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Ferritin Is Required in Multiple Tissues during Drosophila melanogaster Development.

González-Morales N, Mendoza-Ortíz MÁ, Blowes LM, Missirlis F, Riesgo-Escovar JR - PLoS ONE (2015)

Bottom Line: Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother's iron stores, is used in early development.Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress.These functions are required in multiple tissues during Drosophila embryonic development.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro, 76230, México.

ABSTRACT
In Drosophila melanogaster, iron is stored in the cellular endomembrane system inside a protein cage formed by 24 ferritin subunits of two types (Fer1HCH and Fer2LCH) in a 1:1 stoichiometry. In larvae, ferritin accumulates in the midgut, hemolymph, garland, pericardial cells and in the nervous system. Here we present analyses of embryonic phenotypes for mutations in Fer1HCH, Fer2LCH and in both genes simultaneously. Mutations in either gene or deletion of both genes results in a similar set of cuticular embryonic phenotypes, ranging from non-deposition of cuticle to defects associated with germ band retraction, dorsal closure and head involution. A fraction of ferritin mutants have embryonic nervous systems with ventral nerve cord disruptions, misguided axonal projections and brain malformations. Ferritin mutants die with ectopic apoptotic events. Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother's iron stores, is used in early development. We also evaluated phenotypes arising from the blockage of COPII transport from the endoplasmic reticulum to the Golgi apparatus, feeding the secretory pathway, plus analysis of ectopically expressed and fluorescently marked Fer1HCH and Fer2LCH. Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress. These functions are required in multiple tissues during Drosophila embryonic development.

No MeSH data available.


Related in: MedlinePlus

Ferritin mutants cause apoptosis in the CNS and other tissues.(A-D) Whole embryos were stained with an α-CSP3act marking apoptotic cells (green), and an α-Elav marking neurons (red). Ectopic apoptosis was observed in ferritin mutants from stage 12 onwards; at this stage it was mostly restricted to the neurogenic region (B). At stage 15 apoptosis covers most mutant embryonic tissues (D). Quantification of the mean intensity value on CSP3act staining in control and ferritin mutants at stage 15 show a significant difference, with higher levels of staining in mutant embryos (n = 5; T-test, p = 0.0113).
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pone.0133499.g005: Ferritin mutants cause apoptosis in the CNS and other tissues.(A-D) Whole embryos were stained with an α-CSP3act marking apoptotic cells (green), and an α-Elav marking neurons (red). Ectopic apoptosis was observed in ferritin mutants from stage 12 onwards; at this stage it was mostly restricted to the neurogenic region (B). At stage 15 apoptosis covers most mutant embryonic tissues (D). Quantification of the mean intensity value on CSP3act staining in control and ferritin mutants at stage 15 show a significant difference, with higher levels of staining in mutant embryos (n = 5; T-test, p = 0.0113).

Mentions: What are the consequences of ferritin loss in affected tissues? There are links between iron metabolism and apoptosis [39–44]. We hypothesized that in the mutants; disrupted CNS could lead to cell death by an apoptotic mechanism. To test this hypothesis we used an antibody that recognizes solely the cleaved, activated caspase3 in cells as an apoptosis marker [45]. In contrast to control embryos at stage 12 where no apoptotic signal was detected (Fig 5A), ectopic apoptotic activation appeared in mutant embryos (Fig 5B). By stage 15 of embryogenesis control embryos have a weak and restricted apoptotic signal (Fig 5C), whereas in the mutant embryos this signal was massive and covered most of the embryo (Fig 5D; significantly different from control, Fig 5E). Similar patterns were seen with Fer1HCH451 and Fer2LCH35 homozygous mutant embryos (S3 Fig). Thus, early apoptotic activation in ferritin mutants after we see CNS anatomical defects, and subsequent generalized apoptosis, suggest that ferritin mutants may suffer apoptosis as a direct consequence of lack of the ferritin complex (again both mutant alleles show a qualitatively similar apoptosis phenotype), ultimately affecting many tissues.


