Golden Bantam Research Articles

Studies of Maize Streak Virus Isolates from Grass and Cereal Hosts in Nigeria

Maize streak virus (MSV) isolates originating from maize, other cereals, and 18 grass species in Nigeria were characterized based on symptoms, transmission, host range, and serological tests. All isolates could be transmitted to MSV-susceptible sweet corn cv. Golden Bantam using Cicadulina storeyi as a vector, but only some could be transmitted to MSV-susceptible maize cv. Pool 16 (.)

An Aromatase-Producing Sex-Cord Tumor Resulting in Prepubertal Gynecomastia

GYNECOMASTIA in prepubertal children usually results from an increase in endogenous estrogen production. Estrogen biosynthesis involves the transformation of steroid precursors to androgens and then conversion of androgens to estrogens by the enzyme aromatase. Excessive production of estrogen may result from an increase in levels of endogenous substrate, aromatase activity, or both. A model for the isolated increase in aromatase activity is the Sebright Bantam rooster, in which the aromatase activity is increased 100-fold.1 A human counterpart of the Sebright Bantam rooster has also been described in which increased aromatase activity resulted in the overproduction of estradiol and gynecomastia.2 , 3 In . . .

Lack of fructose-1,6-bisphosphatase in a range of higher plants that store starch

The aim of this work was to discover whether fructose-1,6-bisphosphatase (FBPase) is present in higher-plant cells that synthesize storage starch. The following were examined: suspension cultures of soybean (Glycine max), tubers of potato (Solanum tuberosum), florets of cauliflower (Brassica oleracea), developing endosperm of maize and of sweet corn (Zea mays), roots of pea (Pisum sativum), and the developing embryos of round and wrinkled varieties of pea. Unfractionated extracts of each tissue readily converted fructose 1,6-bisphosphate to fructose 6-phosphate in assays for both plastidic and cytosolic FBPase. These conversions were not inhibited by 20 microM-fructose 2,6-bisphosphate. Except in extracts of pea embryos and sweet-corn endosperm, treatment with affinity-purified antibodies to pyrophosphate: fructose-6-phosphate 1-phosphotransferase reduced the above fructose 6-phosphate production to the rate found with boiled extracts. The antibody-resistant activity from sweet corn was slight. In immunoblot analyses, antibody to plastidic FBPase did not react positively with any protein in extracts of soybean cells, potato tuber, cauliflower florets, maize endosperm and pea roots. Positive reactions were found for extracts of embryos of both round and wrinkled varieties of peas and endosperm of sweet corn. For pea embryos, but not for sweet-corn endosperm, the Mr of the recognized protein corresponded to that of plastidic FBPase. It is argued that soybean cells, potato tuber, cauliflower florets, maize (var. White Horse Tooth) endosperm and pea roots lack significant activity of plastidic FBPase, but that this enzyme is present in developing embryos of pea. The data for sweet corn (var. Golden Bantam) are not decisive. It is also argued that, where FBPase is absent, carbon for starch synthesis does not enter the amyloplast as triose phosphate.

Inheritance of the Henny Feathering Trait in the Golden Campine Chicken: Evidence for Allelism with the Gene That Causes Henny Feathering in the Sebright Bantam

The henny feathering mutation causes roosters to develop female feathering morphology as a result of increased conversion of androgen to estrogen (aromatase activity) in extraglandular tissues, including skin. This trait is maintained in two breeds of chickens: the Sebright Bantam and the Golden Campine. To characterize the inheritance of this trait further, we did breeding studies of the Golden Campine and identified the trait by measuring aromatase activity in biopsied skin. As previously established for the Sebright Bantam, the trait is transmitted in the Campine by an autosomal, incomplete dominant mechanism; heterozygous offspring express half the levels of extraglandular aromatase as do homozygous Campines on average. No reversions to wild-type levels were observed in 555 heterozygous offspring of crosses between homozygous Campines and normals. Compound heterozygotes for the trait were obtained by mating homozygous Sebrights and homozygous Campines. When these compound heterozygote birds were crossed to control birds, all 98 offspring had elevated aromatase activity in skin, suggesting that the traits in Sebright and Campine birds are allelic. Furthermore, the restriction fragment length polymorphism pattern performed on genomic DNA was the same in the Sebright and Campine birds. Thus, the phenotypic, endocrine, and genetic features suggest that the traits in Sebright and Campine birds are the same. The trait in the Campine probably was derived from the Sebright.

Spatial, temporal, and species-specific patterns of heterogeneity in growth chamber experiments

Despite the sophistication of contemporary growth chambers, growing conditions cannot be uniformly controlled during experiments. Uniformity trials with bean (Phaseolus vulgaris cv. Spartan) and maize (Zea mays cv. Golden Bantam) in the McGill University Phytotron identified three significant sources of variability. First, not even two identically programmed chambers of the same model and from the same manufacturer provide identical growing environments. Second, programmed environmental conditions are not precisely maintained over time even in a single chamber. Third, the growing environment within a chamber has a consistent pattern of spatial variability with poor growth in the chamber corners and best growth in the center. The importance of these effects varies with species and with the parameters measured, but none can be entirely avoided. Good experimental design with replication of treatments across chambers and blocking within chambers can minimize the negative impact of these sources of uncontrolled experimental variability.

