Del-Pino Eugenia M, Sáenz Fabián E, Pérez Oscar D, Brown Federico D, Avila María-Eugenia, Barragán Verónica A, Haddad Nisrine, Paulin-Levasseur Micheline, Krohne Georg
Departamento de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito.
Int J Dev Biol. 2002 Mar;46(2):227-34.
Somatic and germinal cells of 15 fish and 33 amphibian species were examined by SDS-PAGE followed by immunoblotting to determine the expression of LAP2 (lamina-associated polypeptide 2). LAP2 expression in frogs, salamanders and fish does not vary with the mode of reproduction. In fish and frog cells, a rim-like LAP2 positive region was detected around the nucleus by indirect immunofluorescence microscopy. The cell distribution and expression patterns of LAP2 in fish, frogs and salamanders are comparable with those found in Xenopus and zebrafish. The mammalian somatic cell pattern, which may also occur in gymnophione amphibians, includes LAP2alpha, beta and gamma as major isoforms, whereas LAP2alpha does not occur in cells of fish, frogs and salamanders. In fish, LAP2gamma is the major isoform of somatic cells, suggesting that LAP2gamma may be ancestral. However, in the rainbow trout, as in frogs and salamanders, LAP2beta was the major somatic isoform. Fish and frog sperm only express low molecular weight polypeptides. In contrast, fish and frog oocytes express an oocyte-specific LAP2 isoform of high molecular weight. In the toad Bufo marinus this isoform becomes upregulated in pre-vitellogenic oocytes of 150-200 microm in diameter. The absence of LAP2alpha and the differential expression of LAP2 isoforms in somatic and germ cells, as found in fish and frogs, may be ancestral vertebrate characters. In spite of differences in developmental time, the LAP2 isoforms of somatic cells are upregulated during gastrulation, suggesting that LAP2 may be implicated in the early development of fish and frog.
通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）及免疫印迹法检测了15种鱼类和33种两栖类动物的体细胞和生殖细胞，以确定核纤层相关多肽2（LAP2）的表达情况。青蛙、蝾螈和鱼类中LAP2的表达与繁殖方式无关。在鱼类和青蛙细胞中，通过间接免疫荧光显微镜在细胞核周围检测到一个环状的LAP2阳性区域。鱼类、青蛙和蝾螈中LAP2的细胞分布和表达模式与非洲爪蟾和斑马鱼中的情况相当。哺乳动物体细胞模式（可能也存在于无足目两栖动物中）包括LAP2α、β和γ作为主要异构体，而LAP2α在鱼类、青蛙和蝾螈的细胞中不存在。在鱼类中，LAP2γ是体细胞的主要异构体，这表明LAP2γ可能是祖先形式。然而，在虹鳟鱼中，与青蛙和蝾螈一样，LAP2β是主要的体细胞异构体。鱼类和青蛙的精子只表达低分子量多肽。相比之下，鱼类和青蛙的卵母细胞表达一种高分子量的卵母细胞特异性LAP2异构体。在海蟾蜍中，这种异构体在直径为150 - 200微米的卵黄生成前卵母细胞中上调。如在鱼类和青蛙中发现的那样，LAP2α的缺失以及LAP2异构体在体细胞和生殖细胞中的差异表达可能是脊椎动物的祖先特征。尽管发育时间存在差异，但体细胞中的LAP2异构体在原肠胚形成过程中上调，这表明LAP2可能与鱼类和青蛙早期发育有关。
