regarding the gradual loss of marker from a balancer stock.

[Sayali Rohokale]

hello sir, 

I have a third chromosome balancer stock as - Sb/TM6B ie stubble over tubby.

but over time the stubble is been lost. so I enriched the stubble positive flies but then again after 2-3 generations again stubble is not there in the flies. what would you suggest I do to recover the Sb/TM6B stock ?

[Deepti Trivedi Vyas]

Hi Sayali,

Yes we all see these problems of losing Sb or Ser from TM3 balancers. Here is a paper that might help you to understand the 3rd chromosome balancers better: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4938649/

However practically, all you can only do what you are doing. Keep rebalancing whenever the balancer breaks.  2-3 generations is too fast though according to our experience. Maybe we can send you our third chromosome balancer and you can see if it fares any better.

Best wishes

Deepti