The effect of deoxynivalenol on the secretion activity,proliferation and apoptosis of porcine ovarian granulosa cells in vitro

The aim of this in vitro study was to examine the secretion activity, markers of proliferation and apoptosis in porcine ovarian granulosa cells (GCs) after deoxynivalenol (DON) addition. Ovarian granulosa cells were incubated with DON for 24h: 10, 100 and 1000 ng/mL, while the control group received no DON. The secretion of insulin-like growth factor I (IGF–I) and progesterone was determined by radioimmunoassay (RIA) and expression of cyclin B1, PCNA and caspase-3 by immunocytochemistry. IGF–I release by GCs was inhibited by DON, while progesterone release and the expression of cyclin B1 was stimulated by DON (at 1000 ng/mL but not at 10 and 100 ng/mL). PCNA expression was stimulated by DON (at 100 and 1000 ng/mL but not at 10 ng/mL). Caspase-3 expression was not influenced by DON treatment (at all doses). In conclusion, our results indicate, (1) a direct effect of DON on secretion of growth factor IGF-I and steroid hormone progesterone, (2) expression of markers of proliferation (cyclin B1 and PCNA) but not on the (3) expression of marker of apoptosis (caspase-3) in porcine ovarian granulosa cells. This in vitro study suggests the dose-dependent association of DON on porcine ovarian functions.     

Matching spatial distributions of the sea star Echinaster sepositus and crustose coralline algae in shallow rocky Mediterranean communities

Understanding why a species is present in a particular location and the consequences of its presence is complex but necessary to identify the mechanisms that generate and maintain ecological diversity. The common sea star Echinaster sepositus can be either very abundant or non-existing in nearby localities of the western Mediterranean. Yet, the factors that shape its distribution and the impact of the sea star on natural communities remain uninvestigated. Here, we quantified multiple biotic and abiotic factors that may affect the distribution of E. sepositus and tested whether this sea star can shape the organization of the community it inhabits. Our results showed that the distribution of this sea star was highly contagious and positively correlated with the abundance and distribution of crustose coralline algae from tens of meters to tens of kilometers. Despite significant differences in community composition between localities with high or low abundance of the sea star, experimental addition of E. sepositus to natural communities failed to shift the composition of the algal community in 4 months. Overall, our results suggest that within habitat variability in the abundance of crustose coralline algae may explain the abundance of E. sepositus at multiple geographic scales, emphasizing the need to investigate small-scale processes at larger geographic scales.