The ability to compact and inject the cat germinal vesicle (GV) into a recipient cytoplast allows exploration of a new fertility preservation strategy that avoids whole oocyte freezing. The objective of the present study was to understand the impact of water loss and storage time on GV DNA integrity. Immature cat oocytes were exposed to 1.5M trehalose for 10 min before microwave-assisted dehydration for 0, 5, 10, 15, 20, 25, 30, or 40 min. Oocytes then were rehydrated to assess chromatin configuration and the incidence of DNA fragmentation (TUNEL assay). The moisture content progressively decreased ( p 0.05) after 40 min. Chromatin configuration was unaffected ( p > 0.05) over time. The percentage of GVs with DNA fragmentation was unaltered ( p > 0.05) from 0 to 30 min of treatment (range, 6.1%–12%), but increased ( p 0.05) after 40 min. Chromatin configuration was unaffected ( p > 0.05) over time. The percentage of GVs with DNA fragmentation was unaltered ( p > 0.05) from 0 to 30 min of treatment (range, 6.1%–12%), but increased ( p 0.05) after 40 min. Chromatin configuration was unaffected ( p > 0.05) over time. The percentage of GVs with DNA fragmentation was unaltered ( p > 0.05) from 0 to 30 min of treatment (range, 6.1%–12%), but increased ( p 0.05) thereafter (1 through 4 weeks, 25.0%–35.0%). Collective results demonstrate the feasibility of using microwave processing to dehydrate the mammalian GV to a moisture content that is nonlethal and enables nonfrozen storage, an alternative approach for preserving the maternal genome at cool or ambient temperature.
