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In a permanent cell line derived from Drosophila embryos, cytoplasmic actin is produced as an unstable precursor, which is subsequently converted to a stable form. This conversion results in a reduction in isoelectric point, with no apparent change in molecular weight. The conversion involves an enzymatic acetylation, and results in an insensitivity to aminopeptidase digestion, suggesting N-terminal blockage. Both the acetylated and unacetylated actins can participate in the assembly of F-actin, but with different efficiencies.This work was supported by a grant from the NIH (GM 22866). 相似文献
3.
William H. Petri Mihalis N. Mindrinos Mary F. Lombard Lukas H. Margaritis 《Development genes and evolution》1979,186(4):351-362
Summary TheDrosophila chorion is produced normally in isolated follicles in Robb's chemically defined culture medium. The complex architecture of the shell developed in vitro from follicles as young as early stage 10 is completely normal morphologically. In addition, the time required for in vitro development closely approximates that observed for in vivo development. Comparisons of insect culture media developed by Robb, Grace, Schneider, and Echalier show large variations in their ability to supportDrosophila chorion development. 相似文献
4.
Requirements of eliminating animal proteins from cell culture have intensified in recent years, with the pressure of regulatory agencies related to biopharmaceuticals production. In this work, the substitution of fetal bovine serum by yeastolate and a soy hydrolysate (Hy Soy) for the culture of Drosophila melanogaster Schneider 2 cells transfected for the production of rabies virus G glycoprotein was evaluated. TC100 supplemented with glucose, glutamine, lipid emulsion and Pluronic F68 was employed as basal medium. Results show that yeastolate was more efficient on cell growth stimulation than Hy Soy. Cells adapted in medium formulation supplemented with 3 g/L yeastolate, 1% lipid emulsion, 10 g/L glucose, 3.5 g/L glutamine and 0.1% Pluronic F68 attained a maximum concentration of 10.7 x 10(6) cells/mL, with the expression of 9.4 ng/mL G glycoprotein. 相似文献
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Summary A saline extract was prepared fromDrosophila eggs. When diluted to a concentration of 1% withDrosophila tissue culture medium, it did not support growth of cells from theDrosophila line D1 during the first few days of subculture as well as medium containing serum. When cells reached a stationary phase,
however, the cell density in medium containing extract was greater than in medium containing serum. By altering the concentrations
of the extract, and by adding bovine albumin, a medium was obtained in which D1 cells survived initial culturing, and which
supported cell growth by day 4 as well as medium plus serum. The initial retardation of growth in medium containing egg extract
might be due to the need of the cells to adapt to the new medium. At the present time fourDrosophila cell lines have been maintained in this medium for more than 16 passages. Preliminary experiments with primary embryonicDrosophila cells indicate that medium containing 2% extract and bovine albumin retards the differentiation of these cells.
This work was supported by a grant from the Science Research Council of Great Britain. 相似文献
7.
Peroxidase activity and isoenzymes in the culture medium of NaCl adapted tomato suspension cells 总被引:6,自引:0,他引:6
María A. Sancho Silvia Milrad de Forchetti Fernando Pliego Victoriano Valpuesta Miguel A. Quesada 《Plant Cell, Tissue and Organ Culture》1996,44(2):161-167
The medium of tomato (Lycopersicon esculentum) cells adapted to grow in the presence of 15 g l–1 NaCl had a higher peroxidase activity than the medium of an unadapted tomato cell line. When the adapted cells were cultured in a medium without NaCl, the value found for peroxidase activity was intermediate. The increase in peroxidase activity was parallel to an increase of lignin-like compounds in the cell walls, as well as to an increased content or appearance of neutral and basic peroxidase isoenzymes. Apparently, the high values of peroxidase activity in the medium of the salt-adapted cells reflect the changed mechanical properties of the cell wall which, in turn, could be related to the salt adaptation process.Abbreviations LO
Control tomato cell line unable to grow in the presence of 15 g 1–1 of NaCl
- L15
tomato cell line adapted to 15 g 1–1 of NaCl and growing in this salt concentration
- L15-0
tomato cell line adapted to 15 g 1–1 of NaCl and growing in the absence of this salt
- 2,4-D
2,4-dichlorophenoxyacetic acid
- NAA
naphthaleneacetic acid
- PBS
phosphate buffer saline 相似文献
8.
