Conserved and variable regions in the chromosomal and extrachromosomal DNA of halobacteria

Summary Total DNA from Halobacterium halobium and other halobacteria strains is separated into two fractions, FI and FII, which differ in their G+C content. FI DNA, which represents the major part of the genome is highly conserved in all purple-membrane-forming halobacteria. Fraction II (FII) consists in H. halobium of three DNA specimen: (a) the previously isolated plasmid pHH1, (b) a heterogeneous set of ccc-DNA molecules present in the cell in low copies, termed minor-circular DNA (MCD) and (c) a new type of more A-T rich DNA segments (chromosomal islands) which, as described here and by Pfeifer and Betlach (1985), are integrated in FI. Sequences homologous to pHH1 occur only in Halobacterium species closely related to H. halobium (like H. cutirubrum), whereas MCD sequences are present in all purple-membrane-forming halobacteria. The sequences of the newly identified chromosomal islands are only found like pHH1, in Halobacterium species, closely related to H. halobium. Total DNA from square halobacteria exhibits no extended homologies to FI or FII DNA from H. halobium. The only common DNA sequences found in all halobacteria are certain insertion elements (ISH), such as ISH26. Based on these data, halobacteria can be subdivided in at least three major groups.Dedicated to Prof. Dr. F. Lingens to his 60th anniversary     

DNA-DNA homology studies among strains ofHaloferax and other halobacteria

Deoxyribonucleic acid (DNA)-DNA hybridization was used to determine the relationships of the type strains of the three species of the genusHaloferax to 21 halobacterial strains representing isolates from hypersaline habitats and collection strains. Two genotypic groups with high DNA homology were obtained, belonging to the speciesHaloferax gibbonsii andHaloferax mediterranei. The highest DNA relatedness (74%) was obtained in theHalobacterium salinarium group.Halobacterium denitrificans showed very low DNA homology with the other halobacteria investigated. The G+C content of the eight strains ofHaloferax tested ranged between 59.1 and 65.5 mol%.     

The filtration apparatus of Cladocera: Filter mesh-sizes and their implications on food selectivity

Summary The filtering apparatus of eleven Cladoceran species was studied. The distances between the setulae, which act as filters, were measured. Among adult individuals, they vary from 0.2 m in Diaphanosoma brachyurum to 4.7 m in Sida crystallina. Species can be grouped according to the mesh-sizes, as fine mesh filter-feeders: Diaphanosoma brachyurum, Ceriodaphnia quadrangula, Chydorus sphaericus, Daphnia cucullata and Daphnia magna; medium mesh filter-feeders: Daphnia galeata, D. hyalina. D. pulicaria, Bosmina coregoni, and coarse mesh filter-feeders: Holopedium gibberum and Sida crystallina. In Daphnia hyalina, the distances between setulae increase from 0.3–0.4 m in small juveniles, to 0.8–2.0 m in adults. In Daphnia magna, the mesh-size of the filter does not increase significantly with growth. There is good evidence that the relative abundance of the filter-feeding types varies with the trophic state of the lake. In oligotrophic lakes the coarse mesh filter-feeders usually dominate throughout the year. The seasonal succession of zooplankton species in eutrophic lakes can be interpreted as a succession of feeding types; during winter coarse mesh filter-feeders dominate, while fine mesh filter-feeders are most abundant during summer phytoplankton blooms. Our results support the hypothesis that the species composition of filter-feeding zooplankton is strongly influenced by the amount of suspended bacteria which are available as food only for filter-feeding species with fine meshes.     

