The intrauterine environment affects learning ability of Tokai high avoider rat offspring derived using cryopreservation and embryo transfer-mediated reproduction

• Published in: Biochemical and biophysical research communications 2017-07, Vol.489 (2), p.211-216
• Main Authors: Endo, Hitoshi, Eto, Tomoo, Yoshii, Fumihito, Owada, Satoshi, Watanabe, Tetsu, Tatemichi, Masayuki, Kimura, Minoru
• Format: Article
• Language: English
• Subjects: Animals; Avoidance Learning; Behavior, Animal; Brain - metabolism; Cryopreservation; Embryo Transfer; Female; Intrauterine environment; Male; Phenotype; Pregnancy; Prenatal Exposure Delayed Effects - metabolism; Rats; Rats, Wistar; Strain preservation; THA rats
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2017.05.133

Embryo transfer (ET) to recipient female animals is a useful technique in biological and experimental animal studies. While cryopreservation of two-cell stage rat embryos and ET to recipient rats are currently well-defined, it is unknown whether these artificial reproductive techniques and maternal factors affect offspring phenotype, particularly higher brain functions. Therefore, we assessed the effects of cryopreservation, ET, and maternal care on learning behaviour of the offspring, using Tokai high avoider (THA) rats that have a high learning ability phenotype. We found that the high learning ability of THA rat offspring was not replicated following ET to surrogate Wistar rats with a low-avoidance phenotype. Additionally, the characteristic phenotype of offspring obtained through mating of ET-derived rats was similar to that of THA rats. A postnatal cross-fostering investigation with the offspring of Wistar and THA rats showed that maternal behaviour, including postnatal care and lactation traits, did not differ between the dams of low-avoidance Wistar rats and THA rats; therefore, learning behaviour was retained in both Wistar and THA rat offspring. We conclude that the offspring phenotype, although unchanged, has an imperceptible effect on the learning ability of ET-derived THA rats through the intrauterine environment of the recipient. [Display omitted] •The effects of cryopreservation and embryo transfer on learning behaviour of the offspring were investigated by THA rats.•High learning ability of THA rats was not replicated following embryo transfer to surrogate with a low-avoidance phenotype.•The intrauterine environment is an important factor for the strain preservation of experimental animals.