RESUMO
The disposal of plastics and metal-derived compounds results in the contamination of the environment with nano/microparticles, leading to the exposure of various organisms to these harmful particles. However, the impacts of these particles on pollinating insects, which provide relevant ecosystem services, are not well understood. The aim of this study was to assess the effects of microscopic particles on the tropical pollinator Partamona helleri (Apinae: Meliponini), specifically evaluating the toxicity of plastic microparticles (polystyrene - PS, and polyethylene terephthalate - PET) and nanoparticles of a metal oxide (titanium dioxide - TiO2) via larval ingestion by bees reared in vitro. The survival rate of P. helleri larvae was not affected by the ingestion of particles of PS (500 ng/bee), PET (500 ng/bee), or TiO2 (10 µg/bee) compared to the non-treated diet (control or diet without the particles). Adults derived from treated larvae had increased body weight compared to the control, and the walking behavior of adults was altered by the ingestion of particles. Adults that ingested PET or TiO2 as larvae tended to rest for a longer time and interact more with other bees than the control. Hemocyte counts also changed, with a shift in the proportion of plasmatocytes and prohemocytes in treated individuals. Our findings suggest that even levels considered low for honey bees of exposure to plastic microparticles or metal nanoparticles can harm the health and behavior of stingless bees.
Assuntos
Ecossistema , Microplásticos , Abelhas , Animais , Plásticos/toxicidade , LarvaRESUMO
There are multifactorial causes for the recent decline in bee populations, which has resulted in compromised pollination and reduced biodiversity. Bees are considered one of the most important non-target insects affected by insecticides used in crop production. In the present study, we investigated the effects of acute oral exposure to spinosad on the survival, food consumption, flight behavior, respiration rate, activity of detoxification enzymes, total antioxidant capacity (TAC), brain morphology, and hemocyte count of Apis mellifera foragers. We tested six different concentrations of spinosad for the first two analyses, followed by LC50 (7.7 mg L-1) for other assays. Spinosad ingestion decreased survival and food consumption. Exposure to spinosad LC50 reduced flight capacity, respiration rate, and superoxide dismutase activity. Furthermore, this concentration increased glutathione S-transferase activity and the TAC of the brain. Notably, exposure to LC50 damaged mushroom bodies, reduced the total hemocyte count and granulocyte number, and increased the number of prohemocytes. These findings imply that the neurotoxin spinosad affects various crucial functions and tissues important for bee performance and that the toxic effects are complex and detrimental to individual homeostasis.
Assuntos
Inseticidas , Abelhas , Animais , Inseticidas/toxicidade , Macrolídeos , Combinação de Medicamentos , Dose Letal MedianaRESUMO
The objective of this study was to evaluate the effect of dietary electrolyte balance (DEB) levels on performance characteristics (feed intake, FI; body weight gain, BWG; and feed efficiency, FE), energy balance (retained energy, RE; metabolizable energy ingested, MEI; heat production, HP; and energy retention efficiency, ERE), and the expression of genes related to acid-base balance, nutrient absorption, and transport in broilers from 1 to 21 days of age. A total of 245 male Cobb chickens were used in a completely randomized design with five DEB levels (110, 175, 240, 305, and 370 mEq/kg) and seven replicates of seven birds each. The inclusion of DEB levels influenced FE; 110 mEq/kg provided the better values for this characteristic both in the pre-initial phase and in the initial phase but was different only concerning 175 mEq/kg (1-7 days) and 240 mEq/kg (1-21 days). Birds that ingested diets with a level of 240 mEq/kg of DEB had a higher MEI and HP. This DEB level caused a lesser and greater expression of the SLC12A2 gene in the liver and the ATP1A1 gene in the intestine, respectively. On the other hand, the ATP1A1 gene was less expressed in the liver and kidney of broilers supplemented with 370 mEq/kg compared to a level of 110 mEq/kg. In general, a level of 110 mEq/kg DEB in the ration seems to be the most suitable for good performance, energy balance, and gene expression of broilers from 1 to 21 days of age.
Assuntos
Ração Animal , Galinhas , Equilíbrio Ácido-Base , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas/genética , Galinhas/metabolismo , Dieta/veterinária , Suplementos Nutricionais , Masculino , Nutrientes , Equilíbrio HidroeletrolíticoRESUMO
Coturniculture has been standing out as an industrial poultry activity in several countries around the world because of the several adaptive advantages of quails. Research that considers the analysis of gene expression can enhance this activity. This study aimed to analyze the stability of reference genes (RGs) in different tissues of quails (both males and females) for the recommendation of use in gene expression studies by the quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The expression stability of ten RGs (ACTA1, ACTB, B2M, GAPDH, HMBS, SDHA, HPRT1, MRPS27, MRPS30, and RPL5) was analyzed in four tissues (breast muscle, abdominal fat, liver, and intestine), and assessed using the statistical tools geNorm, NormFinder, comparative ΔCq method, and BestKeeper. The HPRT1 gene was the most stable in all quail tissues tested, followed by MRPS27 and MRPS30 in breast muscle, B2M and RPL5 in abdominal fat, HMBS and B2M in the liver, and RPL5 and HMBS in the intestine. These results may help studies using RT-qPCR assays to assess quail tissues from both sexes because they provide data on the most stable genes, which should be tested as candidate RGs for other experimental conditions.