Regulatory Properties of Glutamate Dehydrogenase from Sulfolobus solfataricus

The purified glutamate dehydrogenase (GDH) from Sulfolobus solfataricus showed remarkable thermostability and retained 90–95% of the initial activity after incubation at –20°C, 4°C, and 25°C for up to 6 months. Unlike mammalian GDHs, the activity of GDH from Sulfolobus solfataricus was not significantly affected by the presence of various allosteric effectors such as ADP, GTP, and leucine. Incubation of GDH with increasing concentration of o-phthalaldehyde resulted in a progressive decrease in enzyme activity, suggesting that the o-phthalaldehyde-modified lysine or cysteine is directly involved in catalysis. The inhibition was competitive with respect to both 2-oxoglutarate (K_i = 30 M) and NADH (K_i = 100 M), further supporting a possibility that the o-phthalaldehyde-modified residues may be directly involved at the catalytic site. The modification of GDH by the arginine-specific dicarbonyl reagent phenylglyoxal was also examined with the view that arginine residues might play a general role in the binding of coenzyme throughout the family of pyridine nucleotide-dependent dehydro-genases. The purified GDH was inactivated in a dose-dependent manner by phenylglyoxal. Either NADH or 2-oxoglutarate did not gave any protection against the inactivation caused by a phenylglyoxal. This result indicates that GDH saturated with NADH or 2-oxoglutarate is still open to attack by phenylglyoxal. Phenylglyoxal was an uncompetitive inhibitor (K_i = 5 M) with respect to 2-oxoglutarate and a noncompetitive inhibitor (K_i = 6 M) with respect to NADH. The above results suggests that the phenylglyoxal-modified arginine residues are not located at the catalytic site and the inactivation of GDH by phenylglyoxal might be due to a steric hindrance or a conformational change affected by the interaction of the enzyme with its inhibitor.     

Ribulose bisphosphate carboxylase activity in halophilic Archaebacteria

Among the several strains of halobacteria grown heterotrophically, ribulose bisphosphate carboxylase activity was detected in those which accumulate poly (-hydroxybutyrate), viz. Haloferax mediterranei, Haloferax volcanii and Halobacterium marismortui. In H. mediterranei, the activity was present in cell extracts prepared after growth on a variety of carbohydrates. The ribulose bisphosphate carboxylase activity in H. mediterranei was inhibited by carboxyarabinitol bisphosphate, and the enzyme cross-reacted with antibodies raised against the spinach enzyme. CO₂ fixation by cell extract was stimulated by the addition of ATP and NADH. Preliminary data suggested that hydrogen could be a possible reductant.Abbreviations RuBP ribulose bisphosphate - Ru5P ribulose 5-phosphate - R5P ribose 5-phosphate - CABP carboxyarabinitol bisphosphate - PHB poly (-hydroxybutyrate) - DTT dithiothreitol     

Unique antibiotic sensitivity of an in vitro polypeptide synthesis system from the archaebacterium Thermoplasma acidophilum. Phylogenetic implications

Summary The susceptibility of Thermoplasma acidophilum (an extremely acidophilic, moderately thermophilic, wall-less sulphur-oxidizing archaebacterium) to 50 ribosome-specific inhibitors of polypeptide elongation was surveyed using efficient poly(U)-and poly(UG)-directed cell-free systems and comparable reference systems derived from eubacterial (Bacillus stearothermophilus, Escherichia coli) and eukaryotic (Saccharomyces cerevisiae) species. Under optimum temperature (58° C) and ionic conditions for polypeptide synthesis Thermoplasma ribosomes are only sensitive to the 70 S/80 S ribosome-directed aminoglycoside neomycin, and to five 80 S ribosome-directed inhibitors all of which (-sarcin, mitogillin, restrictocin, dianthin and gelonin) impair the functioning of the large (60 S) ribosomal subunit. Sensitivity of the three structurally related compounds -sarcin, mitogillin and restrictocin and susceptibility to neomycin place Thermoplasma ribosomes between those of Sulfolobus solfataricus (only sensitive to -sarcin) and Methanococcus vannielli (sensitive to -sarcin, mitogillin, restrictocin and neomycin but also affected by a variety of 70 S ribosome-directed drugs). The phylogenetic significance of the greatly diversified antibiotic sensitivity spectra displayed by archaebacteria in general, as opposed to the uniform ones exhibited by eubacteria and eukaryotes, is discussed.     

Survey for Fusaria that produce and antibiotic that causes conidia of Penicillium digitatum to swell

During screening of Fusarium Lk. ex Fr. strains for antibiotic production, we observed a peculiar conidial swelling of Penicillium digitatum Sacc. strain NRRL 1202 when this sensitive fungus was grown in the presence of methanol extracts of Fusarium roseum Lk. Acuminatum strain NRRL 6227 cultures. In an expanded study to determine the prevalence of a swelling factor among Fusarium species, 23 of 132 strains produced an antibiotic that caused P. digitatum conidia to swell. Eighteen of the producing fungi belonged to the species F. tricinctum (Cda.) Sacc, two were identified as F. roseum Acuminatum, and one strain each was identified as F. roseum Sambucinum, F. roseum Equiseti and F. graminearum Schwabe. These data indicate that production of an antibiotic that causes P. digitatum conidia to swell is not unique to only a few Fusarium cultures.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Ecophysiological studies in Kalanchoë porphyrocalyx (Baker) and K. miniata (Hils et Bojer), two species performing highly flexible CAM

