The present study examined the effects of having bigger amount of protein than usual in competitive season on lean body weight (LBW), cross-sectional area of thigh and abdomen, muscle strengths, blood constituents and urinary urea nitrogen. Seventeen male varsity throwers (javelin, discus, hammer and shot put) ranging from 19 to 22 years of age, were divided into two groups ; Group A (N=9) with a more protein diet (2.1 g·kg^-1·d^-1), and Group B (N=8) with a usual amount diet (1.5 g·kg^-1·d^-1) . The experimental period was 62 days. During this period, they practiced six days a week. Three days were for throwing practice. Other three days were for weight training. All subjects lived in the same dormitory, and their life styles were similar to each other. The averaged daily diet of Group A evaluated by means of a weighing method had 3824 kcal with 175 g of protein (2.0 g·kg^-1·d^-1), 115 g of fat and 552 g of carbohydrate. The averaged daily diet of Group B had 3441 kcal with 130 g of protein (1.5 g·kg^-1·d^-1), 76 g of fat and 559 g of carbohydrate. All the intakes of vitamins (A, B₁, B₂, C) and minerals (calcium and iron) of the diet of each group were higher than the Japanese recommended dietary allowance. After the period, body weight, %fat, fat and LBW of both groups did not change significantly. Muscle strengths and cross-sectional areas in abdomen and thigh of both groups did not change significantly. Urinary urea nitrogen of both groups did not change significantly. Blood constituents (RBC, Hb, Ht, TP, Alb, BUN) of each group were still in normal ranges in spite of significant changes. No significant changes in body composition and muscle strengths were found in each group. These results, therefore, indicated that the more protein diet (2.0 g·kg^-1·d^-1) was not effective for increasing LBW and muscle strength of varsity throwers in competitive season.

To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (ALV)-induced chicken B cell line DT40 to the production of chimeric birds. Methods: The DT40cells incorporated with exogenous gene (lacZ constructs encoding Escherichia coli β-galactosidase: β-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial 1 ) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of β-galactosidase and polymerase chain reaction (PCR) analysis. Results: The survival rates of the manipulated embryos incubated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively.The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, for the survived embryos. Conclusio: The rate of embryonic viability and expression rate of introduced genes were not so high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chick embryos.