Aufnahme von 22Na in die Zellkerne der Speicheldrüsen von Chironomus thummi

1966 ◽  
Vol 21 (3) ◽  
pp. 274-277 ◽  
Author(s):  
Markus Lezzi ◽  
Heinrich Kroeger
Keyword(s):  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Inorganic Ions ◽  
Saturation Curve ◽  
Cell Nuclei ◽  
Chironomus Thummi ◽  
In Vitro Uptake

The in vivo and in vitro uptake of 22Na from the hemolymph into cell nuclei of larval salivary glands was measured and compared. The uptake of 22Na in vivo follows approximately a saturation curve. The respective in vitro curve has a much steeper slope during the first 8 min and this phase is followed by an interval during which the 22Na content of the nuclei decreases (8 to 16 min). After the 16th min it increases again to reach a nuclear 22Na content approximately twice as high as that of nuclei in vivo at 60 minutes. The uptake curves are discussed in relation to recent findings on the induction of puffs in polytene chromosomes by inorganic ions.

Selective stimulation of puffing activity in vitro with a juvenile hormone analogue by polytene chromosomes in the salivary glands of Chironomus thummi (Diptera)

1989 ◽  
Vol 67 (10) ◽  
pp. 2528-2532
Author(s):  
X. Vafopoulou ◽  
C. G. H. Steel ◽  
H. Laufer
Keyword(s):  
Juvenile Hormone ◽  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Hormone Analogue ◽  
Juvenile Hormone Analogue ◽  
Balbiani Rings ◽  
Chironomus Thummi ◽  
Stimulation Of

Salivary glands of Chironomus thummi prepupae were treated in vitro with various concentrations of the juvenile hormone analogue (JHA) methoprene and the puffing activities of Balbiani rings (BR) b and c were scored in cytological preparations of polytene chromosomes. In control cultures, both BRb and BRc regress rapidly. JHA treatment in vitro prevented regression at both these sites. In addition, BRb was found to expand within 60 min to a size two to three times larger than in control contralateral glands. The most effective concentration for stimulation of BRb and BRc in vitro was 10−7 M. In vivo treatment of prepupae with 10−7 M JHA also induced puffing activity in BRb and BRc to a degree similar to that observed following in vitro treatment. It is concluded that BRb, and perhaps also BRc, are juvenile hormone (JH) inducible chromosomal sites in Chironomus thummi salivary glands. This is the first report of chromosomal sites that are stimulated by JH in vitro in the absence of exogenous ecdysteroids. These findings support the view that JH may act at the gene level at separate loci from ecdysone.

Ecdysone-regulated chromosome puffing in the salivary glands of the Mediterranean fruit fly, Ceratitis capitata

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 752-762 ◽  
Author(s):  
Angeliki Gariou-Papalexiou ◽  
Anastassios C Mintzas ◽  
Antigone Zacharopoulou
Keyword(s):  
Protein Synthesis ◽  
Salivary Glands ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Stage 1

The effect of ecdysone on the puffing activity of the polytene chromosomes of Ceratitis capitata has been studied in organ cultures of late-larval salivary glands. Culture of glands from 120-h-old larvae (puff stage 1) in the presence of ecdysone resulted in the initiation of the late-larval puffing cycle that is normally observed in 145-h-old larvae (puff stage 4). During a 7-h period in the presence of ecdysone, the puffing patterns of most loci resembled the in vivo patterns observed in the period between puff stages 4 and 10, indicating that the first puffing cycle can be initiated by the hormone and proceed almost to completion, in vitro. Culture of salivary glands in the presence of ecdysone and a protein-synthesis inhibitor, as well as ecdysone withdrawal and readdition experiments, indicated that most of the ecdysone-regulated puffs could be categorized into three classes: (i) the puffs that were suppressed immediately by ecdysone, even in the absence of protein synthesis; (ii) the puffs that were induced directly by ecdysone; and (iii) the puffs that were induced indirectly by ecdysone, that is, they were induced after a lag period of a few hours and required protein synthesis for their induction.Key words: polytene chromosomes, puffing patterns, ecdysone, Ceratitis capitata.

IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

1970 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Incubation Medium ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Ovariectomized Rats ◽  
Free Medium ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

scholarly journals Seminal Plasma: Relevant for Fertility?

2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca
Keyword(s):  
Seminal Plasma ◽  
Current Knowledge ◽  
Inorganic Ions ◽  
Vitro Fertilization ◽  
Dna And Rna ◽  
Model Animal ◽  
Sexual Glands ◽  
Species Specific

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.

