ISSN:
1040-452X
Keywords:
Metals
;
Developmental biology
;
Vertebrate development
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Zinc is essential for vertebrate development; its deficiency results in multiple congenital malformations. Knowledge of the zinc biochemistry that underlies embryologic development is very limited. This has led us to investigate the zinc, iron, and copper contents of Xenopus laevis oocytes and embryos. Stage 1-6 oocytes, isolated from ovaries, and stage 1-40 embryos, obtained by in vitro fertilization techniques, were washed in metalfree water prior to digestion by 70% ultrapure HNO3. The metal content of the digests was analyzed by atomic absorption spectrometry. Stage 6 oocytes contain 65.8 4, 31.1 ± 3, and 0.68 ± 0.2 ng of zinc, iron and copper, respectively. The corresponding concentrations are 1, 0.5, and 0.01 mM in 1 μl eggs. The metal content varies as a function of egg maturation. The zinc content increases from 3-7 to 〉60 ng by stages 3 and 6, respectively. A similar pattern is noted for iron, which increases from 2-5 to 30 ng at analogous stages. In contrast, the copper content remains virtually unchanged in oocytes undergoing maturation. Importantly, the total of all three metals does not vary throughout the first 50 stages of development, when all tadpole organs are forming. Hence, the full complement of zinc, iron, and copper needed for incorporation into apoproteins during development is already present at a time when oocyte maturation is completed. The specific metalloproteins that store, donate, and accept these metals during induction and organogenesis and the alterations caused by metal deficiency can now be identified. © 1993 Wiley-Liss, Inc.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080360403
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