Golgi Outpost Synthesis Impaired by Toxic Polyglutamine Proteins Contributes to Dendritic Pathology in Neurons

Dendrite aberration is a common feature of neurodegenerative diseases caused by protein toxicity, but the underlying mechanisms remain largely elusive. Here, we show that nuclear polyglutamine (polyQ) toxicity resulted in defective terminal dendrite elongation accompanied by a loss of Golgi outposts (GOPs) and a decreased supply of plasma membrane (PM) in Drosophila class IV dendritic arborization (da) (C4 da) neurons. mRNA sequencing revealed that genes downregulated by polyQ proteins included many secretory pathway-related genes, including COPII genes regulating GOP synthesis. Transcription factor enrichment analysis identified CREB3L1/CrebA, which regulates COPII gene expression. CrebA overexpression in C4 da neurons restores the dysregulation of COPII genes, GOP synthesis, and PM supply. Chromatin immunoprecipitation (ChIP)-PCR revealed that CrebA expression is regulated by CREB-binding protein (CBP), which is sequestered by polyQ proteins. Furthermore, co-overexpression of CrebA and Rac1 synergistically restores the polyQ-induced dendrite pathology. Collectively, our results suggest that GOPs impaired by polyQ proteins contribute to dendrite pathology through the CBP-CrebA-COPII pathway. ? 2017 The Author(s)113Ysciescopu

Linguistic Situation in Twenty sub-Saharan African Countries: A Survey-based Approach

Data on second languages in sub-Saharan Africa are hard to come by. Consequently, any source that contributes to our knowledge beyond the level of primary languages should be appreciated and exploited. This article utilises Round 4 of the Afrobarometer Survey that collects information on ethnicity, home, and additional languages in 20 sub-Saharan African countries. The study has three main contributions. First, it overviews and compares some widely used sources that contain linguistic data and investigates why they show such a diverse picture on language use patterns. Second, it applies the ICP which, according to the author’s knowledge, is the first linguistic measure that takes multilingualism into account. Third, it shows how a simple graphic representation of the ICP can be used to visualise the most important dimensions of a country’s linguistic situation including the order of languages according to their size, the presence of monolingual speakers, and the relation between vernaculars and the former colonisers’ languages. The study findings are expected to be of interest to scholars engaged in language policy and planning and language-related development issues