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1.
Summary The surface tension and foaminess of (a) unlimited, (b) substrate limited, and (c) oxygen transfer limited growth media of Hansenula polymorpha were measured using methanol, ethanol or glucose as a substrate.The time dependence of can be described by the Avrami-Überreiter relationship: log (2.3 log V)=n log t+log b, where V = (O – eq/(t – eq, and O, t and eq are at tM=0, tM=t and tM (equilibrium value).The constants n and b are functions of the fermentation time tF as long as the growth is unlimited but they are constant in the state of limited growth. With glucose substrate, the foaminess can be presented as a definite function of the time, tDG, which is necessary to attain eq. With alcohol as a substrate no definite (tDG) function was found.Symbols b
constant in Eq. (1)
- n
constant in Eq. (1)
- S
substrate concentration
- T
temperature
- tM
time h (measured from the beginning of the determination of the surface tension )
- tF
cultivation time h (measured from the time of inoculation)
- tDG
time (min) necessary to attain the equilibrium surface tension )
- X
dry biomass concentration (gl–1)
- V
(O – eq)/(t – eq)
- VS
equilibrium volume of the foam (cm3)
- VG
volumetric gas flow rate during the estimation of (cm3 s–1)
- vvm
volumetric gas flow rate with regard to the volume of the medium (min–1)
- wSG
superficial gas velocity (cm s–1)
- m
maximum specific growth rate (h–1)
-
VS/VG foaminess (s)
-
surface tension, mMm–1 (milli Newton m–1)
- O
at tM=0
- eq
equilibrium surface tension ( at tM)
- t
at tM=t
- HP
probes from Hansenula polymorpha cultivation
- NLG
non limited growth
- OTLG
oxygen transfer limited growth
- SLG
substrate limited growth 相似文献
2.
E. C. Roumen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(4):498-503
The inheritance of host plant resistance and its effect on the relative infection efficiency for leaf blast was studied in the crosses IR36/CO39 (partially resistant × highly susceptible) and IR36/IR64 (both partially resistant). On the natural scale, gene action appeared multiplicative. After log transformation, additive effects described most of the genetic variation in the cross IR36/CO39, while additive and dominance effects were about equal in magnitude in the cross IR36/IR64. Dominance was towards increased resistance. No transgressive segregation occurred in the cross IR36/CO39. The number of genes that reduce lesion number was estimated to be zero in CO39 and five or more in IR36. The cross IR36/IR64 showed transgressive segregation in both directions, and IR36 and IR64 each contain at least one gene that is not present in the other cultivar. The heritabilities (narrow sense) in the F2 were low (range 0.06–0.16), while narrow sense heritabilities based on F3 lines were much higher (range 0.41–0.68). Lesion numbers in F3 lines were reasonably correlated with those in F5 progenies derived from the same F2 plant (r was±0.6 in both crosses). Partial resistance can be effectively improved by selecting the most resistant plants from the most resistant F3 lines. 相似文献
3.
Jacques Raymond Brahim Mimouni Jean-Louis Azanza 《Plant Systematics and Evolution》1994,193(1-4):69-79
The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (11 and 22). The subunit corresponding to the 11 pair is present inH. petiolaris and in the three populations ofH. annuus studied. The 2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific 2a2 and 44 pairs andH. annuus a specific 33 pair. InH. argophyllus 11 33 or 44 are never observed but are replaced by 13 and 31 pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins. 相似文献
4.
The dynamics of coupled biological oscillators can be modeled by averaging the effects of coupling over each oscillatory cycle so that the coupling depends on the phase difference between the two oscillators and not on their specific states. Average phase difference theory claims that mode locking phenomena can be predicted by the average effects of the coupling influences. As a starting point for both empirical and theoretical investigations, Rand et al. (1988) have proposed d/dt= — K sin ), with phase-locked solutions =arcsin( /K), where is the difference between the uncoupled frequencies and K is the coupling strength. Phase-locking was evaluated in three experiments using an interlimb coordination paradigm in which a person oscillates hand-held pendulums. was controlled through length differences in the left and right pendulums. The coupled frequency c was varied by a metronome, and scaled to the eigenfrequency v of the coupled system K was assumed to vary inversely with c. The results indicate that: (1) and K contribute multiplicatively to (2) =0 or = regardless of K when =0; (3) 0 or regardless of when K is large (relative to ); (4) results (1) to (3) hold identically for both in phase and antiphase coordination. The results also indicate that the relevant frequency is c/v rather than c. Discussion high-lighted the significance of confirming =arcsin(/K) for more general treatments of phase-locking, such as circle map dynamics, and for the 11 phase-entrainment which characterizes biological movement systems. 相似文献
5.
