AA BB Research Articles

PDGF BB stimulates proliferation and differentiation in cultured chondrocytes from rat rib growth plate

The role of two isoforms (PDGF AA and PDGF BB) of platelet derived growth factor either alone or in combination with insuline-like growth factor I, on the regulation of proliferation and differentiation of rat rib growth plate chondrocytes was analyzed. PDGF BB increased DNA-synthesis in a dose dependent manner with a half maximal effect at 1 ng/ml. When PDGF BB was combined with IGF-I, an additive effect on DNA-synthesis was observed. PDGF AA and BB alone or combined with IGF-I had no appreciable effects on proteoglycan synthesis. Both homodimers caused an increase in AP-activity, indicating stimulation of cell differentiation. Cultured chondrocytes bound 125I-PDGF AA and 125I-PDGF BB and after stimulation with PDGF expressed c-fos protein. Thus, both homodimers play an important role in chondrocyte differentiation and together with IGF-I interact in the regulation of longitudinal bone growth.

The v-sis oncogene product but not platelet-derived growth factor (PDGF) A homodimers activate PDGF alpha and beta receptors intracellularly and initiate cellular transformation.

The v-sis oncogene product p28v-sis and the platelet-derived growth factor (PDGF) B chain share 92% homology with each other and over 50% homology with the PDGF A chain. Exogenously added homodimers of PDGF A and PDGF B and of p28v-sis are potent mitogens but only PDGF B and p28v-sis induce transformation when endogenously expressed with a strong promoter. Because exogenous PDGF AA and PDGF BB both initiate a full mitogenic response, understanding the mechanisms underlying the difference in their transforming potential may clarify how growth factor genes act as oncogenes. In this work, we compared cells expressing high levels of PDGF A and v-sis. We observed that transformation by v-sis correlated directly with the rapid degradation (t1/2 approximately 20 min) of the alpha and beta PDGF receptors, with a failure of either the alpha or beta receptor to be fully processed and with the association of high levels of phosphatidylinositol (PI) 3-kinase with immunoprecipitates of the PDGF receptors. In contrast, in cells expressing essentially equal levels of PDGF A, transformation was not detected, alpha and beta PDGF receptor processing was normal, and association of PI 3-kinase with receptors in immunoprecipitates was not found above control values. The ability of v-sis to autoactivate PDGF receptors within processing compartments and to initiate activation of the PI 3-kinase signaling pathway coupled with the failure of PDGF A to activate its receptor intracellularly and to induce transformation when endogenously expressed at high levels suggests that the internal autoactivation of PDGF receptors may be essential for transformation by v-sis.

Chromosome pairing in hybrids of Triticum aestivum and the amphiploid Hordeum chilense x T. turgidum conv. durum

The meiotic behaviour of a hybrid between Triticum aestivum and the amphiploid Hordeum chilense x T. turgidum conv. durum, was studied using a C-banding staining method. This hybrid has the genome formula of AA BB D Hch with 2n=6x=42 chromosomes. The durum wheat chromosomes (genomes A and B) were easily recognized, whereas the D and Hch chromosomes were recognized as a whole. Meiotic pairing was homologous, as expected (14 bivalents from A and B genomes +14 univalents from D and Hch genomes). However, some pollen mother cells at metaphase-I presented pseudobivalents that could have been caused by either homoeologous or autosyndetic pairing amongst D and Hch chromosomes.

Milk Protein Typing of Bovine Mammary Gland Tissue Used to Generate a Complementary Deoxyribonucleic Acid Library

The milk protein genotype of a mammary gland tissue that was used to generate a cDNA library at the University of California, Davis was typed by PAGE. Casein and whey proteins were extracted from the mammary tissue and typed utilizing fast mini-gel procedures that provide excellent resolution of the milk proteins. The genotype of the mammary tissue was classified as κ-casein AB, β-casein A2A1, αs1-casein BB, β-lactoglobulin AA, and α-lactalbumin BB. The genes κ-casein A, β-casein A2, β-lactoglobulin A, and α-lactalbumin B that have been cloned from this cDNA library coincide with those in the above tissue genotype with the exception of the recently reported cloning of the αs1-casein A gene. The gene frequencies for die casein genetic variants for three breeds of dairy cattle is presented and discussed in relation to the low frequency (.3%) of the αs1-casein A in the population.

