Runx1 is required for the endothelial to haematopoietic cell transition but not thereafter

HSCs are the founder cells of the adult hematopoietic system, and thus knowledge of the molecular program directing their generation during development is important for regenerative hematopoietic strategies. Runx1 is a pivotal transcription factor required for HSC generation in the vascular regions of the mouse conceptus - the aorta, vitelline and umbilical arteries, yolk sac and placenta 1, 2. It is thought that HSCs emerge from vascular endothelial cells through the formation of intra-arterial clusters 3 and that Runx1 functions during the transition from ‘hemogenic endothelium’ to HSCs 4, 5. Here we show by conditional deletion that Runx1 activity in vascular endothelial cadherin (VEC) positive endothelial cells is indeed essential for intra-arterial cluster, hematopoietic progenitor, and HSC formation. In contrast, Runx1 is not required in cells expressing Vav, one of the first pan-hematopoietic genes expressed in HSCs. Collectively these data show that Runx1 function is essential in endothelial cells for hematopoietic progenitor and HSC formation from the vasculature, but its requirement ends once or before Vav is expressed

PCR法によるEdwardsiella tardaの病原性株および非病原性株からのtype1線毛遺伝子の検出

Presence of fimbrial genes among fish pathogenic and non-pathogenic strains of Edwardsiella tarda was investigated by polymerase chain reaction (PCR). Four primer sets for PCR were designed to detect the four genes (etfA, etfB, etfC, etfD) of the type 1 fimbrial gene cluster of E. tarda. All the four genes were successfully amplified with the four primer sets in all the pathogenic strains. On the other hand, any of etfA, etfB and etfC were not detected in 13 of 14 non-pathogenic strains. The results suggest that fimbriae play a role in the pathogenicity of E. tarda and that detection of etfA, etfB and etfC by PCR is useful to distinguish between pathogenic and non-pathogenic strains of E. tarda

Room-temperature GaAs/InP wafer bonding with extremely low resistance

Low-temperature direct wafer bonding is a promising technique for fabricating multijunction solar cells with more than four junctions in order to obtain high conversion efficiencies. However, it has been difficult to reduce the bond interface resistance between a GaAs-based subcell wafer and an InP-based subcell wafer. We found that a novel bonding structure comprising heavily Zn-doped (1 x 10(19) cm(-3)) p(+)-GaAs and S-doped (3 x 10(18)cm(-3)) n-InP had an interface resistance of 2.5 x 10(-5) Omega.cm(2), which is the lowest value ever reported. This result suggests that the newly developed room-temperature wafer bonding technique has high potential to realize high-efficiency multijunction solar cells. (C) 2014 The Japan Society of Applied Physics&nbsp