Incorporation of tritiated thymidine into mitochondrial DNA of the liver and kidney cells of chickens and mice in tissue culture

Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

“…As for the macromolecular synthesis in various cells in various organs of experimental animals observed by light and electron microscopic radioautography, it is well known that the silver grains due to the radiola-beled precursor 3 H-uridine demonstrate RNA synthesis (Nagata et al, 1967a(Nagata et al, , 1967bNagata, 1969Nagata, , 1972bNagata, ,c, 1992Nagata, , 1996Nagata, , 1997Nagata, , 2002. The present results obtained from the livers of mice revealed that the incorporation of 3 H-uridine indicating RNA synthesis resulted in silver grain localization over the nuclei and cell bodies of almost all mononucleate and binucleate hepatocytes from perinatal animals at embryonic day 19, postnatal days 1, 2, 9, 14 to adult and senescent stages at postnatal months 1, 2, 6, 12, and 24, which showed the localization of newly synthesized RNA within the mitochondria of hepatocytes.…”

<b>Aging Changes of Macromolecular Synthesis in the Mitochondria of Mouse Hepatocytes as Revealed by Microscopic Radioautography</b>

“…Intramitochondrial nucleic acid syntheses, both DNA and RNA, in mammalian and avian cells were first demonstrated morphologically by the present author by means of electron microscopic radioautography with accurate localization in primary cultured cells of the livers and kidneys of mice and chickens in vitro (Nagata et al, 1967(Nagata et al, , 1979(Nagata et al, , 1982, and then in some other established cell lines such as HeLa cells (Nagata, 1972a,b,c) or mitochondrial fractions prepared from in vivo cells (Nagata, 1974;Nagata et al, 1975). It was later commonly reported in various cells and tissues, not only in vitro obtained from various organs in vivo (Nagata, 1974; but also in vivo cells of various organs as previously reviewed in monographs (Nagata, 2001(Nagata, , 2002.…”

Electron Microscopic Radioautographic Study on DNA Synthesis of Mitochondria in Adrenal Medullary Cells of Aging Mice~!2009-08-12~!2009-09-17~!2009-12-24~!

“…As for the macromolecular synthesis in various cells in various organs of experimental animals observed by light and electron microscopic radioautography, it is well known that the silver grains due to radiolabeled 3 H-thymidine demonstrate DNA synthesis [1,2,3,50,51]. The previous results obtained from the studies on the adrenal cortical cells of aging mice by light microscopic radioautography revealed that silver grains indicating DNA synthesis incorporating 3 Hthymidine were observed over the nuclei of some adrenal cortical cells at perinatal stages from postnatal day 1 to day 14 [39,40].…”

“…All of these authors showed photographs of electron radioautographs with large spiral-formed silver grains (2-3 m in diameter) localizing not only over the mitochondria but also outside the mitochondria. In order to obtain smaller silver grains, we first used elon-ascorbic acid developer after gold latensification [1][2][3][4][5][6], which produced comma-shaped smaller silver grains (0.4-0.8 m in diameter), then later we used phenidon developer after gold latensification, producing dotlike smaller silver grains (0.2-0.4 m in diameter) localizing only inside the mitochondria showing ultrahigh resolution of radioautograms [30,[50][51][52][53]. These papers were the first which demonstrated intramitochondrial DNA synthesis incorporating 3 H-thymidine with accurate intramitochondrial localization in avian and mammalian cells.…”

“…Intramitochondrial nucleic acid syntheses, both DNA and RNA, in mammalian and avian cells were first demonstrated morphologically by the present author by means of electron microscopic radioautography with accurate localization in primary cultured cells of the livers and kidneys of mice and chickens in vitro [1,2] and then in some other established cell lines such as HeLa cells [3][4][5][6] or mitochondrial fractions prepared from in vivo cells [7][8][9]. It was later commonly found in various cells and tissues not only in vitro obtained from various organs in vivo [10][11][12][13][14], but also in vivo cells of various organs such as the salivary glands [15], the liver [16][17][18][19][20][21][22][23][24][25][26][27][28][29], the pancreas [30,31], the trachea [32], the lung [33], the kidneys [34], the testis [35,36], the uterus [37,38], the adrenals [39][40][41], the brains [42], and the retina [43][44]…”