Exploring the Effect of Putative PGF Synthase Genes in A. Burtoni Cichlid

Abstract

Exploring the Effect of Putative PGF2α synthase genes in A. burtoni Cichlid ProstaglandinF2α (PGF2α) drives reproductive behaviors in different species as a hormone and pheromone. In African Cichlids, fertile females produce high levels of PGF2α which are converted to PGF2α metabolites. These metabolites signal and induce male preferential behavior. However, the mechanism behind the synthesis of PGF2α is widely unknown. Using A. Burtoni, we hypothesize that Aldo-Keto Reductase (AKR) enzymes are the putative PGF2α synthases; we proceeded to test the effect of a knockout of AKR using CRISPR-Cas9. In African Cichlids, two paralogs of AKR genes, LOC102291490 and LOC102291786, are hypothesized to be involved in PGF2α synthesis. However, individual knockout (KO) of either enzyme did not result in any significant change in the reproductive behaviors; we predicted that KO of both would result in lower PGF2α levels, circling bouts, and pecking in females. We targeted LOC102291490 in animals already carrying LOC102291786 d53/d53 homozygous mutations and recovered two mutant genotypes, d4 and d12d2. We had two tanks, each containing about 15 mixed-sex WT siblings or dual-KO fish, allowing undisturbed mating. Both tanks were live-recorded and reviewed to compare the male-female interactions between the genotypes. We surprisingly discovered a dual-KO male mouthbrooding eggs, complementing that PGF2α suppresses male mouthbrooding behavior via pheromone signaling. Additional investigation is necessary to examine whether PGF2α signaling suppresses male appetite and if males can discern between food and eggs. This study aids in our comprehension of reproductive behaviors and the mechanisms of hormone and pheromone-mediated behaviors.