The <i>Drosophila melanogaster foraging</i> gene affects social networks

<i>Drosophila melanogaster</i> displays social behaviors including courtship, mating, aggression, and group foraging. Recent studies employed social network analyses (SNAs) to show that <i>D. melanogaster</i> strains differ in their group behavior, suggesting that genes influence social network phenotypes. Aside from genes associated with sensory function, few studies address the genetic underpinnings of these networks. The <i>foraging</i> gene <i>(for)</i> is a well-established example of a pleiotropic gene that regulates multiple behavioral phenotypes and their plasticity. In <i>D. melanogaster,</i> there are two naturally occurring alleles of <i>for</i> called rover and sitter that differ in their larval and adult food-search behavior as well as other behavioral phenotypes. Here, we hypothesize that <i>for</i> affects behavioral elements required to form social networks and the social networks themselves. These effects are evident when we manipulate gene dosage. We found that flies of the rover and sitter strains exhibit differences in duration, frequency, and reciprocity of pairwise interactions, and they form social networks with differences in assortativity and global efficiency. Consistent with other adult phenotypes influenced by <i>for</i>, rover-sitter heterozygotes show intermediate patterns of dominance in many of these characteristics. Multiple generations of backcrossing a rover allele into a sitter strain showed that many but not all of these rover-sitter differences may be attributed to allelic variation at <i>for.</i> Our findings reveal the significant role that <i>for</i> plays in affecting social network properties and their behavioral elements in <i>Drosophila melanogaster</i>.黑腹果蝇（Drosophila melanogaster）展现出包括求偶、交配、攻击行为与群体觅食在内的多种社会行为。近期研究采用社会网络分析（social network analyses, SNAs）证实，黑腹果蝇的不同品系在群体行为上存在差异，这提示基因可对社会网络表型产生影响。除与感觉功能相关的基因外，目前鲜有研究探讨这类社会网络的遗传基础。觅食基因（foraging gene, for）是经典的多效基因范例，其可调控多种行为表型及其可塑性。在黑腹果蝇中，该基因存在两种自然存在的等位基因——漫游者（rover）与滞留者（sitter），二者在幼虫与成虫的觅食行为及其他行为表型上均存在差异。本研究假设，觅食基因会影响构成社会网络的行为要素，乃至社会网络本身，而这类效应可通过调控基因剂量（gene dosage）得以体现。研究发现，漫游者型与滞留者型果蝇在成对互作的时长、频率及互惠性上存在差异，且二者形成的社会网络在同配性（assortativity）与全局效率（global efficiency）上亦有所不同。与该基因调控的其他成虫行为表型一致，漫游者-滞留者杂合子在多数相关特征上表现出中间型的显性模式。将漫游者等位基因回交至滞留者品系多代后发现，这类漫游者与滞留者间的差异中，有部分但并非全部可归因于觅食基因座的等位基因变异。本研究结果揭示，觅食基因在黑腹果蝇社会网络特性及其构成行为要素的调控中发挥着重要作用。