Biocatalytic synthesis of polymers. II. Preparation of [AA–BB]x polyesters by porcine pancreatic lipase catalyzed transesterification in anhydrous, low polarity organic solvents

AbstractEnzyme‐catalyzed preparation of polymers offers several potentially valuable advantages over the usual polymerization procedures. (1) Such polymerizations may allow the polymer to retain functionality that would be destroyed under normal polymerization conditions. (2) The selectivity provided by enzyme catalysts may permit polymers, including optically active polymers, to be prepared that are either not accessible or accessible only with difficulty by other methods. (3) The characteristics of the enzyme and the mild polymerization conditions may permit formation of polymers having highly regular sizes and backbone structures. This report describes the first successful use of an enzyme‐catalyzed polycondensation to prepare a chiral (AA–BB)x polyesters of more than a few repeat units. Polymerization of bis(2,2,2‐trichloroethyl) alkanedioates (BB) with diols (AA) using the enzyme porcine pancreatic lipase (PPL) as a catalyst is detailed. The polycondensations were carried out at ambient temperature in anhydrous, low polarity organic solvents such as ether, THF, and methylene chloride. End group analysis by NMR provided Mn values of 1300–8200 daltons while GPC provided Mw values of 2800–14900 daltons for the polymers. Based on proton NMR spectra obtained during the polymerization, relatively rapid formation of an AA–BB “dimer” and an AA–BB–AA “trimer,” slower formation of a BB–AA–BB “trimer,” and subsequent condensation of these to give higher polymers are suggested to be components of the polymerization mechanism.

Linear A–B and AA–BB polyamides with backbone aryl, alkyl, and alkenyl units

AbstractHigh performance linear AA–BB and A–B polyamides were generated using polymerization schemes that gave polymers in higher yields and having better performance than previous methods. Polymers were characterized with FTIR, solution and solid‐state 13C‐NMR and showed the incorporation of aryl, alkyl, and alkenyl linkages in the polymer backbone. Thermal analysis showed that a significant weight percent of the polymers remained at 1000°C.

Chromosome constitution in G2 and G3 progenies of 6x-triticale × T. turgidum L. hybrids

Rye chromosome constitution and stability in a series of plants of G2 and G3 generations obtained after the cross between hexaploid triticale and durum wheat (F1: 2n=5x=35; genomes AA BB R) are studied using the zymogram phenotype expression for the following isozyme marker genes: Mdh-2c1 (1R), Cpx-c2 (2R), Got-3-c1 (3R), Pgm-c1 (4R), Est-c6 (6R), Got-2-c1 (6R), Acph-c1 (7R) and Got-1-c1 (7R). The results were corroborated using C-banding in a sample of the plant population studied and make clear the utility of biochemical methods in quick cytogenetic analysis. From the results, a different rate of transmission for each rye chromosome is inferred.

Identification of bovine kappa-casein genotypes at the DNA level.

By using a bovine kappa-Cn cDNA as probe and the PstI endonuclease we demonstrate that the DNA restriction patterns of kappa-Cn AA and kappa-Cn BB cows are different. Besides two invariant fragments (about 6.8kb and 1.1kb) the former shows two fragments of about 4.3 kb and 0.3 kb and the latter one fragment of about 4.6 kb. kappa-Cn AB cows show intermediate pattern. Therefore, it is possible to determine the bovine kappa-Cn genotypes even in absence of gene product.

Oxygen equilibrium curve shape and allohemoglobin interaction in sheep whole blood.

Adult sheep (Ovis aries) exhibit hemoglobin heterogeneity controlled by two autosomal alleles with codominant expression (Hb AA, AB, BB). Isoelectric points for Hb A and Hb B were 6.94 and 7.15, respectively; for Hb AB animals, the two allohemoglobins were present in equimolar concentrations (Hb A = 52%, Hb B = 48%). Dynamic O2 equilibrium curves (O2ECs) were generated for sheep whole blood at 39 degrees C using thin-film techniques. Half-saturation PO2 values (P50) at pH 7.50 were 31.3, 35.7, and 40.7 Torr for Hb AA, AB, and BB, respectively. CO2 Bohr coefficients at saturation (S) = 0.5 (delta log P50/delta pH) were similar for all phenotypes, ranging from -0.38 to -0.40. The Bohr slopes were also saturation independent between 0.2 and 0.8 S. Standard O2ECs for each phenotype were accurately fitted to three-constant third-order polynomial expressions. Sheep equilibrium curves were not isomorphic with other mammalian O2ECs (e.g., human and dog); sheep curves exhibited greater sigmoidicity. Furthermore, allohemoglobin interaction was not detected in heterozygous sheep. The blood O2 binding characteristics (P50, curve shape, and delta log PO2/delta pH) for Hb AB sheep and an experimental blood mixture containing equal proportions of Hb AA and Hb BB erythrocytes were equivalent.

