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Abstract The tree shrew (Tupaia belangeri) is a promising emerging model organism in biomedical studies, notably due to their evolutionary proximity to primates. To enhance our understanding of how DNA methylation is implicated in regulation of gene expression and the X chromosome inactivation (XCI) in tree shrew brains, here we present their first genome-wide, single-base-resolution methylomes integrated with transcriptomes from prefrontal cortices. We discovered both divergent and conserved features of tree shrew DNA methylation compared to that of other mammals. DNA methylation levels of promoter and gene body regions are negatively correlated with gene expression, consistent with patterns in other mammalian brains studied. Comparing DNA methylation patterns of the female and male X chromosomes, we observed a clear and significant global reduction (hypomethylation) of DNA methylation across the entire X chromosome in females. Our data suggests that the female X hypomethylation does not directly contribute to the gene silencing of the inactivated X chromosome nor does it significantly drive sex-specific gene expression of tree shrews. However, we identified a putative regulatory region in the 5’ end of the X inactive specific transcript (Xist)gene, a key gene for XCI, whose pattern of differential DNA methylation strongly relate to its differential expression between male and female tree shrews. We show that differential methylation of this region is conserved across different species. Moreover, we provide evidence suggesting that the observed difference between human and tree shrew X-linked promoter methylation is associated with the difference in genomic CpG contents. Our study offers novel information on genomic DNA methylation of tree shrews, as well as insights into the evolution of X chromosome regulation in mammals. 

Teachers of the visually impaired (TVIs) regularly present tactile materials (tactile graphics, 3D models, and real objects) to students with vision impairments. Researchers have been increasingly interested in designing tools to support the use of tactile materials, but we still lack an in-depth understanding of how tactile materials are created and used in practice today. To address this gap, we conducted interviews with 21 TVIs and a 3-week diary study with eight of them. We found that tactile materials were regularly used for academic as well as non-academic concepts like tactile literacy, motor ability, and spatial awareness. Real objects and 3D models served as “stepping stones” to tactile graphics and our participants preferred to teach with 3D models, despite finding them difficult to create, obtain, and modify. Use of certain materials also carried social implications; participants selected materials that fostered student independence and allow classroom inclusion. We contribute design considerations, encouraging future work on tactile materials to enable student and TVI co-creation, facilitate rapid prototyping, and promote movement and spatial awareness. To support future research in this area, our paper provides a fundamental understanding of current practices. We bridge these practices to established pedagogical approaches and highlight opportunities for growth regarding this important genre of educational materials.