Lamina lucida and lamina densa regenerate before new ECM deposition.A) Histological examination of basement membrane (BM) regeneration in axolotls. The uninjured BM is visible as a thick blue-stained fibrous band (yellow arrows). An immature BM has begun to reform (yellow arrow D1) after re-epithelialization and is visible at the wound margin (WM) in contrast to the uninjured BM. The regenerated BM is visible at D47. Yellow arrows at D7 and D21 indicate reforming BM. B) Examination of lamina lucida (laminin) and lamina densa (collagen type IV) during basement membrane regeneration. The uninjured BM is positive for laminin and collagen type IV (yellow arrows) as are the basement membranes surrounding glands and muscle fibers. Following re-epithelialization the basal lamina of the epidermis is negative for laminin and collagen type IV (white arrows) and this is clearly evident at the wound margin (WM). Seven days post injury the BM stains strongly for laminin indicating reformation of the lamina lucida, while staining for collagen type IV is punctuated. The lamina densa is regenerated by D14 based on continuous collagen type IV staining and persists during dermal regeneration. Figure provided by CiteAb. Source: PLoS One, PMID: 22485136.

Rockland anti collagen IV antibody (600-401-106 Lot 25440, 1:400, 45 min RT) showed strong staining in FFPE sections of human kidney (Left) with strong red staining observed in glomeruli and liver (Right) with strong staining in sinusoids. Staining for both tissues was consistent with a basement membrane distribution. Slides were steamed in 0.01 M sodium citrate buffer, pH 6.0 at 99-100°C - 20 minutes for antigen retrieval. Images provided courtesy of LifeSpan Biosciences, Seattle, WA

SMFC tracking in larval newt limb regeneration.(a) Larva (3 months old). It has four limbs, as well as the gills and tail fin. Scale bar, 4 mm. (b) Monitoring of SMFCs (mCherry+) during limb regeneration (n=6). mCherry was not detected in the regenerating part of the limb until ∼30 days when the amputated limb had almost been recovered (see Supplementary Movie 1). Arrowheads: flexor muscle for digits (see Fig. 2). Scale bar, 1 mm. (c) Sections of regenerating limbs (n=3 for each stage). SMFC-derived mCherry+ cells were not observed in the blastema. Lines: amputation site. m: muscle. Scale bar, 100 μm. (d–f) Pax7 immunolabelling of regenerating limbs on day 12 (n=3) and (g) day 15 (n=3) after amputation. (d) On day 12, a few Pax7+ nuclei (arrowheads) were detected in blastema cells and in satellite cells along the muscle fibres. Col IV, collagen type IV immunoreactivity. DAPI (4,6-diamidino-2-phenylindole), nuclei. Scale bar, 300 μm. The Pax7+ nuclei pointed by arrowheads were enlarged in e and f, respectively. Scale bars, 100 μm. (g) On day 15 when the regenerating part of the limb grew more distally, the number of Pax7+ nuclei (arrowheads) in the blastema was dramatically increased. Scale bar, 100 μm. (h) Summary. In larval newts, MPCs, potentially satellite cells, were recruited for new muscle during limb regeneration, whereas SMFCs were not. Figure provided by CiteAb. Source: Nat Commun, PMID: 27026263.

SMFC tracking in larval newt limb regeneration.(a) Larva (3 months old). It has four limbs, as well as the gills and tail fin. Scale bar, 4 mm. (b) Monitoring of SMFCs (mCherry+) during limb regeneration (n=6). mCherry was not detected in the regenerating part of the limb until ∼30 days when the amputated limb had almost been recovered (see Supplementary Movie 1). Arrowheads: flexor muscle for digits (see Fig. 2). Scale bar, 1 mm. (c) Sections of regenerating limbs (n=3 for each stage). SMFC-derived mCherry+ cells were not observed in the blastema. Lines: amputation site. m: muscle. Scale bar, 100 μm. (d–f) Pax7 immunolabelling of regenerating limbs on day 12 (n=3) and (g) day 15 (n=3) after amputation. (d) On day 12, a few Pax7+ nuclei (arrowheads) were detected in blastema cells and in satellite cells along the muscle fibres. Col IV, collagen type IV immunoreactivity. DAPI (4,6-diamidino-2-phenylindole), nuclei. Scale bar, 300 μm. The Pax7+ nuclei pointed by arrowheads were enlarged in e and f, respectively. Scale bars, 100 μm. (g) On day 15 when the regenerating part of the limb grew more distally, the number of Pax7+ nuclei (arrowheads) in the blastema was dramatically increased. Scale bar, 100 μm. (h) Summary. In larval newts, MPCs, potentially satellite cells, were recruited for new muscle during limb regeneration, whereas SMFCs were not. Figure provided by CiteAb. Source: Nat Commun, PMID: 27026263.