The unknown tradition: Continuity and innovation in Soviet ethnography

Conclusion In this article we have not attempted to cover the entire problematic or history of Russian-Soviet ethnography. Instead, we tried to explain the significance of the arguments about social theory and demonstrate why Soviet ethnography must be viewed as part of an intellectual tradition fundamentally different from the Western. At the same time, we believe that the theoretical tradition that took shape in the 1920s and the attempts to revive and further it, inconclusive as they may be, are of great potential significance to Western anthropologists.Among the topics left out of consideration was, for example, the traditional and successful collaboration between ethnography and folklore studies culminating in the structural analysis of Russian fairy tales by Vladimir Ya. Propp. We also did not discuss the study of religion, which in the 1930s–1950s was often disguised as folklore studies, and which in the Soviet context was obviously limited by the doctrine dictating the approach to it as a disappearing form of social consciousness, an embarrassing survival of the past. Another subject left out is the study of material culture and everyday life, which continues the pre-revolutionary Russian tradition. The same may be said about a more recent Soviet revival of interest in ethnicity in so far as it can be traced to the late nineteenth and early twentieth century concern with cultural and ethnic divisions. This interest, of course, has much to do with the practical tasks of integrating over 100 nations, nationalities and various other ethnic groups into one Soviet People.The formation of the Soviet people, which Lenin believed to be an inevitable result of education, and which Stalin spurred using massive violence, is viewed not only as both desirable and inevitable but as an actual reality. The coming into being of the Soviet people was proclaimed by Leonid Brezhnev a decade ago. The theory of ethnicity, as well as the whole problem of interethnic relations are so closely connected to the sensitive issues of nationality policy that even field ethnographers often see and report the desirable rather than the actual situation. The Soviet data, therefore, can be used only with great caution.It is perhaps relevant to note the change that occurred in the Soviet attitude toward psychology. At one time practically banned (along with Freud) in favor of the sociological approach, social psychology, psycholinguistics, and ethnopsychology (a Soviet term) today are legitimate, though often doctrinally limited areas of inquiry. Soviet ethnographers agree that the reflection in people's consciousness of their membership in an ethnos as ethnic self-awareness serves as the final proof of the objective existence of that ethnos.Both in terms of the problems considered to fall within its scope and in terms of the approach to these problems, Soviet ethnography today comes closer to Shternberg's conception than to the view which prevailed after the All-Russian Archaeological-Ethnographic Conference of 1932 described earlier. Bromley claims that the conception of ethnography most widely shared among Soviet scientists today is of a science that deals with the characteristics of the daily life and belief systems of a people which distinguish them ethnically (i.e., culturally), and the origins (ethnogenesis) and history of the ethnic units defined by these characteristics. It embraces the history of culture of all peoples in the past as well as the present. To this end it makes use of data not only of the historical sciences, but of the natural sciences (e.g., biology, ecology, geography) as these relate to formation and functioning of ethnos.Broadly speaking, there are three major characteristics that determine the present status of Soviet ethnography:First, there is an open acknowledgement of the validity of pre-revolutionary Russian tradition. One facet of this is a modest rivival of the Shternberg school that combined rigorous requirements for fieldwork (not unlike