty acid content, weaker motility, upregulation of bacterial aggregation, and biofilm formation. The metamorphosis rate of mussel larvae on ΔtesA biofilms was reduced by ∼ 80% compared with those settling on wild-type P. marina. Exogenous addition of a mixture of extracted fatty acids from P. marina into the ΔtesA biofilms promoted the biofilm-inducing capacity. This study suggests that the bacterial thioesterase gene tesA altered the fatty acid composition of ΔtesA P. marina biofilms (BF) through regulation of its c-di-GMP, subsequently impacting mussel metamorphosis.


Assuntos
Mytilus , Pseudoalteromonas , Animais , Proteínas de Bactérias/genética , Biofilmes , GMP Cíclico , Ácidos Graxos , Regulação Bacteriana da Expressão Gênica , Metamorfose Biológica , Mytilus/metabolismo , Pseudoalteromonas/metabolismo
5.
PLoS One ; 16(10): e0258185, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34644335

RESUMO

Ivermectin is a broad-spectrum antiparasitic medicine, which is often used as a treatment for parasites or as a prophylaxis. While studies have looked at the long-term effects of Ivermectin on helminths, studies have not considered the long-term impacts of this treatment on host health or disease susceptibility. Here, we tracked the effects of early life Ivermectin treatment in Cuban tree frogs (Osteopilus septentrionalis) on growth rates, mortality, metabolically expensive organ size, and susceptibility to Batrachochytrium dendrobatidis (Bd) infection. One year after exposure, there was no effect of Ivermectin exposure on frog mass (X21 = 0.904, p = 0.34), but when tracked through the exponential growth phase (~2.5 years) the Ivermectin exposed individuals had lower growth rates and were ultimately smaller (X21 = 7.78, p = 0.005; X21 = 5.36, p = 0.02, respectively). These results indicate that early life exposure is likely to have unintended impacts on organismal growth and potentially reproductive fitness. Additionally, we exposed frogs to Bd, a pathogenic fungus that has decimated amphibian populations globally, and found early life exposure to Ivermectin decreased disease susceptibility (disease load: X21 = 17.57, p = 0.0002) and prevalence (control: 55%; Ivermectin: 22%) over 2 years after exposure. More research is needed to understand the underlying mechanism behind this phenomenon. Given that Ivermectin exposure altered disease susceptibility, proper controls should be implemented when utilizing this drug as an antiparasitic treatment in research studies.


Assuntos
Anuros/crescimento & desenvolvimento , Anuros/microbiologia , Ivermectina/uso terapêutico , Micoses/tratamento farmacológico , Micoses/veterinária , Animais , Batrachochytrium/efeitos dos fármacos , Suscetibilidade a Doenças , Metamorfose Biológica/efeitos dos fármacos
6.
Mar Genomics ; 60: 100877, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34627550

RESUMO

The settlement and metamorphosis of coral larvae are the bottleneck of coral recruitment. They are critical for the extension of coral population, which is the basis of the restoration of degraded coral reef ecosystem. In this study, we described the genomic characteristics of Metabacillus sp. cB07, which can efficiently induce larvae settlement and metamorphosis of coral Pocillopora damicornis. This function is first reported in the genus Metabacillus. Strain cB07 was isolated from the coral Porites pukoensis, and comprised one circular chromosome of 4,148,576 bp (44.14 mol% G + C content), containing 4148 protein coding sequences. To explore the potential mechanism of coral larvae settlement and metamorphosis induced by Metabacillus sp. cB07, we predicted that numerous genes related to the bacterial inductive ability. The genome of Metabacillus sp. cB07 will be helpful for further insights into the mechanism of bacterial induction of settlement and metamorphosis of coral larvae.


