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1.
Oecologia ; 192(3): 647-656, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31989318

RESUMO

Organisms with annual life cycles are exposed to life stage specific thermal environments across seasons. Seasonal variation in thermal environments can vary across years and among sites. We investigated how organisms with annual life cycles respond to predictable seasonal changes in temperature and unpredictable thermal variation between habitats and years throughout their lives. Field surveys and historical records reveal that the spatially and temporally heterogeneous thermal environments inhabited by the annual mayfly Ephemerella maculata (Ephemerellidae) shift the date for transition to the next, life stage, so that the thermal phenotype of each life stage matches the thermal environment of the specific habitat and year. Laboratory studies of three distinct life stages of this mayfly reveal that life stage transitions are temperature dependent, facilitating timing shifts that are synchronized with the current season's temperatures. Each life stage exhibited specific thermal sensitivity and performance phenotypes that matched the ambient temperature typically experienced during that life stage. Our study across the whole life cycle reveals mechanisms that allow organisms to achieve lifetime eurythermy in a dynamic seasonal environment, despite having narrower thermal ranges for growth and development in each life stage.


Assuntos
Ephemeroptera , Animais , Insetos , Estágios do Ciclo de Vida , Estações do Ano , Temperatura Ambiente
2.
Parasitol Res ; 119(2): 749-753, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897792

RESUMO

Trypanosoma cruzi, the causative agent of Chagas disease, has a complex life cycle that requires the adaptation to different environments. In the absence of traditional mechanisms for regulation of gene expression, this parasite relies on posttranscriptional control events, which allow the progression of its life cycle in different hosts and stress conditions. In this context, different stress conditions trigger the aggregation of RNA-binding proteins and their target mRNAs into cytoplasmic foci known as RNA granules, which act as RNA-sorting centers. In this study, we have characterized the T. cruzi RNA-binding protein ALBA30 during nutritional stress conditions. Using a recombinant form of TcALBA30 to facilitate its detection (rTcALBA30), we showed that this protein resides in the cytoplasm in normal growth conditions but is recruited into cytoplasmic foci after starvation. Moreover, evaluation of rTcALBA30 in parasites that reached the stationary phase of growth also showed the recruitment of this protein into cytoplasmic foci. Our results indicate that, similar to TbALBA3, TcALBA30 aggregates into stress granules in parasites submitted to nutritional stress.


Assuntos
Regulação da Expressão Gênica/genética , Proteínas de Protozoários/genética , Proteínas de Ligação a RNA/genética , Estresse Fisiológico/fisiologia , Trypanosoma cruzi/genética , Animais , Ciclo Celular , Doença de Chagas/parasitologia , Citoplasma/metabolismo , Estágios do Ciclo de Vida/fisiologia , RNA Mensageiro/metabolismo , Inanição
3.
Insect Biochem Mol Biol ; 116: 103259, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31698083

RESUMO

Heliconius butterflies are highly specialized in Passiflora plants, laying eggs and feeding as larvae only on them. Interestingly, both Heliconius butterflies and Passiflora plants contain cyanogenic glucosides (CNglcs). While feeding on specific Passiflora species, Heliconius melpomene larvae are able to sequester simple cyclopentenyl CNglcs, the most common CNglcs in this plant genus. Yet, aromatic, aliphatic, and modified CNglcs have been reported in Passiflora species and they were never tested for sequestration by heliconiine larvae. As other cyanogenic lepidopterans, H. melpomene also biosynthesize the aliphatic CNglcs linamarin and lotaustralin, and their toxicity does not rely exclusively on sequestration. Although the genes encoding the enzymes in the CNglc biosynthesis have not yet been biochemically characterized in butterflies, the cytochromes P450 CYP405A4, CYP405A5, CYP405A6 and CYP332A1 have been hypothesized to be involved in this pathway in H. melpomene. In this study, we determine how the CNglc composition and expression of the putative P450s involved in the biosynthesis of these compounds vary at different developmental stages of Heliconius butterflies. We also establish which kind of CNglcs H. melpomene larvae can sequester from Passiflora. By analysing the chemical composition of the haemolymph from larvae fed with different Passiflora diets, we show that H. melpomene is able to sequestered prunasin, an aromatic CNglcs, from P. platyloba. They are also able to sequester amygdalin, gynocardin, [C13/C14]linamarin and [C13/C14]lotaustralin painted on the plant leaves. The CNglc tetraphyllin B-sulphate from P. caerulea is not detected in the larval haemolymph, suggesting that such modified CNglcs cannot be sequestered by Heliconius. Although pupae and virgin adults contain dihydrogynocardin resulting from larval sequestration, this compound was metabolized during adulthood, and not used as nuptial gift or transferred to the offspring. Thus, we speculate that dihydrogynocardin is catabolized to recycle nitrogen and glucose, and/or to produce fitness signals during courtship. Mature adults have a higher concentration of CNglcs than any other developmental stages due to increased de novo biosynthesis of linamarin and lotaustralin. Accordingly, all CYP405As are expressed in adults, whereas larvae mostly express CYP405A4. Our results shed light on the importance of CNglcs for Heliconius biology and their coevolution with Passiflora.


