Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Instituto Nacional de Ciência E Tecnologia Em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil.
Parasit Vectors. 2022 Oct 18;15(1):374. doi: 10.1186/s13071-022-05529-8.
The study of behavioral and physiological traits in mosquitoes has been mainly focused on females since males are not hematophagous and thus do not transfer the parasites that cause diseases in human populations. However, the performance of male mosquitoes is key for the expansion of populations and the perpetuation of mosquito species. Pre-copulatory communication between males and females is the initial and essential step for the success of copulation and studying the male facet of this interaction provides fertile ground for the improvement of vector control strategies. Like in most animals, reproduction, feeding, and oviposition are closely associated with locomotor activity in mosquitoes. Rhythmic cycles of locomotor activity have been previously described in Aedes aegypti, and in females, they are known to be altered by blood-feeding and arbovirus infection. In previous work, we found that males in the presence of females significantly change their locomotor activity profiles, with a shift in the phase of the activity peak. Here, we investigated whether this shift is associated with changes in the expression level of three central circadian clock genes.
Real-time PCR reactions were performed for the gene period, cycle, and cryptochrome 2 in samples of heads, antennae, and abdominal tips of solitary males and males in the presence of females. Assays with antennae-ablated males were also performed, asking whether this is an essential organ mediating the communication and the variation in activity profiles.
The gene period showed a conserved expression pattern in all tissues and conditions, while the other two genes varied according to the male condition. A remarking pattern was observed in cry2, where the difference between the amplitude of expression at the beginning of photophase and the expression peak in the scotophase was greater when males were in the presence of females. Antennae ablation in males did not have a significant effect on the expression profiles, suggesting that female recognition may involve other senses besides hearing and olfaction.
Our results suggest that the expression of gene cryptochrome 2 varies in association with the interaction between males and females.
由于雄性蚊子不吸血，因此不会传播导致人类疾病的寄生虫，因此对蚊子的行为和生理特征的研究主要集中在雌性蚊子上。然而，雄性蚊子的表现对于种群的扩张和蚊子物种的延续至关重要。雌雄个体之间的求偶前通讯是交配成功的初始和必要步骤，研究这种相互作用的雄性方面为改进病媒控制策略提供了肥沃的土壤。与大多数动物一样，蚊子的繁殖、进食和产卵与运动活动密切相关。在埃及伊蚊中，已经描述了运动活动的节律性周期，并且在雌性蚊子中，它们已知会因吸血和黄病毒感染而改变。在之前的工作中，我们发现，有雌性存在的情况下，雄性蚊子的运动活动谱会发生显著变化，活动峰的相位发生了转移。在这里，我们研究了这种转变是否与三个中央生物钟基因的表达水平变化有关。
对单独的雄性和有雌性存在的雄性的头部、触角和腹部末端样本进行了实时 PCR 反应，检测了 period、cycle 和 cryptochrome 2 基因的表达。还对触角切除的雄性进行了检测，以确定触角是否是介导这种通讯和活动谱变化的必需器官。
period 基因在所有组织和条件下表现出保守的表达模式，而其他两个基因则根据雄性的条件而变化。在 cry2 中观察到一种显著的模式，即当雄性处于有雌性存在的情况下时，光相开始时的表达幅度与暗相峰值之间的差异更大。雄性触角切除对表达谱没有显著影响，这表明雌性识别可能涉及听觉和嗅觉以外的其他感觉。
我们的结果表明，基因 cryptochrome 2 的表达与雌雄个体之间的相互作用有关。
