Growth and Changes in Pool and Macromolecular Components of Schizosaccharomyces Pombe During the Cell Cycle

1971 ◽  
Vol 9 (3) ◽  
pp. 701-717
Author(s):  
NOWELL STEBBING

Amino acids, nucleotide and carbohydrate material were found to account for 46% of the total dry weight of pool material in Schizosaccharomyces pombe growing in minimal medium. The composition of the amino acid pool was also determined by autoanalysis and was found to be unaltered during growth in 2 M sorbitol, indicating that pool amino acids are not important in the osmoregulation of the cell. Kinetic analysis of the amino acid pool using 14C-labelled amino acids showed that amino acids accumulated from the medium enter an ‘expandable’ pool distinct from the ‘internal’ pool which is maintained during growth on minimal medium. Total RNA, protein, pool amino acid and pool ‘nucleotide’ material were estimated in synchronous cultures grown in minimal medium. All these components appeared to accumulate in an exponential manner during the cell cycle. Direct estimation of total cellular dry weight and the total pool in synchronous cultures showed that total cell dry weight increased exponentially and the pool did not fluctuate during growth in minimal medium. This contrasts with previous work on single cells of S. pombe grown in complex medium which showed that the dry weight of the pool fluctuates during the cell cycle and total cell dry weight increased linearly. Linear growth of S. pombe in malt extract broth can be accounted for by the presence of the second (‘expandable’) pool of amino acids formed during growth in complex medium. The phenomenon of linear growth during the cell cycle is shown to occur generally only in cells growing in complex medium. The phenomenon is considered in relation to mechanisms for controlling the size of the pool during growth in complex media.

Genetics ◽  
1979 ◽  
Vol 93 (2) ◽  
pp. 353-360
Author(s):  
S K Guterman ◽  
C L Howitt

ABSTRACT The phenotype of Escherichia coli K-12 carrying rho-15 in the genetic background DW319 ilv lacZ: :IS1 is described. Seventy-eight percent (70/90) of Ilv+ transductants acquired the following phenotype: temperature-sensitive growth on minimal salts medium, Ts+ growth on complex medium and suppression of the lac polar mutation. At 42° on minimal medium, the rho-15 transductants were cross-fed by a substance diffusing from Rho+ transductants or controls. The requirement for this substance was satisfied by methionine or cystathionine, but not by any other single amino acid or combination of amino acids, by spermidine, or by mono- or divalent cationic salts.—Transduction of rho-15 into four other Ilv- recipients revealed two phenotypic patterns. Recipients with rpsL or rpsE ribosomes yielded rho-15 transductants that were Ts on all media, or Ts on minimal medium whether or not methionine was present. The effect of the ribosome on expression of rho15 was confirmed by transduction of appropriate rps alleles into DW319, followed by co-transduction of rho-15 with Ilv+. The growth rate of double rho-15 rpsL or rho-15 rpsE strains was severely reduced at 42° in comparison with strains carrying any of these single mutations. Models for rho and ribosome interaction are presented.


Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Seiichi Urushiyama ◽  
Tokio Tani ◽  
Yasumi Ohshima

Abstract The prp (pre-mRNA processing) mutants of the fission yeast Schizosaccharomyces pombe have a defect in pre-mRNA splicing and accumulate mRNA precursors at a restrictive temperature. One of the prp mutants, prp1-4, also has a defect in poly(A)+ RNA transport. The prp1  + gene encodes a protein of 906 amino acid residues that contains 19 repeats of 34 amino acids termed tetratrico peptide repeat (TPR) motifs, which were proposed to mediate protein-protein interactions. The amino acid sequence of Prplp shares 29.6% identity and 50.6% similarity with that of the PRP6 protein of Saccharomyces cerevisiae, which is a component of the U4/U6 snRNP required for spliceosome assembly. No functional complementation was observed between S. pombe prp1  + and S. cerevisiae PRP6. We examined synthetic lethality of prp1-4 with the other known prp mutations in S. pombe. The results suggest that Prp1p interacts either physically or functionally with Prp4p, Prp6p and Prp13p. Interestingly, the prp1  + gene was found to be identical with the zer1  + gene that functions in cell cycle control. These results suggest that Prp1p/Zer1p is either directly or indirectly involved in cell cycle progression and/or poly(A)+ RNA nuclear export, in addition to pre-mRNA splicing.


