Autosomal dominant mutations of the RNA/DNA binding protein FUS are linked to familial amyotrophic lateral sclerosis (FALS); however, it is not clear how FUS mutations cause neurodegeneration. Using transgenic mice expressing a common FALS-associated FUS mutation (FUS-R521C mice), we found that mutant FUS proteins formed a stable complex with WT FUS proteins and interfered with the normal interactions between FUS and histone deacetylase 1 (HDAC1). Consequently, FUS-R521C mice exhibited evidence of DNA damage as well as profound dendritic and synaptic phenotypes in brain and spinal cord. To provide insights into these defects, we screened neural genes for nucleotide oxidation and identified brain-derived neurotrophic factor (Bdnf ) as a target of FUS-R521C-associated DNA damage and RNA splicing defects in mice. Compared with WT FUS, mutant FUS-R521C proteins formed a more stable complex with Bdnf RNA in electrophoretic mobility shift assays. Stabilization of the FUS/Bdnf RNA complex contributed to Bdnf splicing defects and impaired BDNF signaling through receptor TrkB. Exogenous BDNF only partially restored dendrite phenotype in FUS-R521C neurons, suggesting that BDNF-independent mechanisms may contribute to the defects in these neurons. Indeed, RNA-seq analyses of FUS-R521C spinal cords revealed additional transcription and splicing defects in genes that regulate dendritic growth and synaptic functions. Together, our results provide insight into how gain-of-function FUS mutations affect critical neuronal functions. IntroductionAutosomal dominant mutations in RNA/DNA binding protein fused in sarcoma/translocated in liposarcoma (FUS/TLS) have been causally linked to familial ALS (FALS). The main pathological features in FALS with FUS mutations are FUS-positive protein aggregates in neuronal cytoplasm and dendrites (1, 2). While the majority of these aggregates are identified in the spinal motor neurons, FUS-positive aggregates have also been found in neurons in cerebral cortex and brainstem nuclei (3, 4), raising the possibility that FUS mutations may have a broader impact on the functions of other neuronal subtypes. Consistent with these observations, a subset of FALS-FUS patients also exhibits cognitive impairments during the developmental or degenerative processes.Although the exact mechanism of FUS mutations remains unclear, several previous studies have provided compelling evidence that FUS can regulate DNA damage response, transcription, and RNA processing. For instance, fibroblasts and lymphocytes from fus-null mice show increased sensitivity to ionizing irradiation and genomic instability, respectively (5, 6). Consistent with these results, our recent study shows that WT FUS proteins are rapidly recruited to DNA damage foci in neurons, where it interacts with histone deacetylase 1 (HDAC1), a critical component in

Anopheles sinensis is the most important vector of malaria in Southeast Asia, including China. Currently, the most effective measure to prevent malaria transmission relies on vector control through the use of insecticides, primarily pyrethroids. Extensive use of insecticides poses strong selection pressure on mosquito populations for resistance. Resistance to insecticides can arise due to mutations in the insecticide target site (target site resistance), which in the case of pyrethroids is the para-type sodium channel gene, and/or the catabolism of the insecticide by detoxification enzymes before it reaches its target (metabolic detoxification resistance). In this study, we examined deltamethrin resistance in An. sinensis from China and investigated the relative importance of target site versus metabolic detoxification mechanisms in resistance. A high frequency (>85%) of nonsynonymous mutations in the para gene was found in populations from central China, but not in populations from southern China. Metabolic detoxification as measured by the activity of monooxygenases and glutathione S-transferases (GSTs) was detected in populations from both central and southern China. Monooxygenase activity levels were significantly higher in the resistant than the susceptible mosquitoes, independently of their geographic origin. Stepwise multiple regression analyses in mosquito populations from central China found that both knockdown resistance (kdr) mutations and monooxygenase activity were significantly associated with deltamethrin resistance, with monooxygenase activity playing a stronger role. These results demonstrate the importance of metabolic detoxification in pyrethroid resistance in An. sinensis, and suggest that different mechanisms of resistance could evolve in geographically different populations.

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To better understand the phylogeny and evolution of mosquitoes, the complete mitochondrial genome (mitogenome) of Anopheles stephensi and An. dirus were sequenced and annotated, and a total of 50 mosquito mitogenomes were comparatively analyzed. The complete mitogenome of An. stephensi and An. dirus is 1,5371 bp and 1,5406 bp long, respectively. The main features of the 50 mosquito mitogenomes are conservative: 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, positive AT-skew and negative GC-skew. The gene order trnA-trnR in ancestral insects is rearranged. All tRNA genes have the typical clover leaf secondary structure but tRNA Ser. The control regions are highly variable in size. PCGs show signals of purifying selection, but evidence for positive selection in ND2, ND4 and ND6 is found. Bayesian and Maximum Likelihood phylogenetic analyses based on all PCG nucleotides produce an identical tree topology and strongly support the monophyly of subgenera Cellia, Anopheles, Keterszia and Nyssorhynchus, the sister relationship of the subgenera Nyssorhynchus and Keterszia, and Cellia and Anopheles. The most recent ancestor of the genus Anopheles and Culicini + Aedini exited ~145 Mya ago. This is the first comprehensive study of mosquito mitogenomes, which are effective for mosquito phylogeny at various taxonomic levels.