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The Origination of New genesSpeaker: Xudong ZouTime: 17th April, 2014Peking University ShenZhen Graduate School1OutlineBackground

Molecular mechanismsExon shufflingGene duplicationLateral gene transferGene fusion/fissionDe novo gene origination

Summary2OutlineBackground

Molecular mechanismsExon shufflingGene duplicationLateral gene transferGene fusion/fissionDe novo gene origination

Summary3

In an ancient Chinese legend, the first Chinese emperor Yande (3,000 BC) brother to the Yellow-Emperor, had apretty 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.

The legend of Jingwei4Manyuan Long and the Jingwei gene

Manyuan LongDepartment of Ecology & EvolutionBiological Sciences Collegiate DivisionUniversity of ChicagoJingweiThe 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.51950s--

In 1953, DNA double helix

In 1966, Richard Lewontin and Huby found that natural selection cant 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 genes6LewontinHubby 10%6

CHARLES H. LANGLEYIn 1990, Manyuan Long joined Langleys lab and investigated degree of fitness of neutral theory on DNA.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.7Ashburner7OutlineBackground

Molecular mechanismsExon shufflingGene duplicationLateral gene transferGene fusion/fissionDe novo gene origination

Summary8Exon 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 exon-intron structure.Long interspersed element(LINE)HelitronLong-terminal repeat retrotransposonsExamples:fucosyltransferase, jingwei, Tre2Transposon:9Long MY, et al. Nat Rev Gent. 2003Exon shuffling

Yellow-emperorAdh: a pseudogeneOrigination of jingwei from the following two genes:

Sphinx structure10Long MY, Science. 1993Long MY, et al. Nat Rev Gent. 2003Gene duplicationThis classical model creates a duplicate gene that can evolve new functions, whereas the ancestral copy maintain its original functions.Examples:CG, Cid, RNASE1B

New duplicated genes under positive selection and evolve new functionsGene duplication may be three variable tpyes: Complete gene duplication, partial gene duplication and dispersed gene duplication.11Long MY, et al. Nat Rev Gent. 2003Cardoso-Moreira M and Long MY. 2004Gene 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 RNASE1B12Zhang J, et al. Nature Genet. 2002RNASE1old world RNA12Lateral gene transferExamples:acytylneuraminate lysase, Escherichia coli, mutU and mutS

Lateral gene transfer is the gene tranferred between different organisms. Often in Prokaryotes, rare in eukaryotes.13Long MY, et al. Nat Rev Gent. 2003Cardoso-Moreira M and Long MY. 2004Gene fusion/fissionExamples:Fatty-acid synthesis enzymes,Kua-UEV, SdicTwo 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.

14Long MY, et al. Nat Rev Gent. 2003De novo originationExamples:AFGPs, BC1RNA, BC200RNADe novo genes refer to events, where a coding region originates from a previously non-coding region.

15Long MY, et al. Nat Rev Gent. 2003Cardoso-Moreira M and Long MY. 2004OutlineBackground

Molecular mechanismsExon shufflingGene duplicationLateral gene transferGene fusion/fissionDe novo gene origination

Summary16

17Long MY, et al. Nat Rev Gent. 2003