Egg to embryo: analysis of the activation of early development of Apis mellifera

• Grant number: 17/18941-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2018
• End date: January 31, 2020
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Zilá Luz Paulino Simões
• Grantee: Franciene Rabiço Oliveira
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

AbstractThe onset of embryonic development is unique and each component is programmed to act at a precisely defined time and place. The process of egg activation is the initial step in which a single cell begins to undergo mitoses giving rise to the various cell types present in the adult organism. In insects, the activation of the egg is independent of fertilization, and in Apis mellifera bees, unfertilized eggs develop in males. After the activation of the egg, embryogenesis begins. In its initial phase, the embryo does not present zygotic transcription, being maintained by molecular components deposited by the mother during ovogenesis. As development progresses, maternal factors are being degraded by the joint action of Smaug and Zelda proteins. Zelda is a transcription factor that works in conjunction with Smaug, binding to motifs called Tag team and activating the transcription of thousands of zygotic genes. In previous studies in A. mellifera, we detected increase of smaug and zelda transcripts in the first hours of development. Thus, there is strong evidence that zygotic transcription begins early in mitotic cycles in bees' embryos, unlike the later zygomatic activation observed in Drosophila. Thus, the hypothesis that will be tested in this project is that the zygotic transcription happens at the beginning of development in haploid and diploid embryos. To test this hypothesis, the following steps will be developed: 1) To compare the first events of the embryonic development of haploids and diploids to verify if the duration of the phases is the same in both; 2) To analyze the expression of early genes, such as Zelda and Smaug, in the first hour of development of haploid and diploid embryos of A. mellifera, by means of in situ hybridization and qPCR of the cleavage nuclei; 3) Identify among zygotic genes those regulated by Zelda through the prediction of regulatory elements for this transcription factor. This project will contribute to a better understanding of the events that result in the activation of the zygote genome and thus will allow to understand the molecular bases that shape the initial embryogenesis. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

OLIVEIRA, Franciene Rabiço. From egg to embryo: Analysis of genes expressed in early embryonic stages of Apis mellifera. 2020. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) Ribeirão Preto.