Relationships among violaxanthin deepoxidation,thylakoid membrane conformation,and nonphotochemical chlorophyll fluorescence quenching in leaves of cotton (Gossypium hirsutum L.)

The kinetics and temperature dependencies of development and relaxation of light-induced absorbance changes caused by deepoxidation of violaxanthin to antheraxanthin and zeaxanthin (Z; peak at 506 nm) and by light scattering (S; peak around 540 nm) as well as of nonphotochemical quenching of chlorophyll fluorescence (NPQ) were followed in cotton leaves. Measurements were made in the absence and the presence of dithiothreitol (DTT), an inhibitor of violaxanthin deepoxidase. The amount of NPQ was calculated from the Stern-Volmer equation. A procedure was developed to correct gross AS (S_g) for absorbance changes around 540 nm that are due to a spectral overlap with Z. This protocol isolated the component which is caused by light-scattering changes alone (S_n). In control leaves, the kinetics and temperature dependence of the initial rate of rise in S_n that takes place upon illumination, closely matched that of Z. Application of DTT to leaves, containing little zeaxanthin or antheraxanthin, strongly inhibited both S_n and NPQ, but DTT had no inhibitory effect in leaves in which these xanthophylls had already been preformed, showing that the effect of DTT on A_n and NPQ results solely from the inhibition of violaxanthin deepoxidation. The rates and maximum extents of S_n and NPQ therefore depend on the amount of zeaxanthin (and/or antheraxanthin) present in the leaf. In contrast to the situation during induction, relaxation of Z upon darkening was much slower than the relaxation of S_n and NPQ. The relaxation of S_n and NPQ showed quantitatively similar kinetics and temperature dependencies (Q₁₀=2.4). These results are consistent with the following hypotheses: The increase in lumen-proton concentration resulting from thylakoid membrane energization causes deepoxidation of violaxanthin to antheraxanthin and zeaxanthin. The presence of these xanthophylls is not sufficient to cause S_n or NPQ but, together with an increased lumen-proton concentration, these xanthophylls cause a conformational change, reflected by S_n. The conformational change facilititates nonradiative energy dissipation, thereby causing NPQ. Membrane energization is prerequisite to conformational changes in the thylakoid membrane and resultant nonradiative energy dissipation but the capacity for such changes in intact leaves is quite limited unless zeaxanthin (and/or antheraxanthin) is present in the membrane. The sustained S_n and NPQ levels that remain after darkening may be attributable to a sustained high lumen-proton concentration.Abbreviations A antheraxanthin - DTT dithiothreitol - F, F_m chlorophyll fluorescence yield at actual, full closure of the PSII centers - NPQ nonphotochemical chlorophyll fluorescence quenching - PFD photon flux density - PSII photosystem II - V violaxanthin - Z zeaxanthin - S_n, Z spectral absorbance change caused by light-scattering, violaxanthin deepoxidation We thank Connie Shih for skillful assistance in growing the plants, and for conducting HPLC analyses. A Carnegie Institution Fellowship and a Feodor-Lynen-Fellowship by the Alexander von Humboldt-Foundation to W. B. is gratefully acknowledged. This work was supported in part by Grant No. 89-37-280-4902 of the Competitive Grants Program of the U.S. Department of Agriculture to O.B. This is C. I. W. — D. P. B. Publication No. 1094.     

Genomic organization of human complement protein C8α and further examination of its linkage to C8β

Human C8 is one of five complement components (C5b, C6, C7, C8, C9) that interact to form the cytolytic C5b-9 complex on target membranes. It is composed of three nonidentical subunits (C8, C8, C8) encoded by separate genes. C8 and C8 are linked on chromosome 1p32, whereas C8 is located on 9q22.3-q32. In this study, overlapping genomic clones were isolated and used to decipher the organization of the human C8 gene. The gene contains at least 11 exons spanning 70kb of DNA. When compared to C6, C8 and C9, there is a remarkable similarity in genomic organization, consistent with amino acid sequence comparisons that suggest these proteins are ancestrally related. Regions of each protein that are structurally similar are encoded in exons of correspondingly similar lengths with highly conserved boundaries and phases. Availability of genomic sequence also facilitated a more detailed analysis of C8 and C8 linkage. Based on analysis of genomic digests with cDNA probes, the loci were previously reported to be physically linked (< 2.5kb) and in a 5- 3 orientation. In the present study, results obtained using exon-specific probes indicate the loci are not as closely linked as initially believed. Furthermore, they suggest that cDNA probes used earlier yielded misleading information because they encode exons that are distributed across large segments of genomic DNA.     

