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Complex Traits

Author(s): Nancy Moreno, PhD.

What Causes Long Hair in Dogs?

In this activity, students are introduced to genetic variation by looking at recent research results on hair length in dogs. Short hair is the ancestral (original) condition in dogs. Long-haired dog breeds were found to have a mutation in the gene that signals for the termination of hair growth. The mutation causes a loss of function in hair growth regulation, presumably leading to longer hair. 

The researchers began by studying a gene that was known to contribute to hair growth in other species (called FGF5, named for the “fibroblast growth factor 5” protein). By comparing sequence data from different dog breeds, they found that a single mutation (from G to T) at one location consistently correlated with the presence of long hair. The mutation causes an amino acid change (cystein to phenylalanine). Only dogs that are homozygous (have two copies) for the mutation have long hair. Students will use some of the original published data to find the location and nature of the mutation. 

Procedure (cont.)

6. Ask students, Is there a genetic explanation for long hair in dogs? Have students discuss the information shown above. They should conclude that genetics must be involved, because long hair can be inherited by offspring.

Funded by the following grant(s)

Science Education Partnership Award, NIH

Gene U: Inquiry-based Genomics Learning Experiences for Teachers and Students
Grant Number: 5R25OD011134

Robert Wood Johnson Foundation

Using Learning Technology to Build Human Capital
Grant Number: 57363