# What is the relatedness of sisters in a haplodiploid system if you mate virgin queens with 1 of their sons

So I'm having trouble wrapping my head around this. In haplodiploid insects, sisters are related by 75% on average due to all sharing 100% of dad's genetics and 1/2 of mom's. (males are produced from haploid eggs)

The question I have is, if you take a son of a queen and mate her with her own son, what is the genetic relatedness of her resulting daughters to one another?

Here is an illustration of the haplodiploid system in insects.

Thanks in advance!

• Apr 25, 2018 at 21:52
• It is not a duplicate to me, it is related for sure but the question here is more precise. Maybe we sould rename the question so that it is easier to understand what is asked Apr 26, 2018 at 8:22

## 1 Answer

This question may not be duplicate but I would reconmmend reading the answers of this question first How to calculate relatedness in haplodiploid organisms (mainly full sisters and full brothers)?

I think an image is worth a lot of words so here it is:

To calcul relatedness, I used the formula $\text{relatedness} = \ce{prop_{mother}} \times \ce{shared_{mother}} + \ce{prop_{father}} \times \ce{shared_{father}}$

The little trick here is that we know the father (son of queen) is unique, so we can focus on either of the two possible son of the queen. This gives us a 0.875 relatedness between sisters with a father being the son of the mother. I hope it is clearer now.