J. Crossa C. O. Gardner R. F. Mumm 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,73(3):445-450
Summary Thirteen maize (Zea mays L.) populations including five adapted, five adapted x exotic, two composites of adapted and exotic, and one exotic selected for adaptability were crossed in a diallel mating system. The parents and 78 crosses and nine check hybrids were evaluated for grain yield and plant height in five environments. The Gardner-Eberhart model Analysis II indicated that additive and nonadditive gene effects accounted for 60 and 40% of the total variation among populations, respectively, for grain yield and 86% and 14% of the total variation, respectively, for plant height. Components of heterosis were significant in the combined analysis for both traits. Adapted Corn Belt populations tended to have higher performance in crosses and greater values of variety heterosis than 50% adapted populations. Nebraska Elite Composite, Corn Belt x Mexican, and Corn Belt x Brazilian showed high mean yields in crosses, however, they were not among those with high estimates of variety heterosis. One exotic population (Tuxpeno x Antigua Grupo 2) and three adapted populations [307 Composite, NB(S1)C-3, and NK(S1)C-3] might be combined together to form a high-yielding population. It may be possible to synthesize two useful populations for reciprocal recurrent selection by grouping Tuxpeno x Antiqua Grupo 2, NB(S1)C-3, and NS(FS)LFW-8 into one population and NK(S1)C-3, KrugxTabloncillo, and 307 Composite in the other one.Contribution from the Department of Agronomy, University of Nebraska, Lincoln, NE 68583. Published as Paper No. 8011. Journal Series, Nebr. Agric. Exp. Station. Research was conducted under Project 12-049 相似文献
6.
J. Romero-Andreas F. A. Bliss 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,71(3):478-480
Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F2 progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly. 相似文献
7.
Summary Five subunits (-, -, -, - and -subunits) of the six -and -subunits) in the F1 portion (F1ATPase) of sweet potato (Ipomoea batatas) mitochondrial adenosine triphosphatase were isolated by an electrophoretic method. The - and -subunits were not distinguishable immunologically but showed completely different tryptic peptide maps, indicating that they were different molecular species. In vitro protein synthesis with isolated sweet potato root mitochondria produced only the -subunit when analyzed with anti-sweet potato F1ATPase antibody reacting with all the subunits except the -subunit. Sweet potato root poly(A)+RNA directed the synthesis of six polypeptides which were immunoprecipitated by the antibody: two of them immunologically related to the -subunit and the others to the - and -subunits. We conclude that the -subunit of the F1ATPase is synthesized only in the mitochondria and the -, - and -subunits are in the cytoplasm. 相似文献
8.
