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1.
The complete primary structure of the two hemoglobin components of the fur seal (Arctocephalus galapagoensis) is presented. The two components (HbI and HbII) occur in nearly equal amounts and have identical -chains; whereas the two -chains (I/II) differ by six exchanges Ile/Val, Met/Thr, Ser/Ala, Pro/His, Lys/Gly, and Thr/Ala at positions 10, 34, 35, 50, 78, and 131, respectively. The components were isolated by DEAE-Sephacel chromatography and were separated into the globin chains by RP-HPLC on a column of Nucleocil-C4. The sequences have been determined by Edman degradation in liquid- and gas-phase sequencer, using the native chains and tryptic peptides. The sequences compared with those of other Carnivora species and an adult human globin chains. An identical -chain is found in fur seal and walrus, whereas larger differences were found between I and II compared to -chains.Deceased on May 27, 1989.  相似文献   

2.
Summary The simplest possible model of the sex determination process adding autosomal influence to a minimal number of sex chromosomes was developed to explain matings of Tilapia (Sarotherodon) species. Eighteen different genotypes, each having two autosomes (AA, Aa, or aa) and two sex chromosomes (WX, WY, WW, XY, XX or YY) involved in sex determination, are predicted by the theory. Their sex (10 males and 8 females) were determined using a series of directed graphs, showing the relative strength of the chromosome pairs, developed on the basis of Chen's sex ratio results (Chen 1969). This theoretical model predicts eight different sex ratios (01, 13, 35, 11, 97, 53, 31, 10 ); three of them are not predicted by the WXYZ theory. The greatest part of these sex ratios have been obtained experimentally in extensive series of crosses between related species of Tilapia and their hybrids, carried out by several authors. The theory succeeds in explaining all of Chen's results, including those ratios 53 and 01 seen in certain crosses but not predicted by the WXYZ theory. The importance of the autosomes is seen in comparisons of the genotype pairs (AaWY, aaWY), (AaXY, aaXY) and (AAWW, AaWW) in which the first genotype in each case is male while the second is female as proven by the sex ratio results. The members of the pair differ only in the substitution of one autosome for the other. To test the theory, experiments consisting of hormonal sex reversion and a series of crosses are proposed. Finally, theoretical and practical implications of the theory are discussed.  相似文献   

3.
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   

4.
Summary The carotenoid pigments of the myxobacterium Sorangium compositum were analyzed by chromatographical and chemical techniques and by visible, infra red, and mass spectroscopy. Besides -carotene, neurosporene, torulene, lycopene, and 1,2-dihydro-1-hydroxy--carotene, four new carotenoid glycosides were found. These pigments were identified as 1,2-dihydro-1-hydroxy-torulene glucoside ester (I), 1,2-dihydro-3,1-dihydroxy-torulene glucoside ester (III), 1,2-dihydro-1-hydroxy-torulene rhamnoside (II), and 1,2-dihydro-3,1-dihydroxytorulene rhamnoside (IV).Fifth communication on the carotenoids of myxobacteria. Fourth communication see Arch. Mikrobiol. 76, 364–380 (1971).  相似文献   

5.
The role of -tocopherol uptake system in human erythrocyte in the uptake of plasma -tocopherol has been suggested. However no information is available on -tocopherol uptake activity of human erythrocytes in the presence of high levels of D-glucose which is known to lead to pathological alterations in different cells including human erythrocytes. Therefore, in order to examine the effect of D-glucose on the binding of -tocopherol to human erythrocytes, the binding characteristics of -tocopherol to these cells were established first. Binding of [3H]-tocopherol to human erythrocytes was both saturable and specific. Scatchard analysis of -tocopherol binding to these cells showed the presence of two independent classes of binding sites with widely different affinities. The high affinity binding sites had a dissociation constant (Kd1) of 90 nM with a binding capacity (n1) of 900 sites per cell, whereas the low affinity binding sites had a dissociation constant (Kd2) of 5.2 M and a binding capacity (n2) of 105,400 sites per cell. Trypsin treatment abolished all the -tocopherol binding activity. Competition for the binding of -tocopherol to human erythrocytes was effective with other homologues of -tocopherol (-tocopherol, -tocopherol and -tocopherol) and their potency was almost equal to -tocopherol itself. The order of preference was -tocopherol > -tocopherol -tocopherol -tocopherol. Incubation of human erythrocytes with various concentrations of D-glucose did not affect -tocopherol uptake activity. Our data demonstrate the presence of an -tocopherol uptake system in human erythrocytes and that the -tocopherol uptake activity is not modulated by the presence of D-glucose.  相似文献   

