Avian Germline Cryopreservation

Avian Germline Cryopreservation

Unlike most mammalian species, cryopreservation of ova or early stage embryos has not historically been possible for avian species. As a result, biobanking of a complete germline for a breed or line could only be done through maintaining live flocks, which as a long-term option can be complex, costly and continually at risks to various disease challenges. However, following recent innovations at the Roslin Institute, biobanking of complete germlines for chickens is now possible, through isolation and cryopreservation of cells from early stage embryos (called Primordial Germ Cells) that form the male and female gonads. Biobanking using this approach is now available as a service through Roslin Technologies. The service is offered in three distinct parts:

1) Extraction – of the Primordial Germ Cells

2) Biobanking – of the extracted cells for an agreed period of time

3) Recovery – of the frozen cells to generate live birds

The service can be used to preserve a variety of poultry breeds and genetic lines, from rare and endangered breeds through to valuable commercial lines, which can then be reconstituted when required. It is likely to be of interest to commercial breeders or organisations that may wish to develop ways of safeguarding against future disease challenges or potential losses of specific breeds or genetic diversity, in a practical and cost effective manner. Please contact us if you would like to further discuss some or all parts of this service.

Recovery of frozen genotypes
The current process used for reconstituting the biobanked animals is to directly inject the thawed PCG’s into embryos at a specific developmental stage. The injected PGC then complete with the embryo’s own PCG cells to from the chick’s gonads. As a result, a proportion of the resulting birds will have gonads that have developed from the injected PGC. These birds are then inter-mated to scale up numbers for the reconstituted germline. Advanced genomics techniques offer the means to further increase the efficiency of the re-constitution process. For example, research conducted at The Roslin Institute has resulted in successful production of hens that were sterile. This was achieved by producing hens in which the activity of a single gene in their genome was disrupted, namely DDX4. Further research is on-going to see if other targets may offer the means to produce sterile males and females that would allow the efficiency of the reconstitution process to be improved even further.

Added value through genome editing
Once extracted, fresh or thawed PGC’s also offer a good platform from which to implement targeted genome editing, which may be of interest to commercial poultry breeders. This service is also available through Roslin Technologies.

Please see the genome editing page for more information.