P. R. K. Koduru M. K. Rao 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1980,56(3):137-143
Summary Thirteen spontaneously occurring chlorophyll deficient phenotypes have been described and their genetic basis was established. Ten of these — white, white tipped green, patchy white, white virescent, white striping 1, white striping 2, white striping 4, fine striping, chlorina and yellow virescent showed monogenic recessive inheritance and the remaining three — yellow striping, yellow green and light green seedling phenotypes showed digenic recessive inheritance. The genes for (i) white tipped green (wr) and yellow virescent (yv) and (ii) patchy white (pw) and white striping 1 (wst 1) showed independent assortment. Further, the genes for white (w), white tipped green (wr) and yellow virescent (yv) were inherited independently of the gene for hairy leaf margin (Hm).In the mutants — white tipped green, patchy white, white striping 1, white striping 2, fine striping, chlorina, yellow virescent, yellow striping, yellow green and light green phenotypes total quantity of chlorophyll was significantly less than that in the corresponding controls, while in white virescent there was no reduction in the mature stage. For nine of the mutants the quantity of chlorophyll was also estimated in F1's (mutant x control green). In F1's of six of the mutants — white tip, patchy white, chlorina, yellow virescent, fine striping and yellow striping the quantity of chlorophyll was almost equal to the wild type. In the F1's of three of the mutants — white striping 1, white striping 2 and light green an intermediate value between the mutant and wild types was observed. In yellow virescent retarded synthesis of chlorophyll, particularly chlorophyll a was observed in the juvenile stage. Reduced quantity of chlorophyll was associated with defective chloroplasts. In the mutants — white tipped green, white virescent, fine striping, chlorina, yellow striping, yellow green and light green defective plastids were also observed. In patchy white secondary destruction of chlorophylls and the presence of defective plastids were found to be associated with reduced chlorophyll quantity at maturity.Paper chromatographic studies of leaf flavonoids revealed some variation between the inbreds, but there were three common spots, 7, 8 and 9, except for PDP in which the spot 8 was absent. Chlorophyll deficient mutants differed from their respective controls in the absence of one or more of the spots present in the controls and in the presence of new spots in some of the mutants.Most of the chlorophyll mutants showed higher survival rate in the Kharif season than in Rabi season which was attributed to the higher mean day temperature and longer day light period in the Kharif season than in Rabi season. 相似文献
9.
Mammalian brain tubulin is an heterodimer; both and exist in 6–7 isotypic forms which differ in their amino acid sequences. By the use of isotype-specific monoclonal antibodies, we have previously shown that we can purify the
II,
III, anda
IV tubulin dimers from bovine brain. We have also observed that these isotypes differ in their distributionin vivo and their polymerization and drug-binding propertiesin vitro. We have now explored the question of whether the isotypically purified dimers differ in their overall conformation using as probes compounds of theN,N-polymethylenebis (iodoacetamide) series which are known to form discrete intrachain cross-links in-tubulin. These compounds have the structure ICH2CONH(CH2)
n
NHCOCH2I. One of these cross-links, designated
s, is between cys12 and either cys201 or cys211. The other, designated
*, is between cys239 and cys354. The
* cross-link forms in
II and
IV but not in
III; this is not surprising in view of the fact that
III has serine at position 239 instead of cysteine. However,
III is also unable to form the
s cross-link, although it appears to have all three cysteines which may be involved in the cross-link. This suggests that at least one of the sulfhydryls involved in the cross-link may be inaccessible in
III. Although both
II and
IV can form the
s cross-link, the dependence on cross-linker chain length is different.
II forms
s with derivatives in whichn=2, 4, 5, 6, and 7 but not with those in whichn=3 or 10. In contrast,
IV forms
s with derivatives in whichn=2, 3, 4, 5, 6, 7, and 10. These results imply that the
s sulfhydryls are slightly more accessible in
IV and are therefore less dependent on the conformation of the cross-linker to react with it. It appears, therefore, that the
II,
III, and
IV dimers each have unique conformations. This may help to explain the different assembly and drug-binding properties of these dimers. 相似文献
10.
Integrins: cell adhesives and modulators of cell function 总被引:3,自引:0,他引:3
Fred T. Bosman 《The Histochemical journal》1993,25(7):469-477
Summary Integrins encompass a family of cell-surface molecules which play a crucial role in cell-cell and cell-extracellular matrix interaction. Of these heterodimeric transmembrane glycoproteins (consisting of an and chain) as yet at least 20 different types have been described, all with a different pattern of reactivity with extracellular matrix components. In this review the cell and tissue distribution of the integrins is discussed, with special emphasis on immunohistochemical localization of the 1 integrins and the 64 integrin. The 1 integrins comprise a subfamily in which eight chains combine with one (the 1) chain. The 21, 31 and 61 and the 64 integrins are expressed on a wide variety of epithelia on the basolateral surface or exclusively on the basal surface facing the basement membrane (e.g. 61 and 64). Leucocyte integrins, which share a common 2 chain, occur almost exclusively on white blood cells and their precursors. The vitronectin receptors, which share a common v chain, occur in a wide variety of cell types. Integrins play a major role in the interaction of the cell with the extracellular matrix in order to create and maintain tissue architecture. It has become clear, however, that through integrin-ligand interaction cell function is also modulated. Furthermore, in pathological conditions integrins play a role of some significance. Integrins mediate leucocyte traffic in developing inflammatory processes and function in neoplastic growth when it comes to invasion and metastasis. 相似文献
11.
