Molecular determinants of caste differentiation in the highly eusocial honeybee Apis mellifera

Autor(es)

Barchuk, Angel R. ; Cristino, Alexandre S. ; Kucharski, Robert ; Costa, Luciano F. ; Simões, Zilá L. P. ^[5] ; Maleszka, Ryszard

• Tipo de documento: Artigo Científico
• Fonte: BMC Developmental Biology; v. 7, n. 70 2007.
• Área do conhecimento: Ciências Biológicas - Genética
• Assunto(s): Abelhas Apis mellifera

Resumo

In honeybees, differential feeding of female larvae promotes the occurrence of two different phenotypes, a queen and a worker, from identical genotypes, through incremental alterations, which affect general growth, and character state alterations that result in the presence or absence of specific structures. Although previous studies revealed a link between incremental alterations and differential expression of physiometabolic genes, the molecular changes accompanying character state alterations remain unknown. By using cDNA microarray analyses of > 6,000 Apis mellifera ESTs, we found 240 differentially expressed genes (DEGs) between developing queens and workers. Many genes recorded as up-regulated in prospective workers appear to be unique to A. mellifera, suggesting that the workers' developmental pathway involves the participation of novel genes. Workers up-regulate more developmental genes than queens, whereas queens up-regulate a greater proportion of physiometabolic genes, including genes coding for metabolic enzymes and genes whose products are known to regulate the rate of mass-transforming processes and the general growth of the organism ( e. g., tor). Many DEGs are likely to be involved in processes favoring the development of caste-biased structures, like brain, legs and ovaries, as well as genes that code for cytoskeleton constituents. Treatment of developing worker larvae with juvenile hormone (JH) revealed 52 JH responsive genes, specifically during the critical period of caste development. Using Gibbs sampling and Expectation Maximization algorithms, we discovered eight overrepresented cis-elements from four gene groups. Graph theory and complex networks concepts were adopted to attain powerful graphical representations of the interrelation between cis-elements and genes and objectively quantify the degree of relationship between these entities. We suggest that clusters of functionally related DEGs are co-regulated during caste development in honeybees. This network of interactions is activated by nutrition-driven stimuli in early larval stages. Our data are consistent with the hypothesis that JH is a key component of the developmental determination of queen-like characters. Finally, we propose a conceptual model of caste differentiation in A. mellifera based on gene-regulatory networks. (AU)

• Processo FAPESP: 05/03926-5 - Genômica funcional de Apis mellifera: busca de novos genes e redes funcionais no contexto do desenvolvimento, da diferenciação de castas e da reprodução
• Beneficiário: Zilá Luz Paulino Simões
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 05/53083-4 - Expressão gênica e diferenciação de castas em Apis mellifera
• Beneficiário: Angel Roberto Barchuk
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 04/08928-3 - Desenvolvimento e aplicação de métodos computacionais de alto desempenho para análise de sistemas físicos e biológicos
• Beneficiário: Luiz Nunes de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 99/00719-6 - Abelhas africanizadas: análise integrada do processo de africanização de Apis mellifera com foco sobre determinantes da fertilidade de zangões, rainhas e operárias
• Beneficiário: Zilá Luz Paulino Simões
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 04/03408-1 - Expressão gênica e diferenciação de castas em Apis mellifera
• Beneficiário: Angel Roberto Barchuk
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 05/00587-5 - Modelagem por redes (grafos) e técnicas de reconhecimento de padrões: estrutura, dinâmica e aplicações
• Beneficiário: Roberto Marcondes Cesar Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático