2009 Fiscal Year Final Research Report
Genome Diversity in Primates and Evolution of Their Reiterated Sequences
| Project/Area Number |
17018006
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
| Allocation Type | Single-year Grants |
|---|
| Review Section |
Biological Sciences
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
UEDA Shintaroh The University of Tokyo, 大学院・理学系研究科, 教授 (20143357)
|
|---|
| Project Period (FY) |
2005 – 2009
|
| Keywords | ゲノム / 遺伝子 / 進化 / 人類学 / 神経科学 / アミノ酸リピート / 反復配列 |
|---|
| Research Abstract |
Human spinocerebellar ataxia type 10 is caused by ATTCT expansion in the ATXN10 gene. We found LINE-1 was inserted into ATXN10 intron; Alu was then inserted in the LINE-1; and endogenous retrovilcus K was lastly retrotransposed in the Alu. The ATTCT repeat was located on the 3'-end of the Alu. Using 33 primate species, we revealed that nucleotide substitutions in a poly(A) tail of the Alu element and the following amplification of pentanucleotides occurred in the lineages of catarrhines and that ATTCT repeats originated in the common ancestor of hominoids. Hoxd-13 has taxon-specific polyalanine tracts in amniotes. We replaced the wild-type Hoxd-13 gene with one lacking the 15-residue polyalanine tract. Sesamoid bone formation in knock-in mice was different from that in the wild type. The present study provides the first direct evidence that taxon-specific homopolymeric amino acid repeats are involved in phenotypic diversification at the organismal level. Homopolymeric amino acid repeats are tandem repeats of single amino acids, and are considered to be structurally/intrinsically disordered. We found a number of the repeats predicted to have nondisordered structure and substitution rates showed a higher Ka/Ks ratio for the genes with not disordered repeats than the genes with disordered repeats, showing elevated amino acid substitution rates in genes with nondisordered repeats.
|
