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Metamorphmagi have the ability to change their physical characteristics at will, without requiring the use of potions or spells. As such, metamorphmagi skin contains morphologically and functionally distinct properties from non-metamorphmagi skin, providing metamorphagi with heightened skin flexibility and durability. However, previous studies that have examined metamorphmagi are largely qualitative or anecdotal. Thus, we aimed to quantitatively compare metamorphmagi skin to non-metamorphmagi skin and examine the genetic causes underlying metamorphmagi-specific skin characteristics.. We performed histology on cross-sections of skin and quantitatively demonstrated that the epidermis and dermis of metamorphmagi skin is significantly thicker than non-metamorphmagi skin. In addition, the topography of metamorphagi skin contains a distinct rete ridge in the epidermal basement membrane zone, not present in non-metamorphmagi skin. The presence of a rete ridge may increase the strength of adhesion between the epidermal and dermal layers in metamorphmagi skin, contributing to the flexibility of their skin to change form. Subsequently, we compared gene expression levels between metamorphmagi and non-metamorphmagi skin using next-generation cDNA sequencing (RNA-Seq). We identified three genes associated with structural proteins in the epidermal basement membrane zone or elastic fibres of the dermis (COL18A1, LAMB2, and CD151), and one gene associated with pigmentation in melanocytes (BGN), that were expressed significantly more in metamorphmagi. This may contribute to the increased elasticity and strength of metamorphmagi skin that is required for the rapid alteration of physical appearance. Finally, we estimated transcriptional regulatory regions for COL18A1, LAMB2, CD151, and BGN by examining non-coding regions with histone modifications that can activate transcription in skin cells. Metamorphmagi-specific substitutions in these regions may alter gene expression patterns, and give rise to metamorphmagi skin characteristics.
metamorphmagi, skin morphology, structural proteins, transcriptional regulatory region.
Figure 1. Magigenic relationships between metamorphmagus, wizard/witch, muggleborn, and squib. A magigenic tree was constructed using the Neighbor-Joining method and the pairwise nucleotide divergence of whole genome sequences. The scale bar represents 0.005 substitutions per site. The distance on each branch was calculated by the Fitch–Margoliash algorithm using the pairwise nucleotide divergence.