Summary Short oligocytidylates can act as templates for the self-condensation of guanosine 5-phosphorimidazolide. In the absence of a catalytic metal ion or in the presence of Pb2+ a noticeable template effect is already observed with the dimer and the yield of long oligomers reaches a plateau with a hexamer template. Short templates give oligomers longers than the template length. The products are predominantly 2-5 linked for the Pb2+-catalyzed reaction while mixed linkages are observed in the uncatalyzed reaction.In the presence of Zn2+, a template effect is first observed with the pentamer and is maximal by the heptamer. The products are predominantly 3-5 linked. Oligomers shorter than or as long as the template are obtained in substantial yield, and longer products in much lower yields.Abbreviations G
Guanosine
- Gp
guanosine 2(3)-phosphate
- pG
guanosine 5-phosphate
- Gp!
guanosine cyclic 2,3-phosphate
- ImpG
guanosine 5-phosphorimidazolide
- ImpG*
[8-14C]-guanosine 5-phosphorimidazolide
- pGp
5-phosphoguanosine 2(3)-phosphate
- G2pG
guanylyl-[2-5]-guanosine
- G3pG
guanylyl-[3-5]-guanosine
- ImpGpG
5-phosphorimidazolide of GpG
- (pG)n (n = 2,3)
oligomers of pG
- GppG
P1, P2-diguanosine 5-diphosphate
- GppGpG
5-[guanosine 5-pyrophosphate] of GpG
- NH2pG
guanosine 5-phosphoramidate
- (pG)4+
tetramer and higher oligoguanylates with 5 terminal phosphate
- oligo(G)
oligoguanylate
- Cp
cytidine 2(3)-phosphate
- Cp!
cytidine cyclic 2,3-phosphate
- (Cp)n–1 Cp! (n= 2,3,4)
oligocytidylates terminated by 5-OH groups and 2,3-cyclic phosphates
- oligo(C)
oligocytidylate
- poly(C)
polycytidylic acid
- poly(U)
polyuridylic acid
- poly(C,G)
random copolymer of C and G
- BAP
bacterial alkaline phosphatase (E. coli)
- EDTA
ethylenediaminetetraacetic acid
- Rf
chromatographic mobility 相似文献
12.
Production of -amylase by a strain of Bacillus amyloliquefaciens was investigated in a cell recycle bioreactor incorporating a membrane filtration module for cell separation. Experimental fermentation studies with the B. amyloliquefaciens strain WA-4 clearly showed that incorporating cell recycling increased -amylase yield and volumetric productivity as compared to conventional continuous fermentation. The effect of operating conditions on -amylase production was difficult to demonstrate experimentally due to the problems of keeping the permeate and bleed rates constant over an extended period of time. Computer simulations were therefore undertaken to support the experimental data, as well as to elucidate the dynamics of -amylase production in the cell recycle bioreactor as compared to conventional chemostat and batch fermentations. Taken together, the simulations and experiments clearly showed that low bleed rate (high recycling ratio) various a high level of -amylase activity. The simulated fermentations revealed that this was especially pronounced at high recycling ratios. Volumetric productivity was maximum at a dilution rate of around 0.4 h–1 and a high recycling ratio. The latter had to exceed 0.75 before volumetric productivity was significantly greater than with conventional chemostat fermentation.List of Symbols
a
proportionality constant relating the specific growth rate to the logarithm of G (h)
-
a
1
reaction order with respect to starch concentration
-
a
2
reaction order with respect to glucose concentration
-
B
bleed rate (h–1)
-
C
starch concentration (g/l)
-
C
0
starch concentration in the feed (g/l)
-
D
dilution rate (h–1)
-
D
E
volumetric productivity (KNU/(mlh))
-
e
intracellular -amylase concentration (g/g cell mass)
-
E
extracellular -amylase concentration (KNU/ml)
-
F
volumetric flow rate (l/h)
-
G
average number of genome equivalents of DNA per cell
-
k
l
intracellular equilibrium constant
-
k
2
intracellular equilibrium constant
-
k
s
Monod saturation constant (g/l)
-
k
3
