I currently work on gene networks and specifically, I analyze the brain gene regulatory network of an insect to understand its sexual behaviour. During a recent presentation, I got asked this question which I just couldn't really tackle in a good manner. The question was why do I study the brain gene network to understand sexual activity when I should be studying the gene network of a sexual organ, for eg: the ovary. I got out saying that since the brain decides behaviour, it would be much better to study the brain GRN. However, I got confused and would like to know if different tissue or organs in the same organism have different gene networks? Any idea regarding the theory is welcomed.