International Union for the Study of Social Insects (IUSSI2018), August 5-10, 2018 in Guarujá, Brazil.

only days left!
Find us: Ft

Hormonal control and target genes of ftz-f1 expression in the honeybee Apis mellifera

Author(s):
Angel Roberto Barchuk, Tathyana Rachel Palo Mello , Aline Carolina Aleixo , Daniel Guariz Pinheiro , Francis Morais Franco Nunes , Alexandre Santos Cristino , Márcia Maria Gentile Bitondi , Angel Roberto Barchuk , Zilá Luz Paulino Simões
Institution(s):
Depto. Biologia Celular e do Desenvolvimento, Universidade Federal de Alfenas, MG, Brazil; Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil ; Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil ; Faculdade de Ciências Agrárias e Veterinárias, UNESP - Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil ; Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil ; Translational Research Institute, The University of Queensland Diamantina Institute, Brisbane, Australia ; Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil ; Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil ; Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
Ftz-f1 (Fushi tarazu transcription factor 1) is an orphan member of the nuclear hormone receptor superfamily, with one of its transcriptional variants, βFtz-f1, being homologous to the vertebrate steroidogenic factor SF1. A 20-hydroxyedysone (20E) pulse in hemolymph induces ftz-f1 gene expression, which then regulates the activity of downstream genes involved in major developmental progression events, such as metamorphosis. In honeybees, the expression of certain genes, like vitellogenin (vg), prophenoloxidase (pro-PO), and juvenile hormone esterase (jhe), during late pharate-adult development is known to be hormonally controlled in both, queens and workers by increasing juvenile hormone (JH) titers in the presence of declining levels of ecdysteroids. Even though previous work has implied the nuclear hormone receptor USP in this context in honeybees, USP is unlikely to be the only mediator. So, we were still lacking knowledge concerning molecular factors regulating the expression of these target genes, especially so during pharate-adult development of bees. Here we show that the ftz-f1 gene has a caste-specific transcription profile during this developmental period, with a peak exactly coinciding with the increase in the hemolymph JH titer in the presence of low levels of ecdysteroids. RNAi-mediated knock-down of ftz-f1 gene function showed that the expression of genes essential for adult development (e.g., vg and cuticular protein genes) depends on ftz-f1 gene expression. Our results suggest that ftz-f1 can be considered a competence factor for the expression of several genes during pharate-adult development and, thus, likely represents a key player in the caste differentiation processes in Apis mellifera. Financial support: FAPESP; FAPEMIG; CNPq.
Back