Ferritin Is Required in Multiple Tissues during Drosophila melanogaster Development.

González-Morales N, Mendoza-Ortíz MÁ, Blowes LM, Missirlis F, Riesgo-Escovar JR - PLoS ONE (2015)

Ferritin mutants cause apoptosis in the CNS and other tissues.(A-D) Whole embryos were stained with an α-CSP3act marking apoptotic cells (green), and an α-Elav marking neurons (red). Ectopic apoptosis was observed in ferritin mutants from stage 12 onwards; at this stage it was mostly restricted to the neurogenic region (B). At stage 15 apoptosis covers most mutant embryonic tissues (D). Quantification of the mean intensity value on CSP3act staining in control and ferritin mutants at stage 15 show a significant difference, with higher levels of staining in mutant embryos (n = 5; T-test, p = 0.0113).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4508113&req=5

pone.0133499.g005: Ferritin mutants cause apoptosis in the CNS and other tissues.(A-D) Whole embryos were stained with an α-CSP3act marking apoptotic cells (green), and an α-Elav marking neurons (red). Ectopic apoptosis was observed in ferritin mutants from stage 12 onwards; at this stage it was mostly restricted to the neurogenic region (B). At stage 15 apoptosis covers most mutant embryonic tissues (D). Quantification of the mean intensity value on CSP3act staining in control and ferritin mutants at stage 15 show a significant difference, with higher levels of staining in mutant embryos (n = 5; T-test, p = 0.0113).
Mentions: What are the consequences of ferritin loss in affected tissues? There are links between iron metabolism and apoptosis [39–44]. We hypothesized that in the mutants; disrupted CNS could lead to cell death by an apoptotic mechanism. To test this hypothesis we used an antibody that recognizes solely the cleaved, activated caspase3 in cells as an apoptosis marker [45]. In contrast to control embryos at stage 12 where no apoptotic signal was detected (Fig 5A), ectopic apoptotic activation appeared in mutant embryos (Fig 5B). By stage 15 of embryogenesis control embryos have a weak and restricted apoptotic signal (Fig 5C), whereas in the mutant embryos this signal was massive and covered most of the embryo (Fig 5D; significantly different from control, Fig 5E). Similar patterns were seen with Fer1HCH451 and Fer2LCH35 homozygous mutant embryos (S3 Fig). Thus, early apoptotic activation in ferritin mutants after we see CNS anatomical defects, and subsequent generalized apoptosis, suggest that ferritin mutants may suffer apoptosis as a direct consequence of lack of the ferritin complex (again both mutant alleles show a qualitatively similar apoptosis phenotype), ultimately affecting many tissues.

Bottom Line: Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother's iron stores, is used in early development.Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress.These functions are required in multiple tissues during Drosophila embryonic development.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro, 76230, México.

ABSTRACT
In Drosophila melanogaster, iron is stored in the cellular endomembrane system inside a protein cage formed by 24 ferritin subunits of two types (Fer1HCH and Fer2LCH) in a 1:1 stoichiometry. In larvae, ferritin accumulates in the midgut, hemolymph, garland, pericardial cells and in the nervous system. Here we present analyses of embryonic phenotypes for mutations in Fer1HCH, Fer2LCH and in both genes simultaneously. Mutations in either gene or deletion of both genes results in a similar set of cuticular embryonic phenotypes, ranging from non-deposition of cuticle to defects associated with germ band retraction, dorsal closure and head involution. A fraction of ferritin mutants have embryonic nervous systems with ventral nerve cord disruptions, misguided axonal projections and brain malformations. Ferritin mutants die with ectopic apoptotic events. Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother's iron stores, is used in early development. We also evaluated phenotypes arising from the blockage of COPII transport from the endoplasmic reticulum to the Golgi apparatus, feeding the secretory pathway, plus analysis of ectopically expressed and fluorescently marked Fer1HCH and Fer2LCH. Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress. These functions are required in multiple tissues during Drosophila embryonic development.

No MeSH data available.


Related in: MedlinePlus