| Popis: |
Organelle genomes are known to have large sizes and substantial non-coding content, despite conserved coding regions and low substitution rates. Notably, volvocine green algae exhibit significant variation in plastid genome size, with some species harboring ptDNA ten times larger than the average. To explain this variability, my thesis explores two hypotheses. The first proposes that genetic divergence accumulates due to weak negative selection and genetic drift, resulting in similar evolution rates for coding and non-coding regions. The second suggests high evolution rates in non-coding sequences are due to error-prone repair mechanisms. Analyzing new plastid genomes from volvocine green algae, I found a potential for high silent-site substitution rates in intergenic regions. My analysis shows that these hypotheses can be applied to plastid genomes of close relatives to advance our understanding of the mechanisms of sequence evolution specific to non-coding DNA accumulation within the volvocine green algae. |
