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Oogenesis and egg shell formation in Heterakis gallinarum (Nematoda)
Author(s) -
Lee D. L.,
Lešťan P.
Publication year - 1971
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.1971.tb01305.x
Subject(s) - biology , spermatozoon , yolk , vitelline membrane , oogenesis , cytoplasm , anatomy , microbiology and biotechnology , eggshell , oocyte , granule (geology) , inner membrane , shell (structure) , human fertilization , botany , embryo , ecology , paleontology , materials science , mitochondrion , composite material
The structure of the developing ova and egg shell formation of Heterakis gallinarum has been described. The oogonia are small, undifferentiated cells which are arranged around a central cytoplasmic rachis. The oogonia and young oocytes are in cytoplasmic continuity with the rachis and it is suggested that the rachis may influence synchronous development of the oocytes. The oocytes contain two types of granule; refringent, which give rise to the ascaroside layer of the egg shell, and another kind which appear to be a type of yolk for the developing egg. After fertilization the spermatozoon produces numerous ribosomes; a second unit membrane appears beneath the oolemma, and the chitinous layer of the shell forms between the oolemma and this inner membrane. The refringent granules later produce the ascaroside layer of the shell between the chitinous layer and the inner membrane. The outermost layer of the shell is produced from material secreted by the cells of the uterus.