Boas) with ethnographers' active participation in the lives of the investigated peoples, and a broadly historical dynamic approach to culture.Second, after a period of isolation, the best work in ethnography, as illustrated in the case of kinship studies, is strongly influenced by Western social anthropology. The language and concerns of these studies can be much easier understood in the West than, perhaps, any other Soviet writings. But one should not lose sight of the fact that basic assumptions, such as the general view of evolution, are not the same as in the West.Third, the main struggle in Soviet ethnography now is not against bourgeois theories. More and more it is centered around the inadequacy of the Soviet theoretical heritage itself.The gains in kinship studies, the tacit return to the forcibly broken tradition of the 1920s in conceptualization of culture (Bogoraz, Bukharin) visible in the work of Markarian, and the possibility to question and reject particular hypotheses advanced by Morgan, Engels, or the early Soviet fundamentalists make Soviet ethnography a rich and exciting field. This impression is not diminished by the fact that the thorough theoretical revision of orthodoxy promised by PIDO Two in 1968 never materialized. The intellectual currents that produced it still exist and now and then surface, waiting for a time when the deological climate improves.An important thing to remember is that many theoretical positions in the Soviet Union are arrived at by thrashing out the issues in oral discussions until consensus is gradually formed, not by boldly proclaiming a new approach in an individual paper. Olderogge's rejection of Morgan's Hawaiian hypothesis, as well as the whole project of PIDO Two are but two examples of consensus formed before they were published. We suspect that some work is being done, of which the short conference resumés (unavailable in the West) are often the only and cryptic witnesses.The administrative control over Soviet ethnography remains in the hands of the fundamentalists, who associate true Marxism with doctrine and whose main task is to defend the hypotheses incorporated in official ideology. They are opposed by a vital group of scholars, who gain their inspiration from a general philosophical approach and method of conceptualization they find in classical Marxism. The division into these two camps is not at all clearcut; many people intermittently align themselves with one or the other. And of course, the strong current of Russian intellectual tradition (never demythologized) with its search for an integral and simultaneously ethical social theory brings many of them together.But the discussions persist, and it appears that for non-fundamentalists Marxism provides only a method (and even this is understood in a variety of ways), a theory of cognition, the most general language of theory. No particular hypothesis is sacred. Since the method is not reducible to ethnographic theory, it does not in itself guarantee success. The theory has to be judged on its own merit, not by appeal to the classics. These seem to be the unspoken points underlying the debate today.What is at stake is not only the right of scientists to develop various perspectives on society, culture, and evolution. Whether or not the participants themselves would put it this way, it affects the very nature of theory in social sciences. The rallying point for the non-fundamentalists, regardless of their areas of research or their views on particular problems, is the tacit rejection of theory as doctrine. The revolt is against theory as quasireligion, as the Absolute which is simultaneously a scientific and an ethical doctrine that pits us who know the Truth against them who do not: and this may be nothing less than the beginning of a fundamental break with the Russian intellectual tradition.Dr. Jovan Howe is working on a book on Soviet archaeology.Vladimir Plotkin is a Visiting Professor in Russian and Eastern European Studies at the Henry M. Jackson School of International Studies, University of Washington.     

