Drosophila Brakeless Interacts with Atrophin and Is Required for Tailless-Mediated Transcriptional Repression in Early Embryos

Complex gene expression patterns in animal development are generated by the interplay of transcriptional activators and repressors at cis-regulatory DNA modules (CRMs). How repressors work is not well understood, but often involves interactions with co-repressors. We isolated mutations in the brakeless gene in a screen for maternal factors affecting segmentation of the Drosophila embryo. Brakeless, also known as Scribbler, or Master of thickveins, is a nuclear protein of unknown function. In brakeless embryos, we noted an expanded expression pattern of the Krüppel (Kr) and knirps (kni) genes. We found that Tailless-mediated repression of kni expression is impaired in brakeless mutants. Tailless and Brakeless bind each other in vitro and interact genetically. Brakeless is recruited to the Kr and kni CRMs, and represses transcription when tethered to DNA. This suggests that Brakeless is a novel co-repressor. Orphan nuclear receptors of the Tailless type also interact with Atrophin co-repressors. We show that both Drosophila and human Brakeless and Atrophin interact in vitro, and propose that they act together as a co-repressor complex in many developmental contexts. We discuss the possibility that human Brakeless homologs may influence the toxicity of polyglutamine-expanded Atrophin-1, which causes the human neurodegenerative disease dentatorubral-pallidoluysian atrophy (DRPLA)

Drive counts as a method of estimating ungulate density in forests: mission impossible?

Although drive counts are frequently used to estimate the size of deer populations in forests, little is known about how counting methods or the density and social organization of the deer species concerned influence the accuracy of the estimates obtained, and hence their suitability for informing management decisions. As these issues cannot readily be examined for real populations, we conducted a series of ‘virtual experiments’ in a computer simulation model to evaluate the effects of block size, proportion of forest counted, deer density, social aggregation and spatial auto-correlation on the accuracy of drive counts. Simulated populations of red and roe deer were generated on the basis of drive count data obtained from Polish commercial forests. For both deer species, count accuracy increased with increasing density, and decreased as the degree of aggregation, either demographic or spatial, within the population increased. However, the effect of density on accuracy was substantially greater than the effect of aggregation. Although improvements in accuracy could be made by reducing the size of counting blocks for low-density, aggregated populations, these were limited. Increasing the proportion of the forest counted led to greater improvements in accuracy, but the gains were limited compared with the increase in effort required. If it is necessary to estimate the deer population with a high degree of accuracy (e.g. within 10% of the true value), drive counts are likely to be inadequate whatever the deer density. However, if a lower level of accuracy (within 20% or more) is acceptable, our study suggests that at higher deer densities (more than ca. five to seven deer/100 ha) drive counts can provide reliable information on population size

Dispersion and movement pattern of Wild boar (Sus scrofa L.) in agro-forestry landscape under strong pressure from urbanization in central Poland

The research analyses the use of space by the Wild boar living in a human−transformed landscape. CMR method was used. Animals were caught in two complexes from February 2009 to May 2010. Fifty boars were captured. Information on the location and hunting time were collected. Results show small range of activity of investigated Wild boars. Animals were shot within 4 km from the trapping place. The longest distance that Wild boar had passed amounted to over 20 km. Most boars survived up to 50 days from the date of their catch. The maximum survival time was 373 days. Small dispersion of Wild boars is probably caused by philopatry, sufficient food resources and shelter, and the ability to adapt to human presence near the refuges

Seasonal and daily activity of bait utilization by various animal species in the context of the ASF spread in the forest environment

ASF has existed in Poland since 2014. The main vector of this disease is wild boar (Sus scrofa). Traditional baiting site is one of the most popular elements of wildlife infrastructure for wild boars hunting. Along with the development of ASF in Poland, the bait became an object of attention due to the high probability of contact between healthy and sick animals, and thus as a place of potential spread of the disease. Feeding is currently forbidden, but it is allowed to lure wild boar with small amounts of food for the needs of depopulation. The purpose of this study was to investigate what kind of species penetrate the bait as well as what are the seasonal and diurnal dynamics of bait penetration by different groups of animals. The tests were carried out in north−eastern Poland. Digital Trial Camera SGN−5220 were used to record animals within a radius of up to 10−15 m from the location of phototraps (at night). Once a month, 1 kg of maize was spread evenly over the surface of the bait, as is usually done in practice. During the 18−month of observation, 2929 pictures recorded 21 species of animals that penetrated the bait. They included 9 species of birds (from tit to cranes), 4 species of predators (fox, raccoon, raccoon dog, badger) and 4 species of ungulates (Polish horse, roe deer, fallow deer and deer). Animals that can contribute the most to ASF spread are predators, and among the birds: ravens, crows, jays and cranes. The animals penetrated the bait mainly during the night (except for birds), and the longest during one presence during autumn and winter. In the summer, the bait was penetrated by the largest number of species of wild animals (birds, predators, ungulates and of course wild boars). The question arises whether other places where potential food for wild animals is accumulated can also be a source of potential ASF spread