Assuntos
Borboletas/metabolismo , Glicosídeos/biossíntese , Glicosídeos/metabolismo , Animais , Coevolução Biológica , Borboletas/química , Borboletas/enzimologia , Borboletas/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Perfilação da Expressão Gênica , Glucosídeos/metabolismo , Herbivoria , Larva/enzimologia , Larva/metabolismo , Estágios do Ciclo de Vida/fisiologia , Nitrilos/metabolismo , Passiflora/química
4.
Chemosphere ; 242: 125209, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31677519

RESUMO

The fungicide myclobutanil (MYC) is a common contaminant found in surface water. The aim of this study was to determine the acute toxicity, developmental effects, bioconcentration factor (BCF) and potential bio-molecular mechanisms of MYC toxicity in zebrafish. Susceptibility to MYC toxicity was life-stage dependent with adult fish being the most sensitive (96 h-LC50, 6.34 mg/L) followed by 72 h post-hatch (hph) larvae (8.90 mg/L), 12 hph larvae (20.53 mg/L) and embryos (42.54 mg/L). Zebrafish embryos and larvae (12 hph) responded with decreased hatching, heartbeat and growth, as well as abnormal spontaneous movement and development. BCFs were calculated by quantifying MYC concentrations from different tissues of adult zebrafish exposed to MYC for up to 11 days. Highest BCFs were obtained from gills (18.25 ±â€¯0.07), followed by viscera (16.78 ±â€¯0.04), head (13.13 ±â€¯0.08) and muscle (8.96 ±â€¯0.10). MYC (0.5 mg/L) inhibited gene expression related to cholesterol synthesis pathway, including 24-dehydrocholesterol reductase (DHCR24), 7-dehydrocholesterol reductase (DHCR7), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCRa), HMGCRb, farnesyl-diphosphate farnesyltransferase 1(FDFT1), squa-lene epoxidase (SQLE), isopentenyl-diphosphate delta isomerase 1 (IDI1) and CYP51, while no cholesterol changes were observed in the MYC treated group. These results will contribute to the literature assessing the environmental risk of MYC in aquatic environment.


Assuntos
Colesterol/biossíntese , Nitrilos/toxicidade , Triazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Bioacumulação , Colesterol/genética , Embrião não Mamífero/efeitos dos fármacos , Feminino , Fungicidas Industriais/toxicidade , Larva/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Fatores Sexuais , Peixe-Zebra/metabolismo
5.
Aquat Toxicol ; 218: 105337, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31739108

RESUMO

To understand effects of two widely used antidepressant on the antioxidant defense mechanism in the marine rotifer Brachionus koreanus, we assessed acute toxicity and measured population growth, reactive oxygen species (ROS) levels, glutathione (GSH) levels, and antioxidant enzymatic activities (GST, GR, and SOD) in response to fluoxetine hydrochloride (FLX) and sertraline hydrochloride (SER). The no observed effect concentration-24 h of fluoxetine and sertraline were 1000 µg/L and 450 µg/L, respectively, whereas the median lethal concentration (LC50)-24 h of fluoxetine and sertraline were 1560 µg/L and 507 µg/L, respectively. Both fluoxetine and sertraline caused significant reduction (P < 0.05) in the population growth rate indicating that both antidepressants have a potential adverse effect on life cycle parameters of B. koreanus. The intracellular ROS level and GSH level were significantly modulated (P < 0.05) in response to fluoxetine and sertraline. In addition, antioxidant enzymatic activities have shown significant modulation (P < 0.05) in response to FLX and SER in B. koreanus. Furthermore, transcriptional profiles of antioxidant genes (GSTs, SODs, and GR) have shown modulation in response to FLX compared to SER-exposed B. koreanus. Our results indicate that fluoxetine and sertraline induce oxidative stress, leading to reduction in the population density and modulation of antioxidant defense mechanism in the marine rotifer B. koreanus.


