Proposal of an interaction network of Notch, Wnt, Hippo, TGF-B, IIS, and EGFR signaling pathways and the reproductive capacity of eusocial bees Apini and Meliponini

• Grant number: 19/02374-1
• Support Opportunities: Regular Research Grants
• Duration: August 01, 2019 - July 31, 2022
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Zilá Luz Paulino Simões
• Grantee: Zilá Luz Paulino Simões
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Flávia Cristina de Paula Freitas ; Francis de Morais Franco Nunes

Abstract

Eusocial behavior is a recent and remarkable conquest of the Hymenoptera and is restricted to the Aculeata, a clade comprising ants, bees, and wasps. This way of life involves three pillars: overlapping generations, cooperation in care of the offspring, and division of reproductive labor. The latter presupposes division into castes, a reproductive female that can mate and lay eggs, and workers, who have given up reproduction and are dedicated to the work of maintaining the colony, the offspring and the queen herself. Although genomic and behavioral knowledge on Hymenoptera has increased greatly in recent years, key aspects of biology, including dominance and regulation of reproductive capacity and how these relate to the development of eusociality, remain unknown. The most widely studied bee is Apis mellifera, here considered as a model organism for reproductive castes. Honey bees are known for the efficiency of their work as pollinators of wild species and cultivars, and the plants they pollinate produce 30% of the food consumed by man worldwide. The workers of this species are facultatively sterile. However, their few functional ovarioles can be activated when the queen is absent, producing eggs that develop into haploid males. When we consider the hundreds of species of native social bees, the stingless bees, which pollinate most of the native flowering plants in our country, we find a great diversity of behavioral and reproductive strategies. However, as in the case of A. mellifera, little is known about the evolutionary history of eusociality and associated processes in this group. Unfortunately, both honey bees and stingless bees are greatly threatened by habitat loss and pesticides, a grave concern for both the environment and food production. To better understand a key aspect of the biology of these bees, we propose to study contrasting examples of reproductive control of workers, with A. mellifera as the model of facultative worker reproduction and the native bees Scaptotrigona bipunctata and Frieseomelitta varia as extreme examples of worker reproductive capacity. The workers of S. bipunctata regularly activate their ovaries and compete with their queens for male production, while in F. varia, the opposite occurs. During pre-imaginal development, at an early pupal stage, the ovaries of the workers of this species undergo an intense program of cell death that results in highly modified ovaries; consequently, the workers cannot lay eggs. Here, we propose to construct morphological and behavioral profiles of reproductive and non-reproductive females, and examine possible correlations with the expression and interaction of components of the metabolic pathways of Notch, EGFR, Hippo, TGF-², IIS and Wnt, known to be closely linked to the reproductive process. The results should help us understand how eusociality evolved and will allow us to better understand these bee species, which are important in management and maintenance programs for both native and exotic bees; their presence is critical for the stability of our ecosystems. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BATAGLIA, L.; SIMOES, Z. L. P.; NUNES, F. M. F.. Active genic machinery for epigenetic RNA modifications in bees. Insect Molecular Biology, v. 30, n. 6, AUG 2021. (16/06657-0, 19/02374-1)