An imbalance in autophagy contributes to retinal damage in a rat model of oxygen-induced retinopathy

In retinopathy of prematurity (ROP), the abnormal retinal neovascularization is often accompanied by retinal neuronal dysfunction. Here, a rat model of oxygen-induced retinopathy (OIR), which mimics the ROP disease, was used to investigate changes in the expression of key mediators of autophagy and markers of cell death in the rat retina. In addition, rats were treated from birth to postnatal day 14 and 18 with 3-methyladenine (3-MA), an inhibitor of autophagy. Immunoblot and immunofluorescence analysis demonstrated that autophagic mechanisms are dysregulated in the retina of OIR rats and indicated a possible correlation between autophagy and necroptosis, but not apoptosis. We found that 3-MA acts predominantly by reducing autophagic and necroptotic markers in the OIR retinas, having no effects on apoptotic markers. However, 3-MA does not ameliorate retinal function, which results compromised in this model. Taken together, these results revealed the crucial role of autophagy in retinal cells of OIR rats. Thus, inhibiting autophagy may be viewed as a putative strategy to counteract ROP.     

Potential role of the methylation of VEGF gene promoter in response to hypoxia in oxygen‐induced retinopathy: beneficial effect of the absence of AQP4

Hypoxia‐dependent accumulation of vascular endothelial growth factor (VEGF) plays a major role in retinal diseases characterized by neovessel formation. In this study, we investigated whether the glial water channel Aquaporin‐4 (AQP4) is involved in the hypoxia‐dependent VEGF upregulation in the retina of a mouse model of oxygen‐induced retinopathy (OIR). The expression levels of VEGF, the hypoxia‐inducible factor‐1α (HIF‐1α) and the inducible form of nitric oxide synthase (iNOS), the production of nitric oxide (NO), the methylation status of the HIF‐1 binding site (HBS) in the VEGF gene promoter, the binding of HIF‐1α to the HBS, the retinal vascularization and function have been determined in the retina of wild‐type (WT) and AQP4 knock out (KO) mice under hypoxic (OIR) or normoxic conditions. In response to 5 days of hypoxia, WT mice were characterized by (i) AQP4 upregulation, (ii) increased levels of VEGF, HIF‐1α, iNOS and NO, (iii) pathological angiogenesis as determined by engorged retinal tufts and (iv) dysfunctional electroretinogram (ERG). AQP4 deletion prevents VEGF, iNOS and NO upregulation in response to hypoxia thus leading to reduced retinal damage although in the presence of high levels of HIF‐1α. In AQP4 KO mice, HBS demethylation in response to the beginning of hypoxia is lower than in WT mice reducing the binding of HIF‐1α to the VEGF gene promoter. We conclude that in the absence of AQP4, an impaired HBS demethylation prevents HIF‐1 binding to the VEGF gene promoter and the relative VEGF transactivation, reducing the VEGF‐induced retinal damage in response to hypoxia.     

First record of red cornetfish Fistularia petimba (Syngnathiformes:Fistulariidae) from Antalya and İskenderun Bays along Turkish Coasts of the Mediterranean Sea

Here, we report the first occurrence of red cornetfish Fistularia petimba in the north‐eastern Mediterranean Sea. Altogether four specimens were captured; first two in Antalya Bay on 28 October 2016 and 26 November 2016, and the remaining two in ?skenderun Bay on 21 May 2017 during the bottom trawl surveys along the Mediterranean coast of Turkey. All specimens were young and more or less uniform in size (383, 335, 419 and 453 mm standard length). The possibility that F. petimba could become a new potential invader in the Mediterranean as its congeneric F. commersonii is cautioned against.     