6.
Summary The functional R6K origin is composed of two DNA elements, one of 580 bp carrying the origin sequences and the other of 277 bp containing the seven 22 bp direct repeats previosly identified as also required for and origin activity. These two genetic elements are separated by approximately 3,000 bp of R6K sequences which are dispensable for origin activity. The function of the origin depends on the presence in cis of the 580 bp and the 277 bp fragments and requires that they be oriented as in the intact R6K. Activation of the origin depends on the R6K replication initiation protein .Within the 580 bp of the origin, there is a sequence of 98 bp which appears as an inverted repeat of 96 bp in the replicon. Deletion of the 96 bp or 98 bp results in inactivation of the and the origins respectively. These long repeats are palindromic and it is suggested that these may serve as the recognition signals for initiation of DNA replication in the and the origins of R6K. DNA homology analysis performed on , and origin sequences, also reveals 10–23 bp sequences in the and the origins that are related to the family of 22 bp direct repeats in the origin which were shown previously to be binding sites for the protein.  相似文献   

7.
Summary Gene dosage studies yielded results consistent with assignment of the locus for nucleoside phosphorylase to band 14q13. The red blood cells from a patient with the karyotype 47,XX,+der(14),t(8;14)(8qter8q24: :14q2114pter)pat had enzyme activity 50% higher than red cells from 47 normal controls, two trisomies involving chromosomes other than 14, and five balanced translocations involving chromosome 14. On the other hand, the red cells of a case with a karyotype 45,XX,-14,-22,+der(22),t(14;22)(14qter14q11 or 14q12::22p1122qter)mat and a case with a karyotype 47,XX, +der(14),t(14;16)(14pter14q11::16q2416qter)mat had normal activity.  相似文献   

8.
Summary Large numbers of highly viable mesophyll protoplasts were isolated from shoot cultures of the scion cv Passe Crassane and the rootstock genotype Old Home of common pear (Pyrus communis L.). Protoplasts were cultured for both genotypes either as liquid layers or as liquid-over-agar cultures, in ammonium-free MS medium with 0.5 M mannitol, 50 mg/l casein enzymatic hydrolysate (CEH), 2.0 mg/l NAA and 1.0 mg/l BAP, plus either 0.5 mg/l IAA (for Old Home) or 2.0 mg/l IAA (for Passe Crassane). Protoplast microcalli, obtained by day 60 (Passe Crassane) or day 80 (Old Home), were transferred for further growth to ammonium-free MS medium with 2.0 mg/l NAA and 1.0 mg/l BAP. Shoot bud regeneration from the protoplastderived callus was first attempted between 100 (Passe Crassane) and 120 (Old Home) days after protoplast isolation. For Passe Crassane, shoot buds were regenerated (day 130) on a half-strength MS medium with 0.1 mg/l IBA, 0.5 mg/l BAP, 50 mg/l CEH and 20 mg/l Ca-panthotenate. For Old Home, shoot but regeneration only occurred 30 days later and on the same medium as above, which was additionally supplemented with double the concentration of the group B vitamins found in the original MS formulation and 0.05 mg/l GA3. Following micropropagation and in vitro rooting of shoots, the plants were transferred to soil following standard procedures. Trueness-to-type of the regenerated plants was assessed by analysing their leaf isozyme banding profiles (for EST, AP, PRX, SOD, ENP, LAP, PGI, AAT, ADH, MDH and PGM) and comparing them to those corresponding to the original shoots that provided the protoplasts. No differences between the mother shoots and the protoclones were observed for any one of the 11 isozyme systems studied.  相似文献   

9.
Summary The timing mechanism underlying ultradian (2–3 h) activity patterns in the common vole, Microtus arvalis, was studied using behavioural deprivation experiments. These were aimed at distinguishing between a homeostatic control mechanism, in which the rhythmic behaviour itself is part of the causal loop, and a clock mechanism, independent of the behaviour.In 175 experiments, deprivation of food during 3 ultradian cycles in (subjective) daytime did not result in significant changes in the ultradian periodicity of attempts to obtain the food, compared with ad lib. access to food and water. A minor, but significant increase in ultradian activity time () occurred in the course of the deprivation, but this was compensated by a shorter ultradian rest (). These results were obtained both in intact animals (n = 24), which showed ultradian and circadian rhythmicity in behaviour, and in animals (n = 21) with electrolytic lesions aimed at the suprachiasmatic nuclei (SCN), which lacked the circadian modulation of behaviour. Simultaneous deprivation of water and food in 8 voles without circadian rhythmicity during 40 experiments also did not lead to any change in the ultradian periodicity of feeding attempts.Rest deprivation was studied in 5 SCN lesioned voles, by forcing running wheel activity to continue following spontaneous running. Thus, the experimental activity bout was artificially lengthened to 2–9 h in 67 experiments. The onset of the subsequent rest episodes occurred independent of the duration of the preceding . The duration of was dependent on the preceding, experimental in a periodic fashion. The interval experimental (=lengthened +following ) was equal to one, two or three times the control (obtained on nonexperimental days). This result fits the prediction of a clock model and is in conflict with a monotonicincrease of with , as expected in a homeostatic, restorative process.It is concluded that the ultradian timing of activity in the common vole can be explained neither by homeostatic hunger or thirst mechanisms nor by homeostatic rest/activity regulation. The results strongly suggest an independent clock system generating ultradian feeding rhythms in the common vole.Abbreviations DD continuous darkness - LD light-dark regime - LL continuous light - RCA retrochiasmatic area - ARC arcuate nucleus - SCN suprachiasmatic nuclei - ultradian period - ultradian activity time - ultradian rest time  相似文献   