Mixed fluoroamine complexes of chromium(III)

Mixed difluoro(diamine)(diamme)chromium(III) complexes have been synthesized with ethylenediamine (en), 1,3 propanediamine(tn) and 1,2-cyclohexanediamine(chxn):trans-[CrF2(aa)(bb)]Br (aa=en, bb=tn; aa=tn, bb= chxn) andcis-[CrF2(aa)(bb)]Br (aa=en, bb=chxn). The corresponding fluoroaqua(diamine) (diamine)chromium(III) complexes have been prepared by acid hydrolysis as perchlorate or iodide salts. All have been characterized by chemical analysis, electronic and i.r. spectra and conductivity measurements.

On the exponent of norm residue groups

We compute the exponent of some norm residue groups in the number theoretic case (global fields). We use the method of Galois cohomology and the theory of the Brauer group over global field. Let n be natural number and let K/k be Galois extension of arbitrary fields with bicyclic group G = Z/n X Z/n generated by s and t. By Hr(G, K *), r g Z, we mean the Tate cohomology groups of G with coefficients in the multiplicative group of K. We consider the following diagram of sub fields of K and relative norms: ,A. :■; K(s) = K^ N ~W = K(o We use the known structure of the third Galois cohomological groups (see [4 and 5]): (1) H3(G, K*) = Z3/B3 = NXK2* n N2K*/NK*. where the 3-cocycles are Z3 = [c = (a, b) g K* X &2*\N2aNxb = l} and the 3-coboundaries are B3 = {c= (a,b) G AT* x there exists (x, y, z) g K* X K2* X AT* such that t(x)Nlz = ax, s(y) = byN2z) . The sets Z3 and B3 are multiplicative groups through the operation (a, b)(a b') = (aa bb'). The isomorphism in (1) is induced by the map Z3 -» /VjA^* n N2KX*/NK * which sends c = (a, b) to A/2a = /Vj/b1 mod NK*. The Diophantine equation N(x) = a, g k*, x an indeterminate with value in AT, is of interest. Lemma. Let K/k be Galois extension of arbitrary fields with group G = Z/n X Z/n, n G N. If H3(G, A*) = 0, then k*/NK* has exponent at most n, that is, every nth power of k* is norm. Proof. For all g k*, the 3-cocycle c = (a, a1) is coboundary. Hence the equation N(x) — a has solution. Received by the editors January 16, 1984. 1980 Mathematics Subject Classification. Primary 12A60; Secondary 12G05, 12E15. 'This is joint work done while the first author was staying at Yale University under Swiss National Science Foundation fellowship. ©1985 American Mathematical Society 0002-9939/85 $1.00 + $.25 per page

The addition of Aegilops variabilis chromosomes to Triticum aestivum and their identification

Nine of the 14 possible single chromosome addition lines of the tetraploid species Aegilops variabilis Eig. (CuCuSvSv) to Triticum aestivum L. cv. Chinese Spring (AA BB DD) have been isolated and identified. The nine Aegilops variabilis addition lines were compared with the available addition lines of Aegilops umbellulata (CuCu) and Aegilops longissima (SvSv) to further elucidate the relationship between these two diploids and the tetraploid Aegilops variabilis. Differences were observed between the same chromosomes isolated from the diploid and the tetraploid and discussed. After taking into account banding pattern polymorphisms, Aegilops umbellulata was confirmed as the donor of the Cu genome, and evidence indicated that Aegilops longissima probably is the donor of the other genome (Sv) in the tetraploid Aegilops variabilis.

