12.珠蛋白基因表达的时空特异性 Yolk sac Liver Spleen Bone marrow 50 0 18 30 6 18 30 42 Birth (b) Prenatal age (weeks) Postnatal age(weeks) Chromosome 16 012 5 Chromosome 11 E GY AY 5 B Globin Chain Synthesis 0 20 30 10 20 30 40 Weeks 2E2-Gower 1 2Y2-Hb F Q2B2-HbA YPortland (282-Hb A2 (2E2-Gower 2 Fiaure 13-1 Globin Chain Svnthesis 221 12. 珠蛋白基因表达的时空特异性