A global-wide search for sexual dimorphism of glomeruli in the antennal lobe of female and male Helicoverpa armigera

Abstract

By using immunostaining and three-dimensional reconstruction, the anatomical organization of the antennal lobe glomeruli of the female cotton bollworm Helicoverpa armigera was investigated. Eighty-one glomeruli were identified, 15 of which were not previously discovered. The general anatomical organization of the AL of female is similar to that of male and all glomeruli were classified into four sub-groups, including the female-specific glomerular complex, posterior complex, labial-palp pit organ glomerulus, and ordinary glomeruli. A global-wide comparison on the complete glomerular map of female and male was performed and for the first time the quantitative difference in volume for each individual homologous glomerulus was analyzed. We found that the sexual dimorphism includes not only the sex-specific glomeruli but also some of the other glomeruli. The findings in the present study may provide a reference to examine the antennal-lobe organization more in detail and to identify new glomeruli in other moth species. In addition, the complete identification and global-wide comparison of the sexes provide an important basis for mapping the function of distinct glomeruli and for understanding neural mechanisms underlying sexually dimorphic olfactory behaviors.

A novel major output target for pheromone-sensitive projection neurons in male moths

“…With respect to olfactory brain areas, a pronounced sexual dimorphism is represented by a three-unit MGC in H. armigera males (Zhao et al, 2016b, Skiri et al, 2005). Accordingly, we also identified these three male-specific glomeruli in the individuals examined in the current study.…”

Candidate odorant binding proteins and chemosensory proteins in the larval chemosensory tissues of two closely related noctuidae moths, Helicoverpa armigera and H. assulta

“…assulta [ 6 ], later supplemented by 15 new glomeruli in H . armigera [ 42 ]. Assuming that the number of glomeruli is equal to the number of ORs and IRs [ 43 , 44 ], almost all olfactory receptors were identified in the two species.…”

Evolution of the neural sex‐determination system in insects: does fruitless homologue regulate neural sexual dimorphism in basal insects?

“…Although sexually dimorphic structures have been found in the nervous system of non‐ Drosophila insects (Rössler et al , ; Rospars and Hildebrand, ; Berg et al , ; Nishikawa et al , ; El Jundi et al ., ; Mysore et al , ; Nishino et al , ; Baba etisoforms) were identified using al. , ; Nakanishi et al , ; Hu et al , ; Streinzer et al , ; Roselino et al , ; Zhao et al , ), the molecular, neuronal and developmental mechanisms underlying the sexual dimorphism of the brain are not well understood.…”

“…In the adult Drosophila brain, neurones expressing sex-specific fruitless gene products form sexually dimorphic circuits, which regulate sexually dimorphic behaviours including courtship behaviour and aggression (Manoli and Baker, 2004;Demir and Dickson, 2005;Vrontou et al, 2006;Chan and Kravitz, 2007;Kimura et al, 2008;von Philipsborn et al, 2011;Manoli et al, 2013;Yamamoto and Koganezawa, 2013;Tran et al, 2014). Although sexually dimorphic structures have been found in the nervous system of non-Drosophila insects (Rössler et al, 1998;Rospars and Hildebrand, 2000;Berg et al, 2002;Nishikawa et al, 2008;El Jundi et al, 2009;Mysore et al, 2009;Nishino et al, 2009;Baba etisoforms) were identified using al., 2010;Nakanishi et al, 2010;Hu et al, 2011;Streinzer et al, 2013;Roselino et al, 2015;Zhao et al, 2016), the molecular, neuronal and developmental mechanisms underlying the sexual dimorphism of the brain are not well understood.…”