Towards a nonessentialist class consciousness

Conclusion This paper has presented a concept of class consciousness from the framework of nonessentialist Marxism. Class consciousness as class-expressive discourse is epistemologically and theoretically different from concepts of that consciousness both in and outside the Marxian and nonessentialist frameworks. The concept here was developed within and by means of that framework-through the process of conceptual juxtaposition.I have indicated that instead of viewing a lack of class consciousness as false or mystified consciousness, it is possible to analyze various class conscious discourses. Thus an individual's lack of a capitalist class consciousness is attributed not to his/her inability to perceive the essence of his/her being as a capitalist class member, but as the presence of (multiple and contradictory) class conscious discourses that are themselves determined by the various social and natural processes in society.From the theory of multiple class processes and nonessentialist epistemology, the complexity of class and class consciousness was explored. Neither consciousness nor class was reduced to each other. Rather, their overdetermined complexity was analyzed.Dr. Oakes is currently engaged in fieldwork in Granada under a Fulbright grant.     

Association of β<Subscript>2</Subscript>-microglobulin with the α<Subscript>3</Subscript> domain of H-2D<Superscript>b</Superscript> heavy chain

MHC class I molecules are heterotrimeric complexes composed of heavy chain, ₂-microglobulin (₂m) and short peptide. This trimeric complex is generated in the endoplasmic reticulum (ER), where a peptide loading complex (PLC) facilitates transport from the cytosol and binding of the peptide to the preassembled ER resident heavy chain/₂m dimers. Association of mouse MHC class I heavy chain with ₂m is characterized by allelic differences in the number and/or positions of amino acid interactions. It is unclear, however, whether all alleles follow common binding patterns with minimal contributions by allele-specific contacts, or whether essential contacts with ₂m are different for each allele. While searching for the PLC binding site in the ₃ domain of the mouse MHC class I molecule H-2D^b, we unexpectedly discovered a site critical for binding mouse, but not human, ₂m. Interestingly, amino acids in the corresponding region of another MHC class I heavy chain allele do not make contacts with the mouse ₂m. Thus, there are allelic differences in the modes of binding of ₂m to the heavy chain of MHC class I.     

Histoenzymatic characterization of sub-types of Type I fibres in fast muscles of rats

Summary The histochemical activities of succinic dehydrogenase (SDH), myofibrillar Adenosine triphosphatase (ATPase) and alpha glycerophosphate dehydrogenase were studied in serial sections of rat vastus lateralis (red) (RVL), gastrocnemius and diaphragm muscles. Three main fibre-types were distinguished. The Type I fibres of RVL and gastrocnemius muscles fell into two distinct groups: one category-Type IA showed very low ATPase activity. The second category of Type IB fibres displayed moderate ATPase reaction. The Type IA fibres were divisible into two sub-groups when tested for SDH reaction. Type IA₁ fibres possessed a homogenous distribution of diformazan·granules throughout the fibre: Type IA₂ fibres displayed characteristic moth-eaten pattern of diformazan localization. The diaphragm muscle did not show either Type IB or Type IA₂ varieties. The great majority of Type I fibres were sub-type IA₁ in the three fast muscles studied. It is also demonstrated here that an inherent heterogeneity exists between Type I fibres of diaphragm and leg muscles in regard to -GPD localization. This histochemical data emphasizes the fact that subdivision of Type I striated muscle fibres of mammalian animals into two sub-types is only approximate and that a further subcategorization is possible.     

Genetic characterization of a new splice variant of the β2 subunit of the voltage-dependent calcium channel

This study reports a novel splice variant form of the voltage-dependent calcium channel ₂ subunit (_2g). This variant is composed of the conserved amino-terminal sequences of the _2a subunit, but lacks the -subunit interaction domain (BID), which is thought essential for interactions with the ₁ subunit. Gene structure analysis revealed that this gene was composed of 13 translated exons spread over 107 kb of the genome. The gene structure of the ₂ subunit was similar in exon-intron organization to the murine ₃ and human ₄ subunits. Electrophysiological evaluation revealed that _2a and _2g affected channel properties in different ways. The _2a subunit increased the peak amplitude, but failed to increase channel inactivation, while _2g had no significant effects on either the peak current amplitude or channel inactivation. Other subunits, such as ₃ and ₄, significantly increased the peak current and accelerated current inactivation.     

Current chemical concepts of acids and bases and their application to anionic (“acid”) and cationic (“basic”) dyes

Summary In biomedical studies, dyes are divided into acid and basic dyes. This classification cannot be reconciled with current chemical definitions of acids and bases. Brönsted-Lowry acids are compounds that can donate protons; bases are proton acceptors. The definition of acids and bases is independent of the electric charge, i.e. acids and bases can be neutral, anionic or cationic. Reactions between acids and bases result in formation of new acid-base pairs. Lewis acids and bases do not depend on a particular element, but are characterized by their electronic configurations. Lewis bases are electron donors; Lewis acids are electron acceptors. This classification is also unrelated to the electric charge. Lewis acids and bases interact by formation of coordinate covalent bonds.In histochemistry and histology, dyes containing SO ₃ ^– , –COO^– and/or –O^– groups are classified as acid dyes. However, such compounds are electron pair donors and hence Brönsted-Lowry and Lewis anionic bases. Dyes carrying a positive charge are termed basic dyes. Chemically, many cationic dyes are Lewis acids because they can add a base, e.g. OH^–, acetate, halides. The hypothesis that transformation of –NH₂ into ammonium groups imparts basic properties to dyes is untenable; ammonium groups are proton donors and hence acids. Furthermore, conversion of an amino into an ammonium group blocks a lone electron pair and the color of the dye changes drastically, e.g. from violet to green and yellow. It appears therefore highly unlikely that ammonium groups are responsible for binding of cationic (basic) dyes. In histochemistry, it is usually not of critical importance whether anionic or cationic dyes are chemically acids or bases. It is therefore suggested to substitute the terms anionic for acid and cationic for basic dyes; this nomenclature will always be chemically correct.     