Assuntos
Antidepressivos/toxicidade , Fluoxetina/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Rotíferos/efeitos dos fármacos , Sertralina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Estágios do Ciclo de Vida/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Rotíferos/crescimento & desenvolvimento , Rotíferos/metabolismo
6.
Eur J Protistol ; 72: 125654, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31805440

RESUMO

Hyalophysa clampi Browning and Landers, 2012 was reexamined to determine all stages in the life cycle of this symbiotic ciliate. The cell feeds as a normal exuviotroph within the exoskeleton of its molted crayfish host but does not encyst following the trophont stage. Trophonts transform into swimming tomont stages, which divide by palintomy over successive divisions, splitting to two cells, separating, and repeating. The divisions cease when the daughter cells attain the size of the infestive tomite stage, which attaches to a new crayfish. This unique life cycle is most similar to the European hermit crab symbiont Polyspira delagei, which forms chains of daughter cells during division. Scanning electron microscopy confirmed the unusual presence of two contractile vacuoles in H. clampi, unique among the Apostomatida, and provided ultrastructural details to better understand light microscopy silver staining. The genus diagnosis for Hyalophysa is modified herein to accommodate this new life cycle.


Assuntos
Astacoidea/parasitologia , Oligoimenóforos/crescimento & desenvolvimento , Simbiose , Alabama , Animais , Estágios do Ciclo de Vida , Oligoimenóforos/citologia
7.
Plant Mol Biol ; 102(1-2): 171-184, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31792713

RESUMO

KEY MESSAGE: Thus study found the temporal and spatial relationship between production of aliphatic glucosinolate compounds and the expression profile of glucosinolate-related genes during growth and development in radish, Chinese cabbage, and their intergeneric hybrid baemoochae plants. Glucosinolates (GSLs) are one of major bioactive compounds in Brassicaceae plants. GSLs play a role in defense against microbes as well as chemo-preventative activity against cancer, which draw attentions from plant scientists. We investigated the temporal relationship between production of aliphatic Glucosinolate (GSLs) compounds and the expression profile of GSL related genes during growth and development in radish, Chinese cabbage, and their intergeneric hybrid, baemoochae. Over the complete life cycle, Glucoraphasatin (GRH) and glucoraphanin (GRE) predominated in radish, whereas gluconapin (GNP), glucobrassicanapin (GBN), and glucoraphanin (GRA) abounded in Chinese cabbage. Baemoochae contained intermediate levels of all GSLs studied, indicating inheritance from both radish and Chinese cabbage. Expression patterns of BCAT4, CYP79F1, CYP83A1, UGT74B1, GRS1, FMOgs-ox1, and AOP2 genes showed a correlation to their corresponding encoded proteins in radish, Chinese cabbage, and baemoochae. Interestingly, there is a sharp change in gene expression pattern involved in side chain modification, particularly GRS1, FMOgs-ox1, and AOP2, among these plants during the vegetative and reproductive stage. For instance, the GRS1 was strongly expressed during leaf development, while both of FMOgs-ox1 and AOP2 was manifested high in floral tissues. Furthermore, expression of GRS1 gene which is responsible for GRH production was predominantly expressed in leaf tissues of radish and baemoochae, whereas it was only slightly detected in Chinese cabbage root tissue, explaining why radish has an abundance of GRH compared to other Brassica plants. Altogether, our comprehensive and comparative data proved that aliphatic GSLs biosynthesis is dynamically and precisely regulated in a tissue- and development-dependent manner in Brassicaceae family members.


Assuntos
Brassica/genética , Brassica/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosinolatos/genética , Glucosinolatos/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Genes de Plantas/genética , Imidoésteres/metabolismo , Estágios do Ciclo de Vida , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Transcriptoma
8.
Mol Biol Evol ; 37(1): 240-259, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539080

RESUMO

The functionality of long noncoding RNAs (lncRNAs) is disputed. In general, lncRNAs are under weak selective pressures, suggesting that the majority of lncRNAs may be nonfunctional. However, although some surveys showed negligible phenotypic effects upon lncRNA perturbation, key biological roles were demonstrated for individual lncRNAs. Most lncRNAs with proven functions were implicated in gene expression regulation, in pathways related to cellular pluripotency, differentiation, and organ morphogenesis, suggesting that functional lncRNAs may be more abundant in embryonic development, rather than in adult organs. To test this hypothesis, we perform a multidimensional comparative transcriptomics analysis, across five developmental time points (two embryonic stages, newborn, adult, and aged individuals), four organs (brain, kidney, liver, and testes), and three species (mouse, rat, and chicken). We find that, overwhelmingly, lncRNAs are preferentially expressed in adult and aged testes, consistent with the presence of permissive transcription during spermatogenesis. LncRNAs are often differentially expressed among developmental stages and are less abundant in embryos and newborns compared with adult individuals, in agreement with a requirement for tighter expression control and less tolerance for noisy transcription early in development. For differentially expressed lncRNAs, we find that the patterns of expression variation among developmental stages are generally conserved between mouse and rat. Moreover, lncRNAs expressed above noise levels in somatic organs and during development show higher evolutionary conservation, in particular, at their promoter regions. Thus, we show that functionally constrained lncRNA loci are enriched in developing organs, and we suggest that many of these loci may function in an RNA-independent manner.


