Differential gene expression in brain tissues of aggressive and non-aggressive dogs

Background  

Canine behavioural problems, in particular aggression, are important reasons for euthanasia of otherwise healthy dogs. Aggressive behaviour in dogs also represents an animal welfare problem and a public threat. Elucidating the genetic background of adverse behaviour can provide valuable information to breeding programs and aid the development of drugs aimed at treating undesirable behaviour. With the intentions of identifying gene-specific expression in particular brain parts and comparing brains of aggressive and non-aggressive dogs, we studied amygdala, frontal cortex, hypothalamus and parietal cortex, as these tissues are reported to be involved in emotional reactions, including aggression. Based on quantitative real-time PCR (qRT-PCR) in 20 brains, obtained from 11 dogs euthanised because of aggressive behaviour and nine non-aggressive dogs, we studied expression of nine genes identified in an initial screening by subtraction hybridisation.     

Vegetation and environment of the Rødalen alpine area, Central Norway, with emphasis on the early Holocene

Detailed pollen analysis and pine megafossils from the immediate area of Rødalen in Central Norway have revealed new knowledge of Holocene alpine environments. A period of about 1,000 years characterised by pioneer herbs, dwarf-shrubs (Betula nana, Empetrum) and Juniperus followed the Holocene climatic amelioration. Local birch forest became established around 10.3 ka b.p., ca 150 years earlier than the local pine rise. Pine dominated at 1,100 m a.s.l. from 9.9 to 8.5 ka b.p., followed by birch forests until 1.3 ka b.p. when deforestation occurred. Slightly after 6 ka b.p., pine forests disappeared from the valley floor (930 m a.s.l.), an area that today is dominated by birch forest. Three short-lasting vegetational set-backs at ca 10.7, 10.5 and 10.3 ka b.p. may indicate climate oscillations. A temporary reduction of local forests reflects the Erdalen 2/9.7 ka b.p. event. The influence of the 8.2 event, superimposed on a cooling trend, lasted ca 400 years and involved a two-step vegetational regression: (1) A strong reduction of pine forests due to cooling and (2) reduction of alder due to cold and drought. Winter stress preventing pine regeneration may have caused scarcity of pine megafossils from the latter period. In the early Holocene, vegetation in the present alpine region was not in equilibrium with temperature development. It is suggested that the birch forest establishment lagged by about 1,000 years due to drought, whereas winter stress may have delayed the establishment of pine even longer.     

An Attempt to Evaluate the Spreading of Taenia saginata Eggs in the Environment

Taeniid eggs may be transmitted either abi-otically by e.g. sewage disposal, rainfall and water streams or biotically by vectors as her-bivores, birds and insects. Among the insects especially the flies may play an important role as shown in New Zealand by Lawson & Gemmell (1983, 1985). The fly-borne trans-mission may take place over long distances. Lawson & Gemmell (1983) evaluated that the majority of eggs would be deposited within 1.6 km from their point of origin, but some eggs might be spread even longer.     

Induction of squamous differentiation of normal human bronchial epithelial cells by small amounts of serum

Abstract. Recently we reported a low calcium (110 μM) serum-free medium (LHC-1) for clonal growth of normal human bronchial epithelial (NHBE) cells. NHBE cells within colonies are small (mean surface area = 1,250 μ²) rarely migratory, have few tonofilaments, and multiply with an average population doubling time of 28 h. We have also noted that adding small amounts of blood-derived serum to LHC-1 medium (as little as 2%) significantly decreased the clonal growth rate. We have now found that the growth inhibiting effect of serum is due to the induction of squamous (terminal) differentiation. Serum quickly increases the size of the cells (mean surface area = 4,900 μ²). In addition, the cells acquire numerous desmosomal junctions and an extensive network of keratin bundles. In contrast, human lung carcinoma cells multiply rapidly at clonal density in LHC-1 medium containing as much as 8% serum.
Although high concentrations of calcium ions in the medium are known to induce squamous differentiation of epidermal keratinocytes in the absence of serum, high levels of Ca²⁺ (up to 1,000 μM) increased the number of desmosomal junctions, but did not significantly affect the clonal growth rate or size of the NHBE cells. However, high concentrations of calcium (above 450 μM) were found to potentiate serum differentiation-inducing activity. On the other hand, cholera toxin (10 ng/ml) inhibited the differentiation-inducing acitivy of serum. These results show that squamous differentiation of NHBE cells can be induced by serum and the potency of these serum factors can be modulated. In addition, the data show that lung carcinoma cells differ from their normal counterparts by not undergoing differentiation in the presence of serum.     

