Please help me with this

Question

 Anna wants to study sex determination in sea urchins, where nothing is known so far. She plans to start by isolating urchin homologues of genes controlling sex determination in Drosophila and mouse. Is this a good strategy? Why or why not?

Answer 1

Hi Kamiya Z.,

An extraordinarily poor idea! Echinoderms, Drosophila, and mice are very far apart evolutionarily, a better choice might be something else echinoderm, such as starfish.

Plus which, it appears that someone may be confusing sexual determination with sexual differentiation. The former is controlled by (generally) sex chromosomes of one type or another (with attendant genes or lack thereof) = genotype; the latter by complex processes involving expression of developmental cascades leading to male or female morphology = phenotype, so to speak.

Why try to isolate a gene, when you have a whole chromosome staring you in the face?

-- Cheers, --Mr. d.

P.S. should be no shortage of gamete, the males shed them by the millions at I think at certain conditions.