Premium
The Presence of Intramitochondrial Yolk‐crystals in Oocytes of Hypophysectomized Bullfrog Tadpoles *
Author(s) -
HSÜ CHIHYÜN,
LI KAILIN,
LÜ MEIHUA,
LIANG HSÜMU
Publication year - 1982
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1982.00319.x
Subject(s) - yolk , tadpole (physics) , oocyte , rana , bullfrog , cytoplasm , biology , medicine , xenopus , endocrinology , microbiology and biotechnology , embryo , biochemistry , fishery , physics , particle physics , gene
Ovaries of hypophysectomized Rana catesbeiana tadpoles. weighing I to 14 g, were prepared for electron microscopic study. The oocytes are at the growth phase, ranging from 50 to 190 μm in diameter. The observation on these oocytes has revealed the presence of intramitochondrial yolk‐crystals but not cytoplasmic yolk platelets. The crystalline structure, situated within the intracristal space, consists of a hexagonal array of dense particles about 50 Å in diameter and 72 Å in periodicity. Our data agree with those reported in oocytes of intact ranid species. According to literatures, crystals of intramitochondrial yolk and of cytoplasmic yolk platelets show similar ultrasturctures. The precursor of cytoplasmic yolk platelets in adult Xenopus oocytes is known to be synthesized in the estrogen‐stimulated liver and incorporated via circulation into oocytes by gonadotropin‐dependent micropinocytosis. The present finding suggests that the intramitochondrial yolk could be formed within oocytes, independently of the pituitary control.