Behavioral Genetics 2 Summer 2016 Positions Available: Benson-Amram Zebra Finch Lab Goal: To investigate personality and problem-solving ability in individual and pairs of captive

zebra finches in Dr. Sarah Benson-Amram’s Animal Behavior & Cognition Lab.

Responsibilities:

x Assist with planning and carrying out behavioral experiments with zebra finches. x Help maintain routine husbandry. x Extract data from video-recorded experimental trials.

Qualities Required of Applicants:

x Interest in animal behavior and cognition x Dedication to the project. x Ability to work odd hours and be flexible with scheduling (this is not a typical 9-5 job!). x Ability to work well with others and independently. x Ability to maintain a positive attitude. x Organization skills and proficiency in use of Microsoft Office.

Benefits:

x Students can earn 1-2 credits for completion of summer work. x Successful volunteers will be encouraged to apply for an EPSCoR grant in the fall to

continue working with the Benson-Amram lab. x Successful volunteers can use this experience on their CV/resume and request letters of

recommendation in the future. x Hands-on research experience.

To be considered for this position, interested candidates must submit the following to

Lisa Barrett (Lbarret4@uwyo.edu) no later than* March 11th:

1) Cover letter or letter of interest 2) CV or Resume 3) 3 references (name and contact information)

*If you are ready to begin this position before Summer 2016, please let us know and we will get you started!

Experimental manipulation of gene function: knockout studies

• Knockout technique – Procedure that eliminates the expression of a gene

• single gene-effects

• insert a non-functional gene sequence, compare the resulting phenotype to the ‘wild-type’

fosB +

fosB -

Social environment and gene expression in birds

• Research question: What is the role of the FoxP2 gene in song development? (Haesler et al. 2007)

• Song system – Area of avian brain that

controls song production

Social environment and gene expression in birds

• Methods: – Zebra finches (Taeniopygia guttata) – Knockdown technique – used a virus to

insert short sections of RNA into FoxP2 gene to reduce its expression

– Controls had short sections of RNA placed in a noncoding region of DNA

– Adult male tutors and young juvenile males housed together

– Recorded songs

Social environment and gene expression in birds

Spectrogram: Allows researchers to characterize acoustic structure of vocalizations

Social environment and gene expression in birds

• Results: – Knockdown birds

had much lower FoxP2 expression than controls

Social environment and gene expression in birds

• Results: – Knockdown birds

tended to omit specific syllables in their songs

• Conclusion: – FoxP2 is required for

normal song development

Microarray Analysis

QTL mapping to identify genes associated with behavior

• Quantitative trait loci (QTL) – Stretches of DNA that either contain or are linked to genes

influencing a trait such as behavior • QTL mapping

– Statistical technique that combines genetic information with trait information to determine which regions of the genome contain the genes that influence the trait QTLs

• Candidate genes – Major genes suspected of contributing to a large amount of

the phenotypic variation in a specific trait

QTL mapping

• Use marker loci that are easily assayed, but causally unrelated to the trait in question to identify the approximate locations of the unknown alleles that affect the behavioral trait of interest

QTL mapping• Step 1: Select two parental strains that a) differ

considerably in their values of the trait of interest and b) differ at a set of marker alleles

Genes and Environment• Have focused on genetic influences on behavior. • However, variation in behavior among individuals

results from both variation in gene alleles and variation in environments.

• How can we characterize the effects of each? • We can quantify the relative contributions of

genetic and environmental variation to behavioral variation by thinking about heritability

Heritability (H2)• Indicates what proportion of the total variance in a trait is

due to variation in genes • Heritability can vary from 0.0-1.0 • H2=0: Phenotypic variation not due to genotypic variation • H2=1: All phenotypic variation due to genotypic variation

– H2 is a relative measure, so depends on the population under investigation

– If H2 is high, can be impetus for investigations to identify the responsible gene(s) &/or the mechanisms of trait expression

(Serrano & Tella 2007)

Heritability of colony size preference in the Lesser Kestrel

One way to determine heritability is to regress offspring phenotype with parental phenotype.

The slope of the regression line approximates heritability of trait (if avg. trait value of parents used).

