The configuration and regulation of circadian rhythms in workers of stingless bees (Melipona quadrifasciata)

• Grant number: 22/05723-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2022
• End date: December 31, 2023
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Klaus Hartmann Hartfelder
• Grantee: Arthur Roque Justino
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 20/13296-9 - Molecular basis of behavioral plasticity and reproductive strategies in life histories evolution of Neotropical stingless bees, AP.TEM
• Associated scholarship(s): 23/02449-7 - Investigating circadian clock proteins in the brain of a stingless bee (Melipona quadrifasciata), BE.EP.IC

Abstract

The circadian rhythms of insects are generated through an oscillatory and self-regulatory gene loop, whose organization is poorly characterized in members of the Meliponini tribe, which are the highly eusocial bees native to Brazil. In the honey bee, Apis mellifera, the molecular operation of circadian rhythms is highly characterized, and, strikingly, it has greater similarity with humans than to Drosophila. Moreover, throughout the life cycle, the A. mellifera workers show an interesting transition, from activities with no circadian rhythm while they care for the brood, and rhythmic ones when they become foragers. Therefore, this project aims to characterize the patterns of gene expression of the elements that compose the circadian clock in the stingless bee Melipona quadrifasciata. As rhythmic behaviors have already been observed in nurses and foragers of M. quadrifasciata, we are going to analyze the expression of genes that compose the circadian clock in 15-day-old nurse bees, and in 25-days-old bees transitioning to foragers. We also seek to characterize anatomically the brain regions involved in the circadian organization and generation, using probes for fluorescence in situ hybridization (FISH). Added to that, we are going to verify the hypothesis of whether the queen's presence and the rhythmic activities involved in the Provisioning and Oviposition Process (POP) can function as a regulator of circadian rhythms in stingless bees. To do so, we aim to compare the gene expression of circadian clock components in 15-day-old nurse bees kept for 3 or 10 days in the absence of the queen to queenright control bees.(AU)