Food preferences of wild boars (Sus scrofa L.) in the summer and early autumn expressed by the damage caused in agricultural crops

Wild boars (Sus scrofa) are regarded as food generalists and opportunists, whose great flexibility in food selection enables them to settle in various environments in a wide geographical area inhabited by them. Wild boars are perceived also as agricultural pests, since due to their dietary habits and a method of food seeking more crops are destroyed than consumed. In European habitat of wild boars, which undergoes long−term transformation, cultivated plants are an important ingredient of wild boars' summer and autumn diet. The issue of damage caused by wild boars has not been widely investigated in Poland so far. We analysed what is the crop damage caused by wild boars in summer and early autumn and whether the accessibility of crops (difference in crop acreage) determine the extent of this damage as well as we investigated if wild boars demonstrate preference to particular crops and how flexible they are while selecting food in the period of its oversupply. Research was based on 4215 reports on damage received by the Spała Forest District (C Poland) in 1999−2009 period. In analysed time wild boars caused damage in the wide range of crops. The greatest number of reports concerned damage in potato and in the fields seeded with cereals, while only a few – in beetroot, charlock, buckwheat and rape crops (tab. 1). Statistically significant and high correlation between the area of crops and the extent of damage was recorded. However, the damage was not serious enough to make the proportion of affected area grow bigger along with the area of crops (tab. 2). Although the analysed time span encompassed only 3 months, distinct differences in the extent of damage to cereal (excluding maize) and potato crops were marked. Crops affected the most in July included cereals. In August cereals were still the most affected crops, yet in September a radical change in wild boars' dietary preferences was noticed, while cereals distinctively came second after potatoes (fig. 2). In general, during summer and early autumn wild boars seeking food on fields damage a wide range of cultivated plants without a particular preference towards any species (evident opportunism in the food selection). The number of reported damage and its spatial extent is correlated with the area of particular species cultivation, yet the proportion of damaged area does not increase along with the crops area. Time, which wild boars can spend seeking for food out of the woods appears to be one of the limiting factors. Significant changes in the structure of damage in the short time span prove that wild boars are highly flexible in food selection, which can definitely facilitate their adaptation to new or changing environmental conditions

Potential food resources and cover for Grey partridges (Perdix perdix) reintroduced in the landscape of extensive agriculture

The study assesses potential food resources and cover for Grey partridges reintroduced in extensive agriculture conditions in central Poland. Research material consisted of data from 315 1 m². study plots located in seven types of land use. Significant dynamics of food resources and cover with regard to season and land use form was found. Small crop areas or lack of intensive agrotechnical treatments do not create favourable conditions for partridges occurrence. Cereal fields may be used by the birds only in autumn−winter time. Meadows and barrens are sufficient environment but only by the time they lose their structure because of vegetation development. Stubbles offer the greatest variability of food, but are not stable part of the landscape and soon after the harvest time partridges leave them

Seasonal dynamics of deer browsing and its impact on deciduous saplings during first year after planting

The lack of knowledge about seasonal dynamics and impact of deer browsing on deciduous saplings in plantations in managed forests in Poland raises difficulties in assessing the impact of cervids on forests and in selecting effective methods for protecting plantations against damage caused by deer. The studies covered 1129 saplings of sycamore, oak, beech, linden and birch species that were planted on the unfenced sites accessible for animals and fenced sites left for comparison

The usefulness of repellent Emol Plus BTX LA in Scots pine saplings protection against winter browsing by deer

The paper provides study results on the efficacy of Emol Plus BTX LA repellent used for the protection of Scots pine saplings against browsing by deer. Emol Plus BTX LA contains coarse−grained filler – calcium carbonate and denatonium benzoate (BTX) as active substance. The efficacy of both Emol Plus BTX LA and standard repellents were found to be high