Short-term culture of adult bovine ovarian tissues: Chorioallantoic membrane (CAM) vs. traditional in vitro culture systems
Beck, K., Singh, J., Dar, M.A., Anzar, M. (2018). Short-term culture of adult bovine ovarian tissues: Chorioallantoic membrane (CAM) vs. traditional in vitro culture systems. Reproductive Biology and Endocrinology, [online] 16(1), http://dx.doi.org/10.1186/s12958-018-0337-y
Plain language summary
In Canadian Animal Genetic Resource program, the mammalian ovarian tissues are frozen for long term preservation of female genetics. But there is no universal cryopreservation method for ovarian tissue. In this study, cattle ovarian tissues were either incubated in vitro (non-biological) or grafted on a chick embryo chorio-allantoic membrane (CAM), for 5 days to develop a short-term culture system. In CAM culture, chicken blood vessels developed around the ovarian graft, an indication of tissue health, which is not possible in vitro condition. The numbers of primitive and developed follicles were higher in CAM culture as compared with traditional in vitro culture. It was found that CAM can serve as a short-term culture system for mammalian ovarian tissue. This system can be applied for transport and development of a suitable cryopreservation of mammalian ovarian tissues.
Background: A suitable culture system is important for follicle growth in adult bovine ovarian tissue. This study aimed to assess the avian chorioallantoic membrane (CAM) for short-term culture of adult bovine ovarian tissues compared with a traditional in vitro culture system. Methods: Ovarian cortical tissues (1-2 mm3), collected from slaughtered adult cows, were randomly assigned to control, CAM or in vitro culture groups. In the control group, ovarian tissues were fixed with paraformaldehyde without culture. In CAM and in vitro culture groups, the ovarian tissues were cultured for up to 5 days and then fixed. Ovarian tissues were examined on culture days 0, 1, 3 and 5 for angiogenesis, follicle morphology and growth. In all groups, primordial and growing (healthy and atretic) follicle densities were determined. Results: In the CAM culture, the avian blood vessel density increased (p < 0.01) over time with a decline (p < 0.001) in the bovine blood vessel density. Healthy primordial, atretic primordial and healthy growing follicle densities were higher (p < 0.05) in CAM-cultured ovarian tissues than in vitro-cultured tissues. Regardless of the culture system, the density of healthy primordial follicles decreased (p < 0.001) over time with an increase in healthy growing follicles on day 3 (p < 0.01) and an increase in atretic (primordial and growing) follicles during the 5-day culture period (p < 0.001). The proportions of healthy primordial and atretic growing follicles were also affected by culture day (p < 0.001). Conclusions: The CAM culture in chick embryos supported the bovine ovarian tissue grafts for 3 days demonstrating that CAM can be used as a satisfactory short-term culture system to assess ovarian tissue health, and to study follicle activation and development.