Pendleton Robert, Alday Adrian, Paluru Prasuna, Joyner Jeannettee, Jerome Natalie, Hillman Ralph
Genesis. 2007 Mar;45(3):152-5. doi: 10.1002/dvg.20272.
Tyrosine hydroxylase (TH), the enzyme which catalyzes the conversion of tyrosine to L-DOPA and is rate limiting in catecholamine biosynthesis, is biochemically expressed in late stage wild-type Drosophila oocytes as well as in early embryogenesis. Null mutant alleles of TH (pale) are embryonic lethals with death occurring in the late embryonic or early larval periods of development. Staging of embryos demonstrated that inhibition of the enzymatic activity of TH by alpha-methyl-p-tyrosine (alphaMT) retards the progression of embryos primarily during the organogenesis stages of embryonic development, with lesser effects on earlier and later stages. On the other hand, time of gene action studies with a conditional temperature sensitive pale mutant (ple(ts1)) at its restrictive temperature (29 degrees C) indicate an onset of tyrosine hydroxylase gene action beginning in the oocyte stage of development. Thus, maternal as well as embryonic effects on the secretion and/or functionality of this enzyme may play roles in the early developmental program of the organism.
酪氨酸羟化酶（TH）是一种催化酪氨酸转化为L-多巴且在儿茶酚胺生物合成中起限速作用的酶，在晚期野生型果蝇卵母细胞以及早期胚胎发育过程中进行生化表达。TH的无效突变等位基因（pale）是胚胎致死性的，死亡发生在胚胎发育的晚期或幼虫发育早期。胚胎分期表明，α-甲基-p-酪氨酸（αMT）对TH酶活性的抑制主要在胚胎发育的器官发生阶段延缓胚胎发育进程，对早期和晚期阶段的影响较小。另一方面，在其限制温度（29摄氏度）下对条件性温度敏感的pale突变体（ple(ts1)）进行基因作用时间研究表明，酪氨酸羟化酶基因作用始于发育的卵母细胞阶段。因此，母体以及胚胎对该酶分泌和/或功能的影响可能在生物体的早期发育程序中发挥作用。