Assuntos
Embrião de Mamíferos/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Sequência de Bases , Sequência Conservada , Expressão Gênica , Estágios do Ciclo de Vida , Masculino , Camundongos , Ratos , Seleção Genética , Homologia de Sequência , Transcriptoma
9.
Vet Parasitol ; 277: 108989, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31794909

RESUMO

The aim of this study was to investigate whether the combination of thymol with eugenol has a synergistic effect on the immature life stages of Rhipicephalus sanguineus sensu lato (s.l.), to evaluate the cost-benefit ratio of using these compounds in combination, and to develop a formulation combining thymol with eugenol with activity on immature stages of R. sanguineus s.l. To evaluate synergism, thymol and eugenol, combined (ratio 1:1) or not, were tested at concentrations of 2.5, 5.0, 10.0, 15.0 and 20.0 mg/mL on unfed larvae and nymphs using a larval packet test, and 0.625, 1.25, 2.5, 5.0 and 10 mg/mL on engorged larvae and nymphs using an immersion test. A cost estimate was calculated to produce 1 L of a solution containing a concentration of thymol and eugenol, combined or not, that could cause a tick mortality rate greater than 95 %. Finally, a formulation was developed, consisting of a micellar dispersion containing polymers (MDP), with thymol + eugenol (1:1), at concentrations of 2.5, 5.0, 10.0, 15.0 and 20.0 mg/mL, and the activity was evaluated on unfed and engorged larvae and nymphs. For unfed larvae and nymphs, concentrations of 2.5 and 5.0 mg/mL and 2.5, 5.0 and 10.0 mg/mL, respectively, presented synergistic effects. In tests with engorged larvae and nymphs, respective concentrations of 0.625, 1.25 and 2.5 mg/mL and 2.5 and 5.0 mg/mL had synergistic effects. The estimated costs for producing a solution of 1 L with efficacy greater than 95 % was $5.97 using only thymol (15 mg/mL), $ 5.93 using only eugenol (15 mg/mL), and $ 3.97 using thymol + eugenol (1:1 - 5,0 mg/mL). In tests with MDP, the combination of thymol + eugenol resulted in a mortality rate higher than 95 % at concentration of 10 mg/mL for unfed and engorged larvae and nymphs. Thus, the combination of thymol + eugenol, depending on the concentration, has synergistic effects and this combination lowers the cost for the active ingredients thymol and eugenol. The combination of thymol + eugenol in MDP had acaricidal activity against immature life stages of R. sanguineus s.l.


Assuntos
Eugenol/farmacologia , Rhipicephalus sanguineus/efeitos dos fármacos , Timol/farmacologia , Acaricidas/economia , Acaricidas/farmacologia , Animais , Sinergismo Farmacológico , Eugenol/economia , Estágios do Ciclo de Vida/efeitos dos fármacos , Timol/economia
10.
Gut ; 69(2): 380-392, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31076402

RESUMO

OBJECTIVE: Infection of human hepatocytes by the hepatitis C virus (HCV) is a multistep process involving both viral and host factors. microRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression. Given that miRNAs were indicated to regulate between 30% and 75% of all human genes, we aimed to investigate the functional and regulatory role of miRNAs for the HCV life cycle. DESIGN: To systematically reveal human miRNAs affecting the HCV life cycle, we performed a two-step functional high-throughput miRNA mimic screen in Huh7.5.1 cells infected with recombinant cell culture-derived HCV. miRNA targeting was then assessed using a combination of computational and functional approaches. RESULTS: We uncovered miR-501-3p and miR-619-3p as novel modulators of HCV assembly/release. We discovered that these miRNAs regulate O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) protein expression and identified OGT and O-GlcNAcylation as regulators of HCV morphogenesis and infectivity. Furthermore, increased OGT expression in patient-derived liver tissue was associated with HCV-induced liver disease and cancer. CONCLUSION: miR-501-3p and miR-619-3p and their target OGT are previously undiscovered regulatory host factors for HCV assembly and infectivity. In addition to its effect on HCV morphogenesis, OGT may play a role in HCV-induced liver disease and hepatocarcinogenesis.