Low temperature phototransformations of protochlorophyll(ide) in etiolated leaves

By methods of difference and derivative spectroscopy it was shown that in etiolated leaves at 77 K three photoreactions of P650 protochlorophyllide take place which differ in their rates and positions of spectral maxima of the intermediates formed in the process: P650R668, P650R688, and P650R697. With an increase of temperature up to 233 K, in the dark, R688 and R697 are transformed into the known chlorophyllide forms C695/684 and C684/676, while R668 disappears with formation of a shorter wavelength form of protochlorophyllide with an absorption maximum at 643–644 nm.Along with these reactions, at 77 K phototransformations of the long-wave protochlorophyllide forms with absorption maxima at 658–711 nm into the main short-wave forms of protochlorophyllide are observed. At 233 K in the dark this reaction is partially reversible. This process may be interpreted as a reversible photodisaggregation of the pigment in vivo.The mechanism of P650 reactions and their role in the process of chlorophyll photobiosynthesis are discussed.Abbreviations P650 protochlorophyll(ide) with absorption maximum at 650 nm - C697/684 chlorophyllide with fluorescence maximum at 695 nm and absorption maximum at 684 nm - R697 intermediate with absorption maximum at 697 nm     

The taxonomic significance of the trunk limbs of the chydoridae (Cladocera)

Summary The differences in the structure of the trunk limbs allow to outline three sections of Chydoridae (see table I and fig. 1), coinciding with the sections distinguished according to the structure of the head pores.

---

Chydoridae (Cladocera)

Chydoridae (. ), , .

     

Indirect effect of salmon carcasses on growth of a freshwater amphipod, <Emphasis Type="Italic">Jesogammarus jesoensis</Emphasis> (Gammaridea): An experimental study

The effect of salmon carcasses on the growth of a freshwater amphipod, Jesogammarus jesoensis (Schellenberg) (Gammaridea, Anisogammaridae), was examined experimentally. Growth rate was determined by rearing juvenile amphipods in four food treatments (leaves, salmon, leaves and salmon and leaves with salmon leachate) for 20days. Mass loss and oxygen consumption of the leaves were also measured in the three treatments with leaves. The oxygen consumption rate of leaves was lower in the leaves treatment than in either the leaves and salmon or leaves with salmon leachate treatments, indicating that microbial activity on leaves was enhanced by the presence of salmon carcasses. Mass loss of leaves did not differ between the three treatments with leaves. The growth rate of the amphipods did not differ between the leaves and salmon treatments, or between the leaves and salmon and leaves with salmon leachate treatments. Growth rates in the two latter treatments were higher than rates in the leaves treatment, but not higher than the rates in the salmon treatment. Therefore, it appears likely that consuming leaves fertilized with nutrients from salmon carcasses facilitates growth in this amphipod.     

Polymerization of nucleotide analogues I: Reaction of nucleoside 5′-phosphorimidazolides with 2′-amino-2′-deoxyuridine

Summary 2-Amino-2-deoxyuridine reacts efficiently with nucleoside 5-phosphorimidazolides in aqueous solution. The dinucleoside monophosphate analogues were obtained in yields exceeding 80% under conditions in which little reaction occurs with the natural nucleosides.In a similar way, the 5-phosphorimidazolide of 2-amino-2-deoxyuridine undergoes self-condensation in aqueous solution to give a complex mixture of oligomers.The phosphoramidate bond in the dinucleoside monophosphate analogues is stable for several days at room temperature and pH 7. The mechanisms of their hydrolysis under acidic and alkaline conditions are described.Abbreviations A adenosine - C cytidine - G guanosine - U uridine - T thymidine - U_{N 3} 2-azido-2-deoxyuridine - U_{NH 2} 2-amino-2-deoxyuridine - ImpA adenosine 5-phosphorimidazolide - ImpU uridine 5-phosphorimidazolide - ImpU_{N 3} 2-azido-2-deoxyuridine 5-phosphorimidazolide - ImpU_{NH 2} 2-amino-2-deoxyuridine 5-phosphorimidazolide - pA adenosine 5-phosphate - pU uridine 5-phosphate - pU_{N 3} 2-azido-2-deoxyuridine 5-phosphate - pU_{NH 2} 2-amino-2-deoxyuridine 5-phosphate - UpA uridylyl-[35]-adenosine - UpU uridylyl-[35]-uridine - U_NpA adenylyl-[52]-2-amino-2-deoxy-uridine - U_NpU uridylyl-[52]-2-amino-2-deoxyuridine (pU_N)_n n=2,3,4 [25]-linked oligomers of pU_{NH 2} poly(A) polyadenylic acid - Im imidazole - MeIm l-methylimidazole     

