Visual recognition of the anteroposterior female body axis drives spatial elements of male courtship in <i>Drosophila</i>

Drosophila males exhibit a highly stereotypic courtship ritual towards virgin females, which is comprised of a sequence of specific behavioral elements that depend on inputs from diverse sensory modalities. Particularly, the visual system of the male plays an important role in detecting salient patterns, colors, and motion cues from conspecifics, which can promote or inhibit specific aspects of male courtship such as chase and song production. Here, we use a computer vision and machine learning-based approach, with a simplified courtship paradigm, to show that males also depend on visual cues to determine the anterior-posterior body axis of females, which drives the specific spatial patterns of distinct behavioral courtship elements. We show that the recognition of the female body axis depends, at least in part, on the visual recognition of female eyes as an anterior landmark. Furthermore, we find that in the absence of visual input, courting males adjust not only their relative spatial courtship positioning, but also the relative frequencies at which they engage in each specific courtship element. Finally, analyses of the contributions of specific visual projection neurons to the recognition of the female body axis indicate that, although it is driven by a seemingly simple visual cue, the spatiotemporal release patterns of each individual courtship element appear to depend on the activity of multiple independent populations of visual projection neurons. Together, our results provide novel insights into the possible role of visual anatomical features in driving complex social interactions between conspecifics.