SummaryThe cause of hybrid sterility and inviability has not been analyzed in the fin-fish hybrid, although large numbers of hybridizations have been carried out. In this study, we produced allo-diploid hybrids by cross-fertilization between female goldfish (Carassius auratus) and male golden venus chub (Hemigrammocypris rasborella). Inviability of these hybrids was due to breakage of the enveloping layer during epiboly or due to malformation with serious cardiac oedema around the hatching stage. Spontaneous allo-triploid hybrids with two sets of the goldfish genome and one set of the golden venus chub genome developed normally and survived beyond the feeding stage. This improved survival was confirmed by generating heat-shock-induced allo-triploid hybrids that possessed an extra goldfish genome. When inviable allo-diploid hybrid cells were transplanted into goldfish host embryos at the blastula stage, these embryos hatched normally, incorporating the allo-diploid cells. These allo-diploid hybrid cells persisted, and were genetically detected in a 6-month-old fish. In contrast, primordial germ cells taken from allo-diploid hybrids and transplanted into goldfish hosts at the blastula stage had disappeared by 10 days post-fertilization, even under chimeric conditions. In allo-triploid hybrid embryos, germ cells proliferated in the gonad, but had disappeared by 10 weeks post-fertilization. These results showed that while hybrid germ cells are inviable even in chimeric conditions, hybrid somatic cells remain viable.

中文翻译：

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Carassius auratus 雌性与Hemigrammocypris rasborella 雄性杂种体细胞和生殖细胞的发育潜力

总结尽管已经进行了大量的杂交，但尚未分析有鳍鱼杂种中杂种不育和不育的原因。在这项研究中，我们通过雌性金鱼之间的交叉受精产生了异源二倍体杂种（鲫鱼) 和雄性金星鲢鱼 (半鲫鱼）。这些杂种无法生存是由于在外胚层期间包络层的破损或由于在孵化阶段周围出现严重心脏水肿的畸形。具有两组金鱼基因组和一组金金鱼基因组的自发同种异体三倍体杂种发育正常并在饲养阶段后存活。通过产生具有额外金鱼基因组的热休克诱导的异源三倍体杂种，证实了这种提高的存活率。当在囊胚期将不可行的异源二倍体杂交细胞移植到金鱼宿主胚胎中时，这些胚胎正常孵化，并结合了异源二倍体细胞。这些异源二倍体杂交细胞持续存在，并在一条 6 个月大的鱼身上进行了基因检测。相比之下，从异源二倍体杂种中取出并在囊胚期移植到金鱼宿主体内的原始生殖细胞在受精后 10 天就消失了，即使在嵌合条件下也是如此。在异体三倍体杂交胚胎中，生殖细胞在性腺中增殖，但在受精后 10 周消失。这些结果表明，虽然杂种生殖细胞即使在嵌合条件下也是不可行的，但杂种体细胞仍然是可行的。