Cotyledon detachment inhibits development but does not affect precocious flowering of ‘Duncan’ grapefruit

The role of cotyledons in seedling development and precocious flowering was studied in Duncan grapefruit (Citrus paradisi Macf), a cultivar that displays a high frequency of precocious flowering. Cotyledons were detached from the embryo and the embryos were germinated in vitro to form plantlets. Cotyledon detachment dramatically affected the development of Duncan seedlings. The decotyledonized plants were stunted, with small narrow leaves and thin and underdeveloped roots. Decotyledonization did not change significantly the number of leaves developed. Despite the dramatic effects of the cotyledons on seedling development, decotyledonized Duncan seedlings retained their ability to flower precociously. We conclude that although normal growth and development of Duncan grapefruit seedlings is cotyledon-dependent, the ability to flower precociously does not depend on the presence of cotyledons during in vitro germination.Abbreviations MS Murashige & Skoog's medium     

ααααanti-3.7 type II: a new α-globin gene rearrangement suggesting that the α-globin gene duplication could be caused by intrachromosomal recombination

Summary We report here a new human -globin gene rearrangement carrying the two normal, 2 and 1, and two hybrid, 1/2, globin genes in the order 5-2-1/2-1/2-1-3. Both the hybrid genes, subtyped with ApaI and RsaI restriction enzymes, were found to be of the uncommon anti 3.7 type II. The hybrid genes were expressed at the biosynthetic level and their interaction with the -thalassaemia IVS 1 nt 1 GA mutation caused thalassaemia intermedia. We also report a case of an -globin gene rearrangement in the twin of one of the -globin gene carriers; the duplicated gene was of the anti 4.2 type and was associated with the absence of RsaI polymorphism. The singular finding of an -anti 3.7 cluster with two identical rare hybrid genes suggests that the reciprocal unequal recombination causing the -globin gene rearrangements could be of the intra-chromosomal rather than the interchromosomal type.     

Reduced levels of cytochrome b 6/f in transgenic tobacco increases the excitation pressure on Photosystem II without increasing sensitivity to photoinhibition in vivo

We have examined tobacco transformed with an antisense construct against the Rieske-FeS subunit of the cytochromeb ₆ f complex, containing only 15 to 20% of the wild-type level of cytochrome f. The anti-Rieske-FeS leaves had a comparable chlorophyll and Photosystem II reaction center stoichiometry and a comparable carotenoid profile to the wild-type, with differences of less than 10% on a leaf area basis. When exposed to high irradiance, the anti-Rieske-FeS leaves showed a greatly increased closure of Photosystem II and a much reduced capacity to develop non-photochemical quenching compared with wild-type. However, contrary to our expectations, the anti-Rieske-FeS leaves were not more susceptible to photoinhibition than were wild-type leaves. Further, when we regulated the irradiance so that the excitation pressure on photosystem II was equivalent in both the anti-Rieske-FeS and wild-type leaves, the anti-Rieske-FeS leaves experienced much less photoinhibition than wild-type. The evidence from the anti-Rieske-FeS tobacco suggests that rapid photoinactivation of Photosystem II in vivo only occurs when closure of Photosystem II coincides with lumen acidification. These results suggest that the model of photoinhibition in vivo occurring principally because of limitations to electron withdrawal from photosystem II does not explain photoinhibition in these transgenic tobacco leaves, and we need to re-evaluate the twinned concepts of photoinhibition and photoprotection.Abbreviations Chl chlorophyll - DCMU 3-(3,4-dichlophenyl)-1,-dimethylurea - Fo and Fo minimal fluorescence when all PS II reaction centers are open in dark- and light-acclimated leaves, respectively - Fm and Fm maximal fluorescence when all PS II reaction centers are closed in dark- and light-acclimated leaves, respectively - Fv variable fluorescence (Fm-Fo) in dark acclimated leaves - Fv variable fluorescence (Fm-Fo) in lightacclimated leaves - NPQ non-photochemical quenching of fluorescence - PS I and PS II Photosystem I and II - P680 primary electron donor of the reaction center of PS II - PFD photosynthetic flux density - Q_A primary acceptor quinone of PS II - q_p photochemical quenching of fluorescence - V+A+Z violaxanthin+antheraxanthin+zeaxanthin     