Mutations in rDNA

Summary The action of -amanitin, an inhibitor of RNA synthesis, on the induction by hydroxyurea (HU) of chromosomal aberrations in nucleolus organizer regions of barley was studied. The data obtained show that -amanitin can effectively modify aberration induction in rDNA. Administered before mutagen treatment or in combination with the mutagen, the toxin significantly decreased the HU-induced aberration frequencies in NORs. The data obtained provide further evidence that -amanitin is an effective modulator of aberration induction in NORs either by interfering with RNA synthesis or by modifying chromatin structure.     

Effects of corticosteroids on short-circuit current across the cecum of the domestic fowl,Gallus domesticus

Summary Both avian corticosteroid hormones, aldosterone and corticosterone, increased short-circuit current across the wall of the ceca of the domestic fowl (Gallus domesticus) in vitro. About 80% of this short-circuit current was inhibited by the Na-channel blocking drug amiloride. Corticosterone was about ten times less potent than aldosterone in increasing short-circuit current and it exerted a similar maximal effect. Cortisol (an endogenous corticosteroid hormone in mammals but not birds) was about ten times less potent than corticosterone and this difference appeared to reflect the presence of the 17-OH group in cortisol. Carbenoxolene, which inhibits 11-hydroxysteroid dehydrogenase, increased the effect of corticosterone. This effect is consistent with inhibition of the metabolism of corticosterone to 11-dehydrocorticosterone. The latter was found to be about 100 times less potent than corticosterone. The effects of both aldosterone and corticosterone (also dexamethasone) were abolished by the mineralocorticoid receptor antagonist spironolactone. The results suggest that corticosterone has an effect similar to aldosterone but in vivo its action may be depressed by the activity of 11-hydroxysteroid dehydrogenase. The sensitivity of the cecal preparations to corticosterone indicates that this hormone could contribute to the regulation of transcecal Na transport (absorption) in vivo.Abbreviations 11-HSD 11-Hydroxysteroid dehydrogenase - sc short-circuit current - KRB Krebs bicarbonate solution     

A novel PH-CT-COSY methodology for measuring JPH coupling constants in unlabeled nucleic acids. Application to HIV-2 TAR RNA

A quantitative analysis of J_PH scalar couplings in nucleic acids is difficult due to small couplings to phosphorus, the extreme overlap of the sugar protons and the fast relaxation of the spins involved in the magnetization transfer. Here we present a new methodology that relies on heteronuclear Constant Time Correlation Spectroscopy (CT-COSY). The three vicinal ³J_PH3, ³J_PH5 and ³J_PH5 scalar couplings can be obtained by monitoring the intensity decay of the P_i-H3_{i – 1} peak as a function of the constant time T in a 2D correlation map. The advantage of the new method resides in the possibility of measuring the two ³J_PH5 and ³J_PH5 scalar couplings even in the presence of overlapped H5/H5 resonances, since the quantitative information is extracted from the intensity decay of the P-H3 peak. Moreover, the relaxation of the H3 proton is considerably slower than that of the H5/H5 geminal protons and the commonly populated conformations of the phosphate backbone are associated with large ³J_PH3 couplings and relatively small ³J_{PH5 / H5}. These two facts lead to optimal signal-to-noise ratio for the P-H3 correlation compared to the P-H5/H5 correlation.The heteronuclear CT-COSY experiment is suitable for oligonucleotides in the 10–15 kDa molecular mass range and has been applied to the 30mer HIV-2 TAR RNA. The methodology presented here can be used to measure P-H dipolar couplings (D_PH) as well. We will present qualitative results for the measurement of P-H_base and P-H2 dipolar couplings in the HIV-2 TAR RNA and will discuss the reasons that so far precluded the quantification of the D_PHs for the 30mer RNA.     