Assuntos
Antozoários , Animais , Antozoários/genética , Recifes de Corais , Ecossistema , Larva/genética , Metamorfose Biológica
7.
Zoolog Sci ; 38(5): 427-435, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34664917

RESUMO

No scales of most lepidopterans (butterflies and moths) detach from the wings through fluttering. However, in the pellucid hawk moth, Cephonodes hylas, numerous scales detach from a large region of the wing at initial take-off after eclosion; consequently, a large transparent region without scales appears in the wing. Even after this programmed detachment of scales (d-scales), small regions along the wing margin and vein still have scales attached (a-scales). To investigate the scale detachment mechanism, we analyzed the scale detachment process using video photography and examined the morphology of both d- and a-scales using optical and scanning electron microscopy. This study showed that d-scale detachment only occurs through fluttering and that d-scales are obviously morphologically different from a-scales. Although a-scales are morphologically common lepidopteran scales, d-scales have four distinctive features. First, d-scales are much larger than a-scales. Second, the d-scale pedicel, which is the slender base of the scale, is tapered; that of the a-scale is columnar. Third, the socket on the wing surface into which the pedicel is inserted is much smaller for d-scales than a-scales. Fourth, the d-scale socket density is much lower than the a-scale socket density. This novel scale morphology likely helps to facilitate scale detachment through fluttering and, furthermore, increases wing transparency.


Assuntos
Mariposas/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Voo Animal/fisiologia , Metamorfose Biológica , Mariposas/crescimento & desenvolvimento , Asas de Animais/ultraestrutura
8.
BMC Genomics ; 22(1): 756, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34674639

RESUMO

BACKGROUND: Much of the complex anatomy of a holometabolous insect is built from disc-shaped epithelial structures found inside the larva, i.e., the imaginal discs, which undergo a rapid differentiation during metamorphosis. Imaginal discs-derived structures, like wings, are built through the action of genes under precise regulation. RESULTS: We analyzed 30 honeybee transcriptomes in the search for the gene expression needed for wings and thoracic dorsum construction from the larval wing discs primordia. Analyses were carried out before, during, and after the metamorphic molt and using worker and queen castes. Our RNA-seq libraries revealed 13,202 genes, representing 86.2% of the honeybee annotated genes. Gene Ontology analysis revealed functional terms that were caste-specific or shared by workers and queens. Genes expressed in wing discs and descendant structures showed differential expression profiles dynamics in premetamorphic, metamorphic and postmetamorphic developmental phases, and also between castes. At the metamorphic molt, when ecdysteroids peak, the wing buds of workers showed maximal gene upregulation comparatively to queens, thus underscoring differences in gene expression between castes at the height of the larval-pupal transition. Analysis of small RNA libraries of wing buds allowed us to build miRNA-mRNA interaction networks to predict the regulation of genes expressed during wing discs development. CONCLUSION: Together, these data reveal gene expression dynamics leading to wings and thoracic dorsum formation from the wing discs, besides highlighting caste-specific differences during wing discs metamorphosis.


Assuntos
Discos Imaginais , Transcriptoma , Animais , Abelhas/genética , Humanos , Metamorfose Biológica/genética , Classe Social , Asas de Animais
9.
Int J Legal Med ; 135(6): 2625-2635, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34570269

RESUMO

Estimating the age of the developmental stages of the blow fly Calliphora vicina (Diptera: Calliphoridae) is of forensic relevance for the determination of the minimum post-mortem interval (PMImin). Fly eggs and larvae can be aged using anatomical and morphological characters and their modification during development. However, such methods can only hardly be applied for aging fly pupae. Previous study described age estimation of C. vicina pupae using gene expression, but just when reared at constant temperatures, but fluctuating temperatures represent a more realistic scenario at a crime scene. Therefore, age-dependent gene expression of C. vicina pupae were compared at 3 fluctuating and 3 constant temperatures, the latter representing the mean values of the fluctuating profiles. The chosen marker genes showed uniform expression patterns during metamorphosis of C. vicina pupae bred at different temperature conditions (constant or fluctuating) but the same mean temperature (e.g. constant 10 °C vs. fluctuating 5-15 °C). We present an R-based statistical tool, which enables estimation of the age of the examined pupa based on the analysed gene expression data.