10.
The enhanced expression of the RI subunit of cyclic AMP-dependent protein kinase type 1 (PKA-I) has been correlated with cancer cell growth. We have investigated the effects of sequence-specific inhibition of RI gene expression on the growth of MCF-7 human breast cancer cells. We report that RI antisense treatment results in a reduction in RI expression at both mRNA and protein levels and inhibition of cell growth. The growth inhibition was accompanied by changes in cell morphology, cleavage of poly(ADP-ribose) polymerase (PARP) and appearance of apoptotic nuclei. In addition, bcl-2 protein level was reduced and p53 expression increased in growth arrested cells. Interestingly, RI antisense inhibited cell viability and induced apoptosis in the absence of p53, suggesting that these actions of RI antisense are exerted independent of p53. In contrast, two- and four-base mismatched control oligonucleotides had no effect on either cell growth or morphology. These results demonstrate that the RI antisense, which efficiently depletes the growth stimulatory molecule RI, induces cell differentiation and apoptosis, providing a new approach to combat breast cancer cell growth.  相似文献   

11.
Primary structure analysis of the four river buffalo -globin chains showed that haplotypes A and B differ from each other by a substitution at codon 64 that may encode Ala or Asn. The A haplotype encodes two -globin chains, I1 and II3, which differ at positions 129 and 131: I1 has 64 Ala, 129 Phe, 131 Asn; II3 has 64 Ala, 129 Leu, 131 Ser. The B haplotype encodes two -globin chains, I2 and II4, which differ at positions 10 and 11: I2 has 10 Ile, 11 Gln, 64 Asn; II4 has 10 Val, 11 Lys, 64 Asn. Apart from the Ala/Asn polymorphism at position 64, amino acid substitutions in allelic and nonallelic -globin chains seem to have arisen by single point mutations. Detection of electrophoretically silent mutations due to neutral amino acid substitutions and their influence on the isoelectric point are discussed. Furthermore, primary structures of river buffalo -globin chains are compared to other species of the Bovidae family to suggest evolutionary events that have characterized the amino acid substitutions of river buffalo hemoglobin.  相似文献   

12.
Mesophyll protoplasts were produced from clones of two cultivars of Medicago sativa, Rangelander and Regen S. Protoplasts from the Regen S clone generally gave rise to calli while those from the Rangelander clone would undergo direct embryogenesis. Effects of plant growth conditions, donor tissue pretreatment and protoplast culture conditions on mesophyll protoplast production and subsequent development patterns were investigated. The major factor determining whether or not mesophyll protoplasts would be produced from either of the clones was the pretreatment in water of shoots excised from the donor plants. Pretreatment in water containing growth regulators did not alter protoplast production or development in the Regen S clone. Pretreatment of the Rangelander clone shoots with abscisic acid or naphthaleneacetic acid was slightly beneficial to embryo production while pretreatment with benzylaminopurine was detrimental. Altered leaf morphology induced by growth condition changes did not affect mesophyll protoplast production or subsequent development patterns when shoots were pretreated in water. Culture of protoplasts in liquid droplets or solid agar medium increased low density protoplast survival and subsequent embryo production in the Rangelander clone.  相似文献   

13.
Summary Cholic acid (3,7,12-trihydroxy-5-cholanoic acid) was completely and selectively transformed into 12-ketoursodeoxycholic acid (3,7-dihydroxy-12-oxo-5-cholanoic acid) by means of two consecutive enzymatic steps catalyzed, the first, by 7- and 12-hydroxysteroid dehydrogenase and, the second, by 7-hydroxysteroid dehydrogenase. Coenzyme regeneration was carried out with -ketoglutarate-glutamate dehydrogenase and glucose-glucose dehydrogenase, respectively.  相似文献   

14.
Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions.  相似文献   

15.
A simple one variable caricature for oscillating and excitable reaction-diffusion systems is introduced. It is shown that as a parameter, , varies the system dynamics change from oscillatory ( > 0) to excitable ( < 0) and the frequency of the oscillation vanishes as for 0. When such dynamics are coupled by continuous diffusion in a ring geometry (1-space dimension), propagating wave trains may be found. On an infinite ring excitable devices lead to unique solitary waves which are analogous to pulse waves. A solvable example is presented, illustrating properties of dispersion, excitability, and waves. Finally it is shown that the caricature arises in a natural way from more general excitable/oscillatory systems.  相似文献   

