Project description:The wood mouse (genus Apodemus) is one of the most common rodents in broad-leaf forests in the temperate zone of the Palaearctic region. Molecular studies of wood mice have critically enhanced the understanding of their evolution and ancestral biogeographic events. However, their molecular data are currently only limited to partial mitochondrial sequences and a few genes. Therefore, we sequenced the wood mouse genome to facilitate the acquisition of useful resources for inferring their molecular evolution. We sampled a wild wood mouse at Tsukuba, Japan, and sequenced its whole-genome using the Illumina Hiseq. 2000. To reduce the risk of non-randomness, three paired-end libraries (insert sizes: 150, 300, and 500 bp) and, two mate-pair reads (insert sizes: 8 and 20 kbp) were constructed. In total, we generated approximately 210 Gbp data. From these sequences, we reconstructed 336,124 scaffolds. These data will enhance our understanding of the evolution and ecological factors that affect their genetic constitution. The genome scaffolds generated are available in the National Center Biotechnology Information (NCBI) BioProject with accession number PRJDB5914.
Project description:The large Japanese field mouse (Apodemus speciosus) is a small rodent species endemic to Japan. The genetic characteristics of A. speciosus include different chromosome numbers within the same species. Furthermore, A. speciosus has been used in radiation and genetic research. In the present study, a pregnant A. speciosus was obtained, and histochemical analysis of the implanted embryos was performed and compared with the developmental stages of the mouse (Mus musculus). Although there were some differences, the structures of the implanted embryos, including the primitive streak and placenta of A. speciosus were similar to those of mouse. Our study will be important for the construction of a developmental atlas of A. speciosus.
Project description:The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred after the Great East Japan Earthquake in March 2011 released large quantities of radionuclides to the environment. The long-term effects of radioactive cesium (Cs) on biota are of particular concern. We investigated the accumulation of radioactive Cs derived from the FDNPP accident, and chronic effects of environmental radionuclides on male reproduction, in the large Japanese field mouse (Apodemus speciosus). In 2013 and 2014, wild mice were captured at 2 sites in Fukushima Prefecture and at 2 control sites that were distant from Fukushima. Although the median concentrations of (134)Cs and (137)Cs in the mice from Fukushima exceeded 4,000?Bq/kg, there were no significant differences in the apoptotic cell frequencies or the frequencies of morphologically abnormal sperm among the capture sites. Thus, we conclude that radiation did not cause substantial male subfertility in Fukushima during 2013 and 2014, and radionuclide pollution levels in the study sites would not be detrimental to spermatogenesis of the wild mice in Fukushima.