Uptake of [2-14C]abscisic acid and distribution of 14C in apple embryos

Pyrus malus L. var. Golden delicious embryos were incubated with (±)-[2-¹⁴C]abscisic acid (ABA) (10^-5 M, 355 kBq mol^-1). After incubations of various durations, the radioactivity was measured in whole embryos, cotyledons, and embryonic axes.With either 48-h or 16-d incubation periods, the uptake of [¹⁴C]ABA depended upon the mode of culture used. The lowest values corresponded to the absorption by the embryonic axis, the highest to the absorption by the distal parts of the two cotyledons. The cotyledons accumulated the main part of the radioactivity under all conditions. Dormant and almost completely after-ripened embryos cultivated for 4 d showed no significant differences in the radioactivity uptake for identical modes of culture. There was a linear relationship between exogenous ABA concentrations (0.5 to 3.10^-5 M) and ABA uptake for embryos cultivated for 4 d with the distal parts of the cotyledons immersed in the medium.Abbreviations ABA abscisic acid. RM, RM⁺, C/2 M, and CM are different modes of embryo cultures: embryonic axis immersed alone (RM), together with the proximal parts of the cotyledons (RM⁺); distal parts of the cotyledons immersed alone (CM); embroyo flat on the medium, the root and the external surface of one cotyledon being in contact with the medium (C/2 M) - PP proximal parts of the cotyledons - DP distal parts of the cotyledons     

Predominance of gonadotropin α-subunit resulting from preferential loss of hCGβ production in an established cell line

Summary The BeWo line of trophoblastic cells, maintained in continuous culture since 1966, was employed to investigate the phenomenon of gonadotropin α-subunit predominance that exists in several cell lines. The secretion of complete human chorionic gonadotropin (hCG) relative to α-subunit was compared in several different BeWo sublines, all of which were derived from BeWo stock roller tube colonies. In all of the BeWo sublines, secretion of hCG originally exceeded secretion of α-subunit. With time in culture, however, there was a marked decline in production of hCG/hCGβ, but not in α-subunit. Thus it appears that the production of hCGβ by BeWo choriocarcinoma cells is more labile than the production of the α-subunit.     

Between‐year variations in Little Bustard Tetrax tetrax population densities are influenced by agricultural intensification and rainfall

The Little Bustard is suffering a widespread population decline mainly due to agricultural intensification. This study evaluates the effects of intensification level, habitat availability and rainfall on the population dynamics of this species. The population density of males was monitored for 7 years (2002–2008) at 184 points located within three sites with contrasting levels of agricultural intensification in southern Portugal. Densities decreased along the intensification gradient from 8.2 to 2.3 males / km². Overall, there was an approximately 50% population decline during the period 2002–2008, driven by a decline observed in one of the less intensive sites, whereas in the other two sites densities remained fairly constant. Yearly variations in male densities were influenced by intensification level, amount of grassland habitat and rainfall patterns. Thus, agricultural intensification is having a negative effect on population densities of this threatened species, particularly through the loss of grasslands (fallow fields and pastures) suitable for displaying males. The results also suggest a positive impact of rainfall on male densities, although this is more likely in grasslands within less intensive agricultural regions of poorer soil quality, where higher breeding male densities occur. Grassland habitat quality, driven by both climate and human management, probably plays a major role in the population dynamics of this threatened steppe bird in its strongholds.     

Quantifying the damage of red deer (Cervus elaphus) grazing on grassland production in southeastern Slovenia

The influence of red deer (Cervus elaphus) grazing on grassland production for forage conservation at the forest border during the vegetation period was studied on three locations (Mala gora, Cvišlerji, and Mačkovec) in the Kočevje region (SE Slovenia). The experiment lasted from the 25th of March until the 8th of October 2002. Portable cages were used to exclude red deer from grazing the herbage. At four sampling dates in the season, herbage air dry matter (DM) yield was measured at three different observations (cage-protected plot, cage-protected plot only two to three weeks before sampling date, otherwise freely grazed (removed), and unprotected plot). The results from the experiment showed that red deer grazed on grassland through the entire season and that the regeneration capability of sward was the highest in summer, middle in spring and smallest in autumn. On unprotected plots, an average reduction of 50% of herbage DM yield was found with the most damaged sites also up to 80% reduction.     

Patterns and processes in the evolution of the eukaryotic endomembrane system

Abstract

The eukaryotic endomembrane system (ES) is served by hundreds of dedicated proteins. Experimental characterization of the ES-associated molecular machinery in several model eukaryotes complemented by a recent progress in phylogenomics and comparative genomics have revealed a conserved complex core of the machinery that appears to have been established before the last eukaryotic common ancestor (LECA). At the same time, modern eukaryotes exhibit a huge variation in the ES resulting from a multitude of evolutionary processes operating along the ever-branching paths from the LECA to its descendants. The most important source of evolutionary novelty in the ES functioning has undoubtedly been gene duplication followed by divergence of the gene copies, responsible not only for the pre-LECA establishment of many multi-paralog families of proteins in the very core of the ES-associated machinery, but also for post-LECA lineage-specific elaborations via family expansions and the origin of novel components. Extreme sequence divergence has obscured actual homologous relationships between potentially many components of the machinery, even between orthologous proteins, as illustrated by the yeast Vps51 subunit of the vesicle tethering complex GARP hypothesized here to be a highly modified ortholog of a conserved eukaryotic family typified by the zebrafish Fat-free (Ffr) protein. A dynamic evolution of many ES-associated proteins, especially those centred around RAB and ARF GTPases, seems to take place at the level of their domain architectures. Finally, reductive evolution and recurrent gene loss are emerging as pervasive factors shaping the ES in all phylogenetic lineages.     

Triptolide prevents bone loss via suppressing osteoclastogenesis through inhibiting PI3K-AKT-NFATc1 pathway

Bone loss (osteopenia) is a common complication in human solid tumour. In addition, after surgical treatment of gynaecological tumour, osteoporosis often occurs due to the withdrawal of oestrogen. The major characteristic of osteoporosis is the low bone mass with micro-architectural deteriorated bone tissue. And the main cause is the overactivation of osteoclastogenesis, which is one of the most important therapeutic targets. Inflammation could induce the interaction of RANKL/RANK, which is the promoter of osteoclastogenesis. Triptolide is derived from the traditional Chinese herb lei gong teng, presented multiple biological effects, including anti-cancer, anti-inflammation and immunosuppression. We hypothesized that triptolide could inhibits osteoclastogenesis by suppressing inflammation activation. In this study, we confirmed that triptolide could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells (BMMCs) and RAW264.7 cells and inhibited the osteoclast bone resorption functions. PI3K-AKT-NFATc1 pathway is one of the most important downstream pathways of RANKL-induced osteogenesis. The experiments in vitro indicated that triptolide suppresses the activation of PI3K-AKT-NFATc1 pathway and the target point located at the upstream of AKT because both NFATc1 overexpression and AKT phosphorylation could ameliorate the triptolide suppression effects. The expression of MDM2 was elevated, which demonstrated the MDM-p53-induced cell death might contribute to the osteoclastogenesis suppression. Ovariectomy-induced bone loss and inflammation activation were also found to be ameliorated in the experiments in vivo. In summary, the new effect of anti-cancer drug triptolide was demonstrated to be anti-osteoclastogenesis, and we demonstrated triptolide might be a promising therapy for bone loss caused by tumour.