Related Experiment Videos
SVA elements: a hominid-specific retroposon family
Hui Wang1, Jinchuan Xing, Deepak Grover
1Department of Biological Sciences, Biological Computation and Visualization Center, Center for BioModular Multi-Scale Systems, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, USA.
Journal of Molecular Biology
|November 18, 2005
Summary
SVA elements, composed of SINE, VNTR, and Alu, are the youngest retroposons in primates. Analysis revealed six subfamilies, with some predating human-chimpanzee divergence and others unique to the human lineage, contributing to genomic diversity.
Area of Science:
- Genomics
- Molecular Evolution
- Human Genetics
Background:
- SVA elements are composite repetitive DNA sequences in the human genome.
- Understanding their origin and evolution is key to comprehending primate genome dynamics.
Purpose of the Study:
- To identify and characterize SVA elements in the human genome.
- To analyze the phylogenetic relationships, genomic distribution, and age of SVA subfamilies.
- To investigate the contribution of SVA elements to human genomic diversity and primate evolution.
Main Methods:
- Identification of 2762 SVA elements in the human genome draft sequence.
- Phylogenetic analysis to define six SVA subfamilies (SVA_A to SVA_F).
- Nucleotide divergence analysis for subfamily age estimation.
- Survey of human genomic diversity for SVA insertion polymorphisms.
- Examination of SVA amplification dynamics across the primate order.
Main Results:
- SVA elements are enriched in G+C-rich genomic regions.
- Four subfamilies (SVA_A-D) expanded before human-ape divergence; two (SVA_E-F) are human-specific.
- SVA_E and SVA_F exhibit significant insertion polymorphism frequencies (37.5% and 27.6%).
- SVA elements originated 18-25 million years ago, marking them as the youngest primate retroposon family.
Conclusions:
- SVA elements represent a recently evolved and active retroposon family in primates.
- The differential expansion and human-specific proliferation of SVA subfamilies contribute significantly to primate and human genomic variation.
- SVA elements provide insights into recent evolutionary events in the hominid lineage.