Effects of zinc supplementation (organic and inorganic) on hypopharingeal gland development and Major Royal Jelly Proteins (MRJPs) gene expression of Apis mellifera L. honey bees

• Grant number: 19/17105-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2019
• End date: October 31, 2020
• 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

Royal jelly is produced from a mixture of secretions from the hypopharyngeal and mandibular glands (which make up the cephalic gland system), located on the head of the worker bees of Apis mellifera. Among the royal jelly proteins, the major royal jelly proteins (MRJPs) represent 82% of the total water soluble proteins and about 90% of the total royal jelly proteins. MRJP1 and MRJP5 are considered the nitrogen and amino acid biological reserves for the rapid development of larvae. Although bee feeding is focused on energy and protein foods, other nutrients such as minerals are essential for colony development. In this context, minerals such as zinc are of fundamental importance as structural and functional components, being present in metalloproteins and as a catalyst in enzymatic systems, and can modulate the components of royal jelly. However, the source from which the mineral is offered to the organism (organic or inorganic) may influence its bioavailability. Thus, the hypothesis of the present proposal is to verify if the source of zinc (inorganic and organic) can modulate the quality of royal jelly through gene expression analysis and the development of the hypopharyngeal gland of seven-day-old nursing bees. For this, 15 colonies of A. mellifera bees were submitted to the following treatments: Zn0 (Control), ZnO50 (50 mg L-1 Zinc-methionine) and ZnI50 (50 mg L-1 Zinc Sulphate Monohydrate), supplied in sugar (experiment in progress). Zinc levels will be confirmed by Flame Atomic Absorption Spectrometry (FAAS). Nursing bees (seven days old) will be collected for analysis of MRJP1 and MRJP5 gene expression, using rp49 gene as control. For the morphometry of the gland, 10 bees will be collected from each treatment (previously marked in the region of the pronotum). The slides will be processed in resin sections and analyzed using Leica Qwin Plus® image analysis software to determine the glandular area. Bees mortality and population development will also be evaluated. The results of mortality and population development will be by analysis of variance (ANOVA) followed by Tukey test for comparison of means. For the results of gene expression will be used the Dunnet test. In all tests, results will be considered statistically different when P <0.05.

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)

RIBEIRO, GIOVANNA DO PRADO; KADRI, SAMIR MOURA; JUSTULIN, LUIS ANTONIO; RIBOLLA, PAULO EDUARDO MARTINS; ORSI, RICARDO DE OLIVEIRA. Zinc methionine or zinc sulphate supplementation modulate the development of the hypopharyngeal gland and expression of major royal jelly protein genes in Apis mellifera L. bees. PHYSIOLOGICAL ENTOMOLOGY, v. N/A, p. 7-pg., 2023-04-13. (19/17105-6)