Methods for determining gene function

Study the effects of disrupting gene function (ap3 mutants)

Examine the expression of the gene (GUS, In situ)

Methods for examining the expression of a gene

Reporter construct (AP1::GUS)

Pros: Easy, sensitive, can be used to define promoter region.

Cons: Indirect, only tells you where the promoter sequences you’ve selected express the fused GUS reporter. This does not necessarily correspond to the actual expression pattern of the gene of interest. It also requires transgenic plants.

In Situ Hybridization

Molecular technique that allows one to detect localization of mRNA in a tissue

Pros:

-Represents the best estimate of the actual expression pattern of a gene

-Does not require the production of transgenic plants

Cons:

-Can be technically challenging

-The expression of some genes is difficult to detect

-Cannot be used to determine promoter region

An example of AGAMOUS expression the an inflorescence

SEEDSTICK::GUS is expressed in carpels

SEEDSTICK::GUS is expressed in ovules

AP1 RNA is expressed in flower meristems

FM SAM FM

AP1::GUS is expressed in flower meristems

AG RNA is expressed in cells that will form stamens and carpels

petal

sepalcarpel

leaf

sepalstamen

FUL::GUS is expressed in valves

FRUITFULL RNA accumulates in valves

valve

FRUITFULL RNA accumulates in valves

valvereplum

IND::GUS is positively regulated by SHATTERPROOF

wild type shatterproof

replum valve