T. A. Egorova-Zachernyuk G. J. C. G. M. Bosman A. M. A. Pistorius W. J. DeGrip 《Applied microbiology and biotechnology》2009,84(3):575-581
Preparation of stable isotope-labelled yeastolates opens up ways to establish more cost-effective stable isotope labelling
of biomolecules in insect and mammalian cell lines and hence to employ higher eukaryotic cell lines for stable isotope labelling
of complex recombinant proteins. Therefore, we evaluated several common yeast strains of the Saccharomycetoideae family as
a source of high-quality, non-toxic yeastolates with the major aim to find a primary amino acid source for insect and mammalian
cell culture that would allow cost-effective uniform stable isotope labelling (13C, 15N). Strains of the facultative methylotrophic yeasts Pichia pastoris and Hansenula polymorpha (Pichia angusta) as well as a strain of the baker’s yeast Saccharomyces cerevisiae were compared as a source of yeastolate with respect to processing, recovery and ability to sustain growth of insect and
mammalian cell lines. The best growth-supporting yeastolates were prepared via autolysis from yeast obtained from fed-batch
cultures that were terminated at the end of the logarithmic growth phase. Yeastolates obtained from H. polymorpha performed well as a component of insect cell cultures, while yeastolates from S. cerevisiae and H. polymorpha both yielded good results in mammalian cell cultures. Growth of yeasts in Heine’s medium without lactic acid allows relatively
low concentrations of 13C and 15N sources, and this medium can be reused several times with supplementation of the 13C source only. 相似文献
9.
Sodium citrate, added to culture medium at 2 g l−1, increased inosine production by B. subtilis by 18% to 16 g l−1. The phosphoenolpyruvate (PEP) pool was increased by 2.3-fold, while the pyruvate and acetate pools were decreased by 78% and 57%, respectively. Pyruvate kinase might thus be a regulatory site for inosine synthesis. 相似文献
10.
Kadokura K Sakamoto Y Saito K Ikegami T Hirano T Hakamata W Oku T Nishio T 《Biotechnology letters》2007,29(8):1209-1215
An open reading frame (ORF) encoding chitin oligosaccharide deacetylase (Pa-COD) gene and its signal sequence was cloned from the Vibrio parahaemolyticus KN1699 genome and its sequence was analyzed. The ORF encoded a 427 amino acid protein, including the 22 amino acid signal
sequence. The deduced amino acid sequence was highly similar to several bacterial chitin oligosaccharide deacetylases in carbohydrate
esterase family 4. An expression plasmid containing the gene was constructed and inserted into Escherichia coli cells and the recombinant enzyme was secreted into the culture medium with the aid of the signal peptide. The concentration
of the recombinant enzyme in the E. coli culture medium was 150 times larger than that of wild-type enzyme produced in the culture medium by V. parahaemolyticus KN1699. The recombinant enzyme was purified to homogeneity from culture supernatant in an overall yield of 16%. Substrate
specificities of the wild-type and the recombinant enzymes were comparable. 相似文献
11.
The effects of the physical characteristics of the culture medium on the development of red seaweeds in tissue culture 总被引:3,自引:0,他引:3
Explants of Gelidium versicolor, Grateloupia doryphora and Laurencia sp. were cultivated in Provasoli enriched seawater culture medium (PES) adjusted to several osmolalities (0.5, 0.7, 1.0 and 1.5 Os kg–1) and solidities (agar concentration = 3, 8 and 15 g L–1). Osmolality was adjusted by dilution of seawater with distilled water (50, 70 and 100% seawater) and by NaCl addition. Explants of Laurencia sp. and Grateloupia doryphora showed bud regeneration and callus formation. Explants of Gelidium versicolor only showed bud regeneration. Osmolalities of 0.5 and 1.05 Os kg–1. inhibited or drastically reduced bud regeneration and callus formation. The highest callus formation and bud regeneration were observed at 0.7 to 1.0 Os kg–1. An increase in the agar concentration of the culture medium was positively correlated with callus formation and negatively correlated with bud regeneration. An increase in the percentage of seawater increased the solidity of the culture medium and was positively correlated with callus formation. Glycerol was an effective carbon source for the vegetative propagation of axenic explants of Grateloupia doryphora, promoting growth and bud regeneration. An increase in glycerol concentration in the culture medium increased its osmolality, inhibiting the growth of the explants and their morphogenetic development. 相似文献
12.