Assuntos
Calliphoridae/crescimento & desenvolvimento , Calliphoridae/genética , Expressão Gênica , Metamorfose Biológica , Pupa/crescimento & desenvolvimento , Pupa/genética , Temperatura , Animais , Entomologia Forense , Perfilação da Expressão Gênica
10.
Cells ; 10(9)2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34572025

RESUMO

BACKGROUND: Most work in endocrinology focus on the action of a single hormone, and very little on the cross-talks between two hormones. Here we characterize the nature of interactions between thyroid hormone and glucocorticoid signaling during Xenopus tropicalis metamorphosis. METHODS: We used functional genomics to derive genome wide profiles of methylated DNA and measured changes of gene expression after hormonal treatments of a highly responsive tissue, tailfin. Clustering classified the data into four types of biological responses, and biological networks were modeled by system biology. RESULTS: We found that gene expression is mostly regulated by either T3 or CORT, or their additive effect when they both regulate the same genes. A small but non-negligible fraction of genes (12%) displayed non-trivial regulations indicative of complex interactions between the signaling pathways. Strikingly, DNA methylation changes display the opposite and are dominated by cross-talks. CONCLUSION: Cross-talks between thyroid hormones and glucocorticoids are more complex than initially envisioned and are not limited to the simple addition of their individual effects, a statement that can be summarized with the pseudo-equation: TH ∙ GC > TH + GC. DNA methylation changes are highly dynamic and buffered from genome expression.


Assuntos
Glucocorticoides/metabolismo , Metamorfose Biológica/fisiologia , Transdução de Sinais/fisiologia , Hormônios Tireóideos/metabolismo , Transcriptoma/genética , Xenopus/genética , Xenopus/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento/genética , Genoma/genética
11.
Environ Pollut ; 291: 118226, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34563849

RESUMO

Reclaimed water (RW) obtained from wastewater treatment plants (WWTP) is used for irrigation, groundwater recharge, among other potential uses. Although most pollutants are removed, traces of them are frequently found, which can affect organisms and alter the environment. The presence of a myriad of contaminants in RW makes it a complex mixture with very diverse effects and interactions. A previous study, in which tadpoles were exposed to RW and RW spiked with Carbamazepine (CBZ), presented slight thyroid gland stimulation, as suggested by the development acceleration of tadpoles and histological findings in the gland provoked by RW, regardless of the CBZ concentration. To complement this study, the present work analysed the putative molecular working mechanism by selecting six genes coding for the thyroid-stimulating hormone (TSHß), thyroid hormone metabolising enzymes (DIO2, DIO3), thyroid receptors (THRA, THRB), and a thyroid hormone-induced DNA binding protein (Kfl9). Transcriptional activity was studied by Real-Time PCR (RT-PCR) in brains, hind limbs, and tails on exposure days 1, 7, and 21. No significant differences were observed between treatments for each time point, but slight alterations were noted when the time response was analysed. The obtained results indicate that the effects of RW or RW spiked with CBZ are negligible for the genes analysed during the selected exposure periods.


Assuntos
Glândula Tireoide , Poluentes Químicos da Água , Animais , Carbamazepina/toxicidade , Expressão Gênica , Larva , Metamorfose Biológica , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Xenopus laevis
12.
Environ Toxicol Pharmacol ; 87: 103738, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34492396

RESUMO

The effects of two drugs containing the synthetic thyroid hormone levothyroxine (LEV) and an anti-thyroid drug containing propylthiouracil (PTU) on the three early life stages of Xenopus laevis were evaluated with the Frog Embryo Teratogenesis Assay-Xenopus, Tadpole Toxicity Test, and Amphibian Metamorphosis Assay using biochemical and morphological markers. Tested drugs caused more effective growth retardation in stage 8 embryos than stage 46 tadpoles. Significant inhibition of biomarker enzymes has been identified in stage 46 tadpoles for both drugs. AMA test results showed that LEV-I caused progression in the developmental stage and an increase in thyroxine level in 7 days exposure and growth retardation in 21 days exposure in stage 51 tadpoles. On the other hand, increases in lactate dehydrogenase activity for both drugs in the AMA test may be due to impacted energy metabolism during sub-chronic exposure. These results also show that the sensitivity and responses of Xenopus laevis at different early developmental stages may be different when exposed to drugs.


