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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
Analysis of glucose content during Tribolium castaneum embryogenesis.Glucose content is low during the first 20 hours of embryonic development, and increases from 20 hours on towards maximal levels until larvae hatching (about 96 hours after egg laying). Grey box highlights the region with high glucose content.
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pone-0065125-g002: Analysis of glucose content during Tribolium castaneum embryogenesis.Glucose content is low during the first 20 hours of embryonic development, and increases from 20 hours on towards maximal levels until larvae hatching (about 96 hours after egg laying). Grey box highlights the region with high glucose content.

Mentions: Since glucose is a major energy source for living tissues we measured the glucose content during Tribolium castaneum embryogenesis with particular emphasis on the first 72 hours of development when most cell proliferation and morphogenesis takes place (Figure 2). Glucose levels remain low during the first 20 hours of development. Later, between 20–24 hours a large increase of glucose is observed, which is further reinforced in the next two days of development (24–48 and 48–72 hours). Importantly, after this increase levels are 60% higher than the 0–4 hours of embryonic development. Thus, glucose content changes during T. castaneum embryonic development.


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)

Analysis of glucose content during Tribolium castaneum embryogenesis.Glucose content is low during the first 20 hours of embryonic development, and increases from 20 hours on towards maximal levels until larvae hatching (about 96 hours after egg laying). Grey box highlights the region with high glucose content.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0065125-g002: Analysis of glucose content during Tribolium castaneum embryogenesis.Glucose content is low during the first 20 hours of embryonic development, and increases from 20 hours on towards maximal levels until larvae hatching (about 96 hours after egg laying). Grey box highlights the region with high glucose content.
Mentions: Since glucose is a major energy source for living tissues we measured the glucose content during Tribolium castaneum embryogenesis with particular emphasis on the first 72 hours of development when most cell proliferation and morphogenesis takes place (Figure 2). Glucose levels remain low during the first 20 hours of development. Later, between 20–24 hours a large increase of glucose is observed, which is further reinforced in the next two days of development (24–48 and 48–72 hours). Importantly, after this increase levels are 60% higher than the 0–4 hours of embryonic development. Thus, glucose content changes during T. castaneum embryonic development.

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