Behaviour of domestic rabbits during 2 weeks after weaning.

Thirty three rabbits from five litters that were weaned at the age of 5 weeks were observed. The animals were kept in pens that were enriched with an elevation made of bricks. In total, 150 h of observations made at feeding time (07:30-10:00 and 18:00-20:30 LT, local time) were analysed. A number of affiliative, exploratory, comfort, eating, resting and locomotor behaviours were observed. Agonistic behaviour was not observed. Rabbits showed companion and location preferences: 56 % of animals had a preferred companion, and 84 % preferred a particular place in the pen. Significant effects of group size and time of day on the frequency of some forms of behaviour were found, e.g. rabbits performed comfort behaviours more often in the morning. Sex did not influence the rabbits' behaviour. Correlations were also found between different forms of behaviour, e.g. animals that performed more exploratory behaviours also showed more locomotor behaviours and affiliative interactions.

Enzymatic hydrolysis of cellulose using extracts from insects.

The use of Zophobas morio extracts in the aspect of cellulose hydrolysis is presented for the first time. The aim of this study was to investigate the action of enzymes obtained from Z. morio on cellulose hydrolysis and to determine their influence on the structural properties of cellulose with use the Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Cellulose hydrolysis products were analyzed by high performance liquid chromatography (HPLC). This analysis indicated that microcrystalline cellulose with smaller particle size was more susceptible to enzymatically treatment. Moreover, our investigation of cellulase activity showed a different profile of the used enzyme during particular developmental stages of Z. morio. Midgut extracts obtained from adult insects are more effective in degrading cellulose than extracts from larvae. The analysis of cellulose hydrolysis confirms that the efficiency of this reaction also depends on the structure of cellulosic materials and internal conditions of enzymatic reaction. In this study the cellulolytic activity of Z. morio midgut extracts showed that these insects could be valuable sources of cellulases.

Phoenixin-14 stimulates differentiation of 3T3-L1 preadipocytes via cAMP/Epac-dependent mechanism.

Phoenixin-14 (PNX) is a newly discovered peptide produced by proteolytic cleavage of the small integral membrane protein 20 (Smim20). Previous studies showed that PNX is involved in controlling reproduction, pain, anxiety and memory. Furthermore, in humans, PNX positively correlates with BMI suggesting a potential role of PNX in controlling fat accumulation in obesity. Since the influence of PNX on adipose tissue formation has not been so far demonstrated, we investigated the effects of PNX on proliferation and differentiation of preadipocytes using 3T3-L1 and rat primary preadipocytes. We detected Smim20 and Gpr173 mRNA in 3T3-L1 preadipocytes as well as in rat primary preadipocytes. Furthermore, we found that PNX peptide is produced and secreted from 3T3-L1 and rat primary adipocytes. PNX increased 3T3-L1 preadipocytes proliferation and viability. PNX stimulated the expression of adipogenic genes (Pparγ, C/ebpß and Fabp4) in 3T3-L1 adipocytes. 3T3-L1 preadipocytes differentiated in the presence of PNX had increased lipid content. Stimulation of cell proliferation and differentiation by PNX was also confirmed in rat preadipocytes. PNX failed to induce AKT phosphorylation, however, PNX increased cAMP levels in 3T3-L1 cells. Suppression of Epac signalling attenuated PNX-induced Pparγ expression without affecting cell proliferation. Our data show that PNX stimulates differentiation of 3T3-L1 and rat primary preadipocytes into mature adipocytes via cAMP/Epac-dependent pathway. In conclusion our data shows that phoenixin promotes white adipogenesis, thereby may be involved in controlling body mass regulation.