excretion rate constant (h–1)
-
k
d
first order decay constant (h–1)
-
k
gl
rate constant for glucose production
-
k
st
rate constant for starch hydrolysis
-
k
t1
proportionality constant for -amylase production (gmRNA/g substrate)
-
k
1
translation constant (g/(g mRNAh))
-
KNU
kilo Novo unit
-
m
maintenance coefficient (g substrate/(g cell massh))
-
n
number of binding sites for the co-repressor on the cytoplasmic repressor
-
Q
repression function K1/K2Q1.0
-
R
ratio of recycling
-
R
s
rate of glucose production (g/lh)
-
r
c
rate of starch hydrolysis (g/(lh))
-
R
eX
retention by the filter of the compounds X: starch or -amylase
-
r
intracellular -amylase mRNA concentration (g/g cell mass)
-
r
C
volumetric productivity of starch (g/lh)
-
r
E
volumetric productivity of intracellular -amylase (KNU/(g cell massh))
-
r
r
volumetric productivity of intracellular mRNA (g/(g cell massh))
-
r
e
volumetric productivity of extracellular -amylase (KNU/(mlh))
-
r
s
volumetric productivity of glucose (g/(lh))
-
r
X
volumetric productivity of cell mass (g/(lh))
-
S
0
free reducing sugar concentration in the feed (g/l)
-
S
extracellular concentration of reducing sugar (g/1)
-
t
time (h)
-
V
volume (l)
-
X
cell mass concentration (g/l)
-
Y
yield coefficient (g cell mass/g substrate)
-
Y
E/S
yield coefficient (KNU -amylase/g substrate)
-
Y
E
total amount of -amylase produced (KNU)
-
substrate uptake (g substrate/(g cell massh))
-
specific growth rate of cell mass (h–1)
-
d
specific death rate of cells (h–1)
-
m
maximum specific growth rate of cell mass (h–1)
This study was supported by Bioprocess Engineering Programme of the Nordic Industrial Foundation and the Center for Process Biotechnology, the Technical University of Denmark. 相似文献
13.
G. S. Sidhu G. S. Khush 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1978,53(5):199-203
Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu. 相似文献
14.
Purified ribulose-bisphosphate carboxylase (EC 4.1.1.39) was strongly and equally inhibited either by ADP or GDP and to a lesser extent by IDP. AMP or ATP exerted little effect on activity. Inhibition by the nucleotide diphosphates was competitive with respect to RuBP and non-competitive with respect to CO2 and Mg2+, respectively. Treatment of the enzyme with urea or guanidine-HCl resulted in rapid loss of activity that was not restored by dialysis even in the presence of Mg2+ and cysteine. Sodium dodecyl sulfate electrophoresis of 8.0 M urea treated enzyme revealed the presence of a fast-moving (small) sub-unit with molecular weight 14150 and a slower moving (large) sub-unit with molecular weight 68000. Examination of native enzyme by sodium dodecyl sulfate electrophoresis gave sub-units of 13700 and 55500 respectively. The amino acid content standardized to phenylalanine was essentially similar to that from other sources. Arrhenius plots showed a break at 29°C with an E
a of 12.34 kcal per mole for the steeper part of the curve and a H of 11.43 kcal per mole while for the less steep region, the E
a was 1.04 kcal per mole and the H 1.92 kcal per mole.Abbreviations ADP
adenosine-5-diphosphate
- AMP
adenosine-5-monophosphate
- ATP
adenosine-5-triphosphate
- CDP
cytidine-5-diphosphate
- CMP
cytidine-5-monophosphate
- CTP
cytidine-5-triphosphate
- FDP
fructose-1,6-diphosphate
- F6P
fructose-6-phosphate
- GDP
guanosine-5-diphosphate
- GMP
guanosine-5-monophosphate
- G6P
glucose-6-phosphate
- GTP
guanosine-5-triphosphate
- IDP
inosine-5-diphosphate
- IMP
inosine-5-monophosphate
- PEP
phosphoenolpyruvate
- 6PG
6-phosphogluconate
- R1P
ribose-1-phosphate
- R5P
ribose-5-phosphate
- RuBP
ribulose-1,5-bisphosphate
- SDS
sodium dodecyl sulfate
- TDP
thymidine-5-diphosphate
- TMP
thymidine-5-monophosphate
- TTP
thymidine-5-triphosphate
- UDP
uridine-5-diphosphate
- UMP
uridine-5-monophosphate
- UTP
uridine-5-triphosphate 相似文献
15.
