文章对二倍体大鳞副泥鳅♀×四倍体泥鳅♂杂交后代的染色体进行Ag-NORs、CMA3/DA/DAPI及FISH等系列研究.结果表明,①在对照组泥鳅×泥鳅(2n×2n)杂交后代的间期核和中期分裂相中最高银染点数为2个,杂交组2n×4n杂种后代的间期核和中期分裂相中最高银染点数为3个；②在对照组2n×2n杂交后代有丝分裂中期分裂相中,2条中部着丝粒染色体(M)的端部区域显示有明亮的CMA3阳性部位,杂交组2n×4n杂种后代有丝分裂中期分裂相中3条中部着丝粒染色体(M)的端部区域显示明亮的CMA3阳性部位；③应用荧光原位杂交(FISH)技术可以将核糖体5.8S+28S rDNA清楚地定位在杂交后代中期染色体中部着丝粒染色体(M)的端部区域.在对照组2nx2n中期染色体上可以检测到二簇杂交信号,而在杂交组后代中期染色体上可以检测到三簇杂交信号.通过Ag-NORs、CMA3/DA/DAPI荧光显带及核糖体5.8S+28S rDNA的FISH定位在杂交后代得到的NORs位点相吻合,位点数目为3个.该结果为杂种后代提供了直接的三倍体细胞遗传学证据.%Chromosomes of breedings of the diploid Paramisgurnus dabryanus and tetraploid Misgurnus anguillicaudatus were analyzed by staining with Ag, chromomycinA3(CMA3)/ distamycin A (DA), and DA/4', 6-diamidino-2-phenylindole (DAPI), and using fluorescence in stu hybridization (FISH) with 5.8S+28SrDNA as a probe. Results were as follows: (1)The maximum number of Ag-NORs were two in both interphase and metaphase in the control group 2n × 2n, while they were both three in the cross 2n×4n; (2)CMA3 positive sites were two in 2n×2n, on the telomeric position of the short arms of M chromosomes, while four positive sites in 2n×4n were detected on the same location. (3) By FISH, 5.8S+ 28SrDNA signals were clearly detected in the above telomeric Ag-NOR and CMA3-positive sites in the short arms of M chromosome pair or trio. Two signals were detected in the control group, and three in the cross group. FISH position of ribosomal 5.8S+28S rDNA in hybrid progenies was corresponding with the results of Ag-NORs, CMA3/DA/DAPI, and the number were all three. Results provided an cytoge netic proof that the hybrid progenies were triploid.
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