对杂交三倍体泥鳅Misgurnus anguillicaudatus(2n♀×4n♂,DT)和二倍体泥鳅(2n♀×2n♂,DD)的胚胎发育进行观察,详细记录了其胚胎发育的形态特征和发育特点。结果表明:DT受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需36 h 19 min;对照组DD受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需35 h 57 min;DT(DD)的胚胎发育包括卵裂期、囊胚期、原肠期、神经胚期、器官形成期和孵化出膜期6个时期,DT(DD)受精卵约40 min(40 min)后进入卵裂期,3 h 45 min(3 h 40min)后进入囊胚期,6 h 30 min(6 h 24 min)后进入原肠期,9 h 32 min(9 h 20 min)后进入神经胚期,15 h 45 min(15 h 30 min)后进入器官形成期,36 h 19 min(35 h 57 min)后出膜。研究表明,DT的胚胎发育时序及形态特征与DD基本相似,说明DT具有正常的胚胎发育过程,本研究可为杂交三倍体泥鳅苗种培育提供生物学依据。
We used microsatellite markers to investigate the genetic parameters of three different polyploidy populations of Misgurnus anguillicaudatus from Honghu City, Hubei Province. Polyacrylamide gel electrophoresis banding patterns of diploid（2n）, triploid（3n） and tetraploid loaches（4n） were analyzed with Pop Gen software. A total of 68 alleles were obtained from seven microsatellite loci and the polymorphism information content（PIC） indices were all above 0.5. The average expected mean heterozygosity values（He） were 0.8420, 0.7186 and 0.8521; the average observed mean heterozygosity values（Ho） were 0.9674, 0.9785 and 0.8928; and the HardyWeinberg P values were 0.3078, 0.3151 and 0.3762, for diploid, triploid and tetraploid individuals, respectively. The results indicated that the three populations were highly polymorphic, with no deviations from Hardy-Weinberg equilibrium observed at all the seven microsatellite loci. This indicated a high level of genetic diversity within the populations. A cluster analysis diagram showed that the shortest genetic distance was between diploid and tetraploid loaches and they shared a close phylogenetic relationship. The triploid and tetraploid individuals had the most distant phylogenetic relationship.
Li Ya-juanQi Hong-ruiMa Hai-yanZhou HeXu WenSui YiLi Jia-qi
对杂交三倍体泥鳅(4n♀×2n♂)的胚胎染色体进行了C带及染色体荧光原位杂交(FISH)分析,首次探讨了杂交三倍体泥鳅C带特征,为准确鉴别染色体提供依据,研究了核糖体5.8S+28S r DNA在杂交三倍体泥鳅胚胎中期染色体上的数目和位置。C带结果表明,杂交三倍体泥鳅的染色体C带包括臂端C带和着丝粒C带,没有发现臂间C带。M染色体只有1号染色体既有臂端C带又有着丝粒C带,但臂端C带均比着丝粒C带大,信号也比着丝粒的强;而其他M染色体及SM染色体、T染色体只有着丝粒C带。FISH分析显示,核糖体5.8S+28S r DNA清楚地定位在杂交三倍体泥鳅中期染色体中部着丝粒染色体(M)的端部区域,在杂交三倍体泥鳅中期染色体上可以检测到三簇杂交信号。该结果从分子细胞遗传学层面进一步证实了杂交三倍体泥鳅是含有三套染色体组的遗传三倍体。