Structural study of fucoidan from Cladosiphon okamuranus tokida

A structural study was carried out on a fucoidan isolated from the brown seaweed Cladosiphon okamuranus. The polysaccharide contained fucose, glucuronic acid and sulfate in a molar ratio of about 6.1 : 1.0 : 2.9. The results of Smith degradation showed that this polysaccharide has a linear backbone of 13-linked -fucopyranose with a half sulfate substitution at the 4-positions, and a portion of the fucose residues was O-acetylated. The data obtained from partial acid hydrolysis, a methylation analysis and NMR spectra indicated that the -glucuronic acid residue is linked to the 2-positions of the fucose residues, which were not substituted by a sulfate group. These results indicated that the average structure of this fucoidan is as follows: -[(3Fuc-4(±OSO₃-)1–)₅3[GlcA12]Fuc1–]_n–. (Half of each fucose residue was sulfated. One O-acetyl ester was present in every 6 fucose residues.)     

Optimization of cryopreservation of Artemisia annua L. callus

Cryopreservation of callus tissue of Artimisia annua L. was optimized. Two lines of calli were precultured on MS medium with 5% (v/v) dimethyl sulfoxide, and protected by a cryoprotectant containing 15% (v/v) ethylene glycol, 15% (v/v) dimethyl sulfoxide, 30% (v/v) glycerol and 13.6% (w/v) sucrose. The highest survival rate of callus A201 reached 87% after it was pretreated at 25°C, cryopreserved by liquid nitrogen, recovered in water bath at 25°C and reloaded at 25°C with 34% (w/v) sucrose solution, and that of callus A202 reached 78% after it was treated as callus A201, except pretreated at 35°C, recovered at 35°C and reloaded with 47.8% (w/v) sucrose solution.     

Modernist and postmodernist metaphors of the policy process: Control and stability vs. chaos and reflexive understanding

The complexity of the policy process is such that analysts often resort to metaphorical representations of its most salient aspects. Sometimes these metaphors are used deliberately but, in most cases, they are implicitly built into their theoretical frameworks. This article argues that commonly used metaphors based on the paradigmatic notion of control have ceased to be relevant to the analysis of contemporary policy dilemmas. Two new conceptions of the policy process have emerged from the new sciences of complexity. Both chaos theory and models based on the concept of organizational closure clearly reveal the self-organizing logic inherent in the problems confronting managers and policy-makers today. The main focus here is on examining the rationales for, and the potentials of, metaphors derived from these paradigmatic innovations - innovations which can be situated within an emerging postmodern culture insofar as they emphasize indeterminacy and the role played by social actors in constructing the social situations in which they find themselves. It is also argued, however, that within very specific contexts the notion of control may still be valid.The author wishes to thank Michael Howlett for his helpful comments on an earlier draft.     