Use of pseudorandom noise in studies of frequency selectivity: The periphery of the auditory system

Frequency selectivity of single auditory nerve fibers in the rat was studied using pseudorandom noise based on ternary m-sequences as the stimulus, and the results were compared to those of earlier studies in which noise based on binary m-sequences was used. Pseudorandom noise based on ternary m-sequences has fewer anomalies than noise based on binary m-sequences. Detailed tests using linear and nonlinear filters showed that the present method provides accurate measures of bandwidth and center frequency. Period histograms of the response, locked to the periodicity of the noise, were cross-correlated with one period of the noise to obtain estimates of the impulse response function of the peripheral auditory system. Fourier transforms of these cross-correlograms were used as estimates of the filter function of single auditory nerve fibers. The results obtained using ternary noise were not different from previous results showing a downward shift in center frequency and increase in bandwidth with increasing stimulus intensity for fibers with center frequencies between 1000 and 5000 Hz. The difference between spectral selectivity based on phase-locked responses and that based on discharge rate is discussed.     

Fatty acids in common minke whale (Balaenoptera acutorostrata) blubber reflect the feeding area and food selection,but also high endogenous metabolism

The fatty acid (FA) composition has been analysed in the blubber of 56 minke whales caught during the Norwegian commercial whaling period in 2009–2011. Minke whales from four regions were sampled: the North Sea, Vesterålen, Spitsbergen/Bear Island and Finnmark. The FA profiles of the whale blubber have been compared with FA profiles of potential prey species to investigate if FA analysis can be used to predict the diet of minke whales and how the FA profiles of the blubber reflect the regional ecosystem in which the whales were caught. Clear differences in blubber FA profiles were found between minke whales from different areas, and the results of the present study show that FA analysis of the blubber can be used to indicate the whale's diet, but there appears to be a strong impact from metabolism on several FAs. The whale blubber FAs are separate from those of the prey by having relatively high levels of FAs likely to originate from endogenous metabolism, such as 18:1n9 (Δ9-desaturation of 18:0); chain shortening products of 22:1(n-11); 20:1(n-11) and 18:1(n-11); as well as 22:5(n-3), which is an elongation product of 20:5(n-3). High metabolic activity in the adipose tissue was also evident by the clear stratification of FA profiles found throughout the blubber layer. It is remarkable that the whale blubber has much lower levels of the long-chain PUFAs 20:5(n-3) and 22:6(n-3) than found in the prey organisms. It is likely that this results from selective partitioning of diet FAs between the storage lipids and membrane lipids.     

Transformation of human kidney epithelial cells to tumorigenicity by nickel(II) and V-HA-RAS oncogene

Nickel is a toxic metal of environmental concern that has been found to be carcinogenic in man and animals. Primary human kidney (NHKE) cells were immortalized or rescued from senescence after exposure to NiSO₄. The cell lines (IHKE) displayed abnormal karyotype and anchorage independent growth was observed. However, none of the IHKE cells produced tumor upon injection into athymic nude mice. Transfer of the v-Ha-ras oncogene into IHKE cells induced conversion of the immortalized cells into cell lines (THKE) that were tumorigenic when transplanted into athymic nude mice. Ha-ras DNA was present in the transformed cell lines and expressed at high level.