Regulatory molecules of larval growth and metamorphosis in honeybee workers Apis mellifera

• Grant number: 11/21731-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: December 31, 2013
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Francis de Morais Franco Nunes
• Grantee: Natália Helena Hernandes
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 11/03171-5 - Causal analysis of Apis mellifera development: regulatory genes and hierachical networks of gene expression in the specification of tissue and organs, AP.TEM

Abstract

The metamorphosis of holometabolous insects takes place by successive cycles of growth and molting, mainly driven by a balanced action of ecdysteroids (20E) and juvenile (JH) hormones. The JH promotes growth, but keeps the organism in the larval stage and prevents a premature metamorphorphic molt. When the levels of JH decrease, larvae suffer transformation processes that culminate in larval-pupal transition. During this transition occurs intense programmed cell death of larval tissues, proliferation and differentiation of imaginal discs and consequent formation of adult organs. Hormonal signaling cascades activate or inactivate gene expression in a time- and space-specific manner during the development and metamorphosis of insects. However, growth and metamorphosis regulation in social organisms, such as the honeybee Apis mellifera, is not fully known. In this work we will investigate the transcriptional profiles from the microRNA let-7 and three coding genes: Cal (calponin), GCE (germ-cell expressed) and IDGF4 (imaginal disc growth factor 4) in the fat body and tegument of Apis mellifera, during molting and metamorphosis, under natural conditions and after treatment with 20E and JH. (AU)