Preceding results, based on the determination of stable carbon isotope composition (₁₃C) of leaf tissues from various Kalanchoë species, suggested a close coincidence between the photosynthetic flexibility of the species and their habitat, life form and taxonomic position within the genus. The ability to shift from C₃-to Crassulacean Acid Metabolism (CAM)-type of photosynthesis seemed to concern in particular the more ancestral species in the genus and to be linked to epiphytism and changing climatic situations. For deeper insights into these interrelationships, physiological studies in controlled conditions were carried out on K. miniata and K. porphyrocalyx. These two species differ by their habitat preference and life form. Measurements were conducted on CO₂ exchange patterns, day/night fluctuation of malate content in the leaves and capacity of phosphoenolpyruvate carboxylase (PEPC). The results show that the 2 species can be considered as facultative CAM plants, with very high flexibility in their photosynthetic behaviour. The decrease in water availability seems to be a major factor triggering the shift from C₃ to the CAM mode. In K. miniata, 21 days of drought depressed CO₂ uptake to the level of CAM idling whereas in K. porphyrocalyx, CO₂ exchange was considerably more resistant. At least for K. miniata, short-day treatment was found to be a further CAM-inducing factor. The results are discussed in terms of their ecophysiological significance under the environmental conditions of the sites where the investigated species naturally grow.     

The quantitative analysis of chromosome pairing and chiasma formation based on the relative frequencies of M I configurations

Whilst reliable estimates of chiasma frequencies can usually not be obtained, the probability (b) of a chromosome arm to be bound by at least one chiasma can often be determined. In the absence of interference this probability equals (1–e ^–2), where 2 is the average chiasma frequency of the chromosome arm and the average crossover frequency or map length. In the presence of interference is shown to retain its genetic meaning as an additive metric that may describe the chromosome arm or other distinctive chromosome segment in terms of genetic recombination. It is a form of potential map length, comparable to, but numerically different from the regular map length. It is termed provisionally crossing-over potential.A chromosome with armsm andn with crossing-over potentials and will form ring bivalents with a frequency (1–e ^–2).(1–e ^–2); open bivalents with a frequency (1–e ^–2).e ^–2+(1–e ^–2).e ^–2; univalent pairs with a frequencye ^–2.e ^–2. Estimates of these frequencies yield equations from which and may be solved. In rye (Secale cereale) their ratio (q) is approximately two and differs from the mitotic arm length ratio of 1.4, indicating localization of chiasmata in the long arms.Graphs are given to show how, with constantq, the relation between the probabilitiesb _m andb _n of the two arms being bound changes with changing averageb.Data are presented on chiasma frequencies in M I, and compared with the frequencies expected in the absence of interference to give an impression of the degree of interference. Apparent fusion of chiasmata simulates interference.     

β-D-Glycan synthases and the CesA gene family: lessons to be learned from the mixed-linkage (1→3),(1→4)β-D-glucan synthase

Cellulose synthase genes (CesAs) encode a broad range of processive glycosyltransferases that synthesize (14)-D-glycosyl units. The proteins predicted to be encoded by these genes contain up to eight membrane-spanning domains and four `U-motifs' with conserved aspartate residues and a QxxRW motif that are essential for substrate binding and catalysis. In higher plants, the domain structure includes two plant-specific regions, one that is relatively conserved and a second, so-called `hypervariable region' (HVR). Analysis of the phylogenetic relationships among members of the CesA multi-gene families from two grass species,Oryza sativa and Zea mays, with Arabidopsis thaliana and other dicotyledonous species reveals that the CesA genes cluster into several distinct sub-classes. Whereas some sub-classes are populated by CesAs from all species, two sub-classes are populated solely by CesAs from grass species. The sub-class identity is primarily defined by the HVR, and the sequence in this region does not vary substantially among members of the same sub-class. Hence, we suggest that the region is more aptly termed a `class-specific region' (CSR). Several motifs containing cysteine, basic, acidic and aromatic residues indicate that the CSR may function in substrate binding specificity and catalysis. Similar motifs are conserved in bacterial cellulose synthases, the Dictyostelium discoideum cellulose synthase, and other processive glycosyltransferases involved in the synthesis of non-cellulosic polymers with (14)-linked backbones, including chitin, heparan, and hyaluronan. These analyses re-open the question whether all the CesA genes encode cellulose synthases or whether some of the sub-class members may encode other non-cellulosic (14)-glycan synthases in plants. For example, the mixed-linkage (13)(14)-D-glucan synthase is found specifically in grasses and possesses many features more similar to those of cellulose synthase than to those of other -linked cross-linking glycans. In this respect, the enzymatic properties of the mixed-linkage -glucan synthases not only provide special insight into the mechanisms of (14)-glycan synthesis but may also uncover the genes that encode the synthases themselves.     

