A roof plate-dependent enhancer controls the expression of Homeodomain only protein in the developing cerebral cortex

AbstractThe smallest known homeodomain protein, Homeodomain only protein (Hop), was identified and described here as a temporally and spatially restricted gene in the neurogenic regions of the developing murine CNS including the cerebral cortex. Furthermore, an evolutionarily conserved 418 base pair upstream cis-regulatory DNA sequence was found to confine the Hop expression to the CNS of transgenic mice, but not to the heart which is the second major Hop expressing organ Chen, F., Kook, H., Milewski, R., Gitler, A.D., Lu, M.M., Li, J., Nazarian, R., Schnepp, R., Jen, K., Biben, C., Runke, G., Mackay, J.P., Novotny, J., Schwartz, R.J., Harvey, R.P., Mullins, M.C., Epstein, J.A., 2002. Hop is an unusual homeobox gene that modulates cardiac development. Cell 110, 713–723; Shin, C.H., Liu, Z.P., Passier, R., Zhang, C.L., Wang, D.Z., Harris, T.M., Yamagishi, H., Richardson, J.A., Childs, G., Olson, E.N., 2002. Modulation of cardiac growth and development by HOP, an unusual homeodomain protein. Cell 110, 725–735. The forebrain enhancer activity was successfully reproduced in vitro utilizing a combination of the electroporation and the organotypic brain culture method. Using this approach, the minimal requirement for the forebrain-specific enhancer sequence was delineated down to 200 base pairs. We further demonstrate that the Hop enhancer activity is inducible ectopically in a transgenic tissue by wild-type roof plate transplantation in vitro. Thus Hop is regulated in the forebrain by a so far unidentified paracrine signaling factor from the roof plate. Furthermore, the identified enhancer sequence provides an important tool for the targeted expression of transgenes in the medial cortex and the cortical hem

First data on the expression of the Campanian-Maastrichtian boundary event in Bulgaria: Calcareous nannofossil and carbon isotope record

This is the final version. Available from the Bulgarian Academy of Sciences via the DOI in this recordWe present the first combined calcareous nannofossil and stable isotope data (δ13C and δ18O) from the Kladorub section, NW Bulgaria, to study the local expression of the globally recognized Campanian-Maastrichtian Boundary Event (CMBE). Calcareous nannofossil study proves the completeness of the sedimentary succession, with zones UC15eTPthrough UC20dTPevidenced. The isotope data, derived from benthic foraminifera, show that the carbon isotope excursion (CIE) curve displays the well-known superimposed detailed structure of five small positive peaks (CMBE1 to CMBE5). The CMBE-CIE in the Bulgarian locality is characterized by a significant magnitude of 1.97‰, reaching its maximum value in CMBE1 (1.90‰), while the minimum value (- 0.07‰) is in CMBE2. The Campanian-Maastrichtian boundary, drawn at the LO of the nannofossil species Uniplanarius trifidus, lies at the top of CMBE3. Two more neighbouring events, bracketing the CMBE - namely the Late Campanian (LCE) and the Middle Maastrichtian events (MME), are possibly also recorded in Bulgaria

Yet Another Ranking Function for Automatic Multiword Term Extraction

International audienceTerm extraction is an essential task in domain knowledge acquisition. We propose two new measures to extract multiword terms from a domain-specific text. The first measure is both linguistic and statistical based. The second measure is graph-based, allowing assessment of the importance of a multiword term of a domain. Existing measures often solve some problems related (but not completely) to term extraction, e.g., noise, silence, low frequency, large-corpora, complexity of the multiword term extraction process. Instead, we focus on managing the entire set of problems, e.g., detecting rare terms and overcoming the low frequency issue. We show that the two proposed measures outperform precision results previously reported for automatic multiword extraction by comparing them with the state-of-the-art reference measures

Ablation of BAF170 in developing and postnatal dentate gyrus affects neural stem cell proliferation, differentiation, and learning

The BAF chromatin remodeling complex plays an essential role in brain development. However its function in postnatal neurogenesis in hippocampus is still unknown. Here, we show that in postnatal dentate gyrus (DG), the BAF170 subunit of the complex is expressed in radial glial-like (RGL) progenitors and in cell types involved in subsequent steps of adult neurogenesis including mature astrocytes. Conditional deletion of BAF170 during cortical late neurogenesis as well as during adult brain neurogenesis depletes the pool of RGL cells in DG, and promotes terminal astrocyte differentiation. These derangements are accompanied by distinct behavioral deficits, as reflected by an impaired accuracy of place responding in the Morris water maze test, during both hidden platform as well as reversal learning. Inducible deletion of BAF170 in DG during adult brain neurogenesis resulted in mild spatial learning deficits, having a more pronounced effect on spatial learning during the reversal test. These findings demonstrate involvement of BAF170-dependent chromatin remodeling in hippocampal neurogenesis and cognition and suggest a specific role of adult neurogenesis in DG in adaptive behavior