Interaction sites on phosphorylase kinase for calmodulin

Holophosphorylase kinase was digested with Glu-C specific protease; from the peptide mixture calmodulin binding peptides were isolated by affinity chromatography and identified by N-terminal sequence analysis. Two peptides originating from the subunit, having a high tendency to form a positively charged amphiphilic helix and containing tryptophane, were synthesized. Additionally, a homologous region of the subunit and a peptide from the subunit present in a region deleted in the isoform were also selected for synthesis. Binding stoichiometry and affinity were determined by following the enhancement in tryptophane fluorescence occurring upon 1:1 complex formation between these peptides and calmodulin. Finally, Ca²⁺ binding to calmodulin in presence of peptides was measured. By this way, the peptides 542–566, 547–571, 660–677 and 597–614 have been found to bind specifically to calmodulin.Together with previously predicted and synthesized calmodulin binding peptides four calmodulin binding regions have been characterized on each the and subunits. It can be concluded that endogenous calmodulin can bind to two calmodulin binding regions in as well as to two regions in and . Exogenous calmodulin can bind to two regions in and in . A binding stoichiometry of 0.8mol of calmodulin/ protomer of phosphorylase kinase has been determined by inhibiting the ubiquitination of calmodulin with phosphorylase kinase. Phosphorylase kinase is half maximally activated by 23nM calmodulin which is in the affinity range of calmodulin binding peptides from to calmodulin. Therefore, binding of exogenous calmodulin to activates the enzyme. A model for switching endogenous calmodulin between , and and modulation of ATP binding to as well as Mg²⁺/ADP binding to by calmodulin is presented.     

Resolution of components of non-photochemical chlorophyll fluorescence quenching in barley leaves

Non-photochemical chlorophyll fluorescence quenching (qN) in barley leaves has been analysed by monitoring its relaxation in the dark, by applying saturating pulses of light. At least three kinetically distinct phases to qN recovery are observed, which have previously been identified (Quick and Stitt 1989) as being due to high-energy state quenching (fast), excitation energy redistribution due to a state transition (medium) and photoinhibition (slow). However, measurements of chlorophyll fluorescence at 77 K from leaf extracts show that state transitions only occur in low light conditions, whereas the medium component of qN is very large in high light. The source of that part of the medium component not accounted for by a state transition is discussed.Abbreviations ATP adenosine 5-triphosphate - DCMU 3[3,4-dichlorophenyl]-1,1 dimethylurea - pH trans-thylakoid pH gradient - F_o, F_m room-temperature chlorophyll fluorescence yield with all reaction centres open, closed - F_v variable fluorescence = F_m–F_o - LHC II Light harvesting complex II - PS I, PS II Photosystem I, II - P700, P680 primary donor in photosystem I, II - qP photochemical quenching of variable fluorescence - qN non-photochemical quenching of variable fluorescence - qN_e, qN_t, qN_i non-photochemical quenching due to high energy state, state transition, photoinhibition - qN_f, qN_m, qN_s components of qN relaxing fast, medium, slow - q_r quenching of r relative to the dark state - tricine N-tris[hydroxymethyl]methylglycine - r ratio of fluorescence maximum from photosystem II to that from photosystem I at 77 K     

Water stress-induced oxidative damage and antioxidant responses in micropropagated banana plantlets