Assuntos
Antitireóideos/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Propiltiouracila/toxicidade , Teratógenos/toxicidade , Tiroxina/toxicidade , Xenopus laevis , Acetilcolinesterase/metabolismo , Animais , Carboxilesterase/metabolismo , Embrião não Mamífero/anormalidades , Embrião não Mamífero/enzimologia , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Larva/enzimologia , Larva/crescimento & desenvolvimento , Masculino , Metamorfose Biológica/efeitos dos fármacos , Xenopus laevis/anormalidades , Xenopus laevis/crescimento & desenvolvimento , Xenopus laevis/metabolismo
13.
J Exp Biol ; 224(20)2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34553756

RESUMO

Larvae of many marine invertebrates bear an anteriorly positioned apical sensory organ (ASO) presumed to be the receptor for settlement- and metamorphosis-inducing environmental cues, based on its structure, position and observed larval behavior. Larvae of the polychaete Hydroides elegans are induced to settle by bacterial biofilms, which they explore with their ASO and surrounding anteroventral surfaces. A micro-laser was utilized to destroy the ASO and other anterior ciliary structures in competent larvae of H. elegans. After ablation, larvae were challenged with bacterial biofilmed or clean surfaces and percentage metamorphosis was determined. Ablated larvae were also assessed for cellular damage by applying fluorescently tagged FMRF-amide antibodies and observing the larvae by laser-scanning confocal microscopy. While the laser pulses caused extensive damage to the ASO and surrounding cells, they did not inhibit metamorphosis. We conclude that the ASO is not a required receptor site for cues that induce metamorphosis.


Assuntos
Terapia a Laser , Poliquetos , Animais , Sinais (Psicologia) , Larva , Metamorfose Biológica
14.
Sci Rep ; 11(1): 16434, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385533

RESUMO

In holometabolous insects like Drosophila melanogaster, critical size is an important time point during larval life, for irreversible commitment to metamorphosis. Here, we studied the impact of restricted growth duration in terms of selection for faster pre-adult development in Drosophila melanogaster populations which resulted in the evolution of reduced critical size on adult life history traits. Selection for faster pre-adult development resulted in biochemical adaptation in larval physiology with no compromise in major biomolecules at critical size time point. The flies from the selected populations seem to not only commit to metamorphosis on the attainment of critical size but also seem to channelize resources to reproduction as indicated by similar life-time fecundity of CS and NS flies from selected populations, while the Control CS flies significantly lower life-time fecundity compared to Control NS flies. The flies from selected populations seem to achieve longevity comparable to control flies despite being significantly smaller in size-thus resource constrained due to faster pre-adult development.


Assuntos
Adaptação Fisiológica , Drosophila melanogaster/fisiologia , Longevidade , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Fertilidade , Larva/crescimento & desenvolvimento , Masculino , Metamorfose Biológica
15.
J Insect Physiol ; 134: 104294, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34389412

RESUMO

In insects, some sterols are essential not only for cell membrane homeostasis, but for biosynthesis of the steroid hormone ecdysone. Dietary sterols are required for insect development because insects cannot synthesize sterols de novo. Therefore, sterol-like compounds that can compete with essential sterols are good candidates for insect growth regulators. In this study, we investigated the effects of the plant-derived triterpenoids, cucurbitacin B and E (CucB and CucE) on the development of the fruit fly, Drosophila melanogaster. To reduce the effects of supply with an excess of sterols contained in food, we reared D. melanogaster larvae on low sterol food (LSF) with or without cucurbitacins. Most larvae raised on LSF without supplementation or with CucE died at the second or third larval instar (L2 or L3) stages, whereas CucB-administered larvae mostly died without molting. The developmental arrest caused by CucB was partially rescued by ecdysone supplementation. Furthermore, we examined the effects of CucB on larval-prepupal transition by transferring larvae from LSF supplemented with cholesterol to that with CucB just after the L2/L3 molt. L3 larvae raised on LSF with CucB failed to pupariate, with a remarkable developmental delay. Ecdysone supplementation rescued the developmental delay but did not rescue the pupariation defect. Furthermore, we cultured the steroidogenic organ, the prothoracic gland (PG) of the silkworm Bombyx mori, with or without cucurbitacin. Ecdysone production in the PG was reduced by incubation with CucB, but not with CucE. These results suggest that CucB acts not only as an antagonist of the ecdysone receptor as previously reported, but also acts as an inhibitor of ecdysone biosynthesis.


