Deletion of the long arm of chromosome 4 [46,XX,del(4)(q31)] in a patient with congenital anomalies.

A girl with congenital malformations and del 4(q31), identified by QFQ- and RFA- techniques, is described. The clinical findings are compared with the four cases of 4q- of the literature. Evident variability of the clinical features and the small number of cases of 4q- does not allow the delineation of a clinical syndrome.     

The effect of spectral light deprivation on the spectral sensitivity of the honey bee

Summary The spectral sensitivity of spontaneous phototactic behavior was tested in short wavelength deprived bees and in control bees kept outdoors. Tests were performed with a y-maze with one branch illuminated, the other dark. The relative sensitivities for the control group were: green to blue to UV = 10.272.14. Short wavelength deprived bees show a distinct decrease in their sensitivity to short wavelengths. The relation green to blue to UV here was 10.220.27. Forager bees from outdooors, short wavelength deprived for 10 days, showed a relation of green to blue to UV of 10.261.04. Electrophysiological investigation of the compound eye using electroretinogram recordings showed no difference between deprived and control animals.     

Seasonal and diel movement patterns of brown bears in a population in southeastern Europe

Most animals concentrate their movement into certain hours of the day depending on drivers such as photoperiod, ambient temperature, inter‐ or intraspecific competition, and predation risk. The main activity periods of many mammal species, especially in human‐dominated landscapes, are commonly set at dusk, dawn, and during nighttime hours. Large carnivores, such as brown bears, often display great flexibility in diel movement patterns throughout their range, and even within populations, striking between individual differences in movement have been demonstrated. Here, we evaluated how seasonality and reproductive class affected diel movement patterns of brown bears of the Dinaric‐Pindos and Carpathian bear populations in Serbia. We analyzed the movement distances and general probability of movement of 13 brown bears (8 males and 5 females) equipped with GPS collars and monitored over 1–3 years. Our analyses revealed that movement distances and probability of bear movement differed between seasons (mating versus hyperphagia) and reproductive classes. Adult males, solitary females, and subadult males showed a crepuscular movement pattern. Compared with other reproductive classes, females with offspring were moving significantly less during crepuscular hours and during the night, particularly during the mating season, suggesting temporal niche partitioning among different reproductive classes. Adult males, solitary females, and in particular subadult males traveled greater hourly distances during the mating season in May‐June than the hyperphagia in July–October. Subadult males significantly decreased their movement from the mating season to hyperphagia, whereas females with offspring exhibited an opposite pattern with almost doubling their movement from the mating to hyperphagia season. Our results provide insights into how seasonality and reproductive class drive intrapopulation differences in movement distances and probability of movement in a recovering, to date little studied, brown bear population in southeastern Europe.     

Pyrido pyrimidinones as selective agonists of the high affinity niacin receptor GPR109A: Optimization of in vitro activity

Pyrido pyrimidinones are selective agonists of the human high affinity niacin receptor GPR109A (HM74A). They show no activity on the highly homologous low affinity receptor GPR109B (HM74). Starting from a high throughput screening hit the in vitro activity of the pyrido pyrimidinones was significantly improved providing lead compounds suitable for further optimization.     

Hydrolysis of low-molecular-weight oligosaccharides and oligosaccharide alditols by pig intestinal sucrase/isomaltase and glucosidase/maltase

The ability of purified pig intestinal sucrase/isomaltase (SI; EC 3.2.1.10/48) and glucosidase/maltase (GM; EC 3.2.1.20) to hydrolyze di- and oligosaccharides consisting of D-glucose and D-fructose residues and the corresponding alditols was studied. The products, after incubation, reflect different binding patterns at both catalytic sites of SI. The active site of the sucrase subunit cleaves alpha,beta-(1-->2) glycosidic bonds, and only two monomer units of the substrates bind with favorable affinity. Oligosaccharides and reduced oligosaccharides containing alpha-(1--6) and alpha-(1-->1) glycosidic bonds are hydrolyzed by isomaltase, and for the active site of this subunit more than two subsites were postulated. Moreover, different binding sites for various aglycons seem to exist for isomaltase. Oligosaccharide alcohols are cleaved at lower rates if the reduced sugar residue occupies the aglycon binding site. GM also hydrolyzes alpha-(1-->1) linkages, but at a lower rate. The enzyme has the ability to bind compounds containing residues other than D-glucose. There are indications for similarities between GM and the isomaltase subunit of SI in the binding mode of oligosaccharides.     

Analysis of messages expressed by Echinostoma paraensei miracidia and sporocysts, obtained by random EST sequencing

A lambdaZAP Express cDNA library was constructed with mRNA obtained from immature miracidia within eggs, hatched miracidia, and sporocysts of Echinostoma paraensei. This cDNA library was amplified and 213 expressed sequence tag (EST) sequences (averaging 466 nucleotides in length) were obtained. The mean percentage of unresolved bases within the EST sequences was 0.4%, ranging from 0 to 4.6%. The 213 ESTs represent 151 unique messages. BLAST (version 2.0.8) analysis disclosed that 64 unique E. paraensei messages (42.4%) had significant similarities (BLAST score < or =e-5), at deduced amino acid or nucleotide levels, with known sequences in the nonredundant GenBank databases or the dbEST database (NCBI). The remainder, 57.6% of the unique EST-encoded messages, scored nonsignificant hits. Most of the E. paraensei messages that could be assigned a cellular role based on sequence similarities were involved in gene/protein expression. Several ESTs scored highest similarities with sequences obtained from trematode species. A total of 22,560 nucleotides present in open reading frames from ESTs that aligned with known sequences was used to determine codon usage for E. paraensei. Analysis of a subset of eight ESTs that contained full-length open reading frames did not reveal a bias in codon usage. Also, EST sequences were found to contain 3' untranslated regions with an average length of 69.9 +/- 88.4 nucleotides (n = 46). The EST sequences were submitted to GenBank/dbEST, adding to the 51 available Echinostoma-derived sequences, to provide reference information for both phylogenetic analysis and study of general trematode biology.     

