Targeting chromosome trisomy for chromosome editing.

Area of Science:

• Cell Biology
• Genetics
• Genomics

Background:

• Aneuploidy, specifically trisomy, involves an extra chromosome.
• Trisomic chromosomes may offer unique opportunities for genetic manipulation due to their non-essential nature for cell proliferation.

Purpose of the Study:

• To investigate the feasibility of manipulating trisomic chromosomes in chicken DT40 cells.
• To explore the potential of trisomic chromosomes as a basis for creating artificial chromosomes.

Main Methods:

• Correction of chromosome 2 trisomy to disomy using counter-selection markers.
• Large-scale truncation of chromosome 2 to generate mini-chromosomes by introducing telomere repeat sequences.
• Assessment of mini-chromosome stability and the impact of DDX11 depletion on chromosome loss.

Main Results:

• Correction of trisomy had minimal impact on cell proliferation, suggesting the dispensability of the extra chromosome 2.
• Generated mini-chromosomes (0.7 Mb) exhibited a low rate of loss (0.2% per cell division) in wild-type cells.
• Depletion of DDX11 significantly increased the rate of mini-chromosome loss, highlighting the role of cohesin regulation.

Conclusions:

• Trisomic chromosomes are viable targets for genetic engineering and the creation of artificial chromosomes.
• The DT40 cell line provides a suitable model for studying chromosome stability and manipulation.