Endothelin-1 and insulin induce cellular inactivation of protein kinase FA/glycogen synthase kinase-3α in a common signaling pathway

In this study, we investigate the effects of endothelin-1 (ET-1) and insulin on the cellular activity of protein kinase F_A/glycogen synthase kinase-3 (kinase F_A/GSK-3) in rat adipocytes. The cellular activity of kinase F_A/GSK-3 is inhibited to 50% of control within 30 min when cells are treated with 1 nM ET-1 at 37°C; in addition, significant inhibition to 60% of control is observed at as low as 1 pM ET-1. Conversely, ET-1 at concentrations up to 1 nM has no direct effect on purified kinase F_A/GSK-3 in vitro. Immunoblotting analysis further reveals that the protein level of this kinase is not significantly changed when treated with 1 nM ET-1 for 30 min. Similar to ET-1, insulin as low as 10 nM can also induce inactivation of kinase F_A/GSK-3 to 50% of control in adipocytes when processed under identical conditions. Most importantly, when treated with both insulin and ET-1, the activity of kinase F_A/GSK-3 can be decreased only to 50% of control. Taken together, the results provide initial evidence that ET-1 and insulin may regulate this important multisubstrate/multifunctional protein kinase in a common signaling pathway in cells.     

Magnetic orientation and magnetoreception in birds and other animals

Animals use the geomagnetic field in many ways: the magnetic vector provides a compass; magnetic intensity and/or inclination play a role as a component of the navigational map, and magnetic conditions of certain regions act as sign posts or triggers, eliciting specific responses. A magnetic compass is widespread among animals, magnetic navigation is indicated e.g. in birds, marine turtles and spiny lobsters and the use of magnetic sign posts has been described for birds and marine turtles. For magnetoreception, two hypotheses are currently discussed, one proposing a chemical compass based on a radical pair mechanism, the other postulating processes involving magnetite particles. The available evidence suggests that birds use both mechanisms, with the radical pair mechanism in the right eye providing directional information and a magnetite-based mechanism in the upper beak providing information on position as component of the map. Behavioral data from other animals indicate a light-dependent compass probably based on a radical pair mechanism in amphibians and a possibly magnetite-based mechanism in mammals. Histological and electrophysiological data suggest a magnetite-based mechanism in the nasal cavities of salmonid fish. Little is known about the parts of the brain where the respective information is processed.     

Tight-junction protein ZO-1 isoforms (α+ and α−) show differential extractability and epidermal-growth-factor-induced tyrosine phosphorylation in A431 cells

Summary ZO-1, a cytoplasmic plaque protein of tight junctions, exists in vivo as two major isoforms which are defined by the presence or absence of an 80 amino acid domain termed . The ZO-1 (+) isoform is expressed in most epithelial cells while ZO-1(–) isoform expression is restricted to endothelial cells and some highly specialized epithelial cells, suggesting that the isoforms serve different functions. We had previously demonstrated that both ZO-1 isoforms are expressed in A 431 cells and are tyrosine phosphorylated in response to epidermal-growth-factor treatment. In the present study, we found that the (-) isoform of ZO-1 was more tightly associated with the cytoskeleton than was the (+) isoform, based on extraction in nonionic detergent. In addition, the ZO-1(-) was preferentially tyrosine phosphorylated in response to epidermal-growth-factor treatment. However, both isoforms became more tightly associated with the cytoskeleton after A 431 cells were exposed to epidermal growth factor. Immunofluorescence analysis of A 431 cells with isoform-specific antibodies demonstrated that functional differences in ZO-1 isoform behavior were not due to differences in their subcellular locations. The coincident localization of these isoforms does not rule out different affinities for interacting proteins related to the presence or absence of the domain, and it is these interactions that are likely to explain functional differences between the isoforms.     

