Differentially-expressed miRNAs between precursor chondrocytes (PC) and differentiated chondrocytes (DC) from gestational day 54–56 human embryonic cartilage tissue.

<p>Fold change (f.c.) expression of miRNAs between cells of PC and DC regions are shown. The score (d) and q-values for each differentially-expressed miRNA are shown based on SAM analysis (FDR≤5%; n = 8–9).</p

Enriched pathways of predicted genes targeted by differentially expressed miRNAs (PC>DC).

<p>Enriched pathways of predicted genes targeted by differentially expressed miRNAs (PC>DC).</p

Immunofluorescence staining of different collagen types in a human developing embryonic proximal tibia (gestational day 54).

<p>(<b>A</b>) Localization of the embryonic isoform of type II procollagen (type IIA) in the extracellular matrix (ECM). The anti-IIA antibody recognizes the exon 2-encoded cysteine-rich domain present in the amino propeptide of type IIA procollagen <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0075012#pone.0075012-Oganesian1" target="_blank">[43]</a>. These IIA isoforms are generated predominantly by progenitor chondrocytes seen at the periphery and most proximal area of the developing tibia. Some expression of IIA procollagen has been reported in the pre-hypertrophic and hypertrophic region of developing cartilage <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0075012#pone.0075012-Zhu1" target="_blank">[58]</a> and is also shown here. (<b>B</b>) Type I collagen staining is restricted to the areas of precursor chondrocytes and cells of the perichondrium/periosteum. (<b>C</b>) Type II collagen staining patterns (i.e. the processed triple helical domain of type II collagen) is present throughout the entire developing limb. (<b>D</b>) Collagen X staining is restricted to the ECM containing hypertrophic chondrocytes. Cell nuclei are visualized in blue by DAPI staining. Scale bars = 100 µm. Immunofluorescent images are representative of three independent experiments using gestational day 54 tissue sections from different embryos.</p

Enriched pathways of predicted genes targeted by differentially expressed miRNAs (DC

<p>Enriched pathways of predicted genes targeted by differentially expressed miRNAs (DC</p

Differentially-expressed miRNAs between differentiated chondrocytes (DC) and hypertrophic chondrocytes (HYP) from gestational day 54–56 human embryonic cartilage tissue.

<p>Fold change (f.c.) expression of miRNAs between cells of DC and HYP regions are shown. The score (d) and q-values for each differentially-expressed miRNA are shown based on SAM analysis (FDR≤5%; n = 8–9).</p

Differentially-expressed miRNAs between precursor chondrocytes (PC) and hypertrophic chondrocytes (HYP) from gestational day 54–56 human embryonic cartilage tissue.

<p>Fold change (f.c.) expression of miRNAs between cells of PC and HYP regions are shown. The score (d) and q-values for each differentially-expressed miRNA are shown based on SAM analysis (FDR≤5%; n = 8–9).</p

Enriched pathways of predicted genes targeted by differentially expressed miRNAs (PC

<p>Enriched pathways of predicted genes targeted by differentially expressed miRNAs (PC</p

Safranin-O-stained tissue section of a human embryonic developing proximal tibia (gestational day 54).

<p>Red-orange staining represents proteoglycans in the developing cartilage extracellular matrix. This stage of development is prior to endochondral ossification. Chondrocytes at various stages of differentiation are present at this stage: precursor chondrocytes (<b>PC</b>) are found at the most proximal end of the developing tibia as well as in the surrounding perichondrium; differentiated chondrocytes (<b>DC</b>) are located further down the developing limb and are distinguishable by their cuboidal or flattened phenotype, depending on their location; hypertrophic chondrocytes (<b>HYP</b>) are terminally-differentiated cells easily distinguished by their increased size. Also shown in this image are the developing femoral condyles (fc) of the distal femur. Scale bar = 250 µm.</p

Enriched pathways of predicted genes targeted by differentially expressed miRNAs (DC>HYP).

<p>Enriched pathways of predicted genes targeted by differentially expressed miRNAs (DC>HYP).</p

Top 30 most abundantly expressed miRNAs in precursor, differentiated and hypertrophic chondrocytes from gestational day 54–56 human embryonic cartilage tissue.

<p>Highly expressed miRNAs were identified according to their average (2^-ΔCt) values. Delta (Δ) Ct value for each miRNA was calculated by subtracting the Ct value of endogenous control, RNU44, from the Ct value of the specific miRNA. Expression level average (2^−ΔCt) in a region reflects the average of 2^−ΔCt values across all samples in that region.</p