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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2010.03.013 Byline: Daisuke Kurokawa (a)(b), Tomomi Ohmura (a), Hajime Ogino (c), Masaki Takeuchi (a), Ai Inoue (a), Fumitaka Inoue (a), Yoko Suda (a), Shinichi Aizawa (a) Keywords: Otx2; Head organizer; Anterior visceral endoderm; Anterior mesendoderm; Cis-element; Evolution Abstract: In the mouse, the Otx2 gene has been shown to play essential roles in the visceral endoderm during anterior-posterior axis formation and head induction. While these are primary processes in vertebrate embryogenesis, the visceral endoderm is a tissue unique to mammals. Two enhancers (VE and CM) have been previously found to direct Otx2 expression during early embryogenesis. This study demonstrates that in anterior visceral endoderm the CM enhancer does not have an activity by itself, but enhances the activity of the VE enhancer. These two enhancers also cooperate for the activities in anterior mesendoderm and cephalic mesenchyme. Comparative studies suggest that VE enhancer function was most likely established before the divergence of sarcopterygians into Actinistia, Dipnoi and tetrapods, while the nucleotide sequence corresponding to the VE enhancer was already present in the last common ancestor of bony fishes. The CM enhancer sequence and function would have been also established in ancestral sarcopterygians. The VE/CM enhancers and their gene cascades in the ancestral sarcopterygian head organizer would then have been co-opted by amphibian deep endoderm cells and mammalian visceral endoderm cells for the head development. Author Affiliation: (a) Laboratory for Vertebrate Body Plan, Center for Developmental Biology, RIKEN Kobe, 2-2-3 Minatojima Minamimachi, Chuou-ku, Kobe 650-0047, Japan (b) Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura 238-0225, Japan (c) Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Ikoma 630-0192, Japan Article History: Received 1 December 2009; Revised 15 March 2010; Accepted 16 March 2010

In a random-reference multiplexing scheme, we propose a method of generating different wavefronts without rotating a random pattern-generating element, simply by changing the wavelength of the incident light. A reference pattern with a random wavefront is an important aspect of color recording and readout. The color recording and readout system we propose is simple and compact, and generation of uncorrelated color patterns is easy. An important feature is that simultaneous readout using multiple wavelengths is facilitated. We confirmed the feasibility of this system by simulation and experiment, and we examined color recording and readout using multiple wavelengths. [c] 2010 Optical Society of America OCIS codes: 210.2860, 090.4220.

This study evaluated whether cell sheets containing a network of lymphatic endothelial cells (LECs) promoted lymphangiogenesis after transplantation in vivo. Cell sheets with a LEC network were constructed by co-culturing LECs and adipose-derived stem cells (ASCs) on temperature-responsive culture dishes. A cell ratio of 3:2 (vs. 1:4) generated networks with more branches and longer branch lengths. LEC-derived lymphatic vessels were observed 2 weeks after transplantation of a three-layered cell sheet construct onto rat gluteal muscle. Lymphatic vessel number, diameter and depth were greatest for a construct comprising two ASC sheets stacked on a LEC/ASC (3:2 ratio) sheet. Transplantation of this construct in a rat model of femoral lymphangiectomy led to the formation of functional lymphatic vessels containing both transplanted and host LECs. Further development of this technique may lead to a new method of promoting lymphangiogenesis., (© 2022. The Author(s).)

The bone marrow microenvironment comprises multiple cell niches derived from bone marrow mesenchymal stem cells. However, the molecular mechanism of bone marrow mesenchymal stem cell differentiation is poorly understood. The transcription factor GATA2 is indispensable for hematopoietic stem cell function as well as other hematopoietic lineages, suggesting that it may maintain bone marrow mesenchymal stem cells in an immature state and also contribute to their differentiation. To explore this possibility, we established bone marrow mesenchymal stem cells from GATA2 conditional knockout mice. Differentiation of GATA2-deficient bone marrow mesenchymal stem cells into adipocytes induced accelerated oil-drop formation. Further, GATA2 loss- and gain-of-function analyses based on human bone marrow mesenchymal stem cells confirmed that decreased and increased GATA2 expression accelerated and suppressed bone marrow mesenchymal stem cell differentiation to adipocytes, respectively. Microarray analysis of GATA2 knockdowned human bone marrow mesenchymal stem cells revealed that 90 and 189 genes were upregulated or downregulated by a factor of 2, respectively. Moreover, gene ontology analysis revealed significant enrichment of genes involved in cell cycle regulation, and the number of G1/G0 cells increased after GATA2 knockdown. Concomitantly, cell proliferation was decreased by GATA2 knockdown. When GATA2 knockdowned bone marrow mesenchymal stem cells as well as adipocytes were cocultured with CD34-positive cells, hematopoietic stem cell frequency and colony formation decreased. We confirmed the existence of pathological signals that decrease and increase hematopoietic cell and adipocyte numbers, respectively, characteristic of aplastic anemia, and that suppress GATA2 expression in hematopoietic stem cells and bone marrow mesenchymal stem cells., (Copyright© Ferrata Storti Foundation.)