Faculty of Agriculture, Setsunan University, 45-1 Nagao-Togecho, Hirakata, Osaka 573-0101, Japan.
Faculty of Agriculture, Setsunan University, 45-1 Nagao-Togecho, Hirakata, Osaka 573-0101, Japan.
J Insect Physiol. 2022 Oct;142:104440. doi: 10.1016/j.jinsphys.2022.104440. Epub 2022 Sep 7.
In addition to the blend ratio, the quantity of sex pheromone components secreted by female moths may affect the efficient attraction of conspecific males. The present study using the silkmoth Bombyx mori, which has bombykol as its pheromone component, demonstrated that pheromone titer, body weight, and lipid droplet (LD) diameter in the pheromone gland were affected by the larval diet. Although the artificial diet contained approximately 11-fold more total fatty acids than mulberry leaf, the pheromone titer in the group fed the artificial diet (group AD) was approximately 2-fold higher than that of the group fed mulberry (group M). The diameter of LDs, which store the pheromone-precursor fatty acyl, E10,Z12-16:Acyl, was also larger in the AD group. The relatively small increase in sex pheromone titer by feeding on a fatty-acid-rich diet may be partly attributable to the storage of excess precursors in the LDs. We detected LDs in the pheromone glands of Trilocha varians, the closest non-congener of B. mori available in Bombycidae. T. varians uses bombykal and bombykyl acetate as sex pheromone components, which are biosynthesized via the same precursor fatty acyl as that of B. mori. The presence of LDs in T. varians suggests that the storage and mobilization mechanisms of the pheromone precursor fatty acyl via LDs may be conserved in bombycids.
除了混合比例外，雌蛾分泌的性信息素成分的数量也可能影响同种雄蛾的有效吸引。本研究以具有信息素成分 bombykol 的家蚕（Bombyx mori）为对象，表明信息素滴度、体重和信息素腺中的脂滴（LD）直径受幼虫饮食的影响。尽管人工饲料中总脂肪酸的含量约为桑叶的 11 倍，但喂食人工饲料的组（AD 组）的信息素滴度约为喂食桑叶的组（M 组）的 2 倍。储存信息素前体脂肪酸酰基 E10,Z12-16:Acyl 的 LD 直径在 AD 组中也更大。在富含脂肪酸的饮食中，性信息素滴度的相对较小增加可能部分归因于 LD 中储存的过量前体。我们在 Bombycidae 中最接近的非同源种 Trilocha varians 的信息素腺中检测到了 LD。T. varians 使用 bombykal 和 bombykyl acetate 作为性信息素成分，这些成分是通过与 B. mori 相同的前体脂肪酸酰基生物合成的。T. varians 中存在 LD 表明，通过 LD 储存和动员信息素前体脂肪酸酰基的机制可能在鳞翅目昆虫中保守。