Assuntos
Hepacivirus/patogenicidade , Hepatite C Crônica/genética , N-Acetilglucosaminiltransferases/fisiologia , Regulação da Expressão Gênica/fisiologia , Técnicas de Silenciamento de Genes/métodos , Estudo de Associação Genômica Ampla/métodos , Hepacivirus/fisiologia , Hepatite C Crônica/virologia , Hepatócitos/virologia , Interações Hospedeiro-Patógeno/genética , Humanos , Estágios do Ciclo de Vida/genética , MicroRNAs/genética , Morfogênese/fisiologia , N-Acetilglucosaminiltransferases/genética , Regulação para Cima , Virulência/genética
11.
Vet Parasitol ; 277: 109011, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31841946

RESUMO

In the present study, the tick isolates were collected from Assam state, of northeastern region (NER) and characterized using in vitro bioassay, biochemical and molecular assays. Comparing LC50 value of susceptible IVRI-I and larvae of field isolates, revealed that RF against deltamethrin was highest for Morigaon (MGN = 21.8) and lowest for Sonitpur (SNP = 3.3) isolate. The RF against cypermethrin was highest for Nagaon (NGO = 5.0) and lowest for Barpeta (BPT = 1.2) isolate. Against coumaphos, the highest RF of 4.5 was calculated for BPT (4.5) and lowest for NGO (1.3) isolate. While using adults based assay, highest RF of 24.68 against deltamethrin and lowest RF of 4.96 was determined for MGN and SNP isolate, respectively. In contrast to the results obtained using larvae, against cypermethrin, highest RF was recorded for Kamrup Metropolitan (KMP) while it was NGO isolate using larvae. In case of coumaphos, both larvae and adults of BPT isolate were also highly resistant and lowest RF was detected in SNP (2.30) isolate. All the isolates were susceptible to ivermectin. A significant correlation (p < 0.01) between deltamethrin resistance and higher expression of glutathioneS-transferase was observed while no correlation with esterase and monooxygenase enzymes activity was noted. For the development of possible ecofriendly control measure, different accessions of Argemone mexicana and Datura metel plant species were collected, extracted and screened against adult ticks. Two accessions, NEA-03 and NED-06 collected from Amlighat and Diphu (East Karbi Anglong) were more than 90 % effective. Further dose response study of these accessions determined the LC50 values of 4.86 and 3.96 %, respectively.The resistance status of the collected tick isolates was compared with the data generated from other regions having higher livestock population and possibility of exploitation of identified plant species for the development of natural antitick product is discussed.


Assuntos
Acaricidas/farmacologia , Resistência a Inseticidas , Extratos Vegetais/farmacologia , Rhipicephalus/efeitos dos fármacos , Animais , Bovinos , Índia , Resistência a Inseticidas/efeitos dos fármacos , Dose Letal Mediana , Estágios do Ciclo de Vida/efeitos dos fármacos
12.
Gut ; 69(1): 158-167, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30833451

RESUMO

OBJECTIVE: Hepatitis D virus (HDV) is a circular RNA virus coinfecting hepatocytes with hepatitis B virus. Chronic hepatitis D results in severe liver disease and an increased risk of liver cancer. Efficient therapeutic approaches against HDV are absent. DESIGN: Here, we combined an RNAi loss-of-function and small molecule screen to uncover host-dependency factors for HDV infection. RESULTS: Functional screening unravelled the hypoxia-inducible factor (HIF)-signalling and insulin-resistance pathways, RNA polymerase II, glycosaminoglycan biosynthesis and the pyrimidine metabolism as virus-hepatocyte dependency networks. Validation studies in primary human hepatocytes identified the carbamoyl-phosphatesynthetase 2, aspartate transcarbamylase and dihydroorotase (CAD) enzyme and estrogen receptor alpha (encoded by ESR1) as key host factors for HDV life cycle. Mechanistic studies revealed that the two host factors are required for viral replication. Inhibition studies using N-(phosphonoacetyl)-L-aspartic acid and fulvestrant, specific CAD and ESR1 inhibitors, respectively, uncovered their impact as antiviral targets. CONCLUSION: The discovery of HDV host-dependency factors elucidates the pathogenesis of viral disease biology and opens therapeutic strategies for HDV cure.


Assuntos
Aspartato Carbamoiltransferase/genética , Ácido Aspártico/análogos & derivados , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Di-Hidro-Orotase/genética , Receptor alfa de Estrogênio/metabolismo , Fulvestranto/farmacologia , Hepatite D Crônica/tratamento farmacológico , Ácido Fosfonoacéticos/análogos & derivados , Pirimidinas/biossíntese , Antivirais/farmacologia , Aspartato Carbamoiltransferase/antagonistas & inibidores , Aspartato Carbamoiltransferase/metabolismo , Ácido Aspártico/farmacologia , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/antagonistas & inibidores , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/metabolismo , Linhagem Celular , Di-Hidro-Orotase/antagonistas & inibidores , Di-Hidro-Orotase/metabolismo , Antagonistas do Receptor de Estrogênio/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Inativação Gênica , Hepatite D Crônica/genética , Hepatite D Crônica/metabolismo , Vírus Delta da Hepatite/fisiologia , Hepatócitos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Resistência à Insulina , Estágios do Ciclo de Vida , Mutação com Perda de Função , Ácido Fosfonoacéticos/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Viral/metabolismo , Transdução de Sinais , Replicação Viral
13.
Gen Comp Endocrinol ; 285: 113288, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31557468

