Meeting Abstract
Perhaps the most important event in an organism’s life is reproduction, a complex behavioral process tightly controlled by signaling between the nervous system and the reproductive organs. The metabolic and fitness costs of reproduction are extreme for semelparous individuals, such as octopuses, who produce offspring only once before dying. Octopuses show striking changes in behavior after reproduction: while brooding their clutches, female octopuses will first stop feeding and then undergo a rapid senescent decline leading to death. This sequence of events, including death, is under central hormonal control. Ablation of paired neurosecretory centers, the optic glands, leads to a complete reversal of all maternal behaviors: females cease brood care, resume normal feeding behaviors, and experience a greatly increased lifespan (Wodinsky, 1977). Despite the important roles the optic glands play throughout the octopus’s life, they remain understudied using modern techniques. To explore the molecular bases of optic gland hormone signaling, we carried out Next-Generation RNA sequencing on optic glands of Octopus bimaculoides females at each of the three behavioral epochs of brooding: feeding, fasting, and deterioration. These transcriptomes were compared with those of central brain, optic lobe, viscera, posterior salivary gland and the ovaries. We identified cohorts of genes that are differentially expressed over the behavioral epochs, suggesting an extensive regulatory network dedicated to female reproductive behaviors such as brooding, fasting, and senescence.