A. K. Gupta R. G. Saini S. Gupta S. Malhotra 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1984,67(2-3):215-217
Summary Genetic analysis for leaf rust reaction of two widely adapted cultivars, Sonalika and WL 711, has been done using 21 near isogenic Lr lines and rust culture IL004 — avirulent on the two cultivars and all the Lr lines used. The segregation pattern in the F2 generation indicated the presence of a recessive gene in Sonalika and of a dominant gene in WL 711. These genes in cultivars Sonalika and WL 711 have been identified as Lr 11 and Lr 13, respectively. Gene Lr 13 is no longer effective in WL 711 but it continues to give field resistance in the backgrounds of Chris, Prelude and Thatcher. There has been no significant change in the virulence spectrum of the leaf rust pathogen in India with the release of WL 711. High susceptibility of WL 711 seems to be due to the evolution of more aggressive forms of the pathogen to this cultivar. The gene Lr 11, which behaves as a recessive in Sonalika, was effective against leaf rust when this cultivar was released. The high susceptibility of Sonalika is probably due to an increase in the frequency of race 77 virulent on Lr 11. Lr 11 has shown a dominance reversal in the background of Sonalika. Present results suggest that interaction of resistance genes with the background genotype must be studied for their effective use in breeding programme. 相似文献
16.
Shafer FE Dropulic B Ely C Schaefer CA Freas D Witkowska HE Schechter AN Noguchi CT Dewey M Karlsson S 《Journal of biomedical science》1994,1(3):147-153
Two transgenic lines of mice were produced which contained the S
Antilles- and 2-hemoglobin genes trandemly coupled to the micro locus control region (LCR). The LCRS
Antilles2-hemoglobin transgenic mice expressed high levels of 2-hemoglobin while S
Antilles-hemoglobin expression was virtually undetectable. Abundant 2-hemoglobin protein was observed in the blood of transgenic mice, while S
Antilles-hemoglobin chains could not be detected. Transgenic red blood cells had substantially decreased sensitivity to osmotic lysis. Attempts to produce homozygotes containing the transgene were unsuccessful. The phenotype of these mice closely resembles that of -thalassemic mice. The LCRS
Antilles2 transgenic mice demonstrate that if the LCR is coupled to the S
Antilles- and 2-hemoglobin genes in tandem, only the distal 2-hemoglobin gene is selected for expression to significant levels in adult mice. These results support a reciprocally competitive model for LCR-hemoglobin developmental switching. 相似文献
17.
The Ca2+ channel 1B subunit is a pore-forming component capable of generating N-type Ca2+ channel activity. Although N-type Ca2+ channel plays a role in a variety of neuronal functions, 1B-deficient mice exhibit normal life span without apparent abnormalities of behavior, histology or plasma norepinephrine level, presumably owing to compensation by some other Ca2+ channel 1 or subunit. In this study, we studied the levels of 1A, 1C, 1D, 1E, 1, 2, 3 and 4 mRNAs in adrenal gland of 1B-deficient mice. The 1A mRNA in homozygous mice was expressed at higher level than in wild or heterozygous mice, but no difference in the expression levels of 1C, 1D, 1E, 1, 2, 3 and 4 was found among wild, heterozygous and homozygous mice. The protein level of 1A in homozygous mice was also expressed at higher level than in wild or heterozygous mice. To examine whether increased expression is induced by cis-regulatory element within 5-upstream region of 1A gene, we examined lacZ expression in 1B-deficient × 1A6.3-lacZ mice (carrying a 6.3-kb 5-upstream fragment of 1A gene fused to E. coli lacZ reporter gene), which express lacZ in medullar chromaffin cells, but not in cortex. The levels of lacZ expression in homozygous 1B-deficient × 1A6.3-lacZ mice were higher than in wild or heterozygous mice. Therefore, a possible explanation of the normal behavior and plasma norepinephrine level of 1B-deficient mice is that compensation by 1A subunit occurs and that 6.3-kb 5-upstream region of 1A gene contains enhancer cis-element(s) for compensation in adrenal medulla chromaffin cells. (Mol Cell Biochem 271: 91–99, 2005) 相似文献
18.
