Gottlieb S, Hanes S D, Golden J A, Oakey R J, Budarf M L
Division of Human Genetics and Molecular Biology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Hum Mol Genet. 1998 Sep;7(9):1497-505. doi: 10.1093/hmg/7.9.1497.
The vast majority of patients with DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS) have deletions of chromosomal region 22q11.2. These patients exhibit broad and variable phenotypes that include conotruncal cardiac defects, hypocalcemia, palatal and facial anomalies and developmental delay. Most of these abnormalities are thought to be due to defects in neural crest cell migration or differentiation. We have identified a homeobox-containing gene, Goosecoid-like (GSCL), that is in the region within 22q11 that is deleted most consistently in patients with DGS/VCFS. The GSCL gene is expressed in a limited number of adult tissues as well as in early human development, and is a member of a family of homeobox genes in vertebrates that includes Goosecoid and GSX. In this report, we present functional studies of the GSCL protein and determine the expression pattern of the GSCL gene in mouse embryos. We demonstrate that GSCL exhibits DNA sequence-specific recognition of sites bound by the Drosophila anterior morphogen, Bicoid. Several of these sites (TAATCCC) were found in the 5' upstream region of the GSCL gene itself, and we present evidence suggesting that GSCL might regulate its own transcription. In situ hybridization revealed that the mouse ortholog of GSCL, Gscl, is expressed in the brain starting as early as embryonic day 9.5, and expression continues in adults. This expression pattern is consistent with GSCL having either an indirect role in the development of neural crest-derived structures or a direct role in a subset of the phenotype observed in DGS/VCFS, such as learning disorders or psychiatric disease.
绝大多数狄乔治综合征(DGS)和腭心面综合征(VCFS)患者存在22q11.2染色体区域的缺失。这些患者表现出广泛且多样的表型,包括圆锥动脉干心脏缺陷、低钙血症、腭部和面部异常以及发育迟缓。大多数这些异常被认为是由于神经嵴细胞迁移或分化缺陷所致。我们鉴定出一个含同源异型框的基因,类鹅膏蕈氨酸(GSCL),它位于22q11区域内,该区域在DGS/VCFS患者中缺失最为一致。GSCL基因在少数成年组织以及人类早期发育过程中表达,并且是脊椎动物同源异型框基因家族的成员,该家族包括鹅膏蕈氨酸和GSX。在本报告中,我们展示了GSCL蛋白的功能研究,并确定了GSCL基因在小鼠胚胎中的表达模式。我们证明GSCL对果蝇前部形态发生素Bicoid结合的位点具有DNA序列特异性识别。其中几个位点(TAATCCC)在GSCL基因自身的5'上游区域被发现,并且我们提供的证据表明GSCL可能调控其自身的转录。原位杂交显示,GSCL在小鼠中的直系同源基因Gscl早在胚胎第9.5天就在大脑中表达,并且在成年期持续表达。这种表达模式与GSCL在神经嵴衍生结构发育中具有间接作用或在DGS/VCFS中观察到的部分表型(如学习障碍或精神疾病)中具有直接作用一致。