为了研究cx43基因抑制对斑马鱼胚胎心血管系统发育的影响,针对cx43的翻译起始位点设计两个吗啉修饰的反义寡核苷酸抑制其表达,在斑马鱼受精卵一到两细胞期混合注射并且验证其有效性.注射后用原位杂交和原位免疫荧光检测心脏标志基因的表达以及心脏的表型,同时利用显微荧光造影和原位杂交检测血管的发育情况.用心室心房的标志基因vmhc和amhc反义RNA探针进行的原位杂交结果显示,vmhc表达抑制,而amhc表达上调.原位免疫荧光显示与原位杂交一致的结果表明:心房扩张心室缩小,并且心脏环化不全.用血管标志基因flk-1的RNA探针原位杂交和显微荧光造影表明,cx43基因抑制的斑马鱼胚胎血管无明显缺陷.此外,cx43基因抑制的斑马鱼胚胎心脏功能也有明显改变,包括心脏搏动无力,有血液回流现象.抑制cx43的表达可能通过影响两个细胞群的迁移导致斑马鱼胚胎心脏的发育缺陷,从而影响了心脏的功能,但是未发现胚胎血管系统发育的明显缺陷.
To study the effects of connexin43 down regulation on the development of the embryonic heart and vasculature in zebrafish, two types of well designed morpholino oligonucleotide antisenses were injected into zebrafish embryos to block the translation of cx43 at one or two cells stage. After injection, the phenotypes of heart and vasculature were monitored by whole mount in situ hybridization, whole-mount immunofluorescence and microangiography. Whole-mount in situ hybridization with vmhc and amhc RNA probes showed that the vmhc expression cell domain was reduced; meanwhile, amhc expression cell domain was increased in cx43 down regulation group. Whole-mount immunofluorescence provided the evidence that down regulation of cx43 resulted in enlarged atrium and retrenched ventricle. Both in situ hybridization and microangiography indicated that vasculature pattern of cx43 morphants are almost normal compared with wildtype. Besides, the function of heart was affected obviously. Down regulation of cx43 caused the development defects of zebrafish embryonic heart, which may be involved in the wrong destination of two migratory cell populations, but it did not nearly affect vascular development.