Summary We have synthesized 2(3)-O-(glycyl)-adenosine-5-(O-methylphos-phate), an analogue of the 3-terminus of aminoacylated tRNA. A 0.4M solution of this compound maintained at pH 8.2, yields 5.5% of diglycine and 11.5% of diketopiperazine, in addition to the hydrolysis products glycine and adenosine-5-(O-methylphosphate). Under the same conditions, glycine ethyl ester reacts much more slowly, but ultimately gives similar yields of diglycine and diketopiperazine.The aminolysis of 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) by free glycine is relatively inefficient, but serine reacts 20 times more rapidly and yields up to 50% of N-glycylserine. The prebiotic significance of these reactions is discussed.Abbreviations MepA
adenosine-5-(O-methylphosphate)
- MepA-gly
2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate)
- MepA-bis-gly
2,3-O-(bis-glycyl)-adenosine-5-(O-methylphosphate)
- DKP
diketopiperazine
- gly Et
glycine ethyl ester
- gly-ser
N-glycylserine
- O-gly-ser
O-glycylserine
- O-(gly)-gly-ser
O-(glycyl)-glycylserine
- Boc-gly
N-tert-butyloxycarbonylglycine
- MepA-Boc-gly
2(3)-O-(Boc-glycyl)-adenosine-5-(O-methylphosphate)
- MepA-bis-Boc-gly
2,3-O-(bis-Boc-glycyl)-adenosine-5(O-methylphosphate)
- (gly)2
diglycine
- (gly)3
triglycine 相似文献
19.
The effects of placing small amounts of phosphate fertilizer close to the seed on growth and nutrient concentrations of lettuce 总被引:2,自引:0,他引:2
P. A. Costigan 《Plant and Soil》1984,79(2):191-201
Summary Two glasshouse experiments are described in which the effects of applying starter phosphate fertilizer, 1 cm beneath the seeds, on early growth and nutrient concentrations of lettuce (Lactuca sativa L. cv. Avondefiance) in well fertilized soil were determined. In Experiment 1 various rates of starter P in the form of NH4H2PO4 were applied to soil containing a range of rates of incorporated triple superphosphate. Although there was little response of lettuce dry weight to the incorporated triple superphosphate there was a large response (about 65% increase after 36 days) to the starter. N and P concentrations within the plants were increased by the starter treatments whereas K concentration was reduced. The per cent P in the plants at 36 days from sowing could account for 60% of the variation in plant dry weight. In Experiment 2 the starter P was added as either the Ca, Na or K salt, with or without added (NH4)2SO4. Adding the starter P without ammonum increased the P concentration of the plants by an average of 12% and the dry weight by an average of 39% at 30 days from sowing. The addition of ammonium ions increased plant concentrations of P, Mg and N but decreased plant K concentration. The effect of the ammonium ions on growth depended on the form of phosphate supplied as the starter. This variation in effect of ammonium ions was attributed to the effects of other starter ions on the relative concentration of ammonium in the soil solution. 相似文献
20.
Nemoto K Ukai Y Tang DQ Kasai Y Morita M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):42-47
In floating rice, stem elongation begins much earlier than in non-floating rice, which is the major survival mechanism for flooding. Inheritance of this early elongation ability was studied using diallel and quantitative trait locus (QTL) analyses. The diallel analysis was undertaken using a set of 6×6 half-diallel crosses involving four floating (Goai, Habiganj Aman VIII, Badal 106, and Oryza rufipogon strain W120) and two non-floating (Latisail and Patnai 23) parents. The additive gene effects were higher than the dominant effects. The dominant alleles were concentrated in the cultivated floating parents (Goai, Habiganj Aman VIII, and Badal 106), whereas the recessive alleles were in the wild floating parent (W120). A QTL analysis using a Patnai 23 × Goai F2 population detected two putative QTLs. Of these QTLs, the one on chromosome 12 behaved as a partially dominant major gene that explained more than half of the total genetic variation.Communicated by D.J. Mackill 相似文献