Molecular Genetics Of Early Eye Development

早期眼睛发育的分子遗传学

• 批准号: 7594060
• 负责人: Stanislav I Tomarev
• 金额: $ 30.29万
• 依托单位: NATIONAL EYE INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7594060
• 关键词: Apoptotic; Brain; C-terminal; Cells; Development; Embryo; Exhibits; Eye; Eye Development; Family; Genes; Glaucoma; Glycoproteins; Goals; Injection of therapeutic agent; Inner Nuclear Layer; Length; Molecular Genetics; N-terminal; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 3; Numbers; Oligonucleotides; Optic Nerve; Pathology; Presynaptic Terminals; Prosencephalon; Proteins; Prox 1 protein; RNA; Retina; Retinal Ganglion Cells; Role; Role playing therapy; Staging; Thick; Tissues; Zebrafish; ganglion cell; neurotrophic factor; olfactomedin; protein function; relating to nervous system; size; superior colliculus Corpora quadrigemina; transcription factor

Olfactomedin 1 is a secreted glycoprotein belonging to a family of olfactomedin domain-containing proteins. Two zebrafish olfactomedin 1 genes (olfm1a and olfm1b) are expressed in developing retina and other neuronal tissues. We investigated the functions of Olfactomedin 1 in eye development. Over-expression of full-length Olfactomedin 1, as well as C-terminally truncated forms increased the thickness of the optic nerve and facilitated its branching in the optic tectum. In earlier stage embryos, such over-expression also altered the expression domains of eye-filed markers, rx2 and rx3. Injection of morpholino oligonucleotides against olfm1 reduced eye size, inhibited optic nerve extension, increased the number of apoptotic cells in the retinal ganglion cell and inner nuclear layers, and suppressed the separation of eyes from forebrain. Injection of RNAs encoding full length Olfactomedin 1 or truncated forms lacking the C-terminal olfactomedin domain restored normal eye size in morpholino oligonucleotide-injected embryos, while injection of RNA encoding the N-terminally truncated form of Olfactomedin 1 did not exhibit this rescue effect. The reduction of eye size by morpholino oligonucleotide injection was also rescued by a co-injection of runxb (but not by runxa) RNA encoding a transcription factor expressed in zebrafish neural tissues. The expressions of neurotrophin receptor, trkc, in the retina was slightly increased by olfm1 RNA injection and strongly decreased by morpholino oligonucleotide injection. Zebrafish olfm1s may play roles in early eye determination, differentiation, optic nerve extension and branching of ganglion cell axon terminals. The N-terminal region of Olfactomedin 1 is critical for these effects.

嗅觉素1是属于含橄榄素域蛋白质家族的分泌的糖蛋白。在发育中的视网膜和其他神经元组织中，表达了两个斑马鱼橄榄毒素1基因（OLFM1A和OLFM1B）。我们研究了嗅觉素1在眼睛发育中的功能。全长嗅觉素1的过表达以及C末端截断的形式增加了视神经的厚度，并促进了其在视神经膜中的分支。在较早的阶段胚胎中，这种过表达也改变了眼镜标记RX2和RX3的表达结构域。注射吗啡寡核苷酸对OLFM1的注射减小了眼睛的大小，抑制视神经延伸，增加了视网膜神经节细胞和内部核层中凋亡细胞的数量，并抑制了眼睛与前脑的分离。注入编码全长嗅觉素1或缺乏C末端嗅觉素结构域的截短形式的RNA恢复了形态寡核苷酸注射的胚胎中的正常眼睛尺寸，而编码编码N-末端触发形式1的RNA则没有表现出这种挽救效应。形态上的寡核苷酸注射还可以减少眼睛尺寸，并通过在斑马鱼神经组织中表达的转录因子的RUNXB（但不是RunXa）的共同注射来挽救。视网膜中神经营养蛋白受体TRKC的表达通过OLFM1 RNA的注射略有增加，并且通过注射莫菲诺寡核苷酸的强烈降低。斑马鱼OLFM1可以在早期的眼睛测定，分化，视神经延伸和神经节细胞轴突末端的分支中起作用。嗅觉素1的N末端区域对于这些作用至关重要。