American Spaniel Club Inc. - Home of the Cocker Spaniel

Definitions

What is a Merle color?

Merle is a pattern with patches of intermingled colored and white hairs and other patches of solid color such as red or black.

Heterozygous & Homozygous genes

Each gene is made up of two representative alleles - one inherited from the maternal source (mother) and the other inherited from the paternal source (father)

When a gene is homozygous, both alleles for that gene are the same (ie both the mother and father contributed the same version of the gene)

When a gene is heterozygous, each allele is different

Phenotype & Genotype

Phenotype – An observable physical characteristics of an organism as determined by both genetic and environmental influences

Genotype – The genetic make-up of an organism as opposed to its physical characteristics

Mutation

A mutation is a permanent change in the DNA sequence of a gene

Cryptic Merle Mutation

A cryptic Merle is a dog that does NOT present with the overt Merle phenotype but does possess the Merle genotype. It has the potential to produce Merle offspring, but the mechanism by which this occurs is unknown

Alopecia

Hair loss

Cyclic Neutropenia

An abnormal condition in which the number of neutrophils in the bloodstream is decreased. Neutrophils are a type of white blood cell that defends the body against bacterial infection. Neutropenia affects the body's ability to fight off infections

Retrotransposon & SINE

SINE is a short interspersed element and are “jumping genes” that belong to the retrotransposon class of mobile genetic elements

These genes are capable of propagating in a host genome by a ‘copy and paste’ mechanism

Most SINE insertions occur within regions of the genome that have no functional significance

Occasionally they can insert into regions where they can interrupt a necessary gene as is the case for Merle