Patent ID: 7083941

Claim:
An estrogen dependent transactivation system for gender-sorting in an avian test animal, comprising; a) a first DNA construct comprising a nucleic acid molecule encoding an estrogen receptor having specific binding affinity for said estrogen operably linked to a promoter; b) a second DNA construct comprising a promoter containing a plurality of estrogen response elements, said promoter containing a plurality of estrogen response elements being operably linked to a reporter gene; c) a third DNA construct comprising a nucleic acid sequence encoding a secreted fusion protein comprising beta-glucuronidase and ubiquitin for cleaving an estrogen glucuronide said estrogen glucuronide comprising said estrogen, said nucleic acid sequence encoding said fusion protein being operably linked to a promoter sequence; and d) a host cell comprising said first, second and third DNA constructs, wherein expression of said reporter gene in said host cell is dependent upon cleavage of said estrogen from said estrogen glucuronide present in a biological sample isolated from said avian test animal, reporter gene expression being indicative of the presence of an estrogen which indicates the sex of said avian test animal.