Peking University ShenZhen Graduate School
The Origination of New genes
Speaker: Xudong Zou
Time: 17th April, 2014
1
Outline
Background
Molecular mechanisms
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



Exon shuffling
Gene duplication
Lateral gene transfer
Gene fusion/fission
De novo gene origination
Summary
2
Outline
Background
Molecular mechanisms





Exon shuffling
Gene duplication
Lateral gene transfer
Gene fusion/fission
De novo gene origination
Summary
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The legend of Jingwei
In an ancient Chinese legend, the
first Chinese emperor Yande
(3,000 BC) brother to the YellowEmperor, had a
pretty princess named Jingwei.
Like other legendary southern Chinese goddesses, Jingwei liked to swim. Unfortunately, she
drowned in the East China Sea. She was reincarnated into a beautiful bird, who, to save others
from possible tragedy, carried soil and stones in an attempt to fill in the ocean.
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Manyuan Long and the Jingwei gene
Manyuan Long
Department of Ecology & Evolution
Biological Sciences Collegiate Division
University of Chicago
Jingwei
The first young gene described in the early 1990s. It is a
very young gene that if we set 1 million years as an age
unit, the common old genes are often 1000~3000 years
old, while Jingwei is 2 years old.
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1950s-In 1953, DNA double helix
In 1966, Richard Lewontin and Huby found
that natural selection can’t explain
molecular evolution
In 1968, Motoo Kimura introducing neutral
theory of molecular evolution
1990s-In 1993, Manyuan Long described the Jingwei
gene, open a new field to study the origination
and evolution of new genes
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In 1990, Manyuan Long joined Langley’s lab and
investigated degree of fitness of neutral theory
on DNA.
CHARLES H. LANGLEY
Michael Ashburner told that gene Adh of D.
melanogaster was a pseudogene.
Long found that almost all of the mutation occur
at the third site of a codon. Means it may be a
real gene rather than a pseudogene.
Long confirmed the complex processes of the
origination of this gene and named it Jingwei.
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Outline
Background
Molecular mechanisms





Exon shuffling
Gene duplication
Lateral gene transfer
Gene fusion/fission
De novo gene origination
Summary
8
Exon shuffling
Two or more exons from different genes can be brought together ectopically, often
mediated by transposons, or the same exons can be duplicated to create new exonintron structure.
Transposon:
 Long interspersed element(LINE)
 Helitron
 Long-terminal repeat retrotransposons
Examples:
fucosyltransferase, jingwei, Tre2
Long MY, et al. Nat Rev Gent. 2003
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Exon shuffling
Origination of jingwei from the
following two genes:
 Yellow-emperor
 Adh: a pseudogene
Sphinx structure
Long MY, Science. 1993
Long MY, et al. Nat Rev Gent. 2003
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Gene duplication
This classical model creates a duplicate gene that can evolve new functions, whereas
the ancestral copy maintain its original functions.
New duplicated genes under positive
selection and evolve new functions
Examples:
CGβ, Cid, RNASE1B
Gene duplication may be three variable
tpyes: Complete gene duplication,
partial gene duplication and dispersed
gene duplication.
Long MY, et al. Nat Rev Gent. 2003
Cardoso-Moreira M and Long MY. 2004
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Gene duplication
 RNASE1 and RNASE1B were generated
by recent duplication from other old
world monkey.
 RNASE1 has not changed since
duplication, while RNASE1B
accumulated many substitutions.
 The ability to digesting double-strand
RNA of RNASE1, lost in RNASE1B
Zhang J, et al. Nature Genet. 2002
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Lateral gene transfer
Lateral gene transfer is the gene tranferred between different organisms. Often in
Prokaryotes, rare in eukaryotes.
Examples:
acytylneuraminate lysase, Escherichia coli, mutU and mutS
Long MY, et al. Nat Rev Gent. 2003
Cardoso-Moreira M and Long MY. 2004
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Gene fusion/fission
Two adjacent genes can fuse into a single gene or a single gene can split into two
single genes by mutations on stop codon or initial codon.
Examples:
Fatty-acid synthesis enzymes,
Kua-UEV, Sdic
Long MY, et al. Nat Rev Gent. 2003
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De novo origination
De novo genes refer to events, where a coding region originates from a previously
non-coding region.
Examples:
AFGPs, BC1RNA, BC200RNA
Long MY, et al. Nat Rev Gent. 2003
Cardoso-Moreira M and Long MY. 2004
15
Outline
Background
Molecular mechanisms





Exon shuffling
Gene duplication
Lateral gene transfer
Gene fusion/fission
De novo gene origination
Summary
16
Long MY, et al. Nat Rev Gent. 2003
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