Biomaterial Database

Cytochemical and ultrastructural studies of changes in the nucleus and nucleolus during cell differentiation in the root cortex of Haemanthus katharinae. 1976

A K Kononowicz, and H Kuran, and M J Olszewska

Dimensions,dry mass content, binding of [3H]actinomycin D ([3H]AMD), and [3H]uridine incorporation in the nuclei and nucleoli as well as their ultrastructure during growth and differentiation of the root cortex cells of Haemanthus katharinae were compared. The dry mass of the nuclei did not change, the condensed chromatin content was slightly augmented, and the ability of the nuclei to bind [3H]AMD became somewhat decreased, whereas a considerable reduction was observed in the [3H]uridine incorporation. The highest capability for the binding of [3H]AMD and the highest intensity of RNA synthesis were demonstrated by nuclei in the meristematic zone and during the most intensive cell growth. The size of the nucleoli, their dry mass, the amount of granular component, and the intensity of [3H]uridine incorporation underwent a steady decrease as the cells grew and differentiated. The progressing differentiation of the cells was accompanied by an increasing participation of arginine-rich histones in restraining the capacity for [3H]AMD binding.

UI	MeSH Term	Description	Entries
D008940	Mitotic Index	An expression of the number of mitoses found in a stated number of cells.	Index, Mitotic,Indices, Mitotic,Mitotic Indices
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002466	Cell Nucleolus	Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)	Plasmosome,Cell Nucleoli,Nucleoli, Cell,Nucleolus, Cell,Plasmosomes
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D063245	Plant Development	Processes orchestrated or driven by a plethora of genes, plant hormones, and inherent biological timing mechanisms facilitated by secondary molecules, which result in the systematic transformation of plants and plant parts, from one stage of maturity to another.	Plant Morphogenesis,Development, Plant,Developments, Plant,Morphogeneses, Plant,Morphogenesis, Plant,Plant Developments,Plant Morphogeneses