RESUMO

Chronic stressors have profound impacts on phenotypes and life history strategies on the short term, but delayed effects of stress experienced late in life remain poorly investigated in wild populations. Here, we used a combined laboratory and field experiment to test if chronic stress late in life has immediate and delayed effects on physiological and demographic traits in the common lizard, Zootoca vivipara. We increased plasma corticosterone levels in adults and yearlings during three weeks of the post-reproductive season. We quantified immediate responses in the laboratory, delayed intra-generational effects in field enclosures one month and one year later during the next reproductive season, and delayed inter-generational effects in the first generation of offspring. Our phenotypic assays included metabolism, immune capacities, lipid metabolism and oxidative stress. Relative to placebos, lizards treated with corticosterone had higher body condition and lower oxidative damages but an increased skin swelling response directly after the manipulation. Delayed responses in field enclosures were of three types. First, we found catch-up growth for body mass such the placebos had similar body conditions one month after the laboratory manipulation. Second, we found persistent differences in oxidative damages during one month but not one year later. Third, during the next reproductive season, corticosterone-treated females had higher levels of plasma triglycerides, whereas corticosterone-treated individuals had a higher skin swelling response. We found no delayed inter-generational effects on demographic traits of offspring. Our study demonstrates the potential for long-lasting physiological consequences of chronic corticosterone enhancement despite no obvious changes in life history.


Assuntos
Glucocorticoides/metabolismo , Estágios do Ciclo de Vida , Lagartos/fisiologia , Animais , Antioxidantes/metabolismo , Corticosterona/metabolismo , Feminino , Masculino , Tamanho da Amostra , Estresse Fisiológico/efeitos dos fármacos
14.
Environ Sci Technol ; 54(3): 1293-1303, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31877035

RESUMO

Efforts to compile life cycle inventory (LCI) data at more geographically refined scales or resolutions are growing. However, it remains poorly understood as to how the choice of spatial scale may affect LCI results. Here, we examine this question using U.S. corn as a case study. We compile corn production data at two spatial scales, state and county, and compare how their LCI results may differ for state and national level analyses. For greenhouse gas (GHG) emissions, estimates at the two scales are similar (<20% of difference) for most state-level analyses and are basically the same (<5%) for national level analysis. For blue water consumption, estimates at the two scales differ more. Our results suggest that state-level analyses may be an adequate spatial scale for national level GHG analysis and for most state-level GHG analyses of U.S. corn, but may fall short for water consumption, because of its large spatial variability. On the other hand, although county-based LCIs may be considered more accurate, they require substantially more effort to compile. Overall, our study suggests that the goal of a study, data requirements, and spatial variability are important factors to consider when deciding the appropriate spatial scale or pursuing more refined scales.


Assuntos
Efeito Estufa , Gases de Efeito Estufa , Animais , Estágios do Ciclo de Vida , Zea mays
15.
Ecotoxicol Environ Saf ; 188: 109945, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31753309

RESUMO

Cyanobacterial harmful algal blooms dominated by Microcystis frequently produce microcystins, a family of toxins capable of inflicting harm to pelagic and benthic freshwater invertebrates. Research on the effect of microcystins on invertebrates is inconclusive; from one perspective, studies suggest invertebrates can coexist in toxic blooms; however, studies have also measured negative food-associated effects from microcystins. To test the latter perspective, we examined the reproduction, growth, and survival of laboratory-cultured Ceriodaphnia dubia, Daphnia magna, and Hexagenia spp. exposed to cell-bound microcystins through a series of life-cycle bioassays. Test organisms were exposed to a concentration gradient ranging from 0.5 µg L-1 to 300 µg L-1 microcystins, which corresponds to values typically found in freshwaters during bloom season. Lethal concentrations in C. dubia (LC50 = 5.53 µg L-1) and D. magna (LC50 = 85.72 µg L-1) exposed to microcystins were among the lowest recorded to date, and reproductive effects were observed at concentrations as low as 2.5 µg L-1. Length of D. magna was significantly impacted in microcystin treatments great than 2.5 µg L-1. No lethality or growth impairments were observed in Hexagenia. This information will improve our understanding of the risks posed by microcystins to food webs in freshwaters.


