Ultrastructural Study of Relationships between Germinal Bodies and Mitochondria in Apostichopus japonicus (Echinodermata: Holothuroidea) and Pleuronectes asper (Teleostei: Pleuronectidae)

Autolysis of germ plasm substance in sea urchin spermatogonia under exposure to cadmium

“…Our observations showed that this process is followed by a complete dispersion of both sex determinants and the mitochondrial derivatives in the cytoplasm. This phenomenon was also observed in the spermatogonia of the sea urchin A. crassispina [9], as well as in some holothurians and teleost fish [10]. Apparently, the interaction between the substance of sex determinants and mitochondria, with subsequent dispersion of the electron-dense globules and the mitochondrial matrix is a normal process preceding entering gonial cells in meiosis.…”

“…Using molecular-biological techniques, the presence of mitochondrial ribosomal RNA and some other derivatives of the mitochondrial genome has been detected in the structured substance of germ plasm [2,[6][7][8]. Electronmicroscopic studies showed that, upon contacting with the nuage substance, mitochondria lose the outer membrane and release their matrix into the cytoplasm [4,9,10]. These data account for the presence of molecules of mitochondrial origin in sex determinants.…”

Pluripotent Gametogenic Stem Cells of Asexually Reproducing Invertebrates

“…The export of the ribosomal RNAs from mitochondria to the germinal granules is no longer questioned, but the mechanism underlying a transport is considered unprecedented and enigmatic (Kashikawa et al, 1999;Ding & Lipshitz, 1993;Amikura et al, 2001). Our ultrastructural data indicating the disruption of the outer mitochondrial membrane and the transformation of the mitochondrial matrix with inner membrane cristae into material of germinal granules in representatives of various animal taxa may clarify the mechanism of the export of mitochondrial components into germinal granules (Reunov et al, 2000;Reunov et al, 2004;Isaeva et al, 2005. This phenomenon enables us to suppose the participation of mitochondria in the biogenesis of the germinal granules (Isaeva & Reunov, 2001;Isaeva et al, 2005.…”

“…This phenomenon enables us to suppose the participation of mitochondria in the biogenesis of the germinal granules (Isaeva & Reunov, 2001;Isaeva et al, 2005. Destruction of the outer mitochondrial membrane and transformation of the mitochondrial matrix to the material of germinal granules or nuage have been revealed in the gonial cells of echinoderms and vertebrates (Reunov et al, 2000(Reunov et al, , 2004, planarian , sponge and hydroids . The ultrastructural evidence of mitochondrial origin of the germinal granules (chromatoid bodies) in gonial cells and neoblasts of planarian Girardia tigrina has been obtained: the transformation of mitochondrial matrix with inner membrane cristae into the germinal bodies was observed .…”