Model organisms for studying development (lecture 21)

Question 1

what is developmental biology?

Answer 1

the study of the process by which organisms grow and develop

focuses on growth, differentiation and morphogenesis

important for understanding congenital malformations

Question 2

what is morphogenesis?

Answer 2

the creation of shape

Question 3

what is development?

Answer 3

the period between fertilisation and birth

developing organism is known as an embryo

Question 4

what are the 3 general approaches to studying development?

Answer 4

anatomical

experimental manipulation

genetic

Question 5

anatomical approach to studying development

Answer 5

what things look like as they develop
the oldest approach

what parts of the embryo form what?
how do the cells position themselves?
how does this relate to this?

Question 6

anatomical manipulation approach to studying development

Answer 6

what happens if you interfere with developing structures

what happens if you remove a specific region?
how do drugs affect development?
what happens if you transplant it to a new site?

Question 7

genetic approach to studying development

Answer 7

how genes control development

how do specific genes give instructions for complex form?
how do sets of genes integrate their instructions?
do mutations explain congenital malformations?

Question 8

what is a model organism?

Answer 8

a well-established experimental biological system

Question 9

why are drosophila (fruit flys) useful?

Answer 9

genetics

• most genes have homologues in mammals
• many mutants available
• short life cycles
• large easily accessed larvae
• allowed us to understand the basic gene networks that regulate the early body plan

Question 10

why are zebrafish useful?

Answer 10

genetic and manipulation

• more genetically similar to man than fly
• fundamental developmental processes similar
• easy to genetically manipulate eggs
• capable of regenerating many body parts
• are transparent as embryos
• relatively cheap

Question 11

why are newts and xenopus useful?

Answer 11

manipulation

• large embryos can be easily manipulated
• more similar anatomically
• capable of regenerating many body parts

not as popular anymore as
• have a longer life cycle
• expensive to keep

Question 12

why are chickens and quails useful?

Answer 12

manipulation and anatomical

• large accessible eggs
• easy to manipulate and image
• anatomically similar to humans
• complex genetics

Question 13

why are mice useful?

Answer 13

genetics and anatomy

• anatomically similar to humans
• large number of mutants available
• can manipulate genome
• rapid life cycle

issues
• difficult to physically manipulate as develop in utero
• affordable but expensive to look after
• more ethical issues

Question 14

why can man not be used as a model organism?

Answer 14

cannot genetically manipulate as ethical issues

human genetics very complex

limited access to human embryos

Question 15

what genetic tools are available to us?

Answer 15

• morpholinos
• chemical mutagenesis
• transgenesis (transient and germline)
• single gene knockouts and knockins
• condition gene knockouts
• CRISPR

Question 16

why do we need animal models?

Answer 16

• can’t experiment on humans
• can’t model disease processes in cell culture
• canniest toxicity of new drugs or disease treatments in cell culture
• cant model development or ageing in cell culture

Question 17

what are human organoids?

Answer 17

self-organised 3D cell cultures
derived from stem cells
recapitulate early stages of development in a dish

have been created for many organs 
• eye 
• brain 
• intestine 
• kidney 
• liver

Question 18

potentials of organoids?

Answer 18

drug testing
test drug safety
transplantation
disease modelling

Question 19

what makes a good model organism for developmental genetics?

Answer 19

genome sequenced 
anatomically resembles human 
rapid rate of development to maturity 
large numbers of offspring per generation 
easily manipulated 
readily available