Assuntos
Drosophila melanogaster , Ecdisona , Triterpenos/farmacologia , Animais , Bombyx/efeitos dos fármacos , Bombyx/metabolismo , Proteínas de Drosophila/efeitos dos fármacos , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Ecdisona/antagonistas & inibidores , Ecdisona/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Hormônios Juvenis/farmacologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Metamorfose Biológica/efeitos dos fármacos , Muda/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Extratos Vegetais/farmacologia , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Pupa/metabolismo
16.
Biol Bull ; 241(1): 92-104, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34436961

RESUMO

AbstractThe diversity and consequences of development in marine invertebrates have, for a long time, provided the opportunity to understand different evolutionary solutions to living in variable environments. However, discrete classifications of development can impede a full understanding of adaptation to variable environments when behavioral, morphological, or physiological flexibility and variation exist within traditionally defined modes of development. We report here novel behavioral variability in hatchlings of a marine gastropod, the Florida crown conch (Melongena corona), that has broad significance for understanding the correlated evolution of development, dispersal, and reproductive strategies in variable environments. All hatchlings crawl away from egg capsules after emergence as larval pediveligers. Some subsequently swim for a brief period (seconds to minutes) before crawling again. From detailed observations of 120 individuals over 30 days, we observed 28 (23.3%) hatchlings swimming at least once (8%-50% per maternal brood). The propensity to swim was unrelated to time spent encapsulated or size at hatching and lasted for 22 days. We manipulated hypothesized environmental cues and found that the proportion of hatchlings that swam was highest in the absence of cues related to habitat or juvenile food and lowest when only habitat cues were present. The relative growth rate of hatchlings was highest when habitats contained a putative juvenile food source. About 44% of hatchlings were competent to metamorphose at emergence but did not metamorphose at this time in the lab or the field. The rate of metamorphosis increased with age and depended on the presence of unknown cues in the field. Crawl-away larvae with prolonged swimming ability may be an adaptation to balance the unpredictable risks of exclusively benthic or pelagic development and to allow the option to disperse to higher-quality habitat.


Assuntos
Gastrópodes , Natação , Animais , Ecossistema , Humanos , Larva , Metamorfose Biológica
17.
Arch Insect Biochem Physiol ; 108(1): e21832, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34250644

RESUMO

Autophagy is a critical mechanism for the self-renewal, proliferation, and differentiation of stem cells. Bombyx mori midgut has stem cells that play a role in the regeneration of the larval epithelium in larval stages and the formation of the pupal midgut epithelium during larval-pupal metamorphosis. In this study, the role of the autophagy mechanism in midgut stem cells during the formation of the pupal midgut was investigated. For this purpose, two different doses of autophagy inhibitor chloroquine were administered to B. mori larvae on days 7 and 8 of the fifth larval stage. Morphological changes during the formation process of the pupal epithelium, expression levels of autophagy-related genes Atg8 and Atg12 in stem cells, and the amounts of lysosomal enzyme acid phosphatase were determined after the application. The obtained findings were evaluated in comparison with the control groups. Abnormalities in the formation of the pupal midgut after inhibition of autophagy showed the significance of the autophagy mechanism during this period.


Assuntos
Autofagia , Bombyx , Intestinos , Metamorfose Biológica/fisiologia , Células-Tronco , Fosfatase Ácida/efeitos dos fármacos , Fosfatase Ácida/metabolismo , Animais , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Bombyx/citologia , Bombyx/metabolismo , Bombyx/fisiologia , Cloroquina/farmacologia , Intestinos/citologia , Intestinos/efeitos dos fármacos , Larva/citologia , Larva/metabolismo , Pupa/citologia , Pupa/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
18.
Elife ; 102021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34259633

