Abstract:
A number of perceived future requirements for stored germplasm in agriculture,aquaculture, biotechnology and conservation are discussed in the presentreview. In the light of these broad demands, it is apparent that currentapproaches to gamete and embryo storage need considerable improvement, andthat novel approaches to the technologies of germplasm preservation should bepursued if possible. The present article is presented in response to a requestfor novel future research ideas in this area. Early literature on desiccation,and later research into natural mechanisms of survival during desiccation, isconsidered in relation to the development of freeze-drying and vitrificationmethods. Developments in reproductive technologies themselves may mean thatfreeze-dried spermatozoa could realistically be used for directintracytoplasmic microinjection of oocytes. Other radical methods that mayachieve germplasm preservation are harvesting testicular cells in culture,cryopreserving immature or seasonally regressed testicular material, or acombination of both. Evidence from non-mammalian testicular culture systems,and recent success with the transmeiotic development of mousespermatidsin vitro, suggest that these approaches mayeventually become feasible.