Solution conformations of proline rings in proteins studied by NMR spectroscopy

Summary Three different conformations of proline rings in a protein in solution, Up, Down and Twist, have been distinguished, and stereospecific assignments of the pyrrolidine -, - and -hydrogens have been made on the basis of ¹H-¹H vicinal coupling constant patterns and intraresidue NOEs. For all three conformations, interhydrogen distances in the pairs -³, ³-³, ²-², ²-², and ³-³ (2.3 Å) are shorter than those in the pairs -², ²-³, ³-², ²-³, and ³-² (2.7–3.0 Å), resulting in stronger NOESY cross peaks. For the Up conformation, the ³-² and ²-³ spin-spin coupling constants are small (<3 Hz), and weak cross peaks are obtained in a short-mixing-time (10 ms) TOCSY spectrum; all other vicinal coupling constants are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. For the Down form, the -², ²-³, and ³-² vicinal coupling constants are small, leading to weak TOCSY cross peaks; all other couplings again are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. In the case of a Twist conformation, dynamically averaged coupling constants are anticipated. The procedure has been applied to bovine pancreatic trypsin inhibitor and Cucurbita maxima trypsin inhibitor-V, and ring conformations of all prolines in the two proteins have been determined.     

Eco-physiological studies on Indian arid zone plants

Summary Photosynthetic characteristics of two important grasses of Indian desert have been studied. Pennisetum typhoides, an important cereal crop, known to have Kranz-type leaf anatomy and low CO₂-compensation point, shows the C-4-dicarboxylic acid pathway for photosynthetic carbon reduction. Lasiurus sindicus, a promising forage grass, has also been shown to possess, for the first time, a typical Kranz-type leaf anatomy and a very similar CO₂-fixation pattern like Pennisetum typhoides. It is remarkable that both species after short time exposure to ¹⁴CO₂ show a high labelling not only in malate but also in alanine. This may be due to the activity of an aspartic acid decarboxylase.     

Molecular mapping of a new gene Rrs4 CI 11549 for resistance to barley scald (Rhynchosporium secalis)

Doubled haploid (DH) progeny from a cross between the scald susceptible barley (Hordeum vulgare L.) cultivar Ingrid and the resistant accession CI 11549 (Nigrinudum) was evaluated for resistance in the pathogen Rhynchosporium secalis (Oudem) J.J. Davis. Two linked and incompletely dominant loci confer resistance CI 11549 against isolate 4004. One is an allele at the complex Rrs1 locus on chromosome 3H close to the centromere; the other is located 22 cM distally on the long arm. The latter locus is designated Rrs4. In BC₃-lines into Ingrid from CI 2222 (another Nigrinudum) resistance seems governed by one locus close to the telomeric region of chromosome 7H, probably allelic to Rrs2. In neither case did we find any trace of the recessive gene rh8 reported to be present in Nigrinudum. Various resistance donors of Ethiopian origin designated as Nigrinudum, Jet or Abyssinian were identical to a great extent with respect to markers, but differed in resistance to different isolates of scald or in barley yellow dwarf virus (BYDV) resistance. The implications for their use as differentials in scald tests and screening of germplasm collections are discussed.     

High irradiance response promotion of a subsequent light induction response in Sinapis alba L.

Relative quantum responsivity curves for inhibition of hypocotyl elongation in Sinapis alba L. seedlings previously grown in white light confirm that a marked end of day inhibition response can be induced by a monochromatic light treatment (30 min) at the end of the light period. In dark grown seedlings, however, no growth inhibition can be induced by a 30 min monochromatic light treatment. A prerequisite for an induction response appears to be a pretreatment with continuous light. Far red light is most effective with blue and red light showing a lesser effectiveness. The light pretreatment also shows a marked fluence rate dependency with respect to its ability to allow an induction response to manifest itself. The pretreatment required shows all the characteristics of a classical HIR response. The appearance of the effect in plants treated with the herbicide SAN 9789 seems to exclude chlorophyll as being the photoreceptor.Abbreviations SAN 9789 4-chloro-5-(methylamino)-2-(, , -trifluoro-m-tolyl)-3(2H)-pyridazinone - RG9 light long wavelength far red light (Schott RG9 colour glass) - FR far red light - WL white light - BL blue light - RL red light - D darkness - P_tot total phytochrome - P_fr far red absorbing form of phytochrome - HSR high irradiance response     

