Julian Avila

UNDESTANDING

GENE FUNCTION - I

IN THIS SECTION:

INHERITANCE – MENDELIAN GENETICS

ARABIDOPSIS REPRODUCTION

SEGREGATION

Lusheng is trying to develop plants that express ERECTA with a c-terminal yellow fluorescent protein (YFP) tag and a membrane localization marker tagged with the protein mCherry. The purpose of these lines is to study the particular membrane compartment in which ERECTA is found. Lusheng has two lines that have been generated:- ERECTA-YFP in the er105 mutant background - mCherry in the wild type background

Lusheng decides he is going to cross these two lines in order to analyze the localization of ERECTA. How will the segregation work and how many plants will he have to screen in order to obtain a plant that has both ERECTA-YFP and mCHERRY in the er105 background?

THINK ABOUT THIS PROBLEM

WHAT DO YOU NEED TO KNOW THAT YOU DO NOT KNOW

ALREADY

Adapted from teaching tools: PLANT CELL, copy right American Society of Plant Biologists (ASPB)

“Even if he as a man was subsequently over-lionized by men with their own agendas, even if he was not in fact the heroic father of genetics he was made out to be, that should not diminish what Gregor Mendel truly was: a man with a vision, and the dedication to carry it to its brilliant, radical conclusion.”

GREGOR MENDEL

The Monk in the GardenThe Lost and Found Genius of Gregor Mendel, the Father of Genetics By ROBIN MARANTZ HENIG

135Mb

5,000Mb

149,000

Mb

135,000,000 149,000,000,000

The Arabidopsis genome is small

x

Pisum sativum

4,300Mb

x x

Yellow is dominantGreen is recessive

THE LAWS OF INHERITANCE

There are invisible factors that provide these traits

7 characters were studied

Adapted from teaching tools: PLANT CELL, copy right American Society of Plant Biologists (ASPB)

Deconstruct an organism into divisible masses of simple biological atoms called ''traits.'‘

Some traits are physicial. height, eye color, ear shape and such. Other traits were mental: intelligence, creativity, bravery, musical ability, idiocy. Mendelians offered rules and patterns for inheritance.

The Prince of Peas, August 27, 2000 The New York Times Book Reviews, Joe Cain

MENDEL’S WORK REVEALS THE LAWS OF INHERITANCE

Eugenicists pressed on, suggesting ways to sort these units in human groups by scientific breeding, sterilization and worse.The Prince of Peas, August 27, 2000 The New York Times Book Reviews, Joe Cain

Norman Borlaug 1914-2009

Pics by Jürgen Berger / Heiko Schoof, Electron Microscopy Unit, Max Planck 

InheritanceIn A. thaliana style

Let’s talk about pollination

Arabidopsis Reproductive Organs

Stigma

Style

Ovary

PISTIL STAMEN

Anther

Filament

Ovule

Embryo Sac

 Exp Bot October 1, 2002 vol. 53no. 377 2031-2038

Arabidopsis Gametes

Pics by Jürgen Berger / Heiko Schoof, Electron Microscopy Unit, Max Planck Pics by Jürgen Berger / Heiko Schoof, Electron Microscopy Unit, Max Planck 

Pagnussat et al. 2007

Pollination in Arabidopsis

Pics by Jürgen Berger / Heiko Schoof, Electron Microscopy Unit, Max Planck Pics by Jürgen Berger / Heiko Schoof, Electron Microscopy Unit, Max Planck 

Anja Geitmann, University of Montreal

Stigma

Style

Ovary

Ovule

Embryo Sac

2n 2n

Locus

The alleles for this locus are:

What is a locus?What is an allele?

2n Filial 1; F1

Yellow is dominant to green

Dominance

2n

WHAT HAPPENS IN THE F2?

Segregation

n

Filial 1; F1

X

Y y

Y YY Yy

y Yy yy

PHENOTYPE

GENOTYPE

2n

The wild type gene: LEAFY (LFY)The protein product: LEAFY (LFY)The mutant: leafy (lfy)Different mutant alleles: leafy-1, leafy-2 (lfy-1)Different genes with same symbol: LEAFY1, LEAFY2 (LFY1)

WILD TYPE leafy

NOMENCLATURE

The wild type gene: LEAFY (LFY)The protein product: LEAFY (LFY)The mutant: leafy (lfy)Different mutant alleles: leafy-1, leafy-2 (lfy-1)Different genes with same symbol: LEAFY1, LEAFY2 (LFY1)

WILD TYPE leafy

NOMENCLATURE

In the first page of the articles I am giving you, highlight all of these.

