PSLV: the focus of attention.

• Published in 1973, Dobzhansky’s essay titled ‘Nothing in biology makes sense except in the light of evolution’.

• The essay was engraved in the Jordan Hall of Science at the University of Notre Dame.

A-to-I RNA Editing in Animals and Fungi

• A-to-I mRNA editing is a process where cells transcribe a recipe to make a protein from a gene in the DNA to an mRNA.

• The mRNA is then moved from the nucleus to the ribosome, where it is “read” to make the protein.

• The ribosome reads the mRNA to make the protein, it reads inosine as though it was guanine, leading to A-to-I mRNA editing.

Case Study: Fusarium graminearum

• When F. graminearum grows on an infected plant, its cells don’t do any mRNA editing.

• When the fungus enters its sexual stage, over 26,000 sites transcribed from its DNA into mRNA undergo A-to-I mRNA editing.

• The study focused on 71 F. graminearum genes whose coding sequence was interrupted by a UAG stop codon that the ADAR proteins scrambled.

• The study found that A-to-I mRNA editing was essential for the proper function of the PSC genes during sexual development.

The Future of A-to-I mRNA Editing

• Over time, the genes that benefit from A-to-I mRNA editing may increase and mRNA editing by ADARs will become an essential component of the gene-expression pathway.

• More G-to-A mutations may begin to accumulate in the genome, sheltered by the ADAR-based editing machinery.