Unveiling the Genetic Secrets of Monotreme Skin Differentiation
Published: January 16, 2024
By Geeta Pillai
In a groundbreaking scientific study, the genomes of the platypus and the echidna have been meticulously analyzed to comprehend the gene composition of the Epidermal Differentiation Complex (EDC) in these basal mammals. The EDC is crucial in the differentiation of epidermal keratinocytes into corneocytes, forming the outermost layer of the skin, serving as a formidable barrier against the environment.
Conservation of EDC genes
The research has revealed that mammal-specific subfamilies of EDC genes, including those encoding small proline-rich proteins (SPRRs) and late cornified envelope (LCE) proteins, along with single-copy EDC genes like involucrin, are conserved in monotremes. This suggests that these genes originated in stem mammals, providing insight into the genetic heritage of our distant relatives.
Monotremes and Filaggrin Homology
The research also found that monotremes possess at least one gene homologous to the group of filaggrin (FLG, FLG2) and hornerin (HRNR) found in placental mammals, indicating unique evolutionary trajectories for these basal mammals.
Echidna and Caspase-14
The echidna has at least three gene copies encoding caspase-14, a protease closely associated with keratinocyte differentiation and filaggrin processing. This finding opens up new avenues of exploration in understanding the unique characteristics of echidna skin differentiation.
The study illuminates evolutionarily conserved features of genetic regulation of epidermal differentiation in monotremes, as well as clade-specific traits distinguishing them from other mammals. This deepens our understanding of mammalian skin evolution, a unique keratinocyte-based structure among terrestrial vertebrates, forming hair and associated glands, and undergoing continuous regeneration and cornification.
Geeta Pillai is a renowned international correspondent with a keen focus on global economics and politics. Drawing from a diverse experience across news agencies, print, and digital platforms, Geeta excels in delivering astute and comprehensive reports. With her finger always on the pulse of global shifts, she provides a fresh and discerning take on the world’s unfolding events.