The genomic distribution and the number of elements of eleven transposon families have been compared by the Southern technique between permanent cultured cells, larval salivary glands and the brains and whole flies of an inbred Drosophila line (inb-c) from which the cells were established. In cultured cells, changes in restriction patterns consistent with various types of rearrangements such as amplification, transposition and excision of the elements of copia, 1731, 412, 297 and mdg-4 transposon families are detected whereas B 104, G and blood elements appear stable. In previous reports these rearrangements were not detected among individuals of the inb-c line or among samples of somatic tissues, or in samples spanning years of maintenance of cultured cells. Hence, we believe that they have been induced de novo during the passage to the cell culture. 相似文献
13.
Mendonça RZ de Oliveira EC Pereira CA Lebrun I 《Bioprocess and biosystems engineering》2007,30(3):157-164
In this study, we have described the biological activity of various hydrolysates and its effect on cell growth, growth rate
and doubling time. A potent cell culture enhancer factor was observed in the yeastolate hydrolysates, mainly in the protein
fractions with low molecular weight. In this case, a growth enhancer of 60.66% was obtained. Despite a lower efficiency of
crude lactalbumin hydrolysates (14%), when lactalbumin and yeastolate were added together to the culture, the cell yields
were of 102%, showing a synergic effect. Nevertheless, sub fraction from LMW, of lactalbumin, obtained by Sephadex G-10 gel
filtration chromatography showed a higher positive effect (23.3%) than low molecular weight fraction of lactalbumin without
this chromatography step (11.3%). It is suggested that low molecular weight lactalbumin could have some inhibitory protein.
On the other hand, NZCase low molecular weight showed a positive effect of 29.33%, while its sub fractions showed a negative
effect of 5.5%. With these data we can suggest that these hydrolysates could be an important element to design new media,
serum free, being helpful in protein recombinant production. 相似文献
14.
Elizabeth W. Maas Jurgen Thiele Caryn Thompson Rebecca M. Latter Heather J.L. Brooks 《Journal of applied phycology》2000,12(1):95-98
In order to study saxitoxin (STX) production bymicro-algae in the laboratory, a defined algal culture medium which supports
optimum growth over a longtime-period is a requirement. In the development of such a medium, a number of modifications were
made to a standard algal culture medium (GP) and growth of a STX-producing isolate of Alexandrium minutum in the different formulations was assessed by measuring maximum cell densities and mean generation times (MGT). All experiments
were carried out under controlled conditions in an aerobic atmosphere with increased CO2. Whilst maximum cell densities in the different modifications were similar, the MGT was significantly shortened by the addition
of Tris buffer and the trace metals strontium, selenium and molybdenum. Replacement of natural with artificial seawater and
removal of soil extract did not adversely affect algal growth. Five of the six media formulations supported the growth of
A. minutumover a 9-month period.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Specific expression of the Drosophila midline-jumper retro-transposon in embryonic CNS midline cells
Here we describe of a novel Drosophila LTR-type retrotransposon that is expressed in the embryonic CNS midline glia and in the embryonic germ cells. The element is related to the gypsy and burdock retrotransposons and was termed midline-jumper. In addition to cDNA clones generated from internal retrotransposon sequences, we have identified one cDNA clone that appears to reflect a transposition event, indicating that the midline-jumper retrotransposon is not only transcribed but also able to transpose during Drosophila development. 相似文献
16.
Phosphate-independent nucleoside deoxyribosyltransferase activity was detected in Aerococcus viridans, Leuconostoc mesenteroides, two species of Pediococcus, eight obligately homofermentative and three obligately heterofermentative lactobacilli. In cellfree extracts of one strain of Lactococcus, one strain of Streptococcus and three strains of facultatively heterofermentative lactobacilli no phosphate-independent nucleoside deoxyribosyltransferase could be detected and inosine nucleoside phosphorylase was the only enzyme catalysing pentosyl transfer to purines. A classification based on the presence or absence of these enzymes separates Streptococcus and Lactococcus from the remaining genera which is in agreement with studies using anti-aldolase sera and 16S rRNA oligonucleotide catalogues.Abbreviations NCIMB
National Collection of Industrial and Marine bacteria
- NCDO
National Collection of Dairy organisms
- MRS
deMan Rogosa Sharpe
- Pipes
Piperazine-N,N-bis[2-ethanesulphonic acid] 相似文献
17.