Semi-constitutive expression of an Arabidopsis thaliana α-tubulin gene

In Arabidopsis tissues, the pool of tubulin protein is provided by the expression of multiple -tubulin and -tubulin genes. Previous evidence suggested that the TUA2 -tubulin gene was expressed in all organs of mature plants. We now report a more detailed analysis of TUA2 expression during plant development. Chimeric genes containing TUA2 5-flanking DNA fused to the -glucuronidase (GUS) coding region were used to create transgenic Arabidopsis plants. Second-generation progeny of regenerated plants were analyzed by histochemical assay to localize GUS expression. GUS activity was seen throughout plant development and in nearly all tissues. The blue product of GUS activity accumulated to the highest levels in tissues with actively dividing and elongating cells. GUS activity was not detected in a few plant tissues, suggesting that, though widely expressed, the TUA2 promoter is not constitutively active.     

Characterization and expression analysis of CD3ɛ and CD3γ/δ in fugu, Takifugu rubripes

CD3 is an essential component of the CD3-TCR complex. In this report, we describe the cloning, characterization, and expression analysis of the CD3 and CD3/ chain genes from fugu, Takifugu rubripes. Two distinct CD3 homologue cDNAs, designated as CD3-1 and CD3-2, and a CD3/ homologue cDNA were isolated from the fugu thymus. The deduced amino acid sequences of these cDNAs exhibit conserved essential CD3 chain motifs and overall structures. RT-PCR analysis demonstrated that the CD3 and CD3/ genes were expressed in lymphoid organs (e.g. thymus, head kidney, trunk kidney and spleen), mucosal tissues (gill, skin, and intestine), and peripheral blood leucocytes (PBL). The CD3 and TCR genes were expressed only in the surface IgM^– population, which were separated from PBL using an anti-fugu IgM monoclonal antibody. In addition, in situ hybridization confirmed that CD3-expressing cells were distributed randomly in the head kidney, trunk kidney, and spleen, but in the thymus were restricted to the lymphoid outer zone and epithelioid inner zone only. Collectively, these results suggest that CD3 molecules are useful markers for the identification of T cells in teleost fish. The present study thus provides a critical step in identifying T cells in this model organism.Nucleotide sequence data reported in this paper are available in the DBJ/EMBL/GenBank databases and have been assigned the accession numbers AB166798 (CD3-1), AB166799 (CD3-2), and AB166800 (CD3/).     

Effects of population size on genetic diversity and seed production in the rare <Emphasis Type="Italic">Dictamnus albus</Emphasis>(Rutaceae) in central Germany

It is widely assumed that population size significantly affects the dynamics of plant populations. Smaller populations are threatened by genetic drift and inbreeding depression, both of which may result in a decrease of genetic variation and a resulting negative impact on plant fitness. In our study we analysed the patterns of random amplified polymorphic DNA (RAPD) variation among 10 Dictamnus albuspopulations of varying size. The aim was to examine local differentiation in relation to spatial isolation resulting from limited population size and geographical distancing between populations. Significant correlations were noted between population size and both percentage of polymorphic loci (P <0.01) and genetic diversity (P<0.01). The matrix correlation between genetic and geographical distances revealed that geographical differentiation was reflected in the RAPD profile (Mantel test: r²=0.34, P<0.001). We found the highest level of molecular variance of RAPD patterns among individuals within the populations (72.6%), whereas among-population variation accounted for only 21.6% of variation. These results were highly significant in that they indicated a restricted population differentiation, as would be expected from outcrossing species. An additional analysis of seed production showed that there was significant variation among populations in terms of mean seed number per flower and mean seed mass per population which could be attributed to differences in population size as well as levels of genetic variation.     

A comparison of the lytic action ofCytophaga johnsonii on a eubacterium and a yeast

The non-fruiting myxobacteriumC. johnsonii will not attack living cells ofAerobacter aerogenes orSaccharomyces cerevisiae. Autoclaved cells of both organisms are however lysed but in different ways. WithA. aerogenes the cell contents are dissolved leaving an outer membrane which is not further attacked. With the yeast the wall is lysed and a structure resembling a spheroplast remains. Glucanase is produced by the myxobacterium when grown on autoclaved whole yeast. No glucanase is produced when the organism is grown on autoclavedA. aerogenes.     

