Boer Elena F, Jette Cicely A, Stewart Rodney A
Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, United States of America.
PLoS One. 2016 Dec 22;11(12):e0167278. doi: 10.1371/journal.pone.0167278. eCollection 2016.
The neural crest (NC) is a stem cell-like embryonic population that is essential for generating and patterning the vertebrate body, including the craniofacial skeleton and peripheral nervous system. Defects in NC development underlie many birth defects and contribute to formation of some of the most malignant cancers in humans, such as melanoma and neuroblastoma. For these reasons, significant research efforts have been expended to identify genes that control NC development, as it is expected to lead to a deeper understanding of the genetic mechanisms controlling vertebrate development and identify new treatments for NC-derived diseases and cancers. However, a number of inconsistencies regarding gene function during NC development have emerged from comparative analyses of gene function between mammalian and non-mammalian systems (chick, frog, zebrafish). This poses a significant barrier to identification of single genes and/or redundant pathways to target in NC diseases. Here, we determine whether technical differences, namely morpholino-based approaches used in non-mammalian systems, could contribute to these discrepancies, by examining the extent to which NC phenotypes in fascin1a (fscn1a) morphant embryos are similar to or different from fscn1a null mutants in zebrafish. Analysis of fscn1a morphants showed that they mimicked early NC phenotypes observed in fscn1a null mutants; however, these embryos also displayed NC migration and derivative phenotypes not observed in null mutants, including accumulation of p53-independent cell death. These data demonstrate that morpholinos can cause seemingly specific NC migration and derivative phenotypes, and thus have likely contributed to the inconsistencies surrounding NC gene function between species. We suggest that comparison of genetic mutants between different species is the most rigorous method for identifying conserved genetic mechanisms controlling NC development and is critical to identify new treatments for NC diseases.
神经嵴（NC）是一种类似干细胞的胚胎细胞群，对于脊椎动物身体的形成和模式构建至关重要，包括颅面骨骼和外周神经系统。NC发育缺陷是许多出生缺陷的基础，并促成了人类一些最恶性癌症的形成，如黑色素瘤和神经母细胞瘤。由于这些原因，人们已经投入了大量的研究工作来确定控制NC发育的基因，因为这有望加深对控制脊椎动物发育的遗传机制的理解，并确定针对源自NC的疾病和癌症的新治疗方法。然而，在哺乳动物和非哺乳动物系统（鸡、青蛙、斑马鱼）之间对基因功能进行比较分析时，出现了一些关于NC发育过程中基因功能的不一致之处。这对确定NC疾病中可靶向的单个基因和/或冗余途径构成了重大障碍。在这里，我们通过检查fascin1a（fscn1a）吗啡啉处理胚胎中的NC表型与斑马鱼中fscn1a基因敲除突变体的NC表型相似或不同的程度，来确定技术差异，即非哺乳动物系统中使用的基于吗啉代的方法，是否可能导致这些差异。对fscn1a吗啡啉处理胚胎的分析表明，它们模拟了在fscn1a基因敲除突变体中观察到的早期NC表型；然而，这些胚胎还表现出在基因敲除突变体中未观察到的NC迁移和衍生表型，包括p53非依赖性细胞死亡的积累。这些数据表明，吗啉代可以导致看似特定的NC迁移和衍生表型，因此可能导致了物种间围绕NC基因功能的不一致。我们建议，比较不同物种之间的基因突变体是确定控制NC发育的保守遗传机制的最严格方法，对于确定NC疾病的新治疗方法至关重要。
