Analysis of chicken embryonic gonad expressed sequenced tags.

were produced from an inbred strain ofWhite Leghorn chickens maintained at the University AnimalFarm, Seoul National University, Korea. Dissection and collec-tion of gonads were performed by skilled technicians. TotalRNA was extracted from the gonads using TRIzol reagent(Invitrogen, Carlsbad, CA, USA), and poly(A) mRNA waspurified using the Promega PolyATract mRNA isolation system(Promega, Madison, WI, USA). The libraries were synthesizedusing the ZAP -cDNA synthesis method (Stratagene, LaJolla,CA, USA). Sequencing reactions were performed by polymerasechain reaction (PCR) priming at the 5¢ end of the cDNA andwere analysed on ABI 3700 automated DNA sequencers (PEApplied Biosystems, Foster city, CA, USA) using the manufac-turers protocols.Expressed sequenced tags processing and assembly: The chickenexpressed sequenced tag (EST) trace data were base-called andvector-clipped using Phred