Cryopreservation of Primordial Germ Cells (PGCs) from White Leghorn Embryos Using Commercial Cryoprotectants

Cryopreservation of poultry semen has been reported, but preservation of female genetic material has not been possible because of the large size of their yolk structure. Cryopreservation of primordial germ cells (PGCs) is an alternative way to preserve both female and male genetic material in chicken. In the present study, fertilized eggs were incubated for about 53 hours to obtain embryos at stage 14-16. The blood of the whole embryo was collected from the terminal vein or dorsal aorta using a fine glass micro pipette under a microscope. The PGCs were then purified using Nycodenz density gradient centrifugation. Four commercially available cryoprotectants (A, B, C and D) were used to preserve the PGCs, and DMSO was used as a control. The average recovery rate of PGCs after thawing was 58.2%, 52.9%, 46.5% and 39.4% with the A, B, C and D treatments, respectively. There was no significant difference between the A, B and C treatments and control (DMSO), which showed an average recovery rate of 49.9%. However, the recovery rate obtained using D cryoprotectant was significantly lower than using treatment A. The average viability of the PGCs after thawing were 86.0%, 82.3%, 81.1% and 84.8% for cryoprotectants A, B, C and D, respectively, and the control (DMSO) was 85.3%. There was no statistically significant difference between the four treatments and control. It was concluded that all of the available cryoprotectants examined in this study could be used for preservation of PGCs from embryos ; however, the use of cryoprotectant D should be avoided since the recovery rate was significantly lower, although the viability was not affected.