Juvenile hormone biosynthesis gene expression in the corpora allata of honey bee (Apis mellifera L.) female castes.
Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution.
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Ana Durvalina
AD
Bomtorin
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil ; Departamento de Ciências do Ambiente, Universidade Federal de Mato Grosso do Sul, Campus do Pantanal, Corumbá, Brazil.
Aline
A
Mackert
Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Gustavo Conrado Couto
GC
Rosa
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Livia Maria
LM
Moda
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Juliana Ramos
JR
Martins
Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Márcia Maria Gentile
MM
Bitondi
Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Klaus
K
Hartfelder
Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Zilá Luz Paulino
ZL
Simões
D000818:Animals; D001516:Bees / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D003335:Corpora Allata / Q000254:growth & development / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006458:Hemolymph / Q000737:chemistry; D007605:Juvenile Hormones / Q000096:biosynthesis* / Q000235:genetics; D007814:Larva / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010105:Oxygenases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D005231:Fatty Acids, Unsaturated; D007605:Juvenile Hormones; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C032429:methyl farnesoate; D010105:Oxygenases; C032432:methyl farnesoate epoxidase; D002265:Carboxylic Ester Hydrolases; C038003:juvenile hormone esterase