16.
Summary Racemic [-2H]--amino acids were prepared by heating the corresponding amino acids (Phe, nor-Leu and Dopa) with 0.05 equivalents of benzaldehyde in deuterated-acetic acid. Based on1H-nmr measurement, the isotopic purities of these racemized [-2H]--amino acids were found to be higher than 99.5%. Methylation of these isotope-labelled amino acids was achieved in methanol/thionyl chloride without affecting isotopic purity. Optically pure [-2H]--amino acids were obtained in high yield with high enantiomeric excess via alcalase catalysed resolution.  相似文献   

17.
As the post-genome era is approaching, with vast amount of sequence information available and new technology developed, scientists are presented with opportunities to explore in simple analysis the structure and expression pattern of not just a single gene, but of an entire family of genes, if not the entire genome. The concept of molecular profiling or expression array has thus emerged. The need to simultaneously see all genes in the same family is obvious under the precept of the combinatorial process being an underlying principle of complex biological systems: no gene exists in isolation, for virtually every molecule participates in intermolecular interactions. The activation of receptor tyrosine kinases through homo or hetero-dimerization is the prototypic example. In this review, a tyrosine kinase profile technique and its application to studying the expression of tyrosine kinases and the identification of novel kinases will be discussed. This serves as an introduction to the several interesting papers published in this special kinase issue of theJournal of Biomedical Sciences, using this technique. A new simplified approach, kinase display, which is an extension of the profiling method and requires only restriction digestion and gel analysis will also be introduced.  相似文献   

18.
The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp adenosine 5-triphosphate 3-diphosphate - ppApp adenosine 5-diphosphate 3-diphosphate - pApp adenosine 5-monophosphate 3-diphosphate - pppGpp guanosine 5-triphosphate 3-diphosphate  相似文献   

19.
Restriction fragment analysis was used to examine the inheritance of lentil mitochondrial DNA (mtDNA) in F1 and F5 progeny from intrasubspecific (Lens culinaris ssp. culinaris) crosses and in F1 progeny from intersubspecific (Lens culinaris ssp. orientalis x L. culinaris ssp. culinaris) crosses. Southern blots of digested parental and progeny DNA were hybridized to heterologous maize mtDNA probes specific to coxI and atp6 genes. Two restriction fragment polymorphisms separated L.c. ssp. culinaris Laird and Eston from L.c. ssp. culinaris ILL5588, and one restriction fragment polymorphism distinguished L.c. ssp. culinaris Laird and Eston from L.c. ssp. orientalis LO4. Twelve of 13 f1 progeny and all F5 progeny from the intrasubspecific crosses, and all F1 progeny from intersubspecific crosses had only maternal mtDNA restriction fragments. One f1 plant from an Eston x ILL5588 cross inherited mtDNA fragments from both parents. Nuclear DNA inheritance was biparental in all F1 progeny.NRCC No. 38451  相似文献   

20.
The reliability of 1H chemical shift calculations for DNA is assessed by comparing the experimentally and calculated chemical shifts of a reasonably large number of independently determined DNA structures. The calculated chemical shifts are based on semiempirical relations derived by Giessner-Prettre and Pullman [(1987) Q. Rev. Biophys., 20, 113–172]. The standard deviation between calculated and observed chemical shifts is found to be quite small, i.e. 0.17 ppm. This high accuracy, which is achieved without parameter adjustment, makes it possible to analyze the structural dependencies of chemical shifts in a reliable fashion. The conformation-dependent 1H chemical shift is mainly determined by the ring current effect and the local magnetic anisotropy, while the third possible effect, that of the electric field, is surprisingly small. It was further found that for a double helical environment, the chemical shift of the sugar protons, H2 to H5, is mainly affected by the ring current and magnetic anisotropy of their own base. Consequently, the chemical shift of these sugar protons is determined by two factors, namely the type of base to which the sugar ring is attached, C, T, A, or G, and secondly by the -angle. In particular, the H2 shift varies strongly with the -angle, and strong upfield H2 shifts directly indicate that the -angle is in the syn domain. The H1 shift is not only strongly affected by its own base, but also by its 3-neighboring base. On the other hand, base protons, in particular H5 of cytosine and methyl protons of thymine, are affected mainly by the 5-neighboring bases, although some effect (0.2 ppm) stems from the 3-neighboring base. The H2 protons are mainly affected by the 3-neighboring base. As a result of these findings a simple scheme is proposed for sequential assignment of resonances from B-helices based on chemical shifts.  相似文献   

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