Rhinn Muriel, Lun Klaus, Werner Michaela, Simeone Antonio, Brand Michael
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Dev Dyn. 2004 Feb;229(2):334-9. doi: 10.1002/dvdy.10435.
In zebrafish, gbx1 and otx2 are among the earliest genes expressed in the neuroectoderm, dividing it into an anterior and a posterior domain with a common border that marks the midbrain-hindbrain boundary (MHB) primordium. Here, we describe the sequence and expression pattern of Gbx1 in mouse. The first transcripts are found at embryonic day 7.75 in the hindbrain. Later on, expression of Gbx1 is detectable in the hindbrain (rhombomeres 2 to 7), spinal cord, optic vesicles, and in the ventral telencephalon. In mouse, Gbx1 expression is not observed at the MHB as is the case during early zebrafish development. We suggest that an evolutionary switch occurred: in mouse Gbx2 is involved in the early specification of the MHB primordium, whereas in zebrafish, gbx1 is required instead of gbx2.
在斑马鱼中，gbx1和otx2是神经外胚层中最早表达的基因之一，它们将神经外胚层分为前后两个区域，其共同边界标志着中脑-后脑边界（MHB）原基。在此，我们描述了小鼠中Gbx1的序列和表达模式。最早的转录本在胚胎第7.75天在后脑中被发现。随后，Gbx1的表达可在后脑（菱脑节2至7）、脊髓、视泡以及腹侧端脑中检测到。在小鼠中，与斑马鱼早期发育时的情况不同，在MHB处未观察到Gbx1的表达。我们认为发生了一次进化转变：在小鼠中，Gbx2参与MHB原基的早期特化，而在斑马鱼中，则需要gbx1而非gbx2。
