Wang Lifeng, Zhang Ying, Shao Ming, Zhang Hongwei
Institute of Developmental Biology, Life Science College, Shandong University, Key Lab of Experimental Teratology of the Ministry of Education, Jinan, China.
Int J Dev Biol. 2007;51(3):247-53. doi: 10.1387/ijdb.062218lw.
Glycine amidinotransferase (AGAT or GATM), guanidinoacetate methyltransferase (GAMT) and creatine transporter (CT1) are three proteins involved in the synthesis and uptake of creatine. The expression patterns of these three genes were examined in zebrafish embryos by whole mount in situ hybridization followed by histological sectioning. Expression of agat first appeared in the yolk syncytial layer (YSL) at the gastrula stage and was progressively up regulated during gastrulation. As development proceeds, agat was expressed in the mature somites during the segmentation stage and in the liver at 48 hpf. gamt showed a similar expression pattern to that of agat during embryogenesis. It was first detected in the center of the yolk from the cleavage to the gastrula stage. At the bud stage, its expression shifted to the YSL. gamt was also transiently expressed in the mature somites from 16 hpf to 24 hpf and became strongly expressed in the liver and in epithelial cells of the gut at 48 hpf. ct1 was initially uniformly expressed from the cleavage to the early segmentation stage; it was then strongly expressed in all the somites till 30 hpf and in the gut of 48 hpf embryos. However, ct1 transcripts also appeared in the central nervous system during the segmentation stage, but not in the YSL, the yolk or the liver. Our data reveal for the first time distinct and unique patterns of expression of the creatine metabolism genes agat, gamt and ct1 during zebrafish embryogenesis.
甘氨酸脒基转移酶（AGAT或GATM）、胍基乙酸甲基转移酶（GAMT）和肌酸转运蛋白（CT1）是参与肌酸合成和摄取的三种蛋白质。通过全胚胎原位杂交结合组织切片，在斑马鱼胚胎中检测了这三种基因的表达模式。agat的表达最初出现在原肠胚阶段的卵黄合胞体层（YSL），并在原肠胚形成过程中逐渐上调。随着发育进行，agat在体节形成阶段的成熟体节中表达，并在48 hpf时在肝脏中表达。gamt在胚胎发生过程中表现出与agat相似的表达模式。它在从卵裂到原肠胚阶段的卵黄中心首次被检测到。在芽期，其表达转移到YSL。gamt也在16 hpf至24 hpf的成熟体节中短暂表达，并在48 hpf时在肝脏和肠道上皮细胞中强烈表达。ct1最初在从卵裂到早期体节形成阶段均匀表达；然后在所有体节中强烈表达直至30 hpf，并在48 hpf胚胎的肠道中表达。然而，ct1转录本在体节形成阶段也出现在中枢神经系统中，但在YSL、卵黄或肝脏中未出现。我们的数据首次揭示了斑马鱼胚胎发生过程中肌酸代谢基因agat、gamt和ct1独特的表达模式。