Data-Driven Modeling of Intracellular Auxin Fluxes Indicates a Dominant Role of the ER in Controlling Nuclear Auxin Uptake

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The role of environmental factors in the composition of anuran species in several ponds under the influence of coal mining in southern Brazil

Environmental pollution caused by the disposal of chemicals or toxins into the environment represent a great threat to amphibians. In this study, it was evaluated which environmental factors of ponds under the influence of coal-mining influence the composition of anuran species. For this purpose, anuran samples were performed in ponds in coal extraction areas in southern Brazil. Physical and chemical characteristics of water, sediment and structural characteristics of the ponds were determined. The content of copper in the sediments of the ponds was the main variable to explain the composition of pond species. Besides copper, it is evident the relevance of number of vegetation strata at pond border and pond area on the composition of anurans. It is shown that the composition of species in ponds under the influence of mineral coal mining activity may be a result of historical perturbations, remaining only the most tolerant towards colonization. From the results obtained in this work it can be suggested that there is a synergistic interaction between environmental factors and the coal mining effects on the anurans fauna of impacted ponds. Thus, efforts should be directed to elucidate the effects of pollutants exposure levels on the species, the understanding of sub-lethal and lethal effects of each pollutant on each species, as well as how local populations can be maintained through recruiting rates of larvae and anurans of the impacted ponds.     

First de novo whole genome sequencing and assembly of the pink-footed goose

Annotated genomes can provide new perspectives on the biology of species. We present the first de novo whole genome sequencing for the pink-footed goose. In order to obtain a high-quality de novo assembly the strategy used was to combine one short insert paired-end library with two mate-pair libraries. The pink-footed goose genome was assembled de novo using three different assemblers and an assembly evaluation was subsequently performed in order to choose the best assembler. For our data, ALLPATHS-LG performed the best, since the assembly produced covers most of the genome, while introducing the fewest errors. A total of 26,134 genes were annotated, with bird species accounting for virtually all BLAST hits. We also estimated the substitution rate in the pink-footed goose, which can be of use in future demographic studies, by using a comparative approach with the genome of the chicken, the mallard and the swan goose. A substitution rate of 1.38 × 10^? 7 per nucleotide per generation was obtained when comparing the genomes of the two closely-related goose species (the pink-footed and the swan goose). Altogether, we provide a valuable tool for future genomic studies aiming at particular genes and regions of the pink-footed goose genome as well as other bird species.     

Anaerobic contribution to the time to exhaustion at the minimal exercise intensity at which maximal oxygen uptake occurs in elite cyclists, kayakists and swimmers

Using 23 elite male athletes (8 cyclists, 7 kayakists, and 8 swimmers), the contribution of the anaerobic energy system to the time to exhaustion (t _lim) at the minimal exercise intensity (speed or power) at which maximal oxygen uptake (V˙O_{2 max}) occurs (I _{V˙O2 max}) was assessed by analysing the relationship between the t _lim and the accumulated oxygen deficit (AOD). After 10-min warming up at 60% of V˙O_{2 max}, the exercise intensity was increased so that each subject reached his I _V˙O2max in 30 s and then continued at that level until he was exhausted. Pre-tests included a continuous incremental test with 2 min steps for determining the I _V˙O2max and a series of 5-min submaximal intensities to collect the data that would allow the estimation of the energy expenditure at I _V˙O2max . The AOD for the t _lim exercise was calculated as the difference between the above estimation and the accumulated oxygen uptake. The mean percentage value of energy expenditure covered by anaerobic metabolism was 15.2 [(SD 6)%, range 8.9–24.1] with significant differences between swimmers and kayakists (16.8% vs 11.5%, P≤0.05) and cyclists and kayakists (16.4% vs 11.5%, P≤0.05). Absolute AOD values ranged from 26.4 ml · kg⁻¹ to 83.6 ml · kg⁻¹ with a mean value of 45.9 (SD 18) ml · kg⁻¹. Considering all the subjects, the t _lim was found to have a positive and significant correlation with AOD (r = 0.62, P≤0.05), and a negative and significant correlation with V˙O_{2 max} (r = −0.46, P≤0.05). The data would suggest that the contribution of anaerobic processes during exercise performed at I _V˙O2max should not be ignored when t _lim is used as a supplementary parameter to evaluate specific adaptation of athletes. Accepted: 17 December 1996