Argue Brad J, Kuhlers Daryl L, Liu Zhanjiang, Dunham Rex A
School of Fisheries, Aquaculture and Aquatic Sciences, Alabama Agricultural Experiment Station, Auburn University, Auburn, AL 36849.
Department of Animal Science, Alabama Agricultural Experiment Station, Auburn University, Auburn, AL 36849.
J Anim Sci. 2014 Oct;92(10):4297-305. doi: 10.2527/jas.2013-7549. Epub 2014 Aug 22.
The F1 hybrid between a channel catfish female (Ictalurus punctatus) × a blue catfish (I. furcatus) male outperforms both parental species in most environments. However, reproductive isolating mechanisms between the species made it difficult to mass produce the F1 hybrid for commercialization until recent improvements in hormone usage. This study was undertaken to mix the genomes of the 2 species in an attempt to obtain faster-growing catfish that would eventually be easier to reproduce. Despite the recent improvements, it would still be advantageous to have an animal that does not require hormone dosing for reproduction and does not require the growing of 2 separate species by breeders. Additionally, a F1 backcross or a multigeneration backcross has the possibility of being an improvement compared to an F1 hybrid. At low density, there was no difference in growth between channel catfish and channel-blue F1 hybrids. At higher densities, the F1 hybrid grew faster (666 g) than channel catfish (577 g), blue catfish × F1 (520 g), F1 × F1 (508 g), F1 × channel catfish (436 g), blue catfish (396 g), F1 × blue catfish (379 g), channel catfish × F1 (359 g), and F2 × F2 (359 g; P < 0.05). The channel-blue F1 males were heavier than the F1 females. Individual heterosis had a strong positive effect on growth, whereas individual epistatic recombination loss had a strong negative effect on growth. The channel-blue F1 hybrid and blue catfish had low coefficients of variation, whereas the F2 and F3 hybrids had high coefficients of variation. This gives a high amount of variation for selection, which might be used to select the faster-growing catfish.
斑点叉尾鮰雌鱼（Ictalurus punctatus）与蓝鲶雄鱼（I. furcatus）杂交产生的F1代杂种在大多数环境中表现优于双亲物种。然而，这两个物种之间的生殖隔离机制使得在激素使用取得近期进展之前，难以大量生产用于商业化的F1代杂种。本研究旨在混合这两个物种的基因组，以期获得生长更快、最终更易于繁殖的鲶鱼。尽管近期有所改进，但拥有一种无需激素处理即可繁殖且养殖者无需养殖两个不同物种的动物仍将具有优势。此外，与F1代杂种相比，F1回交或多代回交有可能带来改进。在低密度条件下，斑点叉尾鮰与斑点叉尾鮰 - 蓝鲶F1代杂种的生长没有差异。在较高密度下，F1代杂种（666克）比斑点叉尾鮰（577克）、蓝鲶×F1（520克）、F1×F1（508克）、F1×斑点叉尾鮰（436克）、蓝鲶（396克）、F1×蓝鲶（379克）、斑点叉尾鮰×F1（359克）以及F2×F2（359克；P < 0.05）生长得更快。斑点叉尾鮰 - 蓝鲶F1代雄鱼比F1代雌鱼更重。个体杂种优势对生长有强烈的正向影响，而个体上位重组损失对生长有强烈的负向影响。斑点叉尾鮰 - 蓝鲶F1代杂种和蓝鲶的变异系数较低，而F2代和F3代杂种的变异系数较高。这提供了大量可供选择的变异，可用于选择生长更快的鲶鱼。
