I know AGH is a key gene for sex characteristic of male in crustacean.but i want to know the mechanism of sex determination of crustacean,especially in crab.
For penaeid shrimp, polyploidy induction through temperature or chemical shock (to prevent extrusion of the polar body) can skew the resulting sex ratio to more females (larger size) than males.
If you're interested in sex reversal in shrimp, an excellent reference would be Sellars et al's 2010 paper: Penaeid shrimp polyploidy.
In shrimp Litopenaeus vannamei, sex differentiation starts around PL16. External sex organs are obvious around PL50.
You're right, the androgenic gland hormone controls maleness in crustaceans. In shrimp Penaeus monodon, insulin-like androgenic gland peptides (expressed in the androgenic gland) control male differentiation. If these peptides could be blocked, female monosex cultures (larger shrimp) are theoretically possible.
Sex reversal in a crab? First time I hear it! If you have an example of sex reversal in a crab-like crustacean it is a very interesting finding! Could you please tell which crab is? Brachyuran, Anomuran other?
IAG is not a sex determination gene,it's just a sex-reversal factor.as we all known ,in silkworm,the sex determination gene is doublesex (Dsx),which is a transcriptional regulation factor and regulated by piRNA.I want to know that is something like of the mechanism in crustacean.
evan i have doubt. sex reversal is their in penaeid shrimp's life cycle??. but same time i have seen some specimens having both organs but surely i don't know. whether its right or not.
That is all interesting info. But so far we are just talking about shrimps here. What about crabs? Actually, the original question was about crabs. Somebody knows what the mechanisms are of sex determination in crabs (Brachyura-Anomura) and why there is not sex reversal nor hermaphroditism?