Construction of a normal cDNA library and EST analysis. Five
microgram of mRNA from vitellogenic ovaries of wild P. monodon
was reversed transcribed and second-stranded synthesized using a
ZAP-cDNA Synthesis and Cloning Kit (BD Biosciences Clontech).
Size-selected cDNAs (>500 bp) were cloned into dephosphorylated
EcoRI/Xho I-digested Uni-ZAP® XR and transfected into E. coli
XL1-Blue MRF'. The lambda library was converted into the
pBluescript library by in vivo excision. Recombinant clones were
selected by a lacZ system following standard protocols (Sambrook
and Russell, 2001). Recombinant clones were randomly selected
from those carrying insert sizes greater than 500 bp (Srisuparbh et al.,
2003). Plasmid DNA was extracted and unidirectionally sequenced
on a MegaBase 1000 automated DNA sequencer (GE Healthcare).
EST clustering and assembly. Nucleotide sequences of ESTs were
compared with those previously deposited in the GenBank using