Dopamine and the regulation of cell proliferation in gerbil (Meriones unguiculatus) pyloric mucosa.

The epithelium of the digestive system mucosa consists of a highly dynamic cell population. The conditions under which mitotic activity in the gastrointestinal epithelium is regulated is as yet poorly understood. Nevertheless, it is assumed that some biogenic amines might be involved. Having demonstrated that dopaminergic cells occur in the stomach of gerbils (Meriones unguiculatus), in the present study we examined the influence of dopamine antagonist haloperidol on the proliferation of epithelial cells in the mucosa of the stomach. Proliferating cells were detected immunocytochemically and quantified after in-vivo labeling with 5-bromo-2'-desoxyuridine in both haloperidol- and saline-treated animals. The results show that acute doses of haloperidol significantly increases the proliferation rate in the pyloric mucosa, suggesting that dopamine plays a probable modulatory role in the regulation of mitotic activity. These findings are discussed with regard to the role of paraneurons in regulating epithelial mitosis.

Nuclear localization of a DNA-binding C-terminal domain from Balbiani ring coded secretory protein.

All known Balbiani ring (BR) genes in Chironomus tentans, coding for giant secretory proteins, the sp-I family, end with a short (110 codons) 3'-end exon which is highly conserved in evolution and is structurally unrelated to the sequences characterizing the core of these proteins. We find that the expressed product, the C-terminal domain, shows sequence-specific DNA binding and that it is likely to be absent in one of the sp-I components, sp-Ib, believed to be coded by the BR2.2 gene. Immunohistochemistry shows that material with reactivity towards antibody against the C-terminal domain is present in the nuclei, and specifically enriched in Balbiani ring 1 and 2. Western blotting of extracts from isolated nuclei demonstrates a component with the same antibody reactivity and of an apparent size somewhat larger than that of the domain. The possibility is discussed that the C-terminal part, which is part of the secretion when derived from some of the BR genes, might be cleaved off and function as a feedback signal to control BR gene activity when derived from the BR2.2 gene.

Lampbrush chromosome loop-specificity of transcript morphology in spermatocyte nuclei of Drosophila hydei.

The transcript morphology in the lampbrush chromosome loop pairs ;threads' and ;pseudonucleolus' of the Y chromosome in primary spermatocytes of Drosophila hydei has been investigated by the Miller spreading technique. Each loop pair carries giant transcripts with a secondary structure characteristic of the respective loop. The lengths of the transcribed regions are in the range 500-1500 kb or even larger. The results of our experiments are discussed in the context of loop ultrastructure, molecular structure and loop function. The high degree of secondary structure may be required to assemble specifically loop-specific proteins.

Identification of the heat shock band 2-48B of Drosophila hydei and determination of its haploid DNA content.

The heat shock locus 2-48B situated at the tip of the second chromosome of Drosophila hydei has been studied by various cytologic methods. Both from puffing behaviour and in situ hybridization on both wildtype animals and heterozygotes for the mutant chromosome Df(2)e20 the actual site is localized in band 2-48B8. Electron microscopically this band appears to be a medium size, dotted band. From cytophotometric measurements on Feulgen stained chromosomes and electron microscopic observations the DNA content of band 2-48B8 is calculated to be approximately 40 kb on the haploid level, with a compaction of the DNA of about 160 times. The interbands 2-48B7-8 and 2-48B8-9, flanking the heat shock band, were calculated to contain on the haploid level 1.5 kb and 3.0 kb, respectively. The results are discussed also in relation to the present data on the molecular organization of this locus.

The banding pattern of the salivary gland chromosomes of Drosophila hydei.

The banding pattern of the salivary gland chromosomes of D. hydei was investigated in the electron microscope. We compared the banding pattern of squashed chromosomes with non-squashed preparations and observed that the fixation and squash procedure we used does not introduce artificial changes in the banding pattern of the chromosome. An electron microscopic map was made of the banding pattern of the distal half of the second salivary gland chromosome. On the basis of the number of bands in this part of the second chromosome we calculated a total of about 3700 bands for the whole set of polytene chromosomes of D. hydei. Our data indicate a similar number of bands in the salivary gland chromosomes of evolutionary remote Drosophila species like D. hydei and D. melanogaster.

Heat-shock puff 93 D from Drosophila melanogaster: accumulation of a RNP-specific antigen associated with giant particles of possible storage function.

