INHERITANCE OF LEARNED NOVEL FOOD ODOR PREFERENCES IN Bicyclus anynana BUTTERFLY LARVAE

Abstract

Environmental odor cues can shape an organism's innate odor preferences and host plant choices through learning, with these acquired traits potentially transmitted to subsequent generations via epigenetic or non-genetic factors. While the learning of novel food odors in lepidopteran larvae remains poorly understood, Bicyclus anynana butterfly larvae have been observed to learn and inherit a preference for a novel food odor. However, the mechanisms underlying this preference development and inheritance remain unclear. To investigate, larvae were fed odor-coated leaves for seven generations to assess whether this increased their preference for the odor and if the preference was maintained in subsequent generations without the odor stimulus. Results indicated a rapid development of odor preference within one generation but no increase across generations, with larvae losing their preference once the odor was removed. Hemolymph transfusions from odor-fed larvae induced a preference shift in naïve larvae, suggesting a role of hemolymph in odor preference inheritance. RNA sequencing revealed differential gene expression between control- and odor-fed larvae, implicating mRNAs in odor preference learning. This study highlights the potential role of parental effects and epigenetic factors, such as mRNAs and larval hemolymph, in transmitting learned odor preferences in lepidopteran larvae.