Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
J Fish Biol. 2021 Apr;98(4):1155-1171. doi: 10.1111/jfb.14648. Epub 2021 Jan 7.
Hybrid advantage, described as the superiority of hybrids in some traits over their parents and termed the "heterosis effect," is widely documented in the case of reciprocal crosses of parental species (i.e., hybrids representing the F1 generation). In fish, high survival, fast growth and better health status have been widely documented in F1 hybrids. Nonetheless, the effects of interspecific hybridization on vigour, physiology and immunity-related traits in fish are largely unknown, especially concerning native systems of coexisting parental and hybrid genomes in the same habitat. The present study examined the potential physiological and immune aspects of hybrid heterosis by comparing condition status (measured especially by indexes), haematological profile, glucose concentration and selected parameters of non-specific and specific immunity between the evolutionarily divergent non-congeneric cyprinoid species Abramis brama and Rutilus rutilus and their hybrids representing the F1 generation, all of them caught in nature. Clear differences were documented for vigour-related, physiological and immune parameters between the two divergent species. Hybrids generally tended to express intermediate characters of the measured traits, likely generated by the evolutionary divergence of the hybridizing species; nonetheless, for some traits, hybrids exhibited a character that was more similar to one parental species than to the other. This was interpreted as the heterozygote advantage for F1 hybrids. It is suggested that a maternally inherited genetic background may potentially influence the expression of some branches of non-specific immunity or other aspects related to the fish health status.
杂种优势是指杂种在某些性状上优于其双亲的现象，被称为“杂种优势效应”，在双亲物种的回交（即代表 F1 代的杂种）中得到了广泛的证实。在鱼类中，F1 杂种的高存活率、快速生长和更好的健康状况已被广泛记录。然而，种间杂交对鱼类活力、生理和免疫相关特征的影响在很大程度上尚不清楚，特别是在同一栖息地共存的亲代和杂种基因组的本地系统方面。本研究通过比较进化上不同的非同源鲤科鱼类（Abramis brama 和 Rutilus rutilus）及其代表 F1 代的杂种的状态指数（尤其是通过指标测量）、血液学特征、葡萄糖浓度以及非特异性和特异性免疫的选定参数，来检验杂种优势的潜在生理和免疫方面。这两个不同的物种在活力相关、生理和免疫参数方面存在明显差异。杂种通常表现出介于双亲之间的中间特征，这可能是由杂交物种的进化分歧产生的；然而，对于一些特征，杂种表现出与一个亲代物种更相似的特征，而不是另一个亲代物种。这被解释为 F1 杂种的杂合优势。研究表明，母系遗传背景可能潜在地影响非特异性免疫的某些分支或与鱼类健康状况相关的其他方面的表达。
