During development of the vertebrate lens, the lens epithelium undergoes a final stage of differentiation into lens fibre cells. Lens fibre cells can also be produced by trans‐differentiation from certain extralenticular structures, all of which are of different developmental origin from lens, including embryonic neural retina and retinal pigmented epithelium. Delta‐crystallin is the major lens protein in the chick and appears first in development; it is the major product in trans‐differentiated retina of younger embryos. In both normal differentiation and trans‐differentiation an increase of delta‐crystallin coding RNA is detectable in the nucleus of cells prior to their terminal differentiation into lens fibres. The increase in transcription of delta‐crystallin genes accompanying final differentiation of lens fibres, appears to take place slightly in advance of an increase in the capacity to process and transport this mRNA to the cytoplasm.
The DNA content of human plasma cells from myeloma patients relative to that of leukocytes was determined by flow and microscopic cytofluorometry after propidium iodide and fluorescent Feulgen staining, respectively. Mononucleated myeloma plasma cells from all of the 17 patients studied contained more DNA (17 to 58%) than the leukocytes from the patient. The binucleated and trinucleated plasma cells, which were more prevalent in advanced cases, contained up to two and three times, respectively, the amount of DNA determined in the mononucleated plasma cells. These observations suggest that the ploidy abnormalities of myeloma plasma cells are even more extensive than the numerous karyotypic studies have indicated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.