Sex Identification of Newly Hatched Chicks by Fluorescence in situ Hybridization using a W-specific DNA Probe in Feather Follicle Cells

Abstract

The identification of the sex of chickens or chicken cells has biological and industrial significance. In the laboratory, molecular techniques have utilized W chromosome-specific repetitive DNA sequence fragments, such as Xho I or EcoR I family, for gender identification in chickens. The present study examined a rapid and reliable fluorescence in situ hybridization (FISH) procedure for chick sex identification using an easily obtainable sample: uncultured feather pulp cells. A chicken W chromosome-specific 416-bp partial DNA fragment of Xho I family was digoxigenin-labeled by polymerase chain reaction and used as an FISH probe for chick sex identification. In 60 newly hatched chicks, 28 of the chicks that were subsequently identified as females by the visual identification of ovaries exhibited a positive W-specific probe signal in their feather follicle cells; the others were negative for the W-specific probe signal and were identified as males by the presence of testes. Therefore, the FISH results were in perfect agreement with the anatomical analysis. We suggest that this FISH technique using feather follicle cells and the W-specific DNA probe will be useful for a fast, convenient and accurate sex diagnosis of newly hatched chicks.