We present a catalog of sequences of oligonucleotides produced by T1 ribonuclease digestion of 32P-labeled small-ribosomal-subunit RNA ("18S rRNA) isolated from purified wheat embryo mitochondria. This catalog is compared to catalogs published for prokaryotic and chloroplast 16S rRNAs and to preliminary results for wheat cytosol 18S rRNA. These comparisons indicate that: (1) wheat mitochondrial 18S rRNA is clearly prokaryotic in nature, showing significantly more sequence homology with 16S rRNAs than can be expected to arise by chance (p less than 0.000001); (2) shared oligonucleotide sequences include an especially high proportion of those identified as conserved in the evolution of prokaryotic rRNAs; and (3) wheat embryo mitochondrial and cytosol 18S rRNAs retain no more, and perhaps less, than the minimum sequence homology detectable by this sensitive method. These results argue in favor of an endosymbiotic origin for mitochondria.
1. Myeloblasts can be discriminated in the supravital technique by the great numbers of tiny mitochondria in the cytoplasm and the absence of any other vitally stainable substance.
2. There are three stages in the maturation of myelocytes.
3. These three phases can be correlated with three types of the oxidase reaction.
4. One case of myeloblastic leucemia showed such an amount of an abnormal type of amitosis as to suggest the disordered cell division of neoplasms.
5. In this case transfusions were correlated with a maturation of myeloblasts into myelocytes, with an increase of the oxidase reaction, and with an increase in amitosis.
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