2021 ◽  
pp. 219-225
Author(s):  
Галина Табаленкова

The results of studies of the qualitative composition and quantitative content of amino acids (AAs) in the leaves of three plant species of the genus Artemisia, widespread in the Elton region, were presented. Protein AAs were determined on an AAA T-339 amino acid analyzer (Czech Republic) after hydrolysis of a sample in 6N HCl at 105 °C for 24 h, free AAs – on an AAA-400 amino acid analyzer (Czech Republic) in a lithium buffer system. The protein AAs amount varied from 66 mg / g in A. lerchiana to 113 mg / g dry weight in A. santonica. 17 AAs were found in composition of these species, aspartic and glutamic acids were dominant. The content of free AAs varied from 4.4 mg / g in A. santonica to 8.3 mg / g dry weight in A. pauciflora. 14 AAs have been identified, among them proline was the predominant free AA. The share of proline was 75-81% of the total free AAs. Among the minor components, 3-4 compounds with a content above 2% dominated. The free AAs contain 3 non-proteinogenic ones (ornithine, citruline, and γ-aminobutyric acid). A. lerchiana and A. pauciflora species were similar in protein and free amino acids, probably due to the same growing conditions. A high level of free proline, together with a complex of biologically active substances in Artemisia species, which grow abundantly in the Elton region, allow to consider the possibility of their use as a medicinal raw material.


2010 ◽  
Vol 298 (6) ◽  
pp. R1615-R1626 ◽  
Author(s):  
Neil I. Bower ◽  
Ian A. Johnston

The mRNA expression of myogenic regulatory factors, including myoD1 (myoblast determination factor) gene paralogs, and their regulation by amino acids and insulin-like growth factors were investigated in primary cell cultures isolated from fast myotomal muscle of Atlantic salmon ( Salmo salar). The cell cycle and S phase were determined as 28.1 and 13.3 h, respectively, at 18°C. Expression of myoD1b and myoD1c peaked at 8 days of culture in the initial proliferation phase and then declined more than sixfold as cells differentiated and was correlated with PCNA (proliferating cell nuclear antigen) expression ( R = 0.88, P < 0.0001; R = 0.70, P < 0.0001). In contrast, myoD1a transcripts increased from 2 to 8 days and remained at elevated levels as myotubes were formed. mRNA levels of myoD1c were, on average, 3.1- and 5.7-fold higher than myoD1a and myoD1b, respectively. Depriving cells of amino acids and serum led to a rapid increase in pax7 and a decrease in myoD1c and PCNA expression, indicating a transition to a quiescent state. In contrast, amino acid replacement in starved cells produced significant increases in myoD1c (at 6 h), PCNA (at 12 h), and myoD1b (at 24 h) and decreases in pax7 expression as cells entered the cell cycle. Our results are consistent with temporally distinct patterns of myoD1c and myoD1b expression at the G1 and S/G2 phases of the cell cycle. Treatment of starved cells with insulin-like growth factor I or II did not alter expression of the myoD paralogs. It was concluded that, in vitro, amino acids alone are sufficient to stimulate expression of genes regulating myogenesis in myoblasts involving autocrine/paracrine pathways. The differential responses of myoD paralogs during myotube maturation and amino acid treatments suggest that myoD1b and myoD1c are primarily expressed in proliferating cells and myoD1a in differentiating cells, providing evidence for their subfunctionalization following whole genome and local duplications in the Atlantic salmon lineage.


1978 ◽  
Vol 33 (1) ◽  
pp. 399-411
Author(s):  
J. Creanor

Oxygen uptake was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe. The rate of oxygen uptake was found to increase in a step-wise manner at the beginning of the cycle and again in the middle of the cycle. The increases in rate were such that overall, oxygen uptake doubled in rate once per cell cycle. Addition of inhibitors of DNA synthesis or nuclear division to a synchronous culture did not affect the uptake of oxygen. In an induced synchronous culture, in which DNA synthesis, cell division, and nuclear division, but not ‘growth’ were synchronized, oxygen uptake increased continuously in rate and did not show the step-wise rises which were shown in the selection-synchronized culture. These results were compared with previous measurements of oxygen uptake in yeast and an explanation is suggested for the many different patterns which have been reported.


2006 ◽  
Vol 18 (7) ◽  
pp. 789 ◽  
Author(s):  
Chie Suzuki ◽  
Koji Yoshioka

The effects of glutamine, hypotaurine, taurine and premixed solutions of essential amino acids (EAA) and non-essential amino acids (NEAA) on in vitro development of porcine zygotes were evaluated. The effects of refreshing the medium and replacing polyvinyl alcohol (PVA) with bovine serum albumin (BSA) on embryonic development were also investigated. Porcine zygotes produced by in vitro maturation (IVM) and in vitro fertilisation (IVF) were cultured in porcine zygote medium (PZM), as the basal culture medium, for 5 days after IVF. The total number of cells in blastocysts was significantly increased by the addition of 2 mm glutamine to PZM, as was blastocyst yields after supplementation with 0.25 to 4 mm glutamine. Addition of 1.25 to 10 mm hypotaurine to PZM significantly increased blastocyst yields. Addition of 5 mm taurine to PZM significantly increased blastocyst yield, whereas taurine had no effect on blastocyst yield in cultures already containing 5 mm hypotaurine. Adding 1× EAA significantly increased the rate of blastocyst formation compared with no or 2× EAA, whereas 2× NEAA significantly increased the total cell numbers in blastocysts compared with no NEAA. Refreshing the medium at Day 3 had no effect on blastocyst yields, whereas medium change significantly reduced the total cell numbers in blastocysts. Adjusting the amino acid concentrations of a chemically defined medium can improve the developmental competence of porcine embryo.


