The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants

We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The Physcomitrella genome provides a resource for phylogenetic inferences about gene function and for experimental analysis of plant processes through this plant's unique facility for reverse genetics.     

Die Rolle der mikrobiellen Biomasse und des mineralisch fixierten Ammoniums bei den Stickstoff-Transformationen in niedersächsischen Löß-Ackerböden unter Winter-Weizen. I. Poolgrößenveränderungen

Significance of microbial biomass and non-exchangeable ammonium with respect to the nitrogen transformations in loess soils of Niedersachsen during the growing season of winter wheat. I. Change of pool sizes Nitrogen transformations in loess soils have been examined by laboratory and field experiments. After straw application (· 8 t · ha^?1), N in microbial biomass (N_mic) increased by about 20 mg · kg^?1 soil (· 90 kg N · ha^?1 · 30 cm^?1) after 9 days of incubation (20 °C). Another laboratory experiment yielded an increase of about 400 mg of NH₄+-N · kg^?1 fixed by minerals within 1 h after addition of 1 M NH₄+-acetate. Defixation of the recently fixed NH₄+ after addition of 1 M KCl amounted to only 60 mg · kg^?1 within 50 days. In a field experiment with winter wheat 1991, an increase in N_mic of about 80 kg N · ha^?1 · 30 cm^?1 was observed from March to June. After July, growth of the microbes was limited by decreased soluble carbon concentrations in the rhizosphere. Different levels of mineral N-fertilizer (0, 177 and 213 kg N · ha^?1) did not affect significantly the microbial biomass. The same field experiment yielded a decrease of non-exchangeable ammonium on the “zero”-fertilized plot in spring by 200 kg N · ha^?1 · 30 cm^?1. The pool of fixed ammonium increased significantly after harvest. After conventional mineral N-fertilizer application (213 kg N · ha^?1). NH₄+-defixation was only about 120 kg N · ha^?1 · 30 cm^?1 until July.     

The raccoon dog (Nyctereutes procyonoides) in Germany--an established Neozoon as host and vector for parasites and other pathogenes

Some invasive wildlife species have the potential to act as additional host and vector species for parasitic and other infectious diseases. We used the raccoon dog (Nyctereutes procyonides), a carnivore species that has its origin in Asia, as an example to demonstrate biological and ecological prerequisites which enables an invasive species to occupy a new habitat permanently. Studies conducted during the last ten years identified a total of 23 endoparasites, two ectoparasites, six bacterial or protozoan species and five viruses, found in the Nyctereutes procyonoides ussuriensis subspecies in its newly occupied range or in N. procyonoides koreensis in its original range. Results of studies in Finland and Germany furthermore showed that biological characteristics of the raccoon dog make this carnivore an appropriate host or vector for a variety of parasites and infectious diseases. This may result in a growing importance of this invasive carnivore for the epidemiology of transmissible diseases in Germany. Especially with regard to zoonotic disease outbreaks, the raccoon dog should therefore be paid more attention in disease prevention and eradication strategies.     

Body and claw measurements and pressure distribution under the claws in calves of different cattle breeds

In 58 female calves of the three breeds German Holstein (GH), German Brown (GB) and German Red (GR) the body weight and height were determined at the age of 79 to 188 days. At the right front limb and the left hind limb the following claw measurements were taken: dorsal border length, diagonal length, heel length and height, angle of the dorsal border and hardness of the claw horn. Furthermore, the punctual pressure under the medial and the lateral claw of the right front limb and the left hind limb were determined using an electronic measuring system. The GH calves weighing 136.8 kg were heavier than GB, which was the tallest breed with 106.2 cm height at the sacral bone. GR calves were the smallest (99.1 cm) and weighed 121.1 kg. The length of the diagonal and the angle of the dorsal border were smaller at the hind limb of all breeds which resulted in a smaller area of ground surface for the claw of this limb. The GR calves had the longest and flattest claws. The GB showed the highest pressures per cm2 at the front limb with 25.6 N/cm2 under both claws as well as at the hind limb with 26.7 N/cm2. The AR had the smallest pressure load with 20.8 N/cm2 at the front limb and 20.2 N/cm2 at the hind limb. The animals showed a larger relative weight load and area of ground surface on the medial claws of the front and hind limbs than on the lateral claws. The highest pressures were found underneath the rear part of the medial claw in all breeds. GB calves showed the highest average pressures (33.3 N/cm2 at the front limb) while GR calves had the lowest (26.3 N/cm2 at the hind limb). GR calves had the highest claw hardness at all measuring positions.     

