Dermo-Epidermal Interactions in Reptilian Scales: Speculations on the Evolution of Scales, Feathers, and Hairs

July 2004 in “ Journal of experimental zoology. Part B, Molecular and developmental evolution ”

Lorenzo Alibardi

TLDR Reptilian scales, feathers, and hairs evolved from changes in skin cell interactions.

The paper discussed the role of dermo-epidermal interactions in the formation of reptilian scales and speculated on the evolutionary development of scales, feathers, and hairs. It highlighted that dermal cells connect to specific epidermal areas, forming regions where morphoregulatory molecules are exchanged. These regions' positions change during development, potentially leading to different appendages based on genetic makeup. The study hypothesized that variations in these interactions' localization and extension could explain the evolution from large scales in early amniotes to the specialized structures in modern reptiles, mammals, and birds, such as hard keratin scales, hair, and feathers.

View this study on onlinelibrary.wiley.com →

Discuss this study in the Community →

Research cited in this study

7 / 7 results

research Molecular Mechanisms Regulating Hair Follicle Development

854 citations, February 2002 in “The journal of investigative dermatology/Journal of investigative dermatology”

Understanding hair follicle development can help treat hair loss, skin regeneration, and certain skin cancers.

research The Catalog of Human Hair Keratins

235 citations, July 1999 in “Journal of biological chemistry/The Journal of biological chemistry”

Human hair is made up of different keratins, some strong and some weak, with specific types appearing at various stages of hair growth.

research The Fate of Trichohyalin

135 citations, October 1997 in “Journal of biological chemistry/The Journal of biological chemistry”

Trichohyalin is modified by enzymes to form strong structures in hair cells.

research Molecular Histology in Skin Appendage Morphogenesis

57 citations, August 1997 in “Microscopy Research and Technique”

New molecules involved in skin and hair growth were identified, improving understanding and future treatments.

research Dynamic Expression Patterns of Tenascin, Proteoglycans, and Cell Adhesion Molecules During Human Hair Follicle Morphogenesis

67 citations, February 1994 in “Developmental dynamics”

Specific proteins and molecules play key roles in the development of human hair follicles.

research The Secret Life of the Hair Follicle

745 citations, February 1992 in “Trends in genetics”

Hair follicles create different cell layers and proteins, controlled by various molecules.

research Heterotypic Cell Contacts and Basal Lamina Morphology During Hair Follicle Development in the Mouse: A Light, Scanning, and Electron Microscopic Study at the Site of Tissue Interaction

13 citations, December 1983 in “Canadian journal of zoology”

Heterotypic cell contacts likely help hair matrix cells differentiate during mouse hair follicle development.

Related Community Posts Join

6 / 1000+ results

community Diffuse hair loss and scalp biopsies

in Research 692 upvotes 4 months ago

Scalp biopsies are crucial for diagnosing hair loss conditions like Diffuse Unpatterned Alopecia (DUPA) and retrograde hair loss, as treatments like finasteride and dutasteride may not be effective if other conditions are present. Combining PPAR-GAMMA agonists with retinoids could improve treatments for conditions like Lichen Planopilaris.

community Comprehensive Microneedling Guide

in Microneedling 290 upvotes 2 years ago

Microneedling for hair restoration involves daily use of a 0.3 mm device and weekly use of a 0.5 mm device. Combining microneedling with Minoxidil can enhance hair growth.

community Is it possible for androgenic alopecia to begin at early adolescent years?

in Chat 70 upvotes 1 year ago

Hair loss can begin in early adolescence and cause mental anguish. Treatments mentioned include eating cruciferous vegetables, engaging in physical activity, and maintaining scalp hygiene.

community Fin/min/microneedling ~9 months – no results, actually worse

in Progress Pictures 96 upvotes 1 year ago

User harlital shared their 9-month hair loss journey using finasteride, minoxidil, and microneedling but experienced worse results. Commenters suggested patience, checking for other causes, and considering dutasteride after 12-24 months if no improvement.

community Why is no one pointing out dandruff as the number 1 evidence/symptom of MPB?

in Chat 55 upvotes 1 year ago

The post discusses the theory that persistent dandruff in areas prone to hair loss could be a sign of hair follicles dying due to DHT, indicating balding. The responses vary, with some users noting improvements in dandruff and hair loss with treatments like Dutasteride, while others experienced hair loss without dandruff.

community 9months progress fin/derma pen/minoxidil

in Progress Pictures 1001 upvotes 4 years ago

A user's 9 month progress using Finasteride, Derma Pen/Roller and Minoxidil to treat hair loss. Replies in the conversation include advice on topical application of Minoxidil and Dutasteride for regrowth and hair thickness.

Similar Research

6 / 1000+ results

Fine Structure and Immunocytochemistry of Monotreme Hairs, with Emphasis on the Inner Root Sheath and Trichohyalin-Based Cornification During Hair Evolution

research Fine Structure and Immunocytochemistry of Monotreme Hairs, with Emphasis on the Inner Root Sheath and Trichohyalin-Based Cornification During Hair Evolution

15 citations, July 2004 in “Journal of morphology”

Monotreme hair structure and protein distribution are similar to other mammals, but their inner root sheath cornifies differently, suggesting a unique evolution from reptile skin.

research Evolution of Hard Proteins in the Sauropsid Integument in Relation to the Cornification of Skin Derivatives in Amniotes

86 citations, April 2009 in “Journal of anatomy”

Hard skin features like scales, feathers, and hair evolved through specific protein changes in different animal groups.

research Evo Devo of the Vertebrate Integument

4 citations, June 2023 in “Journal of developmental biology”

The skin systems of jawed vertebrates evolved diverse appendages like hair and scales from a common structure over 420 million years ago.

research Integument Pattern Formation Involves Genetic and Epigenetic Controls: Feather Arrays Simulated by Digital Hormone Models

112 citations, January 2004 in “The International journal of developmental biology”

Feather patterns form through genetic and epigenetic controls, with cells self-organizing into periodic patterns.

research Early Inductive Events in Ectodermal Appendage Morphogenesis

160 citations, January 2014 in “Seminars in cell & developmental biology”

Early development of hair, teeth, and glands involves specific signaling pathways and cellular interactions.

research Understanding Skin Morphogenesis Across Developmental, Regenerative, and Evolutionary Levels

2 citations, April 2019 in “Experimental Dermatology”

The article concludes that studying how skin forms is key to understanding skin diseases and improving regenerative medicine.