Yamaguchi A, Nagahama Y
Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
Cell Struct Funct. 2001 Dec;26(6):693-703. doi: 10.1247/csf.26.693.
In fish and amphibians, B-type lamins are divided into somatic (B1, B2) and oocyte-type (B3) lamins. In this study, we purified nuclear lamins from rainbow trout erythrocytes, raised an anti-lamin monoclonal antibody (L-200) that recognizes goldfish somatic-lamins, and isolated cDNAs encoding goldfish B-type lamins (B1 and B2) from a goldfish cell culture cDNA library. Goldfish B-type lamins are structurally similar to lamins found in other vertebrates with minor amino acid substitutions in the conserved region. Western blot analysis showed that goldfish oocytes contained mainly GV-lamin B3 as well as some somatic lamins. Laser-confocal microscope observations revealed that lamin B3 was present only in GV nuclear lamina, whereas somatic lamins were present in dense fibrillar structures throughout nuclear gels of isolated GVs. Similar nuclear filamentous structures were also observed in GVs of paraffin embedded oocytes. Epitope mapping indicated that L-200 recognized a conserved region containing a short stretch of the alpha-helix coiled-coil rod domain (Y(E/Q)(Q/E)LL). A similar motif is also present in other cytoplasmic intermediate filaments (i.e., vimentin, desmin, peripherin and GFAP). Taken together, these findings suggest that lamins or lamin-related intermediate filaments are an important component of the interior architecture of goldfish vitellogenic oocyte nuclei (GVs).
在鱼类和两栖动物中，B型核纤层蛋白分为体细胞型（B1、B2）和卵母细胞型（B3）核纤层蛋白。在本研究中，我们从虹鳟红细胞中纯化了核纤层蛋白，制备了一种识别金鱼体细胞型核纤层蛋白的抗核纤层蛋白单克隆抗体（L - 200），并从金鱼细胞培养cDNA文库中分离出编码金鱼B型核纤层蛋白（B1和B2）的cDNA。金鱼B型核纤层蛋白在结构上与其他脊椎动物中的核纤层蛋白相似，在保守区域有少量氨基酸替换。蛋白质免疫印迹分析表明，金鱼卵母细胞主要含有生殖泡核纤层蛋白B3以及一些体细胞型核纤层蛋白。激光共聚焦显微镜观察显示，核纤层蛋白B3仅存在于生殖泡核纤层中，而体细胞型核纤层蛋白存在于分离的生殖泡整个核凝胶的致密纤维结构中。在石蜡包埋卵母细胞的生殖泡中也观察到了类似的核丝状结构。表位作图表明，L - 200识别一个保守区域，该区域包含一段短的α - 螺旋卷曲螺旋杆结构域（Y(E/Q)(Q/E)LL）。其他细胞质中间丝（即波形蛋白、结蛋白、外周蛋白和胶质纤维酸性蛋白）中也存在类似的基序。综上所述，这些发现表明核纤层蛋白或核纤层蛋白相关的中间丝是金鱼卵黄生成期卵母细胞核（生殖泡）内部结构的重要组成部分。
