In contrast to other mammals, the spiny mouse (Acomys) regenerates skin and ear tissue, which includes hair follicles, glands, and cartilage, in a scar-free manner. Ear punch regeneration is... Show moreIn contrast to other mammals, the spiny mouse (Acomys) regenerates skin and ear tissue, which includes hair follicles, glands, and cartilage, in a scar-free manner. Ear punch regeneration is asymmetric with only the proximal wound side participating in regeneration. Here, we show that cues originating from the proximal side are required for normal regeneration and use spatially resolved transcriptomics (tomo-seq) to understand the molecular and cellular events underlying this process. Analyzing gene expression across the ear and comparing expression modules between proximal and distal wound sides, we identify asymmetric gene expression patterns and pinpoint regenerative processes in space and time. Moreover, using a comparative approach with nonregenerative rodents (Mus, Meriones), we strengthen a hypothesis in which particularities in the injury-induced immune response may be one of the crucial determinants for why spiny mice regenerate whereas their relatives do not. Our data are available in SpinyMine, an easy-to-use and expandable web-based tool for exploring Acomys regeneration-associated gene expression. Show less
The brain is of bewildering complexity and numerous genes and signaling molecules have been described that affect the architecture and functioning of specific neuronal circuits. Recent evidence... Show moreThe brain is of bewildering complexity and numerous genes and signaling molecules have been described that affect the architecture and functioning of specific neuronal circuits. Recent evidence from genome analysis revealed the existence of a large group of novel RNA molecules with unexpected properties. One such group is called microRNAs, which are small 21-23 nucleotides RNA molecules that are transcribed by the genome. However, they are not translated into proteins but rather control translation of coding mRNA. Particularly in the brain, numerous different microRNAs are expressed in a cell type specific fashion both during development and in adulthood. Aberrant microRNA expression has been implicated in several human diseases including CNS diseases. The aim of this review is to emphasize their role in the development of the brain and their function. In addition, we highlight recent findings on the evolution of mammalian microRNAs and their effect on steroid signaling in the brain. (C) 2009 Elsevier Inc. All rights reserved. Show less
