Independence between Rhythms of Temperature and Progesterone in Mares

We investigated the ultradian and diurnal body temperature and plasma progesterone concentration rhythms and the temporal relationship between them in mares during the midluteal phase. Data were obtained from 6 mares at 3-h intervals for 3 consecutive days. Cosinor analysis showed that body temperature acrophases occurred in the evening, whereas the progesterone acrophases occurred in the early morning (3 mares) and at night (3 mares). The spectral analysis of the temperature data showed periods of 24 hr for all mares and of 8 hr for 1 mare. In contrast, the periods observed for plasma progesterone concentration were quite divergent (24 and 12 hr). The small variation in the rhythmic parameters of body temperature suggests that its oscillator system is stable. No phase relationship was detected between the rhythmometric parameters of body temperature and plasma progesterone concentration, suggesting that the physiological mechanisms of control of the 24 hr and ultradian rhythm of the two variables are not coupled during the midluteal phase.     

Biochemical identification and comparative insecticidal activity of nucleopolyhedrovirus isolates pathogenic for Heliothis armigera (Lep., Noctuidae) larvae

Three Nucleopolyhedrovirus (NPVs) originally isolated from Heliothis armigera larvae, collected from Portugal (HearNPV-PO) and two places in Spain (HearNPV-SP1 and HearNPV-SP2), and three previously described NPVs were compared biochemically and biologically. Restriction endonuclease analysis of the virus genome with several enzymes revealed that isolates HearNPV-SP1 and HearNVP-SP2 are unique but closely related genotypes which represent two new strains of the NPVs of H. armigera. The DNA fragment profiles of HearNPV-PO were distinct from those of the HearNPV-SP1 and HearNPV-SP2, with all the enzymes used, while they were identical to the Mamestra brassicae NPV strain present in the commercial product MAMESTRIN^®. Bioassays in third-instar H. armigera larvae showed that the LD₅₀ value obtained for HearNPV-SP1 (68 occlusion bodies/larva) was about two- and six-times lower than those of HearNPV-SP2 and a Russian isolate, HearNPV-RU, respectively. The corresponding LT₅₀ values were not found to differ significantly between these three virus isolates at comparable doses.     

RNAi Screen of Endoplasmic Reticulum–Associated Host Factors Reveals a Role for IRE1α in Supporting Brucella Replication

Brucella species are facultative intracellular bacterial pathogens that cause brucellosis, a global zoonosis of profound importance. Although recent studies have demonstrated that Brucella spp. replicate within an intracellular compartment that contains endoplasmic reticulum (ER) resident proteins, the molecular mechanisms by which the pathogen secures this replicative niche remain obscure. Here, we address this issue by exploiting Drosophila S2 cells and RNA interference (RNAi) technology to develop a genetically tractable system that recapitulates critical aspects of mammalian cell infection. After validating this system by demonstrating a shared requirement for phosphoinositide 3-kinase (PI3K) activities in supporting Brucella infection in both host cell systems, we performed an RNAi screen of 240 genes, including 110 ER-associated genes, for molecules that mediate bacterial interactions with the ER. We uncovered 52 evolutionarily conserved host factors that, when depleted, inhibited or increased Brucella infection. Strikingly, 29 of these factors had not been previously suggested to support bacterial infection of host cells. The most intriguing of these was inositol-requiring enzyme 1 (IRE1), a transmembrane kinase that regulates the eukaryotic unfolded protein response (UPR). We employed IRE1α^−/− murine embryonic fibroblasts (MEFs) to demonstrate a role for this protein in supporting Brucella infection of mammalian cells, and thereby, validated the utility of the Drosophila S2 cell system for uncovering novel Brucella host factors. Finally, we propose a model in which IRE1α, and other ER-associated genes uncovered in our screen, mediate Brucella replication by promoting autophagosome biogenesis.     

Overabundant wild ungulate populations in Europe: management with consideration of socio-ecological consequences

1. Throughout recent years, ungulates have experienced significant increases in numbers and geographic range sizes in Europe, becoming locally overabundant populations in some regions. Changes in legislation regarding poaching, abandonment of land and re-naturalisation of habitats, and decreasing numbers of hunters, among other things, have led to alarming scenarios in wild ungulate biology. Although ungulates bring some financial benefits for ecosystems and society through tourism and hunting, the problems associated with populations that are no longer controlled can outweigh the advantages. Damage to forestry and agriculture, ungulate-vehicle collisions, and diseases are among the most concerning problems related to ungulate overabundance.
2. To deal with these problems and to decide on the best management strategy to apply, it is essential to have tools available to monitor populations with an integrative approach based on ecological change indicators, and to assess population and ecosystem status. Furthermore, in a globalised world, people’s opinions matter, and sociological studies regarding human perception of wild mammals must take place in order to allow proper management, including consideration of people’s expectations as well as animal and ecosystem needs. Successful and unsuccessful management strategies have already been attempted, and the knowledge of consequences over time enables an adaptive approach.
3. Management of ungulate populations is a complex subject, and each case should be studied, analysing the cost_performance balance of measures to be taken, and ensuring ongoing financial means to carry out and continue with successful ecosystem management strategies. Multidisciplinary teams should be built, including biologists, veterinarians, stakeholders, sociologists, and others, to deal with the management of European wild ungulate populations.

     

Effect of the interval of serial sections of ovarian tissue in the tissue chopper on the number of isolated caprine preantral follicles.

The present work investigated the effect of the interval of serial sections of ovarian tissue on the number of isolated preantral follicles in the goat. Goat ovaries were cut in the tissue chopper at eight different intervals. The quality of isolated follicles were evaluated by histology and transmission electron microscopy. Best results were obtained when the ovaries were cut in the tissue chopper at intervals of 75.0 microm (9664 preantral follicles per ovary). Histochemical and ultrastructural analysis showed that the follicular morphology was preserved after mechanical isolation as demonstrated by the normality of oocytes and granulosa cells as well as by preservation of basement membrane. The percentages of isolated primordial, primary and secondary follicles were 96.3%, 2.5%, and 1.2% and their average diameters were 21.5, 34.7 and 65.3 microm, respectively. It was concluded that the interval of serial sections of ovarian tissue in the tissue chopper affects the number of isolated preantral follicles, and that the follicles remained intact after mechanical isolation in goats.