Assuntos
Daphnia/efeitos dos fármacos , Ephemeroptera/efeitos dos fármacos , Água Doce/química , Microcistinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Daphnia/crescimento & desenvolvimento , Ephemeroptera/crescimento & desenvolvimento , Cadeia Alimentar , Proliferação Nociva de Algas , Dose Letal Mediana , Estágios do Ciclo de Vida , Reprodução/efeitos dos fármacos
16.
Chemosphere ; 239: 124802, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31521933

RESUMO

Pesticides are usually present as mixtures in water environments. Evaluating the toxic effects of individual pesticide may not be enough for protecting ecological environment due to interactions among substances. In this study, we aimed to examine the lethal doses and gene expression changes in zebrafish (Danio rerio) upon exposure to individual and mixture pesticides [malathion (MAL), chlorpyrifos (CHL) and lambda-cyhalothrin (LCY)]. Individual pesticide toxicity evaluation manifested that the toxicity of the three pesticides to D. rerio at various developmental stages (embryonic, larval, juvenile and adult stages) followed the order of LCY > CHL > MAL. On the contrary, the least toxicity to the animals was discovered from MAL. Most of the tested pesticides displayed lower toxicities to the embryonic stage compared with other life stages of zebrafish. Synergistic effects were monitored from two binary mixtures of LCY in combination with MAL or CHL and ternary mixture of MAL + CHL + LCY. The expressions of 16 genes involved in oxidative stress, immunity system, cell apoptosis and endocrine disruption at the mRNA level revealed that embryonic zebrafish were influenced by the individual or mixture pesticides. The expressions of Tnf, P53, TRα, Crh and Cyp19a exerted greater variations upon exposure to pesticide mixtures compared with their individual compounds. Collectively, the transcriptional responses of these genes might afford early warning biomarkers for identifying pollutant exposure, and the data acquired from this study provided valuable insights into the comprehensive toxicity of pesticide mixtures to zebrafish.


Assuntos
Misturas Complexas/toxicidade , Larva/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Clorpirifos/toxicidade , Interações de Medicamentos , Disruptores Endócrinos/toxicidade , Estágios do Ciclo de Vida/efeitos dos fármacos , Malation/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
17.
PLoS Genet ; 15(12): e1008506, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31856180

RESUMO

Malaria parasites follow a complex life cycle that consists of multiple stages that span from the human host to the mosquito vector. Among the species causing malaria, Plasmodium falciparum is the most lethal, with clinical symptoms manifesting during the intraerythrocytic developmental cycle (IDC). During the IDC, P. falciparum progresses through a synchronous and continuous cascade of transcriptional programming previously established using population analyses. While individual parasites are known to exhibit transcriptional variations to evade the host immune system or commit to a sexual fate, such rare expression heterogeneity is largely undetectable on a population level. Therefore, we combined single-cell RNA-sequencing (scRNA-seq) on a microfluidic platform and fluorescence imaging to delineate the transcriptional variations among individual parasites during late asexual and sexual stages. The comparison between asexual and sexual parasites uncovered a set of previously undefined sex-specific genes. Asexual parasites were segregated into three distinct clusters based on the differential expression of genes encoding SERAs, rhoptry proteins, and EXP2 plus transporters. Multiple pseudotime analyses revealed that these stage-specific transitions are distinct. RNA fluorescent in situ hybridization of cluster-specific genes validated distinct stage-specific expression and transitions during the IDC and defined the highly variable transcriptional pattern of EXP2. Additionally, these analyses indicated huge variations in the stage-specific transcript levels among parasites. Overall, scRNA-seq and RNA-FISH of P. falciparum revealed distinct stage transitions and unexpected degrees of heterogeneity with potential impact on transcriptional regulation during the IDC and adaptive responses to the host.


Assuntos
Hibridização in Situ Fluorescente/métodos , Plasmodium falciparum/crescimento & desenvolvimento , Proteínas de Protozoários/genética , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Estágios do Ciclo de Vida , Técnicas Analíticas Microfluídicas , Família Multigênica , Plasmodium falciparum/genética
19.
Parasit Vectors ; 12(1): 517, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685001

