TLDR Cetaceans lost hair due to changes in the Hr and FGF5 genes.
The study investigated the molecular basis of hair loss in cetaceans by analyzing the Hairless (Hr) and FGF5 genes across seven cetacean species. Researchers found that the Hr gene experienced functional loss, while the FGF5 gene was under strong positive selection, particularly in toothed whales, indicating its role in terminating the hair growth cycle. These genetic changes, likely under positive selection, contributed to the hairless phenotype in cetaceans, providing insights into their evolutionary adaptation to aquatic environments. The study highlighted the complex genetic mechanisms behind hair loss in cetaceans and the evolutionary pressures shaping these adaptations.
30 citations,
January 2009 in “Nuclear Receptor Signaling” Hairless protein is crucial for healthy skin and hair, and its malfunction can cause hair loss.
75 citations,
September 2007 in “Journal of Heredity” FGF5 gene mutations cause long hair in domestic cats.
73 citations,
June 2006 in “Animal genetics” The FGF5 gene determines hair length in dogs.
26 citations,
October 2002 in “Journal of Investigative Dermatology” 
1113 citations,
August 1999 in “The New England Journal of Medicine” Hair follicle biology advancements may lead to better hair growth disorder treatments.
126 citations,
October 1998 in “Experimental Dermatology” 745 citations,
February 1992 in “Trends in genetics” Hair follicles create different cell layers and proteins, controlled by various molecules.
3 citations,
May 2020 in “bioRxiv (Cold Spring Harbor Laboratory)” The unique coat of lykoi cats is likely caused by new variants in the Hairless gene.
36 citations,
October 1996 in “Dermatologic Clinics” Mice are useful for researching human hair loss and testing treatments, despite some differences between species.
9 citations,
July 2011 in “Scientific Reports” Changes in the HR gene have influenced hair growth and may lead to hair loss conditions in humans.
224 citations,
March 2006 in “Seminars in Cutaneous Medicine and Surgery” The document concludes that understanding hair follicle biology can lead to better hair loss treatments.
October 2018 in “InTech eBooks” The gene Foxn1 is important for hair growth, and understanding it may lead to new alopecia treatments.
