Possible involvement of SINEs in mammalian-specific brain formation.

@article{citeulike:2692803, abstract = {Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene FGF8 (fibroblast growth factor 8), is an enhancer that recapitulates FGF8 expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that FGF8 expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene SATB2, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor.}, address = {Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-21 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.}, author = {Sasaki, T. and Nishihara, H. and Hirakawa, M. and Fujimura, K. and Tanaka, M. and Kokubo, N. and Kimura-Yoshida, C. and Matsuo, I. and Sumiyama, K. and Saitou, N. and Shimogori, T. and Okada, N. }, citeulike-article-id = {2692803}, doi = {10.1073/pnas.0709398105}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, keywords = {cis-regulatory, mammals, transposon}, month = {March}, number = {11}, pages = {4220--4225}, posted-at = {2008-04-26 19:38:10}, priority = {2}, title = {Possible involvement of SINEs in mammalian-specific brain formation.}, url = {http://dx.doi.org/10.1073/pnas.0709398105}, volume = {105}, year = {2008} }

TY - JOUR ID - citeulike:2692803 L3 - citeulike-article-id:2692803 TI - Possible involvement of SINEs in mammalian-specific brain formation. JF - Proceedings of the National Academy of Sciences of the United States of America VL - 105 IS - 11 SP - 4220 EP - 4225 AD - Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-21 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan. SN - 1091-6490 N2 - Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene FGF8 (fibroblast growth factor 8), is an enhancer that recapitulates FGF8 expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that FGF8 expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene SATB2, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor. KW - cis-regulatory KW - mammals KW - transposon AU - Sasaki, T AU - Nishihara, H AU - Hirakawa, M AU - Fujimura, K AU - Tanaka, M AU - Kokubo, N AU - Kimura-Yoshida, C AU - Matsuo, I AU - Sumiyama, K AU - Saitou, N AU - Shimogori, T AU - Okada, N PY - 2008/03/18/ UR - http://dx.doi.org/10.1073/pnas.0709398105 ER -