Evolutionary Biology & Ecology, Université Libre de Bruxelles, 50, av. F.D. Roosevelt, CP 160/12, B-1050 Brussels, Belgium.
Mol Ecol. 2013 Feb;22(4):947-55. doi: 10.1111/mec.12141. Epub 2012 Dec 7.
Hybridogenesis is a sexual reproductive system, whereby parents from different genetic origin hybridize. Both the maternal and paternal genomes are expressed in somatic tissues, but the paternal genome is systematically excluded from the germ line, which is therefore purely maternal. Recently, a unique case of hybridogenesis at a social level was reported in the desert ant Cataglyphis hispanica. All workers are sexually produced hybridogens, whereas sexual forms (new queens and males) are produced by queens through parthenogenesis. Thus, only maternal genes are perpetuated across generations. Here, we show that such an unusual reproductive strategy also evolved in two other species of Cataglyphis belonging to the same phylogenetic group, Cataglyphis velox and Cataglyphis mauritanica. In both species, queens mate exclusively with males originating from a different genetic lineage than their own to produce hybrid workers, while they use parthenogenesis to produce the male and female reproductive castes. In contrast to single-queen colonies of C. hispanica, colonies of C. velox and C. mauritanica are headed by several queens. Most queens within colonies share the same multilocus genotype and never transmit their mates' alleles to the reproductive castes. Social hybridogenesis in the desert ants has direct consequences on the genetic variability of populations and on caste determination. We also discuss the maintenance of this reproductive strategy within the genus Cataglyphis.
杂种发生是一种有性生殖系统，在此系统中，来自不同遗传起源的亲代杂交。母本和父本基因组都在体细胞组织中表达，但父本基因组被系统地排除在生殖系之外，因此生殖系纯粹是母本的。最近，在沙漠蚂蚁 Cataglyphis hispanica 中报道了一个独特的社会性杂种发生案例。所有工蚁都是有性产生的杂种，而有性形式（新的蚁后和雄蚁）则是由蚁后通过孤雌生殖产生的。因此，只有母系基因在世代中延续。在这里，我们表明，这种不寻常的生殖策略也在 Cataglyphis 属的另外两个属于同一进化群的物种中进化，即 Cataglyphis velox 和 Cataglyphis mauritanica。在这两个物种中，蚁后仅与来自与自身不同遗传谱系的雄性交配，以产生杂种工蚁，而它们使用孤雌生殖来产生雄性和雌性生殖级。与 C. hispanica 的单蚁后群体不同，C. velox 和 C. mauritanica 的群体由几个蚁后领导。群体内的大多数蚁后共享相同的多位点基因型，并且从不将其配偶的等位基因传递给生殖级。沙漠蚂蚁的社会杂种发生对种群的遗传变异性和级型决定有直接影响。我们还讨论了在 Cataglyphis 属内维持这种生殖策略的原因。