H2 = 0.53

– Proportion of phenotypic variation in a population due to genetic variation

P

G

VVh =2

• a measure of how strongly a behavioral phenotype is influenced by genetic differences between individuals

Heritability (H2)Total genotypic variation: VG = VA + VD + VI

where

VA = Additive effects, or the average effect of individual alleles on the phenotype VD = Dominance effects, or the interaction between alleles at one locus VI = Epistasis, or the interaction between genes at different loci

Heritability (H2)

Total phenotypic variation: VP=VG+VE+VI

where:

VP= total phenotypic variation observed in a (behavioral) trait

VG= variation in population due to genotype

VE =variation in population due to environment

VI = variation in population due to interaction of VG with VE

Heritability (H2) Heritability (H2)

H2=VG/(VG+VE+VI)

where:

H2= heritability

VG= variation in population due to genotype

VE =variation in population due to environment

VI = variation in population due to interaction of VG with VE

• Gene-environment interaction (GEI) – When environment has greater effect on one

genotype than other

Rover and sitter foraging behavior in fruit flies

• Research question: Do different behavioral polymorphisms in fruit flies exhibit gene-environment interactions? (Kent et al. 2009)

Rover and sitter foraging behavior in fruit flies Rover and sitter foraging behavior in fruit flies

• Methods: – Exposed adult rover and

sitter phenotypes to different levels of food availability (fed or food deprived)

– Recorded movement from food patch

– Used mass spectroscopy to determine compounds stored in head

Rover and sitter foraging behavior in fruit flies

• Results: – Fed rovers had much

higher food-leaving scores than did food-deprived rovers

– No difference between fed and food-deprived sitters

Figure4.16.Adultroverandsitterfood-leavingbehavior.Mean(+SE)food-leavingscoreforfedandfood-deprivedflies.Notethedifferenceinthechangeinsitter(blue)androver(orange)food-leavingscoresbetweenfedandfood-deprivedflies(Source:Kentetal.2009).

Rover and sitter foraging behavior in fruit flies

• Results: – Rovers and sitters store

food differently • Conclusion:

– Gene-environment interactions affect both behavioral and metabolic traits

Development of Behavior Precocial young

Altricial young

The changes in behavior and its underlying mechanisms in individuals from conception to death.

Behavioral Development

The ontogenetic trajectory of a worker honey bee

This includes the behavior of individuals before they are born!

Waddington’s Epigenetic Landscape (1957) as a metaphor for development

Canalization:a particular developmental process may follow a fairly fixed path, resulting in similarity between individuals of the same species.

When a ball moves to the left or right, the slope brings it back on course. Similarly, regulatory mechanisms keep development on track.

Certain internal and external events can trigger development to change course. Different valleys represent the alternative phenotypic traits.

Differentiation

Genetic, physiological and ecological factors are crucial for an individual’s life-history.

Y chromosome

Royal jelly

Humans pass the same developmental milestones as they grow up.

- walk by 18 months - talk by 2 years of age

- reach sexual maturity before the late teen years

These features would be described by Waddington as ‘canalised’.

Spider’s web spinning

Rodent grooming

Some behavior patterns appear stable in a wide range of environments.

Infant smiling

But these behavioral features can still be modified by experience.

6

Blind babies start to smile at the same age as sighted babies.

But sighted people learn to modify their smiles according to their experience.

Blind people are less responsive and less expressive in facial expression, since they lack visual interaction.

Early social environment can affect behavioral development

– Eg., hatching synchrony (23-24 days) in bobwhite quail chicks can be facilitated by chick clicks

• clicks of more developed chicks hastened hatching date of less developed chicks

• clicks of less advanced chicks deferred hatching date of more developed chicks

Early social environment can affect behavioral development

– Female house mouse maturation & puberty ~35 days – if exposed to male urine or estrus female - earlier– if exposed to urine of group-caged females - later

Social development

What social problems confront an organism during its development?

1)Discriminating animate from inanimate objects 2)Identification & classification of prospective

social partners 3)Attainment of skills necessary for competition

& cooperation, establishing a social position Dispersers in social species must do this

twice! 4)Acquire skills associated with mating:

Identifying, finding, selecting, courting, and copulating

5)Develop parenting skills

early social environment can affect behavioral development

Harlow Experiments–Total Isolates:

–non-normal behavior as juveniles–As adults- inappropriate social, sexual and parenting

–Surrogate mothers: –More normal self-directed behavior–Non-normal social and parenting

–Peer groups: –More normal behavior than when reared with mom alone

Social deprivation: rhesus macaque studies

– required only 20 minutes/day of social contact!– Rehabilitation: 6 month old isolate w/3 month

old non-isolate

Ballen et al. 2014

Early social environment can affect behavioral development

– John Bowlby’s work on Attachment in Orphans from WWII

• often unable later to form any lasting, intense ‘love’ relationships

• Critical importance of the young child’s relationship to at least one specific & dependable adult caregiver responsive to child’s emotional and physical needs

• long-lasting emotional bonds that infants develop towards their primary caregiver

Imprinting• Experience in early life

affects later social and sexual preferences

Filial Imprinting

the process by which animals develop a social

attachment to a particular object

Filial imprinting•After hatching, chicks of many species approach & follow conspicuous objects to which they are exposed for a certain amount of time.

•Chicks will even form a social preference for inanimate objects.

•Chicks become distressed when the familiar object is removed.

Critical (“sensitive”) Periodfor Filial Imprinting

mallard ducklings

sensitive period *

* critical period

Colin Gregory