Studies Related To The Artificial Breeding And Embryo Biotechnology Of Chinese Tree Shrew

The present study was undertaken to investigate the artificial breeding, estrous induction, superovulation and in vitro fertilization of Chinese Tree Shrew (Tupaia belangeri chinesis).1) The possibility of artificial breeding Tree Shrew was explored. Ninety-nine pups of 32 litters were born from 15 pairs of adults within one year, and 59.6% of them survived to the age of weaning. The mean litters of per female were 2.1 and mean litter size was 3.1. The puberty of the young Tree Shrew begins at the age of 3 months old, and the mating action and the first parturition of the female Tree Shrew begins at 4 months old and 6 months old respectively. Results indicate that the Chinese Tree Shrew can grow and breed normally in our experimental conditions.2) The possibility of inducing estrus of Tree Shrew was explored using cloprostenol. Treatment of Tree Shrew by one injection of 10μg or 20μg cloprostenol, two injections of 10μg or 20μg cloprostenol in interval of 10-12ds resulted in 100%, 77.8%, 100% and 87.5% of them showing estrus, 75.0%, 55.6%, 83.3% and 62.5% of them becoming pregnant respectively. The average pregnant rate of treatment groups (67.7%) was significantly higher than that of control group (16.9%, P<0.01). Results show that cloprostenol can be used to induce the estrus of Tree shrew and increase their reproductive rate effectively.3) Methods for superovulation of Tree Shrew were investigated. A satisfactory superovulation result was obtained when Tree Shrews were superovulated by injection of 40-60IUPMSG and 20-30IU hCG, in which 25.6±3.0 of oocytes were recovered.4) Methods for the in vitro maturation and fertilization of ChineseTree Shrew oocytes were investigated. Significantly more oocytes matured when they were cultured in TCM199 ±0.1μgFSH + 5%OCS (56.1%) in comparison with them in Human Maturation Media (17.62%, P<0.05). Co-culture with somatic cells resulted in significantly more zygotes cleaved (18.5%) and developing to the morula and blastocyst stage (8.6%) compared with the somatic cell-free culture (9.6% and 0%, P<0.05). These results indicate that Chinese Tree Shrew oocytes can be matured and fertilized in vitro, and then develop to the blastocyst stage after co-culture with somatic cells.