Pollen richness: a reflection of vegetation diversity or pollen-specific parameters?

Vegetation History and Archaeobotany - Our study aims to increase the understanding about the impacts of potential drivers of pollen richness by using a pollen-vegetation modelling approach. We...     

How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.     

Type 2 Diabetes—Effect of Compensatory Oversecretion as a Reason for β-Cell Collapse

Insulin secretion declines progressively before and during the course of type 2 diabetes. Evidence indicates that this process is, in part, secondary to increased requirement for insulin secretion that is brought about by insulin resistance and by hyperglycemia. The effects of over-secretion extend far beyond a mere reduction of available insulin stores and may cause not only functional but also structural damage. The time is ripe for clinical studies, which explore the therapeutic potential of reducing over-secretion.     

The active site and the phospholipid activation of rat liver lysosomal lipase are not stereospecific

The stereochemical specificity of lysosomal lipase of rat liver was investigated using enantiomeric triacylglycerol analogs, sn-1-alkyl-2,3-diacylglycerol and sn-3-alkyl-1,2-diacylglycerol as substrates. Lysosomal lipase utilized both substrates with equal rates. The dependence of the activity of lysosomal lipase on the stereoconfiguration of activating acidic phospholipid was also studied. Our results showed that both sn-3-phospholipids (diphosphatidylglycerol, phosphatidylserine) and sn-1-phospholipids (bis(monoacylglycero)phosphate (BMP) were efficient activators of this enzyme and thus the stereochemical configuration of the activating phospholipid is not important. Accordingly, the rat liver lysosomal lipase lacks stereospecificity with respect to both the triacylglycerol substrate and the acidic phospholipid activator.