Organization, ontogenetic differentiation and evolution of the inverted rod photoreceptor nuclei

最初，该项目是两个项目的结合，涵盖两个主要研究方向，(I)倒杆状核的功能组织和(Ii)视觉生物学的进化和夜间视网膜的适应组织。第一个主要由伊琳娜·索洛维博士领导，第二个由已故的鲍里斯·约菲博士领导。总的来说，该项目主要是研究夜间动物视杆感光细胞的倒置核团。与所有其他常规核团相比，这些核团获得了显著改变的核结构，这使得它们能够作为微透镜发挥作用，以提高夜间视力(Solovei等人)。2009年)。该项目的目标是(1)描述倒置核中的大规模染色质折叠，以确定它们与常规核的不同；(2)研究视杆感光细胞出生后末端分化过程中常规核向倒置核重塑的分子机制；(3)证明适应夜间视觉可以推动核型和基因组的进化，朝着建立异染色质微透镜所需的异染色质的积累。在两个赠款期间，项目的所有三个部分都取得了相当大的进展。我们在头三年的主要成就是确定了外周异染色质结合的主要机制，这是在真核生物中建立和维持常规核组织的关键因素(Solovei等人，2013)。目前的申请包括一份关于过去两年期间取得的成果的报告，以及一份继续和完成下文概述的一些专题所需的试验性工作的提案。续集将由一位名叫伊琳娜·索洛维的人执行。

Initially the project was a combination of two projects covering two major research directions, (i) Functional organization of inverted rod nuclei and (ii) Evolution of vision biology and Adaptive organization of nocturnal retinas. The first one was predominantly led by Dr. Irina Solovei and the second one - by late Dr. Boris Joffe. Generally, the project is focused on investigation of inverted nuclei of rod photoreceptors in nocturnal animals. These nuclei had acquired a dramatically changed nuclear architecture in comparison to all other conventional nuclei, which allows them to function as microlenses to improve nocturnal vision (Solovei et al. 2009). The objectives of the project are (1) to describe large scale chromatin folding in the inverted nuclei that determines their difference from the conventional nuclei; (2) to study molecular mechanisms underlying remodeling of conventional nuclei to the inverted ones during postnatal terminal differentiation of the rod photoreceptor cells and (3) to prove the hypothesis that adaptation to nocturnal vision can drive the evolution of the karyotype and the genome towards accumulation of heterochromatin necessary to build heterochromatin microlenses. During the two grant periods, considerable progress was made in all three parts of the projects. Our main achievement during the first three years was identification of the major mechanisms of peripheral heterochromatin binding, which is a key element in establishment and maintenance of the conventional nuclear organization in eukaryotes (Solovei et al 2013). The current application consists of a report on results obtained over the last two year period and a proposal of experimental work needed to continue and complete some of the topics outlined below. The continuation will be performed by one person, Irina Solovei.