Correlated Evolution among Six Gene Families in Drosophila Revealed by Parallel Change of Gene Numbers

Proteins involved in a pathway are likely to evolve in a correlated fashion, and coevolving gene families tend to undergo complementary gains and losses. Accordingly, gene copy numbers (i.e., repertoire size) tend to show parallel changes during the evolution of coevolving gene families. To test and verify this hypothesis, here we describe positive correlations among the repertoire sizes of six gene families, that is, trypsin-like serine protease, odorant-binding protein, odorant receptor, gustatory receptor, cytochrome P450, and glutathione S-transferase after excluding the possibility of phylogenetic constraint and random drift. The observed correlations are indicative of parallel changes in the repertoire sizes of the six gene families that are due to similar demands for the quantity of these different genes in different lineages of Drosophila. In conclusion, we propose that the correlated evolution among these six gene families in Drosophila is a signature of a parallel response to ecological adaptation

Brain health and shared risk factors for dementia and stroke

Impaired brain health encompasses a range of clinical outcomes, including stroke, dementia, vascular cognitive impairment, cognitive ageing, and vascular functional impairment. Conditions associated with poor brain health represent leading causes of global morbidity and mortality, with projected increases in public health burden as the population ages. Many vascular risk factors are shared predictors for poor brain health. Moreover, subclinical brain MRI markers of vascular damage are risk factors shared between stroke and dementia, and can be used for risk stratification and early intervention. The broad concept of brain health has resulted in a conceptual shift from vascular risk factors to determinants of brain health. Global campaigns to reduce cardiovascular diseases by targeting modifiable risk factors are necessary and will have a broad impact on brain health. Research is needed on the distinct and overlapping aetiologies of brain health conditions, and to define MRI markers to help clinicians identify patients who will benefit from aggressive prevention measures