Pinto Neto José Paulo da Costa, Goll Leonardo Gusso, Gross Maria Claudia, Feldsberg Eliana, Schneider Carlos Henrique
Instituto Nacional de Pesquisas da Amazônia - INPA, Programa de Pós-graduação em Genética, Conservação e Biologia Evolutiva, Manaus, AM, Brazil.
Instituto de Natureza e Cultura - INC, Benjamin Constant, AM, Brazil.
Genet Mol Biol. 2020 Nov 16;43(4):e20200069. doi: 10.1590/1678-4685-GMB-2020-0069. eCollection 2020.
Cytogenetic characterization was performed on three wandering spiders: Ctenus amphora Mello-Leitão, 1930, C. crulsi Mello-Leitão, 1930 and C. villasboasi Mello-Leitão, 1949. The three species had similar karyotypes, with 2n = 28 (26 + X1X20) in males, with sex chromosomes exhibiting positive heteropicnosis in meiotic cells. 18S rDNA mapping revealed gene sites at the terminal region of one chromosomal pair for all species, with one C. crulsi individual, showing markings in two pairs. C. villasboasi showed markers only in the pachytene phase. The distribution pattern of constitutive heterochromatin was found to be characteristic for the genus, with markings in the centromeric region of all chromosomes, suggesting an acrocentric morphology for all chromosomes of the three analysed species. The results support the fusion of sex chromosomes as an evolutionary tendency for this spider group.
壶形栉足蛛(Ctenus amphora Mello-Leitão,1930年)、克鲁氏栉足蛛(C. crulsi Mello-Leitão,1930年)和维拉波斯栉足蛛(C. villasboasi Mello-Leitão,1949年)。这三个物种具有相似的核型,雄性为2n = 28(26 + X1X2),性染色体在减数分裂细胞中表现出阳性异固缩。18S rDNA定位显示,所有物种在一对染色体的末端区域都有基因位点,其中一只克鲁氏栉足蛛个体在两对染色体上有标记。维拉波斯栉足蛛仅在粗线期显示标记。组成型异染色质的分布模式被发现是该属的特征,在所有染色体的着丝粒区域有标记,表明所分析的三个物种的所有染色体均为近端着丝粒形态。结果支持性染色体融合是该蜘蛛类群的一种进化趋势。