A cytochemical study of oogenesis and cleavage in the mouse

Abstract

INTRODVCTIONRecent advances in several independent fields of biological research have tended to indicate that the desoxyribose nucleic acid (DXA) of clironiosomes exhibits a number of properties which may be coilsidered essential for the identification of a Iiypothetical genic material. These properties are :1. High specific activity, such as shoxn by the transforming principle of microorganisms (Avery, MacLeod and Mc-Carty, '44 ; Roivin, Delaunay, Vcndrely and Lehoult, '45). 2. RerriarkabIe stability during metabolic activity of nniidividing cells as evidenced by low turnover rates observed in the coursc of tracer studies (Brues, Tracy and Cohn, '44; Brown, '48; Bergstrand et al., '48; Furst, Roll and Brown, 3. A quantitative relationship correlated with the knowvn quantitative variations of chromosomal material which is the generally recognizecl carrier of the genes : gross clieniicd analyses g k e strong evidence f o r the existence of characteristic quantities of DKA in cells of different organisms (Eoivin, Vendrely and Vetidrely, '48 ; Vendreley and Vcndrcly, '48 ; Mirsky and Ris, '49) ; photometric analyses operating at the lcrel of individual cells, introduced by Cas-'50).

Relative changes in the RNA contents of oocytes and preimplantation embryos of the mouse

“…Nucleoplasmic RNA polymerases which are sensitive to a-amanitin have been found to be active at this stage (Moore, 1975 Knowland and Graham (1972) reported the presence of extremely small amounts of newly labelled rRNA at the 2 cell stage (see also Hillman and Tasca 1969). In the present study the appearance of basophilic material was first observed at the peripheries of the nucleoli of 4 cell embryos (see also Alfert, 1950 ;Flax, 1953). We have previously demonstrated that it was precisely at this location that the activities of the a-amanitin-resistant, type I RNA polymerases reappeared (Moore, 1975).…”

A Comparison of 35s Methionine Incorporation by the Blastocysts of Normal and Delayed Implanting Mice

“…The metabolic activity during the early cleavage stages of mammals differs in several respects from that of the blastocyst : alkaline phosphatase is not present in rat ova (Mulnard, 1955) ; cytoplasmic levels of rna are reduced in mouse and rat eggs as attested by the use of various techniques (Alfert, 1950;Austin & Braden, 1953). The 2-to 8-celled egg in vitro has limited ability to carry out glycolysis in contrast to late morula and blastocyst stages (Fridhandler, 1961).…”

Hormonal Influence on Nuclear Synthesis. Iv.

“…In the present case the thyroid nuclei of hypophysectomized and normal rats show volumes in a ratio of 1:2, although they evidently contain the same amounts of DNA and are consequently both diploid. Similarly, in previous studies it has been found that the geometric series of nuclear volumes in the testis of Arvelius (Schrader and Leuchtenberger [1950]) and in developing mouse eggs (Alfert [1950]) are not correlated with corresponding differences in chromosome or DNA content. The doubling of nuclear volumes in uterine glands of castrate mice under influence of estrogen (Salvatore [1950]) also is not accompanied by an increase of nuclear DNA content ).…”