Regulation of adenylate cyclase by adenosine

Summary Adenosine may well be as important in the regulation of adenylate cyclase as hormones. Sattin and Rall first demonstrated in 1970 that adenosine was a potent stimulator of adenylate cyclase in the brain. However, adenosine is an equally potent inhibitor of adenylate cyclase in other cells such as adipocytes. The concentration of adenosine required for this regulation of adenylate cyclase is in the nanomolar range (10 to 100 nm). Both the inhibitory and stimulatory effects of low concentrations of adenosine on adenylate cyclase are antagonized by methylxanthines. This antagonism of adenosine action may account for all or part of the effects of methyl xanthines on cyclic AMP levels in many tissues. Adenosine appears to be a particularly important endogenous regulator of adenylate cyclase in brain, smooth muscle and fat cells. Under conditions in which intracellular AMP rises, adenosine formation and release is accelerated. In addition to its direct effects on adenylate cyclase, adenosine (at higher concentrations approaching millimolar) exerts multiple effects on cellular metabolism as a result of its intracellular metabolism and especially conversion to nucleotides.The effects of nanomolar concentrations of adenosine on adenylate cyclase are mediated through an adenosine site possessing strict structural specificity for the ribose moiety of the molecule (the R adenosine site) which is presumably located on the external surface of the plasma membrane. In brain, lung, platelets, bone, lymphocytes, skin, adrenals, Leydig tumors, and coronary arteries adenosine stimulates adenylate cyclase via this site. However, in rat adipocytes, brain astroblasts and ventricular myocardium adenosine inhibits adenylate cyclase through the R or adenosine site. Although the R site requires an intact ribose moiety, adenosine analogs modified in the purine ring such as N⁶-phenylisopropyladenosine appear to be potent agonists for this site. All effects of adenosine mediated via the R site are competitively antagonized by methyl xanthines.The effects of micromolar concentrations of adenosine appear to be mediated via a site with strict structural specificity with respect to the purine moiety of the molecule (the P or adenine adenosine site). This P site is postulated to be located on the intracellular face of the plasma membrane and mediates the effects of adenosine due to conversion of adenosine to 5-AMP or perhaps other nucleotides. The effects of high concentrations of adenosine are always inhibitory to adenylate cyclase activity, are readily demonstrated in broken cell preparations, and are unaffected by methylxanthines. An intact purine ring is required for these adenosine effects but modifications of the ribose moiety of the molecule generally increases the potency of the analog. A prime example is 2,5-dideoxyadenosine, which is the most potent known R-site specific adenosine analog.We propose a unitary model which explains both the stimulatory and inhibitory effects of low concentrations of adenosine on adenylate cyclase. In brief, adenylate cyclase is postulated to exist in three interconvertible activity states: (i) an inactive state (E₀); (ii) a GTP-liganded state with high activity (E_GTP); and (iii) a GDP-liganded state (E_GDP) which is inactive in cells where adenosine stimulates adenylate cyclase, but active in cells where adenosine inhibits adenylate cyclase. We postulate that the enzyme cycles through these states in the following manner: the E₀ state binds GTP and forms the E_GTP state; hydrolysis of bound GTP converts the E_GTP to the E_GDP state; and release of bound GDP converts E_GDP to the E₀ state. The E₀ state is the only form of the enzyme which can be stimulated by either hormones or GTP and its formation from the E_GDP state is rate-limiting in this cycle. The conversion of E_GDP to E₀ regulates the ability of hormones and GTP to activate adenylate cyclase and is postulated to be adenosine sensitive.In cells where both E_GDP and E₀ states are inactive, adenosine stimulates adenylate cyclase activity. In cells where E₀ is inactive, but E_GDP is active, adenosine inhibits adenylate cyclase activity. In addition we suggest that in cells where adenosine inhibits adenylate cyclase activity (cells postulated to have an E_GDP state which is active) high concentrations of GTP favor accumulation of the enzyme in E_GDP and thus are inhibitory to activity. Prostaglandins may also regulate adenylate cyclase in a manner similar to that described above for adenosine.We conclude that adenosine is an important regulator of adenylate cyclase whose role has only been appreciated recently. Further studies are warranted on both its binding to cells and mechanisms by which it regulates adenylate cyclase.This work was supported by United States Public Health Service Research Grant AM-10149 from the National Institute of Arthritis, Metabolism and Digestive Diseases.     

