Do juvenile developmental and adult body characteristics differ among genotypes at the doublesex locus that controls female-limited Batesian mimicry polymorphism in Papilio memnon?: A test for the "cost of mimicry" hypothesis
Do juvenile developmental and adult body characteristics differ among genotypes at the doublesex locus that controls female-limited Batesian mimicry polymorphism in Papilio memnon?: A test for the "cost of mimicry" hypothesis
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DOI：
10.1016/j.jinsphys.2018.02.001
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发表时间：
2018-05-01
影响因子：
2.2
通讯作者：
Sota, Teiji
中科院分区：
文献类型：
--
作者：
Komata, Shinya;Lin, Chung-Ping;Sota, Teiji
雌性有限的贝叶斯模仿可能是因为雌性比雄性面临更大的捕食压力而进化的，但模仿的一些生理代价也可能阻碍雄性模仿的进化。孟农凤蝶（Papilio memnon）具有雌性限制性贝叶斯模仿多态性，双性位点（dsx）的两个等位基因严格控制雌性表型。为了研究模拟基因型在幼鱼期是否存在生理成本，我们比较了三种dsx基因型（HH， HH， HH）在恒温（25℃）和两种不同日长（LD 14:10和LD 12:12，后者可能导致蛹滞育）下的死亡率、幼鱼生长发育和成虫特征。不论日长，所有蛹均直接出蛹，不滞育。出现个体的基因型频率与预期的1:2:1比例HH: HH: HH一致。在两个家庭中，有一个家庭的性别比例明显偏向男性，而另一个家庭则没有。我们没有发现基因型对任何发育或成年特征的影响，尽管大多数特征存在性别差异。雌虫发育时间长，生长速度快于雄虫；雌蝶蛹重、前翅长、胸腹总干质量较大，雄蝶胸腹比较大。白天较短时，蛹的生长速率比白天较长时高，蛹期也比白天较长时长。总的来说，我们没有发现与模拟基因型相关的生理成本的证据。然而，由于我们还没有研究不同基因型的成虫，因此得出模仿的生理代价不会影响这种雌性有限贝叶斯模仿多态性的进化和维持的结论还为时过早。
Female-limited Batesian mimicry may have evolved because of stronger predation pressure on females than on males, but some physiological costs of mimicry may also hinder the evolution of mimicry in males. In Papilio memnon, which possesses a female-limited Batesian mimicry polymorphism, two alleles at the doublesex (dsx) locus strictly control female phenotypes. To examine whether there are physiological costs associated with mimetic genotypes in the juvenile stage, we compered mortality, juvenile growth and development, and the resultant adult characteristics among three dsx genotypes (HH, Hh, hh) at a constant temperature (25 degrees C) and two differing day lengths (LD 14:10 and LD 12:12; the latter might induce pupal diapause) by crossing individuals heterozygous (Hh) for the dsx allele. All pupae emerged directly without diapause irrespective of day length. The genotype frequencies of the emerged individuals were consistent with the expected 1:2:1 ratio of HH:Hh:hh. The sex ratio was significantly male-biased in one of two families, but not in the other. We found no effect of genotype on any developmental or adult characteristic, although there were sex differences in most traits. The larval development time was longer and growth rate higher in females than in males; pupal weight, forewing length, and total dry mass of the thorax and abdomen were greater in females, whereas the thoracic mass/abdominal mass ratio was greater in males. We also found that the growth rate was higher and pupal period longer with a short day than with a long day. Overall, we found no evidence for physiological costs associated with the mimetic genotypes. However, it is too early to conclude that no physiological cost of mimicry affects the evolution and maintenance of this female-limited Batesian mimicry polymorphism because we have not studied the adults of different genotypes.