Responses to Hypersaline Exposure in the Euryhaline Crayfish PAcifastacus Leniusculus: II. Modulation of Haemocyanin Oxygen Binding In Vitro and In Vivo

1982 ◽  
Vol 99 (1) ◽  
pp. 447-467
Author(s):  
MICHÈLE G. WHEATLY ◽  
B. R. MCMAHON
Keyword(s):  
Salt Effect ◽  
Ionic Composition ◽  
Inorganic Ions ◽  
Pacifastacus Leniusculus ◽  
Oxygen Binding ◽  
Complete Saturation ◽  
O2 Delivery ◽  
O2 Binding

The effect of 48 h of hypersaline exposure (25, 50 and 75% SW) on haemocyanin oxygenation properties in the euryhaline crayfish Pacifastacus leniusculus was investigated in vitro and in vivo. In vitro significant increases in affinity and cooperativity were measured, although the magnitude of the Bohr shift was unaffected. In vitro dialysis of haemolymph against physiological salines of variable ionic composition proved that these changes were only partly attributable to altered levels of haemolymph ions, implicating the existence of modulators other than H+ and inorganic ions, the possible identities of which are discussed. Significant depressions of both pre- and postbranchial oxygen tensions (Pv, Ov, O2 and Pa, Oa, O2) were observed, but O2 delivery was maintained by utilization of the venous reserve and by an increase in haemocyanin O2 affinity. This occurred despite a concomitant acidosis whose effect on O2 affinity was directly opposed by the ‘salt’ effect. Under hypersaline conditions, haemocyanin played an increasingly important role in O2 delivery in vivo. Despite a reduction in the concentration of combined O2 at complete saturation of the pigment (CmaxHCyOHCyO2). indicating lowered haemocyanin concentration, compensatory changes in O2-binding and cardiac output precluded an impairment to O2 transfer. Equilibration at the tissues (Et,Ot,O2) in FW was less effective than at the gills (Eb,Ob,O2 but progressively improved with hypersaline exposure reversing this trend. Although effects of increased salinity on O2 equilibrium characteristics were qualitatively similar in vivo and in vitro, some interesting quantitative differences are discussed.

In Vivo and in Vitro Uptake of Boronated Compounds by B16-BL6 Murine Melanoma

1993 ◽  
pp. 619-622
Author(s):  
C. A. Elstad ◽  
K. R. Meinkoth ◽  
B. A. Mathison ◽  
G. G. Meadows ◽  
D. H. Kinder ◽  
...  
Keyword(s):  
Murine Melanoma ◽  
In Vitro Uptake

scholarly journals The closely related Drosophila sry beta and sry delta zinc finger proteins show differential embryonic expression and distinct patterns of binding sites on polytene chromosomes

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 141-149 ◽  
Author(s):  
F. Payre ◽  
S. Noselli ◽  
V. Lefrere ◽  
A. Vincent
Keyword(s):  
Dna Binding ◽  
Binding Sites ◽  
Polytene Chromosomes ◽  
Duplication Event ◽  
Amino Acid Sequences ◽  
Evolutionary Divergence ◽  
Coding Region ◽  
Protein Coding

Serendipity (sry) beta (beta) and delta (delta) are two finger protein genes resulting from a duplication event. Comparison of their respective protein products shows interspersed blocks of conserved and divergent amino-acid sequences. The most extensively conserved region corresponds to the predicted DNA-binding domain which includes 6 contiguous fingers; no significant sequence conservation is found upstream and downstream of the protein-coding region. We have analysed the evolutionary divergence of the sry beta and delta proteins on two separate levels, their embryonic pattern of expression and their DNA-binding properties in vitro and in vivo. By using specific antibodies and transformant lines containing beta-galactosidase fusion genes, we show that the sry beta and sry delta proteins are maternally inherited and present in embryonic nuclei at the onset of zygotic transcription, suggesting that they are transcription factors involved in this process. Zygotic synthesis of the sry beta protein starts during nuclear division cycles 12–13, prior to cellularisation of the blastoderm, while the zygotic sry delta protein is not detectable before germ band extension (stage 10 embryos). Contrary to sry delta, the zygotic sry beta protein constitutes only a minor fraction of the total embryonic protein. The sry beta and delta proteins made in E. coli bind to DNA, with partly overlapping specificities. Their in vivo patterns of binding to DNA, visualised by immunostaining polytene chromosomes, differ both in the number and position of their binding sites. Thus changes in expression pattern and DNA-binding specificity have contributed to the evolution of the sry beta and delta genes.

scholarly journals Interaction between the DrosophilaCAF-1 and ASF1 Chromatin Assembly Factors

2001 ◽  
Vol 21 (19) ◽  
pp. 6574-6584 ◽  
Author(s):  
Jessica K. Tyler ◽  
Kimberly A. Collins ◽  
Jayashree Prasad-Sinha ◽  
Elizabeth Amiott ◽  
Michael Bulger ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Polytene Chromosomes ◽  
Normal Growth ◽  
Chromatin Assembly ◽  
Truncated Form ◽  
Assembly Factor ◽  
Development And Differentiation ◽  
Growth Development

