Dog and cat behaviour

Behavior Genetics and Selection in Dogs and Cats

Introduction

• The transcript discusses the topic of behavior genetics and selection in domesticated animals, specifically dogs and cats.

Key Concepts in Behavior Genetics

• Temperament and Domestication
    - Temperament plays a critical role in the process of domestication of animals.
    - Animals selected for domestication are chosen based on their tolerance of humans and heritable behavioral traits, which remain significant in domestic species.

Types of Behaviors

Learned vs. Innate Behaviors

• Innate Behaviors
    - Characterized by acting instinctively or being “hard wired.”
    - These behaviors do not change in response to environmental conditions.
    - They are likely inherited through a single gene.
      - Examples:
        - Migration
        - Foraging

• Learned Behaviors
    - Adapt in response to changes in the environment.
    - These behaviors are acquired through experience, observation, and repetition.
    - While the ability to learn is inheritable, the traits are likely multifactorial.
      - Examples:
        - Habituation
        - Individuals inherit specific neuronal pathways, learning to integrate these into more complex behaviors.

Maternal Behavior

• Maternal behavior is predominantly innate and encompasses several critical actions:
    - Recognition of Young
      - Acceptance of foster young.
    - Care of Young
      - Cleaning off newborns.
      - Nudging newborns to suckle at a teat.
      - Protecting young from potential predators.
      - Not lying on piglets and pups.

Classic Behavior and Genetic Studies

• Notable studies have shown that genetic factors influence various behavioral traits in domestic animals.
    - Dogs: Scott & Fuller research from the 1950s indicates that dogs exhibit genetic influences on behavior.
    - Vocalization: Distinction noted that wolves rarely bark compared to domestic dogs.
    - Humans: Studies on identical twins raised together and apart contribute to the nature vs. nurture debate.
    - Rodents: Example studies involved maze running or pressing levers for food.
    - Chickens: Important behaviors like dust bathing are measured as indicators of welfare and comfort.

Working Dogs

• Various roles dogs play based on their selection for behavioral traits:
    - Categories:
      - Herding
      - Hunting
      - Livestock guardian
      - Guard dog
      - Service animal

Traits for Selection in Dogs

• The following traits are significant in selecting dogs for specific tasks:
    - Temperament
    - Trainability
      - Showing eagerness to please and motivation from rewards (food, praise).
    - Intelligence
    - Stamina and Drive

Single Gene Traits in Dogs

• Examples of behaviors linked to single gene traits include:
    - Loud trailing in Beagles
    - Dish carrying behavior
    - Soft bite greeting behavior
    - Barking tendency
    - “Splooting” behavior

Development of Behavior in Dogs

• 7 Weeks: Neurological development reaches completion.

• 7-14 Weeks: Key socialization period occurs, with the most critical window being 8-12 weeks.
    - Develop social bonds and explore their environment, with an emphasis on resilience during the “bounce back” period.

Selection of Dog Behavior

• Two types of behavioral selections:
    - Active Defense vs. Passive Defense
      - Active defense includes responses like biting or chasing.
      - Passive defense includes freezing behaviors.
      - Different roles include guard dogs versus herding dogs.
      - Example: Bison displaying a charge behavior versus muskox which stand and defend.

Dominance and Social Structures

• Dominant vs. Submissive Behaviors
    - Indicators of leadership within a herd are notable.
      - The dominant cow typically leads the herd, which can be observed in herds of cattle.

Independence vs. Social Attraction

• Dogs and cats exhibit varying levels of independence:
    - Cats are typically solitary hunters.
    - Dogs are either working/kennel dogs versus companion/house dogs.
      - Examples:
        - Sight hounds may be seen as aloof.
        - Poodles often display clinginess, earning the nickname “velcro dog.”

Sound Sensitivity in Animals

• Differences between sound-sensitive coyotes and hunting dogs highlight behavioral variations in response to auditory stimuli.

Breeding Stock Selection for Behavior

• Early identification of behavioral traits allows for reduced environmental impact on phenotype, showcasing the extent of genetic contributions among behavioral traits.

Selection in Dogs and Cats

• Breeding practices are discussed in the selection for specific behavioral traits.

Specific Breeds and Traits

• Dwarf Dog Breeds:
    - Descendents exhibit shortened limbs while maintaining normal torso and head proportions.
    - These breeds are more prone to intervertebral disc degeneration (IVDD).
    - The trait is linked to the FGF4 retrogene and is recessive.
    - Examples include Basset Hound and Corgi breeds.

• Munchkin Cats:
    - Exhibit achondroplastic dwarfism as an autosomal dominant trait, where homozygosity leads to lethality.
    - Associated with deletion of UGDH (UDP-glucose 6 dehydrogenase), putting them at risk for osteoarthritis and congenital defects such as lordosis and pectus excavatum.
    - Reference: Mattioli et al., 2022.

• Brachycephalic Breeds:
    - Selection for shortened skull shapes is indicated as a polygenic trait, involving multiple genes.
    - Common health issues include impaired breathing due to brachycephalic obstructive airway syndrome (BOAS), characterized by elongated soft palate, hypoplastic trachea, and stenotic nares.
    - References: VetSurg, Vetcetera, Purina.

Coat Color Genetics

• E locus (MC1R): Determines black/brown vs. red/yellow coat colors.

• K locus: Influences the solid vs. agouti color patterns.

• A locus (agouti) and B locus (TYRP1): Changes black to brown pigmentation.

• D locus (dilute): Results in blue and cream coat colors.

White Coat Color in Dogs

• MITF plays a role in determining white coat coloration and white spotting.

• PMEL: Associated with double merle traits resulting in health issues like deafness and microphthalmia.

• Albinism: Results from variations in the SLC45A2 gene.

White Coat Color in Cats

• KIT: Dominant white trait leading to white coloration and white spotting, with blue-eyed white cats frequently exhibiting deafness.

• Tyrosinase (TYR): Linked with albinism in cats.

Coat Length Genetics

• Short coat length is a dominant trait over long coat length, influenced by an FGF5 mutation.

• Some breeds like the Dachshund can exhibit multiple coat lengths: smooth, long, and wirehair.
   

Coat Texture Genetics

• Wirehair Coat:
    - Autosomal dominant trait associated with mutations in RSPO2 within the 3'-UTR.

• Curly Coat:
    - Also an autosomal dominant trait associated with KRT71 mutation, notable in curly coated retrievers.

• Corded Coat: Observed in breeds like the Komondor.

Coat Texture in Cats

• Different mutations of the KRT71 gene result in various coat textures in cats:
    - Selkirk Rex: Dominant mutation.
    - Devon Rex: Recessive mutation.
    - Sphynx: Recessive mutation resulting in hairlessness.
    - Cornish Rex: Recessive mutation linked to LPAR6.