Identification and DNA sequence analysis of a γ-type gliadin cDNA plasmid from winter wheat

Summary Recombinant cDNA plasmids possessing the coding sequences for the -type gliadins were isolated from a cDNA library prepared from wheat seed poly (A⁺) RNA. One of these plasmids, pGliB48, specifically hybridizes to poly (A⁺) RNA molecules 1 400–1 500 bases in length that direct the synthesis of polypeptides at 38 Kd and 46 Kd, the latter size characteristic of the -type gliadins. The cDNA sequence of pGliB48 was determined and encompasses the 3 untranslated region as well as 245 amino acids from the C-terminus of the -type gliadin polypeptide. The 5-end of the DNA coding sequence consists of a tandem repeat unit composed of eight amino acids. Localized regions of homology are observed for the /-type and -type gliadin cDNA sequences.     

Localization of mitochondria in plant cells by vital staining with rhodamine 123

The positively-charged fluorescent dye rhodamine 123 (r-123) specifically stains mitochondria in living plant protoplasts, suspensionculture cells, and root hairs. This dye functions as a vital stain and permits visualization of the localization, distribution and movement of the mitochondria. Dehydration of root hairs caused mitochondria to aggregate into clumps. Mitochondria were either homogenous or heterogeneous and were frequently seen to accumulate in the perinuclear regions of suspension-culture cells but not in those of protoplasts or root-hair cells. Dinitrophenol and high concentrations of ethyleneglycol-bis(-aminoethyl ether)-N,N,N,N-tetraacetic acid and KCl immediately eliminated fluorescence in r-123-stained mitochondria whereas ionomycin enhanced it. Treatment of seedlings with r-123 resulted in differential brightness of fluorescence in different tissues. Meristematic tissues, such as root and shoot tips, exhibited the brightest fluorescence. The cytotoxicity of r-123 in both germinating seedlings and suspension-culture cells was low. The specificity, sensitivity and low toxicity of r-123 should make it a useful tool in experiments designed to examine agents and conditions which affect the location, the physiological status or the viability of mitochondria.Abbreviations EGTA ethyleneglycol-bis-(-aminoethyl ether)N,N,N,N-tetraacetic acid - DAPI 46-diamidino-2-phenylindole - r-123 rhodamine 123     

Formation of P1, P2-dinucleoside 5′-pyrophosphates under potentially prebiological conditions

Summary Organic pyrophosphates such as UppA and NAD are formed when a solution containing a nucleotide, a nucleoside 5-polyphosphate, Mg²⁺ and imidazole are allowed to dry out. We suggest that this synthesis may have occured concurrently with oligonucleotide formation.Abbreviations Im Imidazole - CDI 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride - EDTA ethylenediaminetetraacetic acid - A adenosine - U uridine - p_nA adenosine 5-poly-phosphate containing n phosphate residues - pU uridine 5-phosphate - AppA P₁,P₂-diadenosine 5-pyrophosphate - UppA P₁-(uridine 5)-P₂-(adenosine 5)-pyrophosphate - ImpA adenosine 5-phosphorimidazolide - NMN nicotinamide mononucleotide - NAD nicotinamide-adenine dinucleotide     

The evolution of the α- and β-globin gene clusters in human populations

Summary DNA analysis of the - and -globin gene clusters has revealed substantial variability between individuals and populations. As well as restriction enzyme site and length polymorphisms, variation in gene copy number and type is observed. Because of this extensive polymorphism DNA analysis offers a highly informative method of studying genetic affinities between human populations. Haplotypes, consisting of a set of restriction enzyme polymorphisms distributed along the cluster, have been developed for both loci. Analysis of the molecular basis of numerous -thalassaemia alleles has revealed, in general, different sets of mutations in different populations, indicating that these postdate the racial divergence. Recent microepidemiological studies on the distribution of -thalassaemia support the hypothesis that this condition, like the {ie16-1}, has been selected because it confers protection against malaria. Population-specific DNA polymorphisms at these and other loci promise to be of considerable value to genetic anthropology.