Effect of subletal dose of the herbicide glyphosate on the expression of genes from the Major Royal Jelly Proteins (MRJPs) family of Apis mellifera L. bees in the nursing phase

• Grant number: 21/00658-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2021
• End date: May 31, 2022
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ricardo de Oliveira Orsi
• Grantee: Giovanna do Prado Ribeiro
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The use of pesticides has been identified as one of the factors responsible for behavioral changes and the disappearance of Apis mellifera bees around the world, causing great damage to commercial apiaries and pollination services, both in native areas and in crops of commercial interest. Glyphosate is one of the most widely used herbicides worldwide, acting on enzymatic activity and inhibiting plant amino acid metabolism. Its use in the environment can take this herbicide into the hive, which in a sublethal dose, can remain stored for long periods, until the resources are used by the bees, generating a negative impact for the colony. The sublethal dose effect (small doses that do not have an immediate effect on bees, but that can remain for a long time in the colony) receives little attention compared to a lethal dose. These pesticides, once ingested by bees, can also exert an influence on the hypopharyngeal glands, related to the production of royal jelly and affect the expression of the Main Royal Jelly Proteins (MRJPs), which represent 82% of the total water-soluble proteins and around 90% of total royal jelly proteins. MRJP1 and MRJP5 are considered as biological reserves of nitrogen and amino acid for the rapid development of larvae. Therefore, the hypothesis of the present research is to verify if the herbicide Glyphosate, in sublethal dose, affects the expression of the MRJP1 and MRJP5 genes in six day old bees, in the nursing phase. For that, eight colonies of A. melífera bees will be submitted to the supply of syrup containing sublethal dose of the herbicide glyphosate, during six days. Afterwards, bees in the nursing stage (six days of life), previously marked, will be harvested for the analysis of gene expression, using the rp49 gene as a control. Bee mortality and population development will also be obtained. The results of mortality and population development will appear through Analysis of Variance (ANOVA) followed by the Tukey test for comparison of means. The results of the analysis of gene expression will be compared by the Kruskal-Wallis test, with Dunn's post hoc test. In all tests, the results will be considered statistically different when P <0.05.