Oxidative injury and antioxidant responses were investigated in two banana genotypes (Musa AAA Berangan and Musa AA Mas) subjected to 40 % PEG-induced water stress. PEG treatment resulted in oxidative injury, as expressed in increased lipid peroxidation and reduced membrane stability index, in both cultivars; however, greater oxidative injury was detected in Mas. Under PEG treatment, catalase activity and glutathione reductase activity were enhanced in both cultivars, but were higher in Mas. Ascorbate peroxidase activity was enhanced in Berangan under water stress, but was unaffected in Mas. Meanwhile, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in Berangan. Higher ascorbate peroxidase and superoxide dismutase activities were associated with greater protection against water stress-induced oxidative injury.     

Screening of turfgrass species and cultivars for NaCl tolerance

Summary Information regarding the relative levels of salt tolerance between cultivars of Kentucky bluegrass (Poa pratensis L.) is lacking. The objectives of this study were to 1) develop a simple, quick and sensitive method of screening turfgrass species for NaCl tolerance and 2) to compare the relative salt tolerance of five cultivars of Kentucky bluegrass (Ram I, Adelphi, Baron, Bensun, and Nassau) to other known salt tolerant turfgrass species such as alkalaigrass (Puccinellia distans (L.) Parl. cv. Fults) and two cultivars of red fescue (Festuca rubra L. Dawson, and Checker).Alkalaigrass and both cultivars of red fescue retained a high level of salt tolerance compared to the Kentucky bluegrass cultivars. Significant variability in salt tolerance was apparent among the Kentucky bluegrass cultivars with Adelphi and Ram I exhibiting the best overall tolerance.     

Sterol conjugates of two phenotypically different calli of Beta vulgaris

Steryl glycosides are the predominant form of sterol at 88% of the total sterol in non-betalain producing calli of Beta vulgaris. The total sterol decreases and sterol form shifts from steryl glycosides to 97% free sterol upon the transition of non-betalain to betalain producing calli. A substantial decrease in stigmasterol (24--ethylcholesta-5,22E-dien-3-ol) and sitosterol (24-ethylcholest-5-en-3-ol) levels is observed during this transition, and alters the ratio of ⁷:⁵ sterols. Spinasterol (24- ethyl-5-cholesta-7,22E-dien-3-ol) is the dominant sterol at 43% and 95% of the total sterol in non-betalain producing and betalain producing calli. The level of 22-dihydrospinasterol (24-ethyl-5-cholest-7-en-3-ol) is reduced in both calli to 3% from 25% in leaves. Lanosterol (4,4,14-trimethyl-cholesta-8(9),24-dien-3-ol) and cycloartenol (9,19-cyclopropyl-4,4,14-trimethyl-cholest-24-en-3-ol) were identified in betalain and nonbetalain producing callus respectively.     

Genetic linkage maps of two apple cultivars (<Emphasis Type="Italic">Malus</Emphasis> × <Emphasis Type="Italic">domestica</Emphasis> Borkh.) based on AFLP and microsatellite markers

Genetic linkage maps for two apple cultivars were constructed using AFLP and SSR markers and the pseudo-testcross mapping strategy. The F₁-mapping population was produced by crossing the cultivar Braeburn to the cultivar Telamon and consisted of 257 individuals. Out of the 182 AFLP primer combinations screened, a total of 48 were selected. Using these, 463 AFLP markers segregating 1:1 in the progeny were identified, of which 231 were heterozygous in Telamon and 232 in Braeburn. Eighty-five AFLP markers present in both cultivars (3:1 segregation) were scored in the whole mapping population. Twenty-one SSR primer pairs were tested, which clearly screened 23 loci (some multi-locus markers). This resulted in the identification of 3 loci heterozygous only in Telamon (1:2:1), 5 loci heterozygous only in Braeburn (1:2:1) and 15 loci which were heterozygous in both cultivars (1:1:1:1). Two linkage maps were produced. The Telamon map comprised 259 markers (242 AFLPs and 17 SSRs) divided into 17 linkage groups. The total map length was 1039 cM with a marker density of 4.0 cM. At = 0.05, 8.9% of the mapped loci showed distorted segregation. The Braeburn map consisted of 264 markers (245 AFLPs and 19 SSRs) mapped on 17 linkage groups and spanning 1245 cM. The average distance between two markers was 4.7 cM and segregation distortion was observed for 18.6% of the mapped markers ( = 0.05). Fourty-six markers common to both maps (32 AFLPs and 14 SSRs) allowed the identification of 16 homologous linkage groups. The seventeenth pair of homologous linkage groups from Telamon and Braeburn was identified by 2 SSR markers which were in common to the genetic linkage maps of Fiesta and Discovery, two other apple cultivars.     