You are characterizing an important gene in your lab. Being a modest scientist you decide to name it after yourself. Fill in the blanks using the gene you named after yourself: The striking dominant phenotype of the _______ mutant was found to be caused by a 4 amino acid deletion in the coding sequence of _______. An in vitro analysis using purified _______ revealed that the removal of the 4 a.a missing in the _______ allele causes an increase in catalytic activity. A similar mutant allele ________ with a weak phenotype was found to carry a non-synonymous substitution in one of the 4 a.a. missing in ________.

wild type yourname

The wild type gene: LEAFY (LFY)

The protein product: LEAFY (LFY)

The mutant: leafy (lfy)

Different mutant alleles: leafy-1, leafy-2 (lfy-1)

Different genes with same symbol: LEAFY1, LEAFY2 (LFY1)

You are characterizing an important gene in your lab. Being a modest scientist you decide to name it after yourself. Fill in the blanks using the gene you named after yourself: The striking dominant phenotype of the _julian-1_ mutant was found to be caused by a 4 amino acid deletion in the coding sequence of _JULIAN__. An in vitro analysis using purified _JULIAN_ revealed that the removal of the 4 a.a missing in the _julian-1_ allele causes an increase in catalytic activity. A similar mutant allele __julian-2_ with a weak phenotype was found to carry a non-synonymous substitution in one of the 4 a.a. missing in _JULIAN_.

wild type yourname

The wild type gene: LEAFY (LFY)

The protein product: LEAFY (LFY)

The mutant: leafy (lfy)

Different mutant alleles: leafy-1, leafy-2 (lfy-1)

Different genes with same symbol: LEAFY1, LEAFY2 (LFY1)

Lusheng is trying to develop plants that express ERECTA with a c-terminal yellow fluorescent protein (YFP) tag and a membrane localization marker tagged with the protein mCherry. The purpose of these lines is to study the particular membrane compartment in which ERECTA is found. Lusheng has two lines that have been generated:- Line 1: ERECTA-YFP (LOCUS 1) in the er105

(LOCUS 2) mutant background - Line 2: mCherry (LOCUS 3) in the wild type

background.

Lusheng decides he is going to cross these two lines in order to analyze the localization of ERECTA. How will the segregation work and how many plants will he have to screen in order to obtain a plant that has both ERECTA-YFP and mCHERRY in the er105 background?

Line 1 Line 2What is the genotype of the plants to be crossed?

Lusheng is trying to develop plants that express ERECTA with a c-terminal yellow fluorescent protein (YFP) tag and a membrane localization marker tagged with the protein mCherry. The purpose of these lines is to study the particular membrane compartment in which ERECTA is found. Lusheng has two lines that have been generated:- Line 1: ERECTA-YFP (LOCUS 1) in the er105

(LOCUS 2) mutant background - Line 2: mCherry (LOCUS 3) in the wild type

background.

Lusheng decides he is going to cross these two lines in order to analyze the localization of ERECTA. How will the segregation work and how many plants will he have to screen in order to obtain a plant that has both ERECTA-YFP and mCHERRY in the er105 background?

Line 1 Line 2What is the genotype of the plants to be crossed?

er105 ER

Lusheng is trying to develop plants that express ERECTA with a c-terminal yellow fluorescent protein (YFP) tag and a membrane localization marker tagged with the protein mCherry. The purpose of these lines is to study the particular membrane compartment in which ERECTA is found. Lusheng has two lines that have been generated:- Line 1: ERECTA-YFP (LOCUS 1) in the er105

(LOCUS 2) mutant background - Line 2: mCherry (LOCUS 3) in the wild type

background.

Lusheng decides he is going to cross these two lines in order to analyze the localization of ERECTA. How will the segregation work and how many plants will he have to screen in order to obtain a plant that has both ERECTA-YFP and mCHERRY in the er105 background?

Line 1 Line 2What is the genotype of the plants to be crossed?

er105