Early Purchaser Involvement in Open Innovation- the case of an advanced purchasing function triggering the absorption of external knowledge in the French automotive industry

International audienceThis paper investigates the mechanisms that trigger the absorption of external knowledge in an innovative French automotive firm. An ethnographic-inspired study conducted by an academic embedded within the Innovation Purchasing Department has enable us to present a rare and new function of Purchasing that plays an important role between potential new suppliers and Research and Development personnel

DNA Methylation

<p><b>A</b>. X Chromosome DNA Methylation and XIST Expression. Methylation levels of genes in the X-chromosome (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.s009" target="_blank">S6A Table</a>) are shown on the heatmap. Hierarchical clustering was performed on the samples, as indicated by the dendrogram. The genes are ordered according to their location (from the beginning to the end of the chromosome). Samples that show loss of DNA methylation for the “Enz” cluster are highlighted in blue, those that show DNA methylation for the “Ecm” cluster are highlighted in pink, and for both clusters in mauve. Genes located in the regions of loss of DNA methylation are listed to the right of the heatmap. XIST expression is shown on the line graph, with the detection limit for the microarray indicated by the red line. <b>B</b>. DNA methylation at imprinted loci. Methylation levels for imprinted probes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.s009" target="_blank">S6B Table</a>) are shown on the heatmap. Hierarchical clustering was performed on the samples, as indicated by the dendrogram. The genes are ordered according to chromosome location; genes are listed to the left. The inset at the right shows a detail of the NESP/GNAS complex locus, indicating the positions of the CpG sites that were hypermethylated (red triangle) vs. hypomethylated (green triangle) in the late passage samples relative to the NESP/GNAS and NESPAS exons. <b>C, D, E</b>. Heatmaps showing differential DNA methylation genes for early vs. late passage <b>(C)</b>, mechanical vs. enzymatic passage <b>(D)</b>, and Mef vs. Ecm substrate <b>(E)</b>. In heatmap <b>(C)</b>, the black boxes indicate genes for which the DNA methylation levels in the late passage MefMech (P103) samples was more similar to those in the early passage samples. Probes were selected by multivariate regression. Functional enrichments identified by GREAT analysis are shown to the right of the heatmaps, visualized using REVIGO [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.ref013" target="_blank">13</a>]. Samples were arranged according to passage and culture method, and hierarchical clustering was performed on the genes only. In the functional enrichment results, the size of the node indicated the number of contributing GO terms, and color of the nodes indicates the FDR (darker color for lower FDR), and the edge length indicates the similarity between GO terms (shorter edge for more similar terms).</p

OECM activity is neutralized by Follistatin but not Noggin.

<p>OECM activity is neutralized by Follistatin but not Noggin.</p

Follistatin but not Noggin neutralizes OECM activity.

<p>(A). Noggin was pre-mixed with OECM before being applied to mitral/tufted cells in culture. Compared with cultures grown with OECM, addition of Noggin (50–200 ng/ml) did not appear to reduce the trophic activity. Noggin when applied alone at 100 ng/ml, did change the growth of mitral/tufted cells. (B). Follistatin at 50 ng/ml, when pre-mixed with OECM, did not completely neutralize the OECM activity. Follistatin at 100 and 200 ng/ml completely abolished the OECM activity, while Follistatin alone did not alter the neurite length of mitral/tufted cells. * Indicated significant difference in neurite length was observed when compared to the control.</p

Olfactory epithelium derived activity promotes the extension of mitral/tufted cell processes.

<p>Mitral/tufted cells identified by GFP expression were dissociated from E14 olfactory bulb of NT-GFP mice (A). Mitral/tufted cells extend a few short neurite processes at 2DIV (a–a’’’) in the control. When cultured with olfactory epithelium conditioned medium (OECM), increases in neurite length were observed at 2DIV (b–b’’’) and most of them bear a single longer neurite (arrows in b–b’’). Total neurite length of each mitral/tufted cell was significantly longer (*) in OECM than the control (B) but the cortical tissue conditioned medium (CXCM) did not exhibit this effect. Longest neurite length of each mitral/tufted cell was also significantly longer (*) in OECM than the control (C). Bar = 30 µm.</p

Olfactory epithelium interacts with dendrites of the olfactory bulb (OB) neurons.

<p>On a sagittal section of the E14 OB, mitral cells extend dendritic processes labeled by MAP2 immunostaining (A). Olfactory axons labeled with olfactory marker protein (OMP) expression (B) were distributed overlapping with the dendritic processes of the OB neurons (C). When olfactory bulb explants from E12 were cultured alone, dendritic processes of the OB neurons are visualized with MAP2 expression (D) and interneurons with Calretinin (E) and mitral/tufted cells with Glutamate immunostaining (F). While no increase in the interneurons (H) and glutamatergic neuron numbers was observed (I), an increase in the density of dendritic processes were observed (G) when OB explants were co-cultured in contact with the olfactory epithelium explants. Bar = 120 µm in A, 50 µm in D.</p

Developmental regulation of mitral/tufted cell responses to OE derived activity.

<p>(A). OE derived trophic activity was present in both embryonic (E14 and E16) and postnatal (P0) OE when tested using mitral/tufted cells from E14 OB. (B). Mitral/tufted cells (MC) from E14 to P0 OB are tested for their responsiveness to OECM (from E14 OE). Compared to neurons from the same developmental stage in the control media (normalized as 1), E14, E16 and E18 mitral/tufted cells responded to the OECM trophic activity. Total neurite length per cell was significantly increased compared to the control at each embryonic stages tested.. No significant neurite promoting response was detected when P0 mitral/tufted cells were exposed to OECM (from E14 OE). (C). Mitral/tufted cells from P0 olfactory bulb exhibit similar morphology when cultured with OECM compared to the control. Bar = 40 µm.</p

Molecular weight of the trophic activity in olfactory epithelium conditioned medium (OECM) is between 50–100 kD.

<p>OECM separated by MWCO filters was evaluated by E14 mitral/tufted cell for its neurite promoting activity. While 30 kD and 50 kD MWCO filter maintained OECM activity, the activity was lost when 100 kD filter was applied.</p

Distributions of infant haemoglobin at 6 months of age by studies.

<p>Distributions of infant haemoglobin at 6 months of age by studies.</p

Trophic factors promote mitral/tufted cell dendritic outgrowth.

<p>Exposure to BMP2 (100 ng/ml), BMP5 (500 ng/ml) and BMP7 (50 and 100 ng/ml) showed significant bioactivity while exposure to NGF caused a slight increase in the neurite length of mitral/tufted cells.</p