Studies on 18O2-Uptake in the Light by Entire Plants of Different Tobacco Mutants

Photorespiratory activity was measured in entire plants of five tobacco variants. These tobacco variants are: the green type N. tabacum var. John William’s Broadleaf (su/su Aur/aur or su/su Aur/Aur) the chlorophyll-deficient tobacco mutant Su/su (Su/su Aur/Aur) and the chlorophyll- deficient mutant Su/su var. Aurea (Su/su Aur/aur). Furthermore, two recently characterized phenotypes originating from N. tabacum var. Consolation namely “consolation green” (Aa Bb) and “consolation yellow-green” (aa bb). In entire plants of these phenotypes photorespiration was measured as 18O2-uptake in the light. This uptake was compared with the enhancement of CO2- fixation in the Warburg effect i. e. when the oxygen partial pressure is lowered from 21% Oz to 3% O2. The principal conclusion from these measurements is firstly that under the assay conditions which are identical for all 5 phenotypes (330 ppm CO2, 14000 lux white light and 25 °C) all five phenotypes yield considerable differences in photorespiratory activity. Furthermore, we were able to show that in the different phenotypes the global O2-uptake in the light is repartitioned to different degrees among different metabolic pathways. Thus, in JWB which is under the assay conditions the only fast growing species, only half of the measured 18O2-uptake belongs to glycolate metabolism or photorespiration proper, the other half belongs to a Mehler type reaction in which excess reducing power is eliminated apparently already at the level of photosynthetic electron transport. In the chlorophyll-deficient mutant Su/su, however, the observed 18O2-uptake in the light belongs under the assay conditions exclusively to glycolate metabolism (no Mehler type reaction). The chlorophyll-deficient mutant Su/su var. Aurea behaves more like JWB, that is, part of its 18O2-uptake is due to a Mehler type reaction and only the remainder is involved in CO2- metabolism, which has been already found out previously by genetic analysis. In addition photorespiration depends in Su/su more on the temperature than in the other phenotypes tested. One of the implications of our results could be that it makes a difference to the plant whether excess reducing power is disposed of at the level of the photosynthetic electron transport chain (via a Mehler type reaction) or at the level of CO2-metabolism.

Relationships between hemoglobin type and reproduction, lamb, wool and milk production and health-related traits in crossbred ewes.

Relationships among hemoglobin (Hb) types and production traits were examined in 294 crossbred ewes from North Country Cheviot, Dorset, Finnsheep and Romney rams, and Suffolk and Columbia-type ewes. Hb BB ewe lambs were youngest at first estrus, while Hb AA ewe lambs were oldest. Ewe lamb fertility was similar for Hb AB and Hb BB ewes, and both were superior to Hb AA ewes. When Finnsheep crossbreds were excluded, from which Hb BB was absent, Hb BB ewes had higher ewe lamb fertility than did Hb AB ewes. There was a minor advantage of the A over the B allele in ewe lamb prolificacy. Hb BB ewes were highest, Hb AB ewes were intermediate and Hb AA ewes were lowest for average fertility, prolificacy per ewe lambing, lambs born per ewe exposed to mating, total number of lambs weaned and total kilograms of lamb weaned. Grease wool production, staple length, fiber diameter grade, incidence of medullated fibers and incidence of cotted fleeces all were similar across Hb types. Likewise, Hb type did not affect milk production or composition. Ewes with Hb AB had the lowest incidence of footrot; Hb AA and Hb BB ewes were similar. Ewes with Hb AA had the lowest fecal parasite egg counts, while ewes with Hb AB or Hb BB were similar. Ewes with Hb AA also had the lowest incidence of mastitis, Hb BB ewes were intermediate and Hb AB ewes were highest. The combination of overdominance (as for footrot resistance), beneficial effects of the A allele on health-related traits (as for mastitis and parasite resistance) and the beneficial effect of the B allele on reproductive traits, if real, could partly explain the genetic polymorphism commonly reported at the Hb locus in sheep.

Genetic Markers of Resistance to Leptospirosis in Pigs of the Large White Polish Breed

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Preparation of poly amides via the phosphorylation reaction. I. Wholly aromatic polyamides and polyamide‐hydrazides

AbstractAromatic polyamides of the AB, AA–BB, and ordered copolyamide types plus aromatic hydrazide and amide–hydrazides were prepared via the phosphorylation reaction. The relationship of the molecular weight, as evidenced by the inherent viscosity values obtained, of the several polymers to the structural features and properties of the monomers used and the polymers obtained is discussed in detail. Some salient observations are that poor solubility of the rodlike polymers definitely appears to set limits to obtaining high molecular weight and strongly basic groups, e.g., —CO—NH—NH2, in monomers, prevent the attainment of high molecular weight because such groups coordinate more strongly with the phosphite complex than does the pyridine catalyst in the phosphorylation reaction. Fibers were spun from two aromatic polyamides prepared via the phosphorylation reaction. Excellent tensile properties were achieved for fiber from poly–p–benzamide (PPB) and the polyisophthalamide of 4, 4′‐methylenedianiline despite the relatively low molecular weight of these polymers (?7inh 1.6 and 1.1, respectively). The PPB fiber was spun from both isotropic and anisotropic spinning solutions. Fiber obtained from the anisotropic dope had moderately high tensile strengths (8–12 gpd) and remarkably high initial modulus values (435–745 gpd). These results indicate that polymers made by the phosphorylation route would give fibers with as high tensile properties as polymer made by the diacid chloride‐diamine polycondensation route providing that the inherent viscosities of polymer prepared by the former process could be increased to equal those by the latter process.