The monoclonal antibody P11 is directed against a 38 000 dalton protein of Drosophila melanogaster. On polytene chromosomes this protein is present in a subset of the RNA polymerase II-containing loci. Here we show by density centrifugation and enzyme-linked immunosorbent assay tests that the P11 antigen is part of nuclear ribonucleoprotein (RNP) complexes. Indirect immunofluorescence shows that, after prolonged heat-shock, the P11 antigen is present only in the heat-shock puff 93 D. Identical distribution patterns were obtained with another monoclonal antibody, Q18. Unlike P11, this antibody also cross-reacts with D. hydei and D. virilis polytene chromosomes, where the puffs 48 B and 20 CD, respectively, are the only loci prominently stained after heat-shock. The small and giant RNP complexes previously described in these puffs were also observed in puff 93 D. Both types of particle contain the P11 antigen as shown by immunoelectron microscopy. We suggest that the P11 antigen is associated with a special class of RNPs which are possibly involved in the storage of primary transcription products inside the nucleus.

Chromosomal arrangement of heat shock locus 2-48B in Drosophila hydei.

cDNA, copied from nuclear RNA isolated from heat shocked Drosophila hydei cells, has been cloned. From this collection of clones a clone, N09-15, with a 450 bp insert has been isolated that hybridizes in situ to the heat shock locus-2-48B of Drosophila hydei. The N09-15 sequence is present in two different genomic arrangements, as shown by restriction mapping, in our wild type D. hydei population. These genomic arrangements are allelic. Both alleles contain multiple copies of the N09-15 sequence but differ in their lengths and in the distribution of Msp I and Taq I sites.

Bristle patterns, clones and cell competition along the anterior margin ofNotch wings ofDrosophila hydei.

The bristle pattern along the anterior margin ofNotch (N1-22.3) wings ofDrosophila hydei and the occurrence ofyellow (y 1-38.8) marked clones induced by X-ray irradiation during various larval stages are described. UnirradiatedN/N + wings show gaps ('notches') in the longitudinal bristle rows along the 1st longitudinal vein, with tufts of bristles particularly near gaps. X-ray irradiation increases the number and total length of the gaps. The patterning of bristles along the margin depends on theN (+) genotype of the induced clones. RecombinantN +/N + clones from irradiated wings show excessive growth with an autonomous wildtype bristle pattern. Characteristically, these clones do not respect the dorso-ventral compartment boundary along the wing margin, do not follow an exponential (2n) growth pattern, tend to fill the gaps with bristles and theiryellow medial row bristles are less often interspersed withy + bristles than described forN +/N + wings. HomozygousN appears to be a cell lethal condition inD. hydei as it is inD. melanogaster. When y clones were kept phenotypicallyNotch (viz.,N/N/N +) as the background cells, we found a lower number ofy bristles, a lower percentage of mosaic wings but also a reltive deficiency ofy + interspersions. The latter is discussed in relation to a possible clonal originof the notches.

Bristle patterns and clones along a compartment border in the anterior wing margin ofDrosophila hydei.

The bristle pattern along the first longitudinal vein of the wing ofD. hydei differs from that ofD. melanogaster. Instead of a triple row,D. hydei and some allied species show a pattern of five parallel bristle rows of which the medial row (MR) is comparable to the medial triple row (MTR) ofD. melanogaster. Cells of the MR can be made homozygousyellow (y) by induction of mitotic recombination in heterozygousy/y + females. Until 70 h after egg laying (AEL), the MR clones inD. hydei overlap with one or more of the accompanying dorsal and ventral bristle rows. Between 70 and 120 h AEL the MR clones only overlap with dorsal bristle rows. Some time later they also become separated from both dorsal rows. The resulting MR clone pattern fits with the overall longitudinal clone pattern in the wing blade ofD. melanogaster described by Bryant (1970) and others. The MR clones inD. hydei, however, often show a fragmented appearance with many indentations of the surroundingy + tissue even when induced after fixation of the DV compartment boundary. This result contrasts with the commonly held notion, derived from work withD. melanogaster, that compartment boundaries are smooth lines.

[Statistical study of results of Hemalog D (author's transl)]. / Etude statistique des résultats de l'Hemalog D.

The data which Hemalog D obtains from blood samples of non hematologic patients have been analyzed statistically and compared with those obtained from an eye count. As well as usual statistical techniques, i.e. correlation coefficient and paired t-test, a more sophisticated multidimensional method was used : the Factorial Analysis of Correspondences. We have analyzed two samples. For the first sample, that of "all-comers", the reproductibility of the results given by the machine was shown to be excellent, and always superior to that of the eye count. The machinen-technician agreement is reasonably good except for the monocytes and basophiles. The preceeding conclusions were found to be true for the second sample, i.e. "with discrepancies", and in addition, it was shown that an eye count on 400 elements gives a result closer to that of the machine than does a reading on 100 elements.