RESUMO

Individual neurons can undergo drastic structural changes, known as neuronal remodeling or structural plasticity. One example of this is in response to hormones, such as during puberty in mammals or metamorphosis in insects. However, in each of these examples, it remains unclear whether the remodeled neuron resumes prior patterns of connectivity, and if so, whether the persistent circuits drive similar behaviors. Here, we utilize a well-characterized neural circuit in the Drosophila larva: the moonwalker descending neuron (MDN) circuit. We previously showed that larval MDN induces backward crawling, and synapses onto the Pair1 interneuron to inhibit forward crawling (Carreira-Rosario et al., 2018). MDN is remodeled during metamorphosis and regulates backward walking in the adult fly. We investigated whether Pair1 is remodeled during metamorphosis and functions within the MDN circuit during adulthood. We assayed morphology and molecular markers to demonstrate that Pair1 is remodeled during metamorphosis and persists in the adult fly. MDN-Pair1 connectivity is lost during early pupal stages, when both neurons are severely pruned back, but connectivity is re-established at mid-pupal stages and persist into the adult. In the adult, optogenetic activation of Pair1 resulted in arrest of forward locomotion, similar to what is observed in larvae. Thus, the MDN-Pair1 neurons are an interneuronal circuit - a pair of synaptically connected interneurons - that is re-established during metamorphosis, yet generates similar locomotor behavior at both larval and adult stages.


Assuntos
Drosophila/fisiologia , Larva/fisiologia , Locomoção/fisiologia , Neurônios Motores/fisiologia , Animais , Drosophila melanogaster/fisiologia , Interneurônios , Metamorfose Biológica/fisiologia , Plasticidade Neuronal , Optogenética , Sinapses
19.
Sci Rep ; 11(1): 15113, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301989

RESUMO

Metamorphosis is a key innovation allowing the same species to inhabit different environments and accomplish different functions, leading to evolutionary success in many animal groups. Astigmata is a megadiverse lineage of mites that expanded into a great number of habitats via associations with invertebrate and vertebrate hosts (human associates include stored food mites, house dust mites, and scabies). The evolutionary success of Astigmata is linked to phoresy-related metamorphosis, namely the origin of the heteromorphic deutonymph, which is highly specialized for phoresy (dispersal on hosts). The origin of this instar is enigmatic since it is morphologically divergent and no intermediate forms are known. Here we describe the heteromorphic deutonymph of Levantoglyphus sidorchukae n. gen. and sp. (Levantoglyphidae fam. n.) from early Cretaceous amber of Lebanon (129 Ma), which displays a transitional morphology. It is similar to extant phoretic deutonymphs in its modifications for phoresy but has the masticatory system and other parts of the gnathosoma well-developed. These aspects point to a gradual evolution of the astigmatid heteromorphic morphology and metamorphosis. The presence of well-developed presumably host-seeking sensory elements on the gnathosoma suggests that the deutonymph was not feeding either during phoretic or pre- or postphoretic periods.


Assuntos
Metamorfose Biológica/genética , Metamorfose Biológica/fisiologia , Ácaros/genética , Ácaros/fisiologia , Âmbar , Animais , Evolução Biológica , Ecossistema , Fósseis , Humanos , Líbano
20.
Sci Rep ; 11(1): 14610, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272460

RESUMO

The resilience of coral reefs is dependent on the ability of corals to settle after disturbances. While crustose coralline algae (CCA) are considered important substrates for coral settlement, it remains unclear whether coral larvae respond to CCA metabolites and microbial cues when selecting sites for attachment and metamorphosis. This study tested the settlement preferences of an abundant coral species (Acropora cytherea) against six different CCA species from three habitats (exposed, subcryptic and cryptic), and compared these preferences with the metabolome and microbiome characterizing the CCA. While all CCA species induced settlement, only one species (Titanoderma prototypum) significantly promoted settlement on the CCA surface, rather than on nearby dead coral or plastic surfaces. This species had a very distinct bacterial community and metabolomic fingerprint. Furthermore, coral settlement rates and the CCA microbiome and metabolome were specific to the CCA preferred habitat, suggesting that microbes and/or chemicals serve as environmental indicators for coral larvae. Several amplicon sequence variants and two lipid classes-glycoglycerolipids and betaine lipids-present in T. prototypum were identified as potential omic cues influencing coral settlement. These results support that the distinct microbiome and metabolome of T. prototypum may promote the settlement and attachment of coral larvae.


Assuntos
Antozoários/fisiologia , Bactérias/classificação , Bactérias/metabolismo , Larva/fisiologia , Metaboloma , Microbiota , Rodófitas/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Recifes de Corais , DNA Bacteriano , Ecologia , Ecossistema , Biologia Marinha , Metamorfose Biológica , RNA Ribossômico 16S , Rodófitas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...