ABSTRACT The assembly of newly synthesized DNA into chromatin is essential for normal growth, development, and differentiation. To gain a better understanding of the assembly of chromatin during DNA synthesis, we identified, cloned, and characterized the 180- and 105-kDa polypeptides of Drosophila chromatin assembly factor 1 (dCAF-1). The purified recombinant p180+p105+p55 dCAF-1 complex is active for DNA replication-coupled chromatin assembly. Furthermore, we have established that the putative 75-kDa polypeptide of dCAF-1 is a C-terminally truncated form of p105 that does not coexist in dCAF-1 complexes containing the p105 subunit. The analysis of native and recombinant dCAF-1 revealed an interaction between dCAF-1 and theDrosophila anti-silencing function 1 (dASF1) component of replication-coupling assembly factor (RCAF). The binding of dASF1 to dCAF-1 is mediated through the p105 subunit of dCAF-1. Consistent with the interaction between dCAF-1 p105 and dASF1 in vitro, we observed that dASF1 and dCAF-1 p105 colocalized in vivo inDrosophila polytene chromosomes. This interaction between dCAF-1 and dASF1 may be a key component of the functional synergy observed between RCAF and dCAF-1 during the assembly of newly synthesized DNA into chromatin.

scholarly journals Histone carbonylation in vivo and in vitro

2000 ◽  
Vol 351 (3) ◽  
pp. 769-777 ◽  
Author(s):  
Georg T. WONDRAK ◽  
Daniel CERVANTES-LAUREAN ◽  
Elaine L. JACOBSON ◽  
Myron K. JACOBSON
Keyword(s):  
Histone H1 ◽  
Nuclear Proteins ◽  
Carbonyl Groups ◽  
Cell Nuclei ◽  
Strand Breaks ◽  
Core Histones ◽  
Dna Strand ◽  
And Function

Non-enzymic damage to nuclear proteins has potentially severe consequences for the maintenance of genomic integrity. Introduction of carbonyl groups into histones in vivo and in vitro was assessed by Western blot immunoassay and reductive incorporation of tritium from radiolabelled NaBH4 (sodium borohydride). Histone H1 extracted from bovine thymus, liver and spleen was found to contain significantly elevated amounts of protein-bound carbonyl groups as compared with core histones. The carbonyl content of nuclear proteins of rat pheochromocytoma cells (PC12 cells) was not greatly increased following oxidative stress induced by H2O2, but was significantly increased following alkylating stress induced by N-methyl-N´-nitro-N-nitrosoguanidine or by combined oxidative and alkylating stress. Free ADP-ribose, a reducing sugar generated in the nucleus in proportion to DNA strand breaks, was shown to be a potent histone H1 carbonylating agent in isolated PC12 cell nuclei. Studies of the mechanism of histone H1 modification by ADP-ribose indicate that carbonylation involves formation of a stable acyclic ketoamine. Our results demonstrate preferential histone H1 carbonylation in vivo, with potentially important consequences for chromatin structure and function.

RNA binding by Sxl proteins in vitro and in vivo

1994 ◽  
Vol 14 (7) ◽  
pp. 4975-4990
Author(s):  
M E Samuels ◽  
D Bopp ◽  
R A Colvin ◽  
R F Roscigno ◽  
M A Garcia-Blanco ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Target Genes ◽  
Rna Binding ◽  
Polytene Chromosomes ◽  
Regulatory Sequences ◽  
Acceptor Site ◽  
Nuclear Extracts ◽  
Preferential Binding

Sxl has been proposed to regulate splicing of specific target genes by directly interacting with their pre-mRNAs. We have therefore examined the RNA-binding properties of Sxl protein in vitro and in vivo. Gel shift and UV cross-linking assays with a purified recombinant MBP-Sxl fusion protein demonstrated preferential binding to RNAs containing poly(U) tracts, and the protein footprinted over the poly(U) region. The protein did not appear to recognize either branch point or AG dinucleotide sequences, but an adenosine residue at the 5' end of the poly(U) tract enhanced binding severalfold. MBP-Sxl formed two shifted complexes on a tra regulated acceptor site RNA; the doubly shifted form may have been stabilized by protein-protein interactions. Consistent with its proposed role in pre-mRNA processing, in nuclear extracts Sxl was found in large ribonucleoprotein (RNP) complexes which sedimented significantly faster than bulk heterogeneous nuclear RNP and small nuclear RNPs. Anti-Sxl staining of polytene chromosomes showed Sxl protein at a number of chromosomal locations, among which was the Sxl locus itself. Sxl protein could also be targeted to a new chromosomal site carrying a transgene containing splicing regulatory sequences from the Sxl gene, following transcriptional induction. After prolonged heat shock, all Sxl protein was restricted to the heat-induced puff at the hs93D locus. In contrast, a presumptive small nuclear RNP protein was observed at several heat puffs following shock.

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