Transcript Slide 1

Zebra Corn
By Andrew Greenwood, Martha Swenson, and Julia Kunberger
School of Arts & Sciences
zb4_AG_JJK_MS, 1-13-05
zebra crossbands4 (zb4), AG, JJK, MS, 1-13-05
About Our
Project
Throughout the semester,
we have been studying
mutant corn. We decided to
study zebra Crossbands4
(zb4), a mutant known for its
exotic stripes. This is our
project.
Slender, so slender
Its stalk bends under dew—
Little yellow ear
zb4_AG_JJK_MS, 1-13-05
-A Zen Poet
What is Wrong?
Our mutant is called “Zebra” because of it’s zebra-like stripes on the leaves.
The mutation is called zebra crossbands4 (zb4).
The mutation has a recessive mode of inheritance.
The zb4 gene has not yet been cloned.
What causes these stripes?
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What causes these stripes?
There are many different theories on what causes the zebra-like stripes
on the leaves. Scientists have not yet discovered the exact cause for the
stripes. We have some simple theories based on our knowledge.
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Genotype & Phenotype Chart
Genotype
of individual
ZZ
Zz
zZ
zz
Relationship of the pairs of alleles* Phenotype
of individual
Homozygous
Dominant
Normal leaves
2 Dominant alleles
(wild-type)
Heterozygous
Normal leaves
1 Dominant allele
1 recessive allele
(wild-type, carrier)
Homozygous
recessive
Striped leaves
2 recessive alleles
(mutant)
zb4_AG_JJK_MS,
1-13-05
* Alleles = different forms
of the same gene
Diagram
Young Leaf
Barely striped
Middle-Aged Leaf
Light stripes (developing)
Old Leaf
Vibrant yellow & green stripes
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Growth Chart
Date
9/10
9/24
Height Width Mean H
30 mm
Color
1 mm 48.7 mm Pale green.
Very small and weak.
124 mm 15 mm 150 mm Red at base. Light green.
NOT ZEBRA! Some leaves
have dead patches.
The
of inheritance
10/11mode
198 mm
10 mm 190 mm for
Yellow,zb4
brown,is
andrecessive
green. Stems: purple.
Starting to shrivel turn brown.
Starting to die!
Stopped growing and started dying.
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Discoverer and References
(1932) HK Hayes. Zebra Crossbands.
Journal of Heredity. Volume 23, pages 415-419.
(1938) HK Hayes. Zebra Seedling, zb4, has been located in chromosome 1.
Maize Newsletter. Volume 12, page 1.
(1939) HK Hayes. Recent Linkage studies in maize. III. Zebra Seedling-4.
Genetics. Volume 24, page 60-61.
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The End
zb4_AG_JJK_MS, 1-13-05