Department of Ecology & Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland.
Hintermann & Weber SA, Rue de l'Eglise-Catholique 9b, 1820, Montreux, Switzerland.
Sci Rep. 2017 Oct 6;7(1):12768. doi: 10.1038/s41598-017-12942-y.
Hybridogenesis is a special mode of hybrid reproduction where one parental genome is eliminated and the other is transmitted clonally. We propose that this mechanism can perpetuate the genome of extinct species, based on new genetic data from Pelophylax water frogs. We characterized the genetic makeup of Italian hybridogenetic hybrids (P. kl. hispanicus and esculentus) and identified a new endemic lineage of Eastern-Mediterranean origin as one parental ancestor of P. kl. hispanicus. This taxon is nowadays extinct in the wild but its germline subsists through its hybridogenetic descendant, which can thus be considered as a "semi living fossil". Such rare situation calls for realistic efforts of de-extinction through selective breeding without genetic engineering, and fuels the topical controversy of reviving long extinct species. "Ghost" species hidden by taxa of hybrid origin may be more frequent than suspected in vertebrate groups that experienced a strong history of hybridization and semi-sexual reproduction.
杂种发生是一种特殊的杂种繁殖模式，其中一个亲本基因组被消除，而另一个则以无性繁殖的方式传递。我们提出，基于来自Pelophylax 水蛙的新遗传数据，这种机制可以使已灭绝物种的基因组得以延续。我们对意大利杂种发生杂种（P. kl. hispanicus 和 esculentus）的遗传构成进行了描述，并确定了一种源自东地中海的新特有谱系，是 P. kl. hispanicus 的一个亲本祖先。该分类群如今在野外已灭绝，但它的生殖系通过其杂种发生的后代得以存续，因此可以被视为“半活化石”。这种罕见的情况需要通过选择性繁殖而不是基因工程来进行现实的灭绝后恢复努力，这也加剧了复活已灭绝物种的热门争议。在经历了强烈杂交和半性繁殖历史的脊椎动物群中，隐藏在杂种起源类群中的“幽灵”物种可能比人们所怀疑的更为频繁。
