Novel sites in the p65 subunit of NF-kappaB interact with TFIIB to facilitate NF-kappaB induced transcription

The citM gene from Lactococcus lactis CRL264 was demonstrated to encode for an oxaloacetate decarboxylase. The enzyme exhibits high levels of similarity to malic enzymes (MEs) from other organisms. CitM was expressed in Escherichia coli, purified and its oxaloacetate decarboxylase activity was demonstrated by biochemical and genetic studies. The highest oxaloacetate decarboxylation activity was found at low pH in the presence of manganese, and the K_m value for oxaloacetate was 0.52 ± 0.03 mM. However, no malic activity was found for this enzyme. Our studies clearly show a new group of oxaloacetate decarboxylases associated with the citrate fermentation pathway in gram-positive bacteria. Furthermore, the essential catalytic residues were found to be conserved in all members of the ME family, suggesting a common mechanism for oxaloacetate decarboxylation.     

Long‐term changes in habitat selection and prey spectrum in a reintroduced Eurasian lynx (Lynx lynx) population in Switzerland

When wild‐caught Eurasian lynx (Lynx lynx) from the Slovak Carpathian Mountains were reintroduced to Central Switzerland in the early 1970s and spread through the north‐western Swiss Alps (NWA), they faced a largely unfamiliar landscape with strongly fragmented forests, high elevations, and intense human land use. For more than 30 years, radio‐collared lynx have been monitored during three different project periods (in the 1980s, 1990s, and 2010s). Our study explored, how lynx over generations have learned to adjust to the alpine environment. We predicted that (1) lynx nowadays select more strongly for open habitats, higher elevations, and steep slopes compared to the early stages of recolonization and that (2) consequently, there were significant changes in the Eurasian lynx’ prey spectrum. To test our predictions, we analyzed telemetry data (VHF, GPS) of 13 adult resident lynx in the NWA over 35 years, using Resource Selection Functions. Furthermore, we compared kills recorded from different individuals inhabiting the same region during three project periods. In general, lynx preferred forested areas, but over the years, they avoided open habitat less. Compared to the early stage of the recolonization, lynx in the most recent project period selected for higher elevations and the proportion of chamois in their prey spectrum surmounted that of roe deer. Potential driving factors for the observed changes could be increasing tolerance to human presence, intraspecific competition, or fitness benefits through exploitation of new resources. Long‐term studies like ours provide important insight into how animals can respond to sudden environmental changes, e.g., in the course of translocations into new areas or anthropogenic alterations of their habitats.     

Individual Distinctiveness and Possible Function of Song Parts of Short-toed Treecreepers (Certhia brachydactyla). Evidence from Multivariate Song Analysis

Sonagram analyses of short-toed treecreeper (= STT) song by use of discriminant analysis revealed consistent individuality in the songs predominantly sung by each male (P-songs). The P-songs had been digitized and over 30 song variables were used in the analysis to separate different individuals. In the end, 7 of these variables were needed for a correct classification of 100% of the 203 P-songs recorded of 39 individuals in 1986. Most of these variables were derived from the first part of the song. A similar analysis with data from 1987 showed that by use of all variables with unskewed distribution complete discrimination of all 271 P-songs of 47 individuals ensued. The reduction of variables to the 10 most important led to the correct classifications of 99.5%. Using the 7 best discriminators of the 1986 data set 94.2% of the 1987 data were correctly classified, thus confirming the 1986 results. Wrong assignments were mainly due to P-songs from second or third recording dates which in some cases could not be separated from other P-songs of the same males by the analysis. Further analysis of the data showed that although the most important discriminators were found in the first part of the song, the combination of all characters of the end part would also allow for a virtually complete discrimination of individuals. The song features of STT P-song are so distinctive that territory holders should have no difficulties in separating individuals (e.g. neighbours from strangers). Corresponding playback experiments have yet to be carried out on STT.     

The origin and age of haplochromine fishes in Lake Victoria, east Africa

According to a widely held view, the more than 300 species of haplochromine cichlid fishes in Lake Victoria (LV), East Africa, originated from a single founder species in less than 12,000 years. This view, however, does not follow from the published geological and molecular evidence. The former does indeed suggest that the LV basin dried out less than 15,000 years ago, but it does not provide any information about the species that re-colonized the new lake or that remained in the rivers draining the area. The molecular evidence is inconclusive with respect to the origin of the LV haplochromines because cichlids from critical regions around LV were not adequately sampled; and as far as the age of the LV haplochromines is concerned, it in fact led to an estimate of 250,000-750,000 years old. In the present study, mitochondrial DNA (control region) variation was determined by heteroduplex and sequencing analyses of more than 670 specimens collected at widely distributed East African riverine and lacustrine localities. The analyses revealed the existence of seven haplogroups (I-VII) distinguishable by characteristic substitutions. All endemic LV samples tested fell into one of these haplogroups (V) which, however, was also found to be present at various other localities, both riverine and lacustrine, outside LV. Within this haplogroup, four subgroups (VA through VD) could be distinguished, two of which (VB and VC) were represented in LV and at other localities. The great majority of the LV haplochromine species could be classified as belonging to the VC subgroup, which was found only in LV and in the rivers draining into it. Hence, while the endemic haplochromine species of LV could not have originated from a single founding population, the lake does harbour a large species flock which probably arose in situ.     

Classification and phylogenetic relationships of African tilapiine fishes inferred from mitochondrial DNA sequences

African cichlid fishes are composed of two major lineages, the haplochromines and the tilapiines. Whereas the phylogenetic relationships of the haplochromines have been studied extensively, primarily because of their spectacular adaptive radiations in the Great Lakes of East Africa, little is known about the relationships among the tilapiine species, despite the fact that they have become an important component of African, indeed world, aquaculture. To remedy this situation, molecular phylogenetic analysis of tilapiine fishes was undertaken. A segment of mitochondrial DNA encompassing the terminal part of the tRNA(Pro) gene and the most variable part of the control region was amplified by the polymerase chain reaction with DNA samples isolated from 42 tilapiine species, and the amplification products were subjected to heteroduplex analysis and sequencing. Phylogenetic trees based on 68 sequences revealed the existence of 11 sequence groups and 11 single-sequence branches. The groups, designated Ti1 through Ti11, were distinguished by specific combinations of diagnostic substitutions, formation of monophyletic clusters, and separation by genetic distances in excess of 0.04. Although the relationships among the groups could not be resolved, the sequences separated Oreochromis and Sarotherodon from Tilapia, as defined by Trewavas. The Oreochromis sequences clustered with the Sarotherodon sequences and thus supported the hypothesis that the mouthbrooding behavior of the tilapiine fishes evolved only once from the substrate-spawning behavior. Since on phylogenetic trees the O. alcalicus (sub)species were always separated from O. amphimelas by other Oreochromis species, it was concluded that the adaptation to life in water with a high salt concentration and high pH values evolved independently at least twice in the tilapiine fishes. The tilapiines diverged from the haplochromines more than 8 million years ago; most of the intragroup divergences among the tilapiines took place an estimated 1.1 to 6 million years ago.     

Satellite associations and NOR staining in mitoses of trisomy 21 mosaicism

Summary Ten variants of erythrocyte glucose-6-phosphate dehydrogenase were identified in 22 patients with G6PD deficiency from three districts of Bulgaria. corinth-like and Fayoum-like variants were the most frequent; Mediterranean, Ohut II, Kilgore, Boston, Poznan, and Panay variants and two new variants, Petrich and Gotze Delchev, were each found in one or two carriers. No correlation was revealed between clinical and biochemical polymorphism.