Differential expression of hypoxia pathway genes in honey bee (Apis mellifera L.) caste development

Author(s)

Azevedo, Sergio Vicente ^[1] ; Martinez Caranton, Omar Arvey ^[1] ; de Oliveira, Tatiane Lippi ^[2] ; Hartfelder, Klaus ^[2]

Affiliation

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Genet, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biol Celular & Mol & Bioagentes Patogen, BR-14049900 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF INSECT PHYSIOLOGY; v. 57, n. 1, p. 38-45, JAN 2011.
• Web of Science Citations: 16

Abstract

Diphenism in social bees is essentially contingent on nutrient-induced cellular and systemic physiological responses resulting in divergent gene expression patterns. Analyses of juvenile hormone (JH) titers and functional genomics assays of the insulin-insulin-like signaling (IIS) pathway and its associated branch, target-of-rapamycin (TOR), revealed systemic responses underlying honey bee (Apis mellifera) caste development. Nevertheless, little attention has been paid to cellular metabolic responses. Following up earlier investigations showing major caste differences in oxidative metabolism and mitochondrial physiology, we herein identified honey bee homologs of hypoxia signaling factors, HIF alpha/Sima, HIF beta/Tango and PHD/Fatiga and we investigated their transcript levels throughout critical stages of larval development. Amsima, Amtango and Amfatiga showed correlated transcriptional activity, with two peaks of occurring in both queens and workers, the first one shortly after the last larval molt and the second during the cocoon-spinning phase. Transcript levels for the three genes were consistently higher in workers. As there is no evidence for major microenvironmental differences in oxygen levels within the brood nest area, this appears to be an inherent caste character. Quantitative PCR analyses on worker brain, ovary, and leg imaginal discs showed that these tissues differ in transcript levels. Being a highly conserved pathway and linked to IIS/TOR, the hypoxia gene expression pattern seen in honey bee larvae denotes that the hypoxia pathway has undergone a transformation, at least during larval development, from a response to environmental oxygen concentrations to an endogenous regulatory factor in the diphenic development of honey bee larvae. (C) 2010 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 08/07231-0 - Molecular and cellular basis of caste differentiation in the honey bee (Apis mellifera L., Hymenoptera)
• Grantee: Klaus Hartmann Hartfelder
• Support Opportunities: Regular Research Grants
• FAPESP's process: 07/04859-5 - Insulin signaling pathway in caste varieties development in honey bees and labor division
• Grantee: Sergio Vicente de Azevedo
• Support Opportunities: Scholarships in Brazil - Doctorate