Extended base pair complementarity between U1 snRNA and the 5' splice site does not inhibit splicing in higher eukaryotes, but rather increases 5' splice site recognition

Spliceosome formation is initiated by the recognition of the 5′ splice site through formation of an RNA duplex between the 5′ splice site and U1 snRNA. We have previously shown that RNA duplex formation between U1 snRNA and the 5′ splice site can protect pre-mRNAs from degradation prior to splicing. This initial RNA duplex must be disrupted to expose the 5′ splice site sequence for base pairing with U6 snRNA and to form the active spliceosome. Here, we investigated whether hyperstabilization of the U1 snRNA/5′ splice site duplex interferes with splicing efficiency in human cell lines or nuclear extracts. Unlike observations in Saccharomyces cerevisiae, we demonstrate that an extended U1 snRNA/5′ splice site interaction does not decrease splicing efficiency, but rather increases 5′ splice site recognition and exon inclusion. However, low complementarity of the 5′ splice site to U1 snRNA significantly increases exon skipping and RNA degradation. Although the splicing mechanisms are conserved between human and S.cerevisiae, these results demonstrate that distinct differences exist in the activation of the spliceosome.     

Nutrient return with leaf litter fall in Fagus sylvatica forests across a soil fertility gradient

Leaf litter fall is an important nutrient flux in temperature deciduous forests which supplies a large part of the rapidly mineralisable nutrient fraction to the soil. This study investigates nutrient return with leaf litter fall in 36 old-growth forest stands of Fagus sylvatica across a broad gradient of soil fertility covering 9 mesozoic and kaenozoic parent material types (three limestones, two sandstones, two clay stones, one sand and one loess substrate). Study objectives were to analyse (i) the dependency of leaf litter nutrient concentrations on soil fertility, and (ii) the relationship between soil fertility and nutrient return with leaf litter at the stand level. Beech stands on the nine parent material types produced similar annual leaf litter masses irrespective of soil fertility or acidity. Leaf litter from the nine parent materials showed only minor variation with respect to N and K concentrations (factors of 1.5 and 1.4), moderate variation for Ca, Mg and P concentrations (factors of 2.2 to 2.9), and high variation for Al and Mn concentrations (factors of 6.7 and 10.5). Consequently, annual nutrient return with litter fall (leaf litter mass x litter nutrient concentration) was more similar among the parent materials for N (165–273 mmol m⁻² yr1) ⁻¹ and K (16–30 mm m⁻² yr⁻¹) than for Ca, P, Mg, Mn and Al. A possible explanation is increased N deposition in recent time. According to a correlation analysis, return rates of N, P, K and Mg (but not Ca) were independent of the pool size of the respective nutrient in the soil. N return rate was neither influenced by the soil pools of Nt, plant- available P (Pa) or exchangeable Ca, K and Mg, nor by soil acidity or the exchangeable Al pool. P return, in contrast, showed a negative relation to soil fertility. We hypothesize that nutrient fluxes with leaf litter fall do not necessarily reduce the fitness of tree populations as has been postulated from a tree-centred view. Rather, we suggest that nutrient fluxes with litter fall can increase, instead of decrease, plant fitness by improving nutrient availability in the densely rooted topsoil which reduces the roots’ carbon and nutrient costs of nutrient acquisition.     

Diversity and technological properties of predominant lactic acid bacteria from fermented cassava used for the preparation of Gari, a traditional African food

Traditional fermentation of cassava is dominated by a lactic acid bacteria (LAB) population. Fermentation is important for improving product flavour and aroma as well as safety, especially by reduction of its toxic cyanogenic glucosides. The production of Gari from cassava in Benin typically occurs on a household or small industrial scale, and consequently suffers from inconsistent product quality and may not always be safe for consumption. Therefore, the diversity of LAB from a typical cassava fermentation for the preparation of Gari, and their technologically relevant characteristics were investigated with a view towards selection of appropriate starter cultures. A total of 139 predominant strains isolated from fermenting cassava were identified using phenotypic tests and genotypic methods such as rep-PCR and RAPD-PCR. DNA-DNA hybridisation and sequencing of the 16S rRNA genes were done for selected strains. Lactobacillus plantarum was the most abundantly isolated species (54.6% of isolates), followed by Leuconostoc fallax (22.3%) and Lactobacillus fermentum (18.0%). Lactobacillus brevis, Leuconostoc pseudomesenteroides and Weissella paramesenteroides were sporadically isolated. The L. plantarum strains were shown to be better acid producers and capable of faster acid production than the L. fallax or L. fermentum strains. The incidence of beta-glucosidase (linamarase) activity was also highest among strains of this species. Production of antagonistic substances such as H2O2 and bacteriocins, however, was more common among L. fallax and L. fermentum strains. Strains of all three species were capable of utilising the indigestible sugars raffinose and stachyose. Therefore, a starter culture containing a mixture of strains from all three species was recommended.