Intracellular sites of the synthesis of sweet potato mitochondrial F1ATPase subunits

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.     

Fluorescence methods for the histochemical demonstration of monoamines

Summary The histochemical fluorescence method of Falck and Hillarp for the demonstration of catecholamines and certain tryptamines, e.g. 5-hydroxytryptamine is based on the principle that these amines can be condensed with formaldehyde to yield strongly fluorescent 6,7-dihydroxy-3,4-dihydroisoquinolines and 6-hydroxy-3,4-dihydro--carbolines respectively. The investigation here reported presents the fluorescence characteristics and relative fluorescence yields for formaldehyde treated biogenic monoamines and certain related compounds enclosed in a dried protein layer. The fluorescence properties of some synthetic 6,7-substituted-3,4-dihydroisoquinolines and 3,4-dihydro--carbolines are given, and the fluorescence characteristics in relation to the molecular structure are discussed.Abbreviations used A adrenaline - DA dopamine - DOPA 3,4-dihydroxyphenylalanine - DOPS 3,4-dihydroxyphenyl-serine - 5-HT 5-hydroxytryptamine - 5-HTP 5-hydroxytryptophan - 5-MT 5-methoxytryptamine - -m-DA -methyl-dopamine - -m-DOPA -methyl-3,4-dihydroxyphenylalanine - -m-NA -methyl-noradrenahne - MTA 3-methoxy-tyramine - NA noradrenaline - NM normetanephrine - T Tryptamine - Try Tryptophan     

Expression of α-amylase in response to wounding in mung bean

The activity of -amylase (EC 3.2.1.1) in mung bean (Vigna radiata (L.) Wilczek) cotyledons increased markedly in response to wounding. The changes in enzyme activity were in parallel with those in enzyme content. The level of -amylase mRNA also notably increased in wounded cotyledons and attained its maximum level during the period between 1 and 2 d after wounding. The level of mRNA for phenylalanine ammonia-lyase, which is one of the well-characterized stress-inducible proteins, also increased after wounding, but the increase in mRNA level was faster than that of -amylase mRNA. On the other hand, the content of mRNA for actin, a housekeeping protein, was almost the same in wounded and unwounded cotyledons. The increase in -amylase mRNA level in wounded cotyledons was severely inhibited by -amanitin and cordycepin. -Amylase expression in the first leaves of mung-bean seedlings was also induced by wounding.Abbreviations PAL phenylalanine ammonia-lyase - SSC standard saline citrate We greatly acknowledge Prof. Richard Meagher, Department of Genetics, University of Georgia, Athens, USA for the gift of soybean actin gene clone. We also thank Mr. Kaoru Ishiwata for technical assistance.     

Demonstration of ‘cardiac-specific’ myosin heavy chain in masticatory muscles of human and rabbit

Summary Human and rabbit masticatory muscles were analyzed immuno-and enzyme-histochemically using antibodies specific to cardiac , slow and fast myosin heavy chain isoforms. In human masseter, temporalis, and lateral pterygoid muscle cardiac myosin heavy chain is found in fibres that contain either fast, or fast and slow myosin heavy chain. In rabbit masseter, temporalis and digastric muscles, fibres are present that express cardiac myosin heavy chain either exclusively, or concomitantly with slow myosin heavy chain or fast myosin heavy chain. Our results demonstrate a much broader distribution of cardiac myosin heavy chain than hitherto recognized and these might explain in part the specific characteristics of masticatory muscles. The cardiac myosin heavy chain is only found in skeletal muscles originating from the cranial part of the embryo (including the heart muscle) suggesting that its expression might be determined by the developmental history of these muscles.     

Carotenoid pigments of Sorangium compositum (Myxobacterales) including two new carotenoid glucoside esters and two new carotenoid rhamnosides

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).