Abstract
These experiments were carried out to obtain basic information necessary for sexing embryos by chromosomal analysis. To observe metaphase chromosomes, all embryos developed to blastocysts were cultured in Ho, pp. & Pitts' medium containing 0.001% Colcemid under the gas phase of 5% CO2 in air at 37$^{\circ}C$ for 2 hours. The sex chromosome of mouse embryos shown normal development after culture in medium containing H-Y antiserum (10%, v/v) and complement (20%, v/v) also was confimed by chromosomal analysis. The results obtained in these experiments were summarized as follows: 1. Among 89 mouse blastocysts, the number of embryos identified to have XX and XY chromosome was 22(25%) and 25(28%), respectively and 42(47%) embryos were not identified. 2. Of total 40 mouse balstocysts cultured in medium containing H-Y antiserum and complement, 23(58%) embryos which were able to be discriminated their sex chromosomes were identified to be XX bearing embryos. 3. Sex chromosomes of a number of embryos subjected to chromosomal analysis were not identified. This result may be due to absence or poor quality of metaphase spreads.