Immunohistological analyses of neutral glycosphingolipids and gangliosides in normal mouse skeletal muscle and in mice with neuromuscular diseases

The expression of neutral glycosphingolipids (GSLs) and gangliosides was investigated in cryosections of normal mouse skeletal muscle and in muscle of mice with neuromuscular diseases using indirect immunofluorescence microscopy. Transversal and longitudinal sections were immunostained with specific polyclonal antibodies against lactosylceramide, lacto-N-neotetraosylceramide, globoside, G_M3(Neu5Ac), G_M3(Neu5Gc) and G_M1(Neu5Ac) as well as monoclonal anti-Forssman GSL antibody. In normal CBA/J mouse muscle (control) the main immunohistochemically detected ganglioside was G_M3(Neu5Ac) followed by moderately expressed G_M3(Neu5Gc) and G_M1. The neutral GSLs lactosylceramide and globoside were stained with almost identical, high fluorescence intensity. Low amounts of lacto-N-neotetraosylceramide and trace quantities of Forssman GSL were immunostained. All GSLs were detected in the sarcolemma, but also in considerable amounts at the intracellular level. Mice with neuromuscular diseases were the A2G-adr mouse mutant (a model for human recessive myotonia of Becker type), the BL6-wr mutant (a model for motor neuron disease) and the BL10-mdx mouse mutant (a model for human Duchenne muscular dystrophy). No changes in GSL expression were found in the A2G-adr mouse, while muscle of the BL6-wr mouse showed increased intensity of immunofluorescence in stainings with anti-lactosylceramide and anti-G_M3(Neu5Ac) antibodies. Muscle of BL10-mdx mice showed the most prominent changes in GSL expression with reduced fluorescence intensity for all antibodies. Major differences were not observed in the intensities of GSLs, but there were significant differences in the patterns of distribution on plasma membrane and at the subcellular level. The exact nature and pathogenesis of these changes should be elucidated since such investigations could furnish advances in understanding the functional role of neutral GSLs and gangliosides in normal as well as in diseased muscle. Abbreviations: BSA, bovine serum albumin; DAPI, 4, 6-diamidine-2-phenylindole-dihydrochloride; DTAF, dichlorotriazinylamino-fluorescein; GSL(s), glycosphingolipid(s); Neu5Ac,N-acetylneuraminic acid; Neu5Gc,N-glycolylneuraminic acid [53]; PBS, phosphate buffered saline. The designation of the following glycosphingolipids follows the IUPAC-IUB recommendations [54] and the nomenclature of Svennerholm [55]. Lactosylceramide or LacCer, Gal1-4Glc1-1Cer; gangliotriaosylceramide or GgOse₃Cer, GalNAc1-4Gal1-4Glc1-1Cer; globotriaosylceramide or GbOse₃Cer, Gal1-4Gal1-4Glc1-1Cer; gangliotetraosylceramide or GgOse₃Cer, Gal1-3GalNAc1-4Gal1-4Glc1-1Cer; globotetraosylceramide or GbOse₄Cer, GalNAc1-3Gal1-4Gal1-4Glc1-1Cer; lacto-N-neotetraosylceramide or nLcOse₄Cer, Gal1-4GlcNAc1-3Gal1-4Glc1-1Cer; Forssman GSL or GbOse₅Cer, GalNAc1-3GalNAc1-3GAl1-4Gal1-4Glc1-1Cer; G_M3, II³Neu5Ac-LacCer; G_M1, II³Neu5Ac-GgOse₄Cer.     

Genetics of α-amylases from rye endosperm

Summary Fifteen inbred lines of rye, F₁ and F₂ progenies from crosses between lines were studied using polyacrylamide gel electrophoresis. Conventional genetic analysis of -amylase zymograms showed that the 19 bands detected in the endosperm of germinating caryopses were controlled by three linked structural loci and one independent modifying locus, which influenced the electrophoretic mobility of isozymes. Two codominant alleles were found at the -Amy1, -Amy2 structural loci and the M--Amy modifying locus while the -Amy3 locus had three alleles. Double-banded expression of the -amylase alleles was probably due to the simultaneous presence of modified and unmodified forms of isozymes on the zymogram.This work was supported by Polish Academy of Sciences under project MR-II/7 and was also a part of the author's PhD Thesis