Abstract: Attempting a new method of gender-controlling nematode infection in animal production, differentially expressed male and female cDNA libraries of the adult Ascaris suum were constructed using the technique of suppression subtractive hybridization (SSH). The gender specificity of the constructed archives was determined using Southern blots with Digoxigenin(DIG)- labeled male and female cDNA probes. Twenty-five clones from each archive were selected ad libitum for sequence determination and homology analysis by BLAST online. Twenty of the 25 ESTs from the male cDNA library have a homology to the genes from C. elegans and 11 of the 19 ESTs from the female cDNA library have a homology to the genes from C. elegans. The successful construction of differentially expressed male and female cDNA libraries have provided a foundation for further study of the gender-specific genes.

Key words: Ascaris suum, Subtractive spression hbridization（SSH）, Gender rlated gne, cDNA lbrary, Southern blot