Virulence genotype of Pasteurella multocida strains isolated from different hosts with various disease status

To learn more about the molecular biology of Pasteurella multocida 289 strains isolated from various clinically healthy and diseased hosts were examined for capsule biosynthesis genes (capA, B, D, E, and F) and 14 virulence associated genes by PCR and DNA-DNA-hybridization. As expected, capsule type A strains were highly adapted to bovines (92.3%) and poultry (85.7%) while we mainly found capA (34.9%)- and capD (58.1%)-positive strains in swine. A noticeable amount of capD-positive strains also originated from small ruminants (34.9%) and capF was detected in wild type strains from diseased cattle (2.2%) and cats (7.4%). None of the isolates harboured capE, while capB was exclusively found in all strains from buffaloes. Nearly all isolates showed a combination of genes encoding outer membrane proteins, colonization factors, iron aquisition factors and superoxid-dismutases without any clue for host specificity. In contrast, the transferrin binding protein encoding gene tbpA (31.5%) was limited to ruminant strains and only 37.0% of all P. multocida strains harboured pfhA, coding for a filamentous hemagglutinin, supposed to be a putative adhesion- und serum resistance factor. PfhA revealed a strong positive association to the outcome of disease in bovine hosts and in combination with toxA to that in swine. The dermonecrotoxin encoding toxA, present in 12.5% of all strains, was detected in isolates from swine, small ruminants, cattle, and poultry. A significant association to the disease status, however, was only existent in swine, although with 66.7% we found a notably high prevalence of the toxin gene among strains from small ruminants. The genes toxA, tbpA and pfhA as well as capsule biosynthesis genes are supposed to be important epidemiological marker genes for characterizing P. multocida field strains.     

Adrenal function in cats with hyperthyroidism

Adrenal function may be altered in animals with hyperthyroidism. The aim of the study was to assess adrenal function of hyperthyroid cats (n = 17) compared to healthy cats (n = 18) and cats with chronic diseases (n = 18). Adrenal function was evaluated by adrenocorticotropic hormone (ACTH) stimulation test and the urinary cortisol to creatinine ratio (UCCR) was determined. Length and width of both adrenal glands were measured via ultrasound. Hyperthyroid cats had significantly higher cortisol levels before and after stimulation with ACTH than the other groups. However, the UCCR was not elevated in hyperthyroid cats. The size of the adrenal glands of hyperthyroid cats was not significantly different from the size of those of healthy cats. The results indicate that cats with hyperthyroidism have a higher cortisol secretory capacity in a hospital setting. The normal size of the adrenal glands suggests that cortisol levels may not be increased permanently.     

Chemerin analog regulates energy metabolism in sheep

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500 µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high‐density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20 min but then increased gradually from 60 to 180 min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep.     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.     

Influence of environmental conditions on biofilm formation by Hafnia alvei strains

Hafnia alvei is considered an opportunistic pathogen of animal and humans, affecting a wide range of homeothermic and poikilothermic hosts with different body temperatures. In this work, H. alvei strains isolated from different sources were studied with regard to their capacity to form biofilms under different environmental conditions. Strain, growth phase, temperature and culture media dependent changes of biofilm formation were semiquantitatively monitored using a microtiter plate method. Our study shows that all strains used could form biofilms in vitro, and that biofilm formation increases dramatically during growth at 25 degrees C but not at 37 degrees C, and decreases at both temperatures in presence of glucose. At 16 degrees C only one strain isolated from a lizard was able to form a dense biofilm showing that the ability to form biofilms in this species is regulated by environmental factors and is also strain specific.