The pattern of spontaneous mutation can be inferred from the pattern of substitution in pseudogenes, which are known to be
under very weak or no selective constraint. We modified an existing method (Gojobori T, et al., J Mol Evol 18:360, 1982) to infer the pattern of mutation in bacteria by using 569 pseudogenes from Mycobacterium leprae. In Gojobori et al.’s method, the pattern is inferred by using comparisons involving a pseudogene, a conspecific functional
paralog, and an outgroup functional ortholog. Because pseudogenes in M. leprae are unitary, we replaced the missing paralogs by functional orthologs from M. tuberculosis. Functional orthologs from Streptomyces coelicolor served as outgroups. We compiled a database consisting of 69,378 inferred mutations. Transitional mutations were found to
constitute more than 56% of all mutations. The transitional bias was mainly due to C→T and G→A, which were also the most frequent
mutations on the leading strand and the only ones that were significantly more frequent than the random expectation. The least
frequent mutations on the leading strand were A→T and T→A, each with a relative frequency of less than 3%. The mutation pattern
was found to differ between the leading and the lagging strands. This asymmetry is thought to be the cause for the typical
chirochoric structure of bacterial genomes. The physical distance of the pseudogene from the origin of replication (ori) was found to have almost no effect on the pattern of mutation. A surprising similarity was found between the mutation pattern
in M. leprae and previously inferred patterns for such distant taxa as human and Drosophila. The mutation pattern on the leading strand of M. leprae was also found to share some common features with the pattern inferred for the heavy strand of the human mitochondrial genome.
These findings indicate that taxon-specific factors may only play secondary roles in determining patterns of mutation.
Electronic Supplementary Material Electronic Supplementary material is available for this article at
and accessible for authorised users.
[Reviewing Editor:Dr. Dmitri Petrov] 相似文献
18.
Summary We have devised techniques to culture whole, dissected embryos of Drosophila melanogaster. We examine multiple aspects of the morphological and physiological development of the epidermis, musculature, nervous system, and internal organs in this cultured preparation, and show that in vitro development closely parallels normal embryogenesis. These techniques permit a wide range of experimental manipulations during embryogenesis and allow us to extend observations through late embryonic stages, after cuticle deposition. Applications of this technique are presented. 相似文献
19.
The possibility that cells of multicellular organisms may compete with one another has been postulated several times. It was experimentally confirmed in Drosophila, probably for the first time, when cells with different metabolic rates were mixed: cells that would have been viable on their own disappeared due to the presence of metabolically more active cells. After almost 30 years of neglect, genetic analysis in Drosophila has started to reveal a gene network that regulates the competitive behavior of cells. If the genes regulating cellular competitiveness in Drosophila have a conserved function in mammals, the study of cell competition could have an impact in several biomedical fields, including functional degeneration, cancer, or stem cell therapies. 相似文献
20.
Rubria Marlen Martínez-Casares Norberto Manjarrez Alvarez Aida Solís Oba Liliana Hernández Vázquez Alberto López-Luna 《Nucleosides, nucleotides & nucleic acids》2017,36(10):652-665
The separation of the diastereoisomers of the nucleoside derivatives of uridine, inosine and adenosine was performed by HPLC using chiral and no chiral columns, it was observed with the no chiral columns the resolution was good enough to determine diastereoisomeric excess. These methods were compared with 1H NMR, and no significant differences were observed between the three techniques. Diastereoisomeric uridine (3a), inosine (3b) and adenosine (4c) cyanohydrins were resolved by 1H nuclear magnetic resonance (1H NMR), chiral normal phase-high-performance liquid chromatography-diode array detector (NP-HPLC-DAD) and reversed phase (RP-HPLC-DAD); these methods allowed the assesment of the percent diastereoisomeric excess (% de) of the nucleosidic cyanohydrins of 3a (4, 6 and 4), 3b (10, 8 and 6) and 4c (4, 4 and 4). To the best of our knowledge, there are no reports using analytical techniques for the separation of the epimers of 3a, 3b and 4c. 相似文献