2015 ◽  
Vol 27 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Kubiczek ◽  
M. Rakowska

Total and soluble nitrogen, protein and non-protein -nitrogen was determined as well as the amino acid composition of the caryopses of ten rye varieties including three bred in Poland and cultivated on a commercial scale: 'Dańkowskie Złote', 'Dańkowskie Selekcyjne' and 'Borkowskie Tetra'. and seven foreign varieties characterized by a high total protein content (11.9-16.4% in dry weight). In the varieties examined the amount of protein nitrogen increased in the same degree as did the content of total nitrogen. The amino acids limiting the nutritive value of the protein in rye caryopses were mostly lysine and methionine, and in the varieties with high protein content tryptophan. The low-protein varieties had a relatively higher content of lysine, sulphur amino acids, tryptophan and other amino acids (as % of protein) than the high protein ones, but their absolute amino acid content (as % of dry weight) was lower.


2020 ◽  
Vol 18 (3) ◽  
pp. 487-495
Author(s):  
Nguyen Phuong Lan ◽  
Do Thi Thanh Trung ◽  
Van Thu Vu ◽  
Le Tat Thanh

Mud crab Scylla sp. is a common sea crab species in Vietnam as well as in Asia Pacific. Today, mud crabs are raised on a large scale to be harvested at the soft molting stage because of the high economic value of the finished shell crabs. At present, the processing of soft shell crabs is limited to whole packaging and exporting. However, 30% of soft-shelled crabs in processing often lose their feet and claws, which reduce production costs. Therefore, it is necessary to study the technology of processing soft-shell crabs to improve the value of soft-shelled crab products. Recently, the application of enzymes in processing has brought many benefits such as being environmentally friendly and creating many bioactive substances. In this journal, we built the procedure to determine amino acid content in the processing of Scylla sp. to ensure the quality of products obtained after processing. This procedure based on HPLC using a fluorescence reader. The results showed that the amino acid content after hydrolysis process by enzyme technology reached 65.58% dry weight and contains many valuable amino acids such as lysine, leucine, valine, methionine, histidine.


1970 ◽  
Vol 7 (2) ◽  
pp. 523-530
Author(s):  
C. J. BOSTOCK

The effect of different concentrations of 2-phenyl ethanol (PE) on growth and DNA synthesis of Schizosaccharomyces pombe is described. o.3% PE inhibits the entry of cells into S phase, but allows a doubling in the number of cells in the culture. The effect of o.2% PE on random and synchronous cultures of S. pombe shows that, in the continued presence of the inhibitor, the S phase is moved to a different point in the cell cycle. Cells continue to grow in the presence of o.2% PE with a G1 phase occupying a significant portion of the cell cycle. This differs from normal growth when the G1 phase is absent.


1981 ◽  
Vol 51 (1) ◽  
pp. 219-228
Author(s):  
K.I. Mills ◽  
L.G. Bell

The incorporation of tritiated thymidine, uridine and leucine, into the acid-precipitable material of DNA. RNA and proteins, respectively, was studied by autoradiography throughout the cell cycle of Amoeba proteus. DNA synthesis occupied the first 17 h of the cycle (57 h long) and 2 peaks between 0.5 and 9.13 h accounted for the majority of the thymidine incorporation. RNA synthesis was represented by a series of peak uridine grain counts, the 3 major peaks occurring at 10, 26–27 and 47–48 h. The incorporation of leucine also followed a pattern of peaks and dips, the main peaks occurring 1–2 h after the major increases in uridine incorporation. The fraction of label present over the nucleus decreased during the cell cycle, and this was probably due to a lowered incorporation of the leucine label by proteins synthesized in the cytoplasm and destined to become nuclear proteins. The incorporation patterns of 6 amino acids (arginine, aspartic acid, leucine, lysine, serine and valine) were studied individually during 3 periods of the cell cycle: 0-10 h (S phase); 20–30 h (early G2); and 40–50 h (mid-late G2). Variations in the intensity and timings of the incorporation maxima of the amino acids were observed, although the timings of increased grain counts of some of the amino acids frequently coincided. “Unique” incorporation peaks (i.e. only observed in one of the amino acids studied) possibly indicate the synthesis of phase-specific proteins. The amino acid and nucleoside incorporation profiles presented in this paper will enable the results obtained from future studies on amoebae to be related to the macromolecular synthesis patterns.


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