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Delayed fertilization of anuran amphibian (Xenopus) eggs leads to reduced numbers of primordial germ cellsSeveral media were tested for the extent to which they promoted high fertilization efficiencies in ovulated, stripped Xenopus eggs. One medium was selected for maintaining eggs in a 'delayed fertilization' (DelF) condition. DelF eggs displayed several unusual characteristics, including shift of the center of gravity, prominent sperm entrance site, and occasional polyspermy. The frequency of normal pattern formation varied according to the length of time eggs were maintained in the DelF condition. Various developmental abnormalities were observed during gastrulation, neurulation, and organogenesis. Most abnormalities appeared, however, to be related to morphogenesis of the endoderm. Primordial germ cell (PGC) development was examined in DelF eggs which displayed normal external morphological features at the swimming tadpole stage. PGC counts were usually normal in short-duration (eg, 5 hr) DelF eggs, but frequently substantially reduced or completely diminished in longer-duration (eg, 25h) tadpoles. Six spawnings were compared and shown to exhibit considerable variability in fertility, morphogenesis, and PGC development. Yolk platelet shifts and developmental parameters were examined in two additional spawnings. The subcortical cytoplasm in which the germ plasm is normally localized appeared to be disrupted in longer duration DelF eggs. That observation may account for low PGC counts in DelF tadpoles.
Document ID
20040089806
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Wakahara, M.
(Indiana University Bloomington, United States)
Neff, A. W.
Malacinski, G. M.
Date Acquired
August 21, 2013
Publication Date
January 1, 1984
Publication Information
Publication: Gamete research
Volume: 9
Issue: 4
ISSN: 0148-7280
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAGFW-60
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Number 40-20
Non-NASA Center
NASA Program Space Biology
NASA Discipline Developmental Biology

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