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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 result in CNS phenotypes, as revealed by ɑ-Elav staining.(A) Mutant CNS (B-H) appear twisted and irregular (E, G); often, holes are seen within the ventral nerve cord (white arrows). Holes can range in sizes from small, partially (B, C) or completely (H) interrupting the ventral nerve cord, to large (F). There can also be multiple holes (D), as compared to wild type. Embryonic brains are also disrupted (F, opposite white arrow). Embryos are photographed at stages 14–15. (I) Quantification and distribution of CNS defects in different ferritin mutants that present CNS defects; statistical difference compared to control following a Chi squared test, at p<0.0001, and is denoted by an asterisk (n = 32, 10, and 138 embryos, respectively).
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pone.0133499.g003: Ferritin mutants result in CNS phenotypes, as revealed by ɑ-Elav staining.(A) Mutant CNS (B-H) appear twisted and irregular (E, G); often, holes are seen within the ventral nerve cord (white arrows). Holes can range in sizes from small, partially (B, C) or completely (H) interrupting the ventral nerve cord, to large (F). There can also be multiple holes (D), as compared to wild type. Embryonic brains are also disrupted (F, opposite white arrow). Embryos are photographed at stages 14–15. (I) Quantification and distribution of CNS defects in different ferritin mutants that present CNS defects; statistical difference compared to control following a Chi squared test, at p<0.0001, and is denoted by an asterisk (n = 32, 10, and 138 embryos, respectively).

Mentions: We then stained embryos with antibodies against several neuronal markers. Anti-Elav, which marks neuronal nuclei, showed that some ferritin mutants harbor holes in the abdominal CNS segments (Figs 2 and 3). More severe phenotypes were also present, albeit in fewer embryos, including aberrant condensation of the CNS, twisted CNS, and loss of parts of the brain and peripheral nervous system (PNS). Importantly, and consistent with our analysis of the cuticle phenotypes discussed above, these phenotypes were observed with both ferritin alleles and with the 2.2 kb genomic deletion that specifically deletes both Fer1HCH and Fer2LCH (Fig 3B-3H, distribution of defects in 3I, compared with the control 3A). These phenotypes were significantly different from control embryos (Fig 3I). The developing CNS consists of at least four types of cells: neuroblasts, ganglion mother cells, neurons, and glia. Neuroblasts are CNS precursor cells and give rise to ganglion mother cells; and these, in turn, give rise to neurons and glia [36]. In order to test whether neuroblasts and ganglion mother cells were affected in ferritin mutant embryos, we performed antibody staining against Deadpan (Dpn) and Evenskipped (Eve) [37,38]. Anti-Deadpan staining, which marks all neuroblasts, shows that CNS defects are already present within neuroblast cell lineages in at least some mutant embryos (Fig 4A-4D). As expected for early CNS defects, mutant embryos can also be found where Eve positive ganglion mother cells are affected (Fig 3E-3H). CNS defects are detected from the time neuroblast cell lineages are specified in some mutant embryos, at stages 7–8, precisely during germband extension-retraction, when the earliest cuticle defects are seen. These early defects may result in more maturecontorted and aberrant nervous systems, as seen with anti-Elav.


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 result in CNS phenotypes, as revealed by ɑ-Elav staining.(A) Mutant CNS (B-H) appear twisted and irregular (E, G); often, holes are seen within the ventral nerve cord (white arrows). Holes can range in sizes from small, partially (B, C) or completely (H) interrupting the ventral nerve cord, to large (F). There can also be multiple holes (D), as compared to wild type. Embryonic brains are also disrupted (F, opposite white arrow). Embryos are photographed at stages 14–15. (I) Quantification and distribution of CNS defects in different ferritin mutants that present CNS defects; statistical difference compared to control following a Chi squared test, at p<0.0001, and is denoted by an asterisk (n = 32, 10, and 138 embryos, respectively).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0133499.g003: Ferritin mutants result in CNS phenotypes, as revealed by ɑ-Elav staining.(A) Mutant CNS (B-H) appear twisted and irregular (E, G); often, holes are seen within the ventral nerve cord (white arrows). Holes can range in sizes from small, partially (B, C) or completely (H) interrupting the ventral nerve cord, to large (F). There can also be multiple holes (D), as compared to wild type. Embryonic brains are also disrupted (F, opposite white arrow). Embryos are photographed at stages 14–15. (I) Quantification and distribution of CNS defects in different ferritin mutants that present CNS defects; statistical difference compared to control following a Chi squared test, at p<0.0001, and is denoted by an asterisk (n = 32, 10, and 138 embryos, respectively).
Mentions: We then stained embryos with antibodies against several neuronal markers. Anti-Elav, which marks neuronal nuclei, showed that some ferritin mutants harbor holes in the abdominal CNS segments (Figs 2 and 3). More severe phenotypes were also present, albeit in fewer embryos, including aberrant condensation of the CNS, twisted CNS, and loss of parts of the brain and peripheral nervous system (PNS). Importantly, and consistent with our analysis of the cuticle phenotypes discussed above, these phenotypes were observed with both ferritin alleles and with the 2.2 kb genomic deletion that specifically deletes both Fer1HCH and Fer2LCH (Fig 3B-3H, distribution of defects in 3I, compared with the control 3A). These phenotypes were significantly different from control embryos (Fig 3I). The developing CNS consists of at least four types of cells: neuroblasts, ganglion mother cells, neurons, and glia. Neuroblasts are CNS precursor cells and give rise to ganglion mother cells; and these, in turn, give rise to neurons and glia [36]. In order to test whether neuroblasts and ganglion mother cells were affected in ferritin mutant embryos, we performed antibody staining against Deadpan (Dpn) and Evenskipped (Eve) [37,38]. Anti-Deadpan staining, which marks all neuroblasts, shows that CNS defects are already present within neuroblast cell lineages in at least some mutant embryos (Fig 4A-4D). As expected for early CNS defects, mutant embryos can also be found where Eve positive ganglion mother cells are affected (Fig 3E-3H). CNS defects are detected from the time neuroblast cell lineages are specified in some mutant embryos, at stages 7–8, precisely during germband extension-retraction, when the earliest cuticle defects are seen. These early defects may result in more maturecontorted and aberrant nervous systems, as seen with anti-Elav.

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