BIOL 160 Lecture 3

What is the central dogma?

• a region of genes of DNA that codes for a protein

• It is transcribes (copied into mRNA)

• then translated to a polypeptide/ amino acid

Does Genotype and Envionremnt affect behavior?

• Since genotype is inherited from parents, this will not change throughout their lifetime

• Members of the same species share the same genes and are shared between distantly related species

• There is lots of variation of DNA sequence of most genes

Taking into account the environment, the development, social, and abiotic environments are all influences by the expression of genotype (working together)

For example in lecture what is the behavioral development in honey bees?

Bees will experience behavioral changes in workers. Making stark differences of queens vs. workers.

Ex. Worker: Sterile diploid female

Queen: reproductive diploid female

Drone: fertile haploid male

What is ontogeny?

The development of an organisms from an early stage on (young to old)

For example when understanding the behavioral development in honey bees:

There was an association between change in behavior change in gene expression regardless of age. (Looking at the brains of nurses vs. foragers)

Looking at components in lifestyle of bees:

Royal jelly determines whether a larva will develop as a worker or queen.

• Workers secrete royal jelly and feed it to larvae, all larvae get some but future queens are fed ONLY royal jelly

What is epigenetic modifications:

• Alters the accessibility of DNA for proteins to be involved in transcription w/o changing DNA sequence:

  • removing methyl groups to DNA

  • Chemical modifications to histone tails

  • Small non-coding RNAs

• Stable throughout lifetime

• Transmitted across generations

• Changes in response to environment

What is an example of an epigenetic modifications?

proteins in royal jelly alters the expression of hundreds of genes

What is an example of researching an epigenetic modifications?

Proving the whether or not the proteins in royal jelly alter gene expression by regulating DNA methylation levels throughout the genome.

• Observing the silence expression of Dnmt3 the gene responsible for adding methyl groups

What should be observed when examining the modifications in the bee example?

• Looking at the silent expression

• Being fed the typical amount of royal jelly

• Count the groups

• And phenotypes

Continue wit bee example and the burrow & birds

What is the Evo-Devo approach to behavior?

• Forward Genetics

• Reverse Genetics

What does forward genetics mean?

starts with a phenotype and identifying the gene or genes responsible

What does reverse genetics mean?

It starts with the gene and finding the related phenotype

• What are 2 types of ways to observe/determine how early life conditions affect fitness later in life?

• Developmental Constraint Hypothesis

  • Low quality environment reduce fitness later in life?

• Predictive Adaptive Response Hypothesis

  • Environment cues during development adjust to an individual’s phenotype later in life?

Go over the hypothesis findings and clues etc.

What is phenotypic plasticity?

the capacity for one genotype to produce more than one phenotype, depending on environmental cues

What does broadly variable phenotype mean?

• Lots of variation around a single mean

  • May or may not be phenotypic plasticity

What is a highly catalyzed phenotype?

• A minimal variation around a single mean

  • Where there’s no phenotypic plasticity

• What is polyphenism?

• a discontinuous variation with two or more means

  • Special case of plasticity

What is density dependent polyphenism?

Social and feeding polyphenism in locusts

• Crowding causes neuro signals, changes gene expression, hormonal release and causes behavioral changes, coloration changes, and muscle and skeletal changes

  • Basically makes the fly more erratically and aggressive behavior

What is a food-induced polyphenism?

What is a socially-induced polyphenism?

What is a predator-induced polyphenis?

What is behavioral polymorprism?

The loss of the ability to plastically regulate behavioral roles according to environmental conditions (often controlled by supergenes)

What are supergenes?

A region of DNA, that contains many genes that influence a trait (like behavioral phenotype)

Look over the example of the birds, and snakes etc.