RESUMO

BACKGROUND: Bovine besnoitiosis, caused by the cyst-forming apicomplexan parasite Besnoitia besnoiti, is a chronic and debilitating cattle disease that continues to spread in Europe in the absence of control tools. In this scenario, in vitro culture systems are valuable tools to carry out drug screenings and to unravel host-parasite interactions. However, studies performed in bovine target cells are scarce. METHODS: The objective of the present study was to obtain primary bovine aortic endothelial cells (BAECs) and fibroblast cell cultures, target cells during the acute and the chronic stage of the disease, respectively, from healthy bovine donors. Afterwards, expression of surface (CD31, CD34 and CD44) and intracellular markers (vimentin and cytokeratin) was studied to characterize cell populations by flow cytometry. Next, the lytic cycle of B. besnoiti tachyzoites was studied in both target cells. Invasion rates (IRs) were determined by immunofluorescence at several time points post-infection, and proliferation kinetics were studied by quantitative PCR (qPCR). Finally, the influence of bovine viral diarrhea virus (BVDV) co-infection on the host cell machinery, and consequently on B. besnoiti invasion and proliferation, was investigated in BAECs. RESULTS: Morphology and cytometry results confirmed the endothelial and fibroblast origins. CD31 was the surface marker that best discriminated between BAECs and fibroblasts, since fibroblasts lacked CD31 labelling. Expression of CD34 was weak in low-passage BAECs and absent in high-passage BAECs and fibroblasts. Positive labelling for CD44, vimentin and cytokeratin was observed in both BAECs and fibroblasts. Regarding the lytic cycle of the parasite, although low invasion rates (approximately 3-4%) were found in both cell culture systems, more invasion was observed in BAECs at 24 and 72 hpi. The proliferation kinetics did not differ between BAECs and fibroblasts. BVDV infection favoured early Besnoitia invasion but there was no difference in tachyzoite yields observed in BVDV-BAECs compared to BAECs. CONCLUSIONS: We have generated and characterized two novel standardized in vitro models for Besnoitia besnoiti infection based on bovine primary target BAECs and fibroblasts, and have shown the relevance of BVDV coinfections, which should be considered in further studies with other cattle pathogens.


Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Células Endoteliais/parasitologia , Fibroblastos/parasitologia , Sarcocystidae/crescimento & desenvolvimento , Animais , Antígenos CD34/metabolismo , Bovinos , Coccidiose/parasitologia , Receptores de Hialuronatos/metabolismo , Estágios do Ciclo de Vida , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Fatores de Tempo
20.
Parasit Vectors ; 12(1): 516, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685020

RESUMO

BACKGROUND: Haemoproteus parasites (Haemosporida, Haemoproteidae) are cosmopolitan in birds and recent molecular studies indicate enormous genetic diversity of these pathogens, which cause diseases in non-adapted avian hosts. However, life-cycles remain unknown for the majority of Haemoproteus species. Information on their exoerythrocytic development is particularly fragmental and controversial. This study aimed to gain new knowledge on life-cycle of the widespread blood parasite Haemoproteus majoris. METHODS: Turdus pilaris and Parus major naturally infected with lineages hPHYBOR04 and hPARUS1 of H. majoris, respectively, were wild-caught and the parasites were identified using microscopic examination of gametocytes and PCR-based testing. Bayesian phylogeny was used to determine relationships between H. majoris lineages. Exoerythrocytic stages (megalomeronts) were reported using histological examination and laser microdissection was applied to isolate single megalomeronts for genetic analysis. Culicoides impunctatus biting midges were experimentally exposed in order to follow sporogonic development of the lineage hPHYBOR04. RESULTS: Gametocytes of the lineage hPHYBOR04 are indistinguishable from those of the widespread lineage hPARUS1 of H. majoris, indicating that both of these lineages belong to the H. majoris group. Phylogenetic analysis supported this conclusion. Sporogony of the lineage hPHYBOR04 was completed in C. impunctatus biting midges. Morphologically similar megalomeronts were reported in internal organs of both avian hosts. These were big roundish bodies (up to 360 µm in diameter) surrounded by a thick capsule-like wall and containing irregularly shaped cytomeres, in which numerous merozoites developed. DNA sequences obtained from single isolated megalomeronts confirmed the identification of H. majoris. CONCLUSIONS: Phylogenetic analysis identified a group of closely related H. majoris lineages, two of which are characterized not only by morphologically identical blood stages, but also complete sporogonic development in C. impunctatus and development of morphologically similar megalomeronts. It is probable that other lineages belonging to the same group would bear the same characters and phylogenies based on partial cytb gene could be used to predict life-cycle features in avian haemoproteids including vector identity and patterns of exoerythrocytic merogony. This study reports morphologically unique megalomeronts in naturally infected birds and calls for research on exoerythrocytic development of haemoproteids to better understand pathologies caused in avian hosts.


Assuntos
Doenças das Aves/parasitologia , Haemosporida/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Passeriformes/parasitologia , Infecções Protozoárias em Animais/parasitologia , Aves Canoras/parasitologia , Animais , Teorema de Bayes , Aves , Ceratopogonidae/parasitologia , Haemosporida/classificação , Haemosporida/genética , Filogenia
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