The HMGN proteins are a group of non-histone nuclear proteins that associate with the core nucleosome and alter the structure of the chromatin fiber. We investigated the distribution of the three best characterized HMGN family members, HMGN1, HMGN2 and HMGN3 during mouse eye development. HMGN1 protein is evenly distributed in all ocular structures of 10.5 days post-coitum (dpc) mouse embryos however, by 13.5dpc, relatively less HMGN1 is detected in the newly formed lens fiber cells compared to other cell types. In the adult, HMGN1 is detected throughout the retina and lens, although in the cornea, HMGN1 protein is predominately located in the epithelium. HMGN2 is also abundant in all ocular structures of mouse embryos, however, unlike HMGN1, intense immunolabeling is maintained in the lens fiber cells at 13.5dpc. In the adult eye, HMGN2 protein is still found in all lens nuclei while in the cornea, HMGN2 protein is mostly restricted to the epithelium. In contrast, the first detection of HMGN3 in the eye is in the presumptive corneal epithelium and lens fiber cells at 13.5dpc. In the lens, HMGN3 remained lens fiber cell preferred into adulthood. In the cornea, HMGN3 is transiently upregulated in the stroma and endothelium at birth while its expression is restricted to the corneal epithelium in adulthood. In the retina, HMGN3 upregulates around 2 weeks of age and is found at relatively high levels in the inner nuclear and ganglion cell layers of the adult retina. RT-PCR analysis determined that the predominant HMGN3 splice form found in ocular tissues is HMGN3b which lacks the chromatin unfolding domain although HMGN3a mRNA is also detected. These results demonstrate that the HMGN class of chromatin proteins has a dynamic expression pattern in the developing eye.

中文翻译：

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HMGN 染色质蛋白家族在眼部发育过程中的差异表达。

HMGN 蛋白是一组与核心核小体相关并改变染色质纤维结构的非组蛋白核蛋白。我们研究了小鼠眼发育过程中三个最有特征的 HMGN 家族成员 HMGN1、HMGN2 和 HMGN3 的分布。HMGN1 蛋白均匀分布在性交后 10.5 天 (dpc) 小鼠胚胎的所有眼部结构中，然而，到 13.5dpc，与其他细胞类型相比，在新形成的晶状体纤维细胞中检测到的 HMGN1 相对较少。在成人中，在整个视网膜和晶状体中都检测到 HMGN1，尽管在角膜中，HMGN1 蛋白主要位于上皮中。HMGN2 在小鼠胚胎的所有眼部结构中也很丰富，但是，与 HMGN1 不同，在 13.5dpc 的晶状体纤维细胞中保持强烈的免疫标记。在成年人眼里，HMGN2 蛋白仍然存在于所有晶状体细胞核中，而在角膜中，HMGN2 蛋白主要局限于上皮细胞。相比之下，眼中 HMGN3 的首次检测是在 13.5dpc 的假定角膜上皮和晶状体纤维细胞中。在晶状体中，HMGN3 一直是首选的晶状体纤维细胞。在角膜中，HMGN3 在出生时在基质和内皮中瞬时上调，而在成年后其表达仅限于角膜上皮。在视网膜中，HMGN3 在 2 周龄左右上调，并在成人视网膜的内核和神经节细胞层中以相对较高的水平被发现。RT-PCR 分析确定在眼组织中发现的主要 HMGN3 剪接形式是 HMGN3b，尽管也检测到 HMGN3a mRNA，但它缺乏染色质解折叠结构域。