Differences in egg hatching time between cyclical and obligate parthenogenetic lineages of aphids
Differences in egg hatching time between cyclical and obligate parthenogenetic lineages of aphids
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DOI：
10.1111/1744-7917.12493
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发表时间：
2019-02-01
期刊：
影响因子：
4
通讯作者：
Simon, Jean-Christophe
中科院分区：
文献类型：
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作者：
Dedryver, Charles-Antoine;Bonhomme, Joel;Simon, Jean-Christophe
许多蚜虫物种表现出的繁殖模式的变化，这是冬季气候制度的影响，与周期性孤雌生殖（CP）线占主导地位，在寒冷的冬季地区（因为他们产生耐寒的鸡蛋）和专性孤雌生殖（OP）的温和的冬季地区（因为他们的孤雌越冬）。对几种蚜虫的遗传研究表明，OP性状可以在涉及两种品系的有性事件中传播。这种遗传系统可以被认为是OP等位基因的局部保护机制，以防严重霜冻杀死所有单性繁殖越冬个体。然而，这种策略将只有效地恢复本地多态性的育种系统，如果新孵化的OP重组保持竞争力超过他们的CP同行。在这项研究中，我们比较了卵孵化序列的CP和OP F1克隆从几个十字架获得的2种谷物蚜虫，麦长管蚜（恒定5摄氏度，8小时的光）和禾谷缢管蚜（冬季室外条件）。对于鼠伤寒沙门氏在燕麦中，我们从6个杂交组合中获得了F_1后代，涉及4个无性系，而在R.从14个无性系的11个杂交组合中获得了水稻F_1。我们发现，在这两个物种的OP克隆比例较高的前一半的后代相对于后一半。此外，F1 OP克隆的平均孵化时间比它们的CP同胞早约一周，这使它们在生长季节开始时具有人口统计学优势。然后，我们讨论了这种健身优势的后果，在蚜虫种群的OP性状的维护和传播。
Many aphid species exhibit a variation in reproductive mode which is influenced by winter climate regimes, with cyclical parthenogenetic (CP) lines dominating in cold winter areas (because they produce cold-resistant eggs) and obligate parthenogenetic (OP) ones in mild winter regions (because of their parthenogenetic overwintering). Genetic studies on several aphid species have shown that the OP trait can be transmitted during sexual events involving the 2 types of lines. This genetic system could be considered as a local safeguarding mechanism for OP alleles in case severe frost would have killed all parthenogenetically overwintering individuals. However, this strategy would only be efficient in restoring local polymorphism in breeding systems if the newly hatched OP recombinants remain competitive over their CP counterparts. In this study we compared egg hatching sequences of CP and OP F1 clones from several crosses obtained for 2 cereal aphid species, Sitobion avenae (constant 5 degrees C, 8 h of light) and Rhopalosiphum padi (winter outdoor conditions). For S. avenae, we obtained F1 offspring from 6 crosses, involving 4 clones while in R. padi F1 were obtained from 11 crosses involving 14 clones. We showed that in both species proportions of OP clones were higher in the first half of the progeny relative to the second half. In addition, F1 OP clones hatched in the mean about a week earlier than their CP sibs, which gives them a demographic advantage at the start of the growth season. We then discussed the consequences of this fitness advantage for the maintenance and spread of the OP trait in aphid populations.