Ultra-Conserved Elements:
A study found that Ultra-Conserved Elements (UCEs) in the Tra2b (Transformer-2 beta) gene have remained unchanged for 80 million years due to their role in preventing infertility by regulating protein levels.
Key Findings of the Study on Ultra-Conserved Elements:
- Deleting the UCE in mouse testes caused excess Tra2β protein, sperm cell death, and infertility.
- A UCE in the Tra2b gene regulates Tra2β protein production by acting as a poison exon.
- When Tra2β protein levels are too high, the UCE triggers an extra exon in the gene’s RNA, introducing a stop codon that halts protein synthesis, preventing overproduction.
- Mutations disrupting UCE’s protein-limiting function cause infertility, preventing inheritance. Thus Natural selection has preserved UCEs across species for millions of years.
- UCEs are Deoxyribonucleic acid (DNA) sequences of at least 200 base-pairs that have remained completely unchanged across multiple species for 80 million years or more.
- These sequences are found in humans, mice, rats, chickens, and even fish, indicating their critical biological importance.
- Across the human genome (an entire set of DNA instructions found in a cell), there are nearly 500 UCEs.
- UCEs exhibit nearly identical DNA sequences across diverse species, even those that are evolutionarily distant.
- They do not usually code for proteins but are involved in gene regulation.
