My worry is that you’re probably trying to identify then add/​turn-on too much (i.e. all of the genes that code for egg laying).
I’m sure its probably not straightforward to change shell colour, which would be the best method of identification of chick sex (maybe shell development is determined by the hen rather than the embryo?), but there’s probably still a couple of additions you could make to the Z and W chromosomes to ultimately achieve the same outcome. And a couple of additions would likely be at least an order of magnitude easier than identifying then adding/​turning-on a bunch of genes.
At least one idea that comes to mind is using insights from gene drive theory to disrupt male embryo development enough to be identifiable using a light shined through an egg. For instance, you could insert a gene into both Z chromosomes coding for a CRISPR complex that disrupts some key embryo development process. Additionally, you insert a gene into the W chromosome that codes for a CRISPR complex that modifies/​disrupts the CRISPR complex on the Z chromosomes.
Maybe there’s a really obvious reason why that wouldn’t work or wouldn’t be that simple, but I suppose my point is that maybe you should aim to find and pursue a more simple solution unless you’re sure that no obvious and simple strategies would work.
Either way, I really hope you and your efforts succeed.
So the project is not looking to target the genes that code for egg-laying. We are testing regulatory sequences for their ability to selectively suppress the expression of the gene DMRT1 in gonadal tissue, resulting in the development of ovaries instead of testes. In other words, we are causing male-to-female sex reversal by targeting a single gene: DMRT1. There is the possibility, however, that a gene on the W chromosome either promotes ovary development or ovulation. We do not know this for certain.
The genetics of eggshell colour hasn’t fully been elucidated. It involves several pigments and enzymes but the genes encoding them haven’t been functionally tested and it’s still uncertain how the pigments are synthesized, transported etc. So I think this approach would be very cumbersome and challenging.
But I do agree, pursing a more straightforward solution will have the greatest chances of success.
My worry is that you’re probably trying to identify then add/​turn-on too much (i.e. all of the genes that code for egg laying).
I’m sure its probably not straightforward to change shell colour, which would be the best method of identification of chick sex (maybe shell development is determined by the hen rather than the embryo?), but there’s probably still a couple of additions you could make to the Z and W chromosomes to ultimately achieve the same outcome. And a couple of additions would likely be at least an order of magnitude easier than identifying then adding/​turning-on a bunch of genes.
At least one idea that comes to mind is using insights from gene drive theory to disrupt male embryo development enough to be identifiable using a light shined through an egg. For instance, you could insert a gene into both Z chromosomes coding for a CRISPR complex that disrupts some key embryo development process. Additionally, you insert a gene into the W chromosome that codes for a CRISPR complex that modifies/​disrupts the CRISPR complex on the Z chromosomes.
Maybe there’s a really obvious reason why that wouldn’t work or wouldn’t be that simple, but I suppose my point is that maybe you should aim to find and pursue a more simple solution unless you’re sure that no obvious and simple strategies would work.
Either way, I really hope you and your efforts succeed.
So the project is not looking to target the genes that code for egg-laying. We are testing regulatory sequences for their ability to selectively suppress the expression of the gene DMRT1 in gonadal tissue, resulting in the development of ovaries instead of testes. In other words, we are causing male-to-female sex reversal by targeting a single gene: DMRT1. There is the possibility, however, that a gene on the W chromosome either promotes ovary development or ovulation. We do not know this for certain.
The genetics of eggshell colour hasn’t fully been elucidated. It involves several pigments and enzymes but the genes encoding them haven’t been functionally tested and it’s still uncertain how the pigments are synthesized, transported etc. So I think this approach would be very cumbersome and challenging.
But I do agree, pursing a more straightforward solution will have the greatest chances of success.