Limits...
Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

Fraga A, Ribeiro L, Lobato M, Santos V, Silva JR, Gomes H, da Cunha Moraes JL, de Souza Menezes J, de Oliveira CJ, Campos E, da Fonseca RN - PLoS ONE (2013)

Bottom Line: In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis.Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality.Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos.

View Article: PubMed Central - PubMed

Affiliation: Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Núcleo de Pesquisas Ecológicas e Sócioambientais de Macaé (NUPEM), Universidade Federal do Rio de Janeiro (UFRJCampus Macaé), Rio de Janeiro, Brazil.

ABSTRACT
Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3) and hexokinase (HexA) genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

Show MeSH
Hexokinase (Hex) locus structure in Tribolium and Hex gene evolution in insects.(A) Snapshot of the Beetlebase [42], [43] showing relative expression of Tc-HexA1 (Tc-Glean00319) and Tc-HexA2 (Tc-Glean00318) at 6 hours, 14 hours and 30 hours of embryonic cDNA libraries. Note that Tc-HexA1 is expressed at early stages while Tc-HexA2 seems to be upregulated only at later stages. (B) Phylogenetic analysis using maximum likelihood method. Amino acid substitution model: WAG+G. In Drosophillids four Hex genes exist (HexC, HexT1, HexT2 and HexA), while in most other insects only one Hex gene exists. Bootstrap values (1,000 replicates) are indicated as percentages. Aae - Aedes aegypti; Ad - Anopheles darling; Am - Apis mellifera; Cq - Culex quinquefasciatus; Dmel - Drosophila melanogaster; Dpse - Drosophila pseudoobscura; Nv - Nasonia vitripennis; Tc - Tribolium castaneum. Accession numbers for the NCBI are available upon request.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3672164&req=5

pone-0065125-g003: Hexokinase (Hex) locus structure in Tribolium and Hex gene evolution in insects.(A) Snapshot of the Beetlebase [42], [43] showing relative expression of Tc-HexA1 (Tc-Glean00319) and Tc-HexA2 (Tc-Glean00318) at 6 hours, 14 hours and 30 hours of embryonic cDNA libraries. Note that Tc-HexA1 is expressed at early stages while Tc-HexA2 seems to be upregulated only at later stages. (B) Phylogenetic analysis using maximum likelihood method. Amino acid substitution model: WAG+G. In Drosophillids four Hex genes exist (HexC, HexT1, HexT2 and HexA), while in most other insects only one Hex gene exists. Bootstrap values (1,000 replicates) are indicated as percentages. Aae - Aedes aegypti; Ad - Anopheles darling; Am - Apis mellifera; Cq - Culex quinquefasciatus; Dmel - Drosophila melanogaster; Dpse - Drosophila pseudoobscura; Nv - Nasonia vitripennis; Tc - Tribolium castaneum. Accession numbers for the NCBI are available upon request.

Mentions: Interestingly, T. castaneum contains two Hex genes arranged in tandem in the genome suggesting a recent duplication event (Figure 3A). Both genes Tc-HexA1 (Glean_00319) and Tc-HexA2 (Glean_00318) encode proteins more similar in amino acid sequence to HexA from other insects (Figure 3B). Both genes display high identity to each other (over 80% at amino acid level). Closer inspection of the Tc-HexA genes using expression arrays of the BeetleBase [42], [43] revealed interesting features of this locus, which contains both genes Tc-HexA1 and Tc-HexA2. Tc-HexA1 is highly expressed during early embryogenesis at six hours of embryonic development, while Tc-HexA2 seems to be upregulated only at later embryonic stages (Figure 3A-30 hours). Since our major interest was to investigate the metabolism during early embryogenesis, we analyzed the expression and function of Tc-HexA1, the early expressing hexokinase from T. castaneum.


Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

Fraga A, Ribeiro L, Lobato M, Santos V, Silva JR, Gomes H, da Cunha Moraes JL, de Souza Menezes J, de Oliveira CJ, Campos E, da Fonseca RN - PLoS ONE (2013)

Hexokinase (Hex) locus structure in Tribolium and Hex gene evolution in insects.(A) Snapshot of the Beetlebase [42], [43] showing relative expression of Tc-HexA1 (Tc-Glean00319) and Tc-HexA2 (Tc-Glean00318) at 6 hours, 14 hours and 30 hours of embryonic cDNA libraries. Note that Tc-HexA1 is expressed at early stages while Tc-HexA2 seems to be upregulated only at later stages. (B) Phylogenetic analysis using maximum likelihood method. Amino acid substitution model: WAG+G. In Drosophillids four Hex genes exist (HexC, HexT1, HexT2 and HexA), while in most other insects only one Hex gene exists. Bootstrap values (1,000 replicates) are indicated as percentages. Aae - Aedes aegypti; Ad - Anopheles darling; Am - Apis mellifera; Cq - Culex quinquefasciatus; Dmel - Drosophila melanogaster; Dpse - Drosophila pseudoobscura; Nv - Nasonia vitripennis; Tc - Tribolium castaneum. Accession numbers for the NCBI are available upon request.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672164&req=5

pone-0065125-g003: Hexokinase (Hex) locus structure in Tribolium and Hex gene evolution in insects.(A) Snapshot of the Beetlebase [42], [43] showing relative expression of Tc-HexA1 (Tc-Glean00319) and Tc-HexA2 (Tc-Glean00318) at 6 hours, 14 hours and 30 hours of embryonic cDNA libraries. Note that Tc-HexA1 is expressed at early stages while Tc-HexA2 seems to be upregulated only at later stages. (B) Phylogenetic analysis using maximum likelihood method. Amino acid substitution model: WAG+G. In Drosophillids four Hex genes exist (HexC, HexT1, HexT2 and HexA), while in most other insects only one Hex gene exists. Bootstrap values (1,000 replicates) are indicated as percentages. Aae - Aedes aegypti; Ad - Anopheles darling; Am - Apis mellifera; Cq - Culex quinquefasciatus; Dmel - Drosophila melanogaster; Dpse - Drosophila pseudoobscura; Nv - Nasonia vitripennis; Tc - Tribolium castaneum. Accession numbers for the NCBI are available upon request.
Mentions: Interestingly, T. castaneum contains two Hex genes arranged in tandem in the genome suggesting a recent duplication event (Figure 3A). Both genes Tc-HexA1 (Glean_00319) and Tc-HexA2 (Glean_00318) encode proteins more similar in amino acid sequence to HexA from other insects (Figure 3B). Both genes display high identity to each other (over 80% at amino acid level). Closer inspection of the Tc-HexA genes using expression arrays of the BeetleBase [42], [43] revealed interesting features of this locus, which contains both genes Tc-HexA1 and Tc-HexA2. Tc-HexA1 is highly expressed during early embryogenesis at six hours of embryonic development, while Tc-HexA2 seems to be upregulated only at later embryonic stages (Figure 3A-30 hours). Since our major interest was to investigate the metabolism during early embryogenesis, we analyzed the expression and function of Tc-HexA1, the early expressing hexokinase from T. castaneum.

Bottom Line: In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis.Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality.Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos.

View Article: PubMed Central - PubMed

Affiliation: Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Núcleo de Pesquisas Ecológicas e Sócioambientais de Macaé (NUPEM), Universidade Federal do Rio de Janeiro (UFRJCampus Macaé), Rio de Janeiro, Brazil.

ABSTRACT
Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3) and hexokinase (HexA) genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

Show MeSH