puh, this is a quite general question - you'd need to specify a bit more to get a reply to this one. Generally there is no best strategy per se. It all depends on what is already known about your gene and what you are trying to find out. Molecular function, disease mechanism etc.what´s your interest? If nothing is known at all you may start with very basic stuff like expression pattern, sub cellular localisation; if you are interested in interactions with other genes you´d go for interaction studies ... . But unless you specify what you are looking for specifically there are too many options.

However, I assume you don´t want to tell which gene it is and what exact question you are tackling for fear of being scooped. Hence, you´ll have to sit down, read a lot and figure out yourself what needs to be done to answer your question.

I fully share Christoph's opinion.

The attached article could be of "general" interest.

Best regards

Robert

One thing that one needs to consider when using the UAS-GAL4 system in neurodegenration studies is the toxic effect that GAL4 itself has shown to have on neuron development and function. 

Thank you all for the answers shared here with me. To target the point raised by Christoph Metzendorf I should say that few genes are discovered through a case control study on patients with genetic intellectual disabilities in Iran. Unfortunately these genes do not have orthologs in Drosophila melanogaster. Number of them are known to participate in electron transport chain. Some other genes have ATP-dependent RNA helicase activity and so on. Now can you provide me specific options. With Best Regards