The Cytology of Autotetraploid Kale, <i>Brassica oleracea</i>

1. Autotetraploid kale forms from 2 to 5 quadrivalents per cell at diakinesis, with a mean of 4 per nucleus.2. Only 57% of the second metaphase plates contained 18, the balanced number of chromosomes.3. The seed fertility of autotetraploid kale is about 35% of that found in the diploid.4. Secondary associations of chromosomes were examined in the diploid and in the tetraploid.(a) A high frequency of associations of three chromosomes was found in the diploid. This was, not found by Catcheside (1937). This difference between the two sets of material appears to be a real one and is either genetical or environmental.(b) At second metaphase in the tetraploid, there are very many different types of plates containing different numbers of associations of 4, 3, and 2 chromosomes. This is to be expected from the fact that if the haploid set can be represented as AA BB CC D E F, then the diploid set in the tetraploid is AAAA BBBB CCCC DD EE FF.

Progressive Growth Stages of a Heritable Melanotic Neoplastic Disease in Fishes from the Day of Birth

The production of spontaneous melanotic overgrowths in adult hybrid fishes by genetic methods of breeding was outlined in the first of a series of papers in this journal in 1931. The system of matings employed in obtaining one-day-old hybrid fishes having the melanotic disease was presented in 1937. Briefly it is as follows. First, the spotted platyfish, Platypoecilus maculatus, is mated with the swordtail, Xiphophorus hellerii; then, the first generation melanotic hybrids are back-crossed to the swordtail or bred brother to sister. Such matings produced fishes in which evidence of melanotic neoplastic disease was detected, in a mendelian proportion of the brood, on the day of birth. The genetic symbols SpSp aa bb have been used to represent the spotted platyfish and spsp AA BB to represent the swordtail; Sp denotes the presence of large black spots composed of macromelanophores in the platyfish (Gordon 1927, 1931a); A and B denote the presence in the swordtail of hereditary factors which modify the normal growth characteristics of the macromelanophores in the intergeneric hybrids. When the melanotic hybrid fish of the first generation (SpSp Aa Bb) are back-crossed to the pure swordtail (spsp AA BB), half of the brood are normal while the other half are intensely melanotic. The intensity of melanosis in the melanotic half of the brood is not uniform. It is thought that those melanotic back-cross hybrids which exhibit an advanced state of melanosis probably have inherited, in addition to the dominant Sp factor for macromelanophores, the full complement (4) of the dominant modifying factors, Spsp AA BB; whereas those of the brood with less intense melanosis have probably inherited only 2 or 3 of the dominant modifying factors.

Inheritance of the Elytral Color Patterns of the Lady-Bird Beetle, Harmonia axyridis Pallas

1. The inheritance of elytral patterns of the lady-bird beetle, Harmonia axyridis Pall, was analyzed genetically. 2. The results tend to show that the plain yellow elytron succinea is a simple recessive to any form with black-margined patterns. 3. Among the black-margined beetles, there were three types of patterns analyzed, viz., conspicua, spectabilis and aulica. The genetic results indicate that these characters are each due to an independent Mendelian factor with conspicua epistatic over spectabilis and the spectabilis over aulica in a series. 4. In adapting the symbol A for aulica, S for spectabilis and C for conspicua, the genetic formula for succinea (also for frigida and 19-signata) is therefore aa bb cc; for aulica, AA ss cc; for spectabilis, aa SS cc. (or AA SS cc); and for conspicua, aa ss CC (or AA ss CC or aa SS CC or AA SS CC). The authors wish to express indebtedness to Dr. C. B. Bridges and to Professor Th. Dobzhansky, of the California Institute of Technology, for their suggestions of the nomenclature used in describing the different variations and for their many other constructive criticisms of this paper.