No abstract

No abstract

In untreated cell cultures of Indian muntjac (Munticus muntiacus vaginalis; 2n = 6 female, 7 male) we observed that spontaneous aneuploidy is limited primarily to the Y2 chromosome. We therefore treated the cells with aneugenic agents to determine if induced aneuploidy follows the same pattern and, hence, if there are limitations on the generation of aneuploidy or survival of cells lacking certain chromosomes. Exposing the cells to benomyl (8-100 micrograms/ml for 1 h), caffeine (5 x 10(-5)-2 x 10(-4) M for 2, 24 and 72 h) and colchicine (2 x 10(-4) and 5 x 10(-5) M for 1, 24, 48 and 72 h) resulted in cells primarily aneuploid for the Y2 chromosome. The frequency of cells lacking Y2 was far higher than those having an extra Y2 chromosome. The frequency of cells aneuploid for all other chromosomes combined was much lower than that for Y2. The data imply that the Indian muntjac genome can tolerate loss of the Y2 chromosome only and that aneuploidy for other chromosomes might cause lethality. This might be because the small number of chromosomes in the genome predisposes aneuploid cells to an imbalance of genes carrying out the basic activities required for cell division and cell survival. Because of the small chromosome number, the large size of the chromosomes and the ease of distinguishing every chromosome without banding or any other special treatment, e.g. FISH, this system could be useful and convenient in the study of induction of aneuploidy. This simple and inexpensive system can be utilized as a screening system for preliminary studies dealing with induced aneuploidy.

We adapted previously published methods for nonspecific esterase and alkaline phosphatase staining of white blood cells in suspension for use on a Technicon H-1 hematology analyzer. The objective was to develop a semiautomated method using whole blood that could be employed on a large scale for hematology laboratory applications, including toxicology studies, measurement of neutrophil left shift, and cytochemical classification of myeloid leukemias. The nonspecific esterase method uses the pararosaniline stain, generating the unstable substrate from two stable precursors. Whole blood is added to the substrate plus dye mix. Next, acid lysis and fixation steps destroy red cells and stabilize the monocyte staining. The alkaline phosphatase stain employs a stable naphthy1 phosphate sulbstrate and fast blue B coupling dye. The red cells are lysed with a pH 10.3 propanediol buffer, and the white blood cells are then stabilized with formalin fixation. For both methods the staining is performed off-line, and the sample is then diluted with propanediol to match the refractive index of the sheath on the H-1 analyzer, before aspirationinto the direct cytomelxy port. A cytogram of scattered versus absorbed light is obtained. The number of cells staining and the intensity of the stain can be quantified from the cytogrann.

No abstract