Correlation between Root-Generated Ionic Currents, pH, Fusicoccin, Indoleacetic Acid, and Growth of the Primary Root of Zea mays

Correlations between root-generated ionic currents, extracellular pH, indoleacetic acid, fusicoccin, and growth were investigated. Current consistently entered the meristematic and elongating tissues of intact growing roots of Zea mays cv Golden Bantam. Mature root regions generated the outward limb of the current loop. Ion-substitution and pH-profile experiments suggested that the bulk of the ionic current was carried by H(+). Calcium ions did not carry current, but calcium may regulate the proton circulation since the proton current density was slightly larger in calcium-depleted media. Increased root elongation at low pH was associated with increased current density and an extended zone of inward current. Conversely decreased elongation at high pH was associated with a reduced current density and a more restricted zone of inward current. The effect of the fungal toxin fusicoccin was to increase the current density of the inward limb of the ion current and to increase root extension. Concentrations of indoleacetic acid that reduced root growth, also reduced the density of the inward current and shortened the inward current zone. The results emphasize the point that roots are electrically contiguous over many millimeters and that the electrophysiology of root growth is best studied in intact root systems.

Ion Currents and Growth Regulators in Plant Root Development.

Factors that promote (low pH and fusicoccin) or reduce (high pH and IAA) the elongation rate of intact primary roots of Zea mays cv. Golden Bantam increased or decreased, respectively, the density of positive current flowing into the meristematic and elongating tissues of the developing root apex. Mature non-growing root regions generated the outward limb of the current loop. Ion-substitution and pH-profile experiments suggested that the bulk of the ion current was carried by H+. Calcium ions did not carry a significant portion of the current, but calcium appeared to regulate the proton circulation since the current density was larger in calcium-depleted media. Increased root elongation at low pH was associated with increased current density and a basipetally extended zone of inward current. Conversely, decreased elongation at high pH was associated with a reduced current density and a more restricted zone of inward current. The fungal toxin fusicoccin increased the current density of the inward limb of the ion current and increased root extension. Concentrations of IAA that reduced growth also reduced the density of the inward current and shortened the inward current zone. The effects of both fusicoccin and IAA were dependent on the pH of the bathing medium.

Characterization of maize streak virus: description of strains; symptoms

Twenty‐four isolates of maize streak virus (MSV) derived from maize, sugarcane and grasses were compared to a maize isolate of the virus (M(N)M) from Nigeria, using symptoms, gel diffusion and ELISA. Fourteen isolates were identified as maize strains, eight other isolates were serologically related to M(N)M but were distinct. In most cases the maize strain could be identified by the symptoms in Zea mays cv. Golden Bantam but symptom expression in grasses was not always sufficient to identify the economically important maize strain. In general, however, symptoms were similar in both grass and maize hosts. Identification by symptoms alone was further complicated by the possibility that some isolates were mixtures. There was no evidence that adaptation to grass hosts occurred, as all isolates could be transmitted to maize. It was not possible to transmit certain strains to the host species from which they were derived, even though they were transmissible to other hosts. This was assumed to be related to vector feeding behaviour. Insect toxin was responsible for certain stunting symptoms, leaf curling and vein enations often associated with MSV.

Effects of N, P, and K Deficiencies on Light-dependent Anthocyanin Formation in Zea mays L. Seedlings

The effects of mineral nutrient deficiencies on light-dependent anthocyanin formation in seedlings of Zea mays L., cv. Golden Bantam were investigated. Anthocyanin accumulation in roots and shoots was significantly higher in seedlings grown on N or P deficient than on K deficient or complete nutrient solutions. However, less ethylene was produced by seedlings grown on N or P deficient solutions than by those grown on K deficient or complete nutrient media. Absorption of ethylene by permanganate or inhibition of ethylene production or action by C O 2+ or Ag + ions brought about increased anthocyanin production in roots and shoots of seedlings grown on complete and N, P, and K deficient nutrient solutions, respectively, above the anthocyanin levels found in these organs of the control plants. Elimination of differences in anthocyanin production among seedlings grown on complete, N, or K deficient nutrient solutions in the presence of permanganate or C O 2+ ions indicates that ethylene may act in a core of responses caused by N or K deficiencies. However, other factors in addition to decreased ethylene formation appear to be involved regarding higher anthocyanin production under P deficiency.

Chlorophyll Fluorescence in Leaves and Cells of Light-Grown Maize ( Zea mays) during Development

A comparison of chlorophyll a fluorescence in segments chosen from different parts of developing maize ( Zea mays L. cv. Golden Bantam) leaf show differences in the relative variable fluorescence intensities of the induction time course at room temperature (Kautsky curves). The low temperature fluorescence emission spectra of intact leaf samples and diluted powder samples which were prepared from different sections of the leaf were measured. Older leaf segments (tip) showed more variable fluorescence and less relative fluorescence of light harvesting chlorophyll a/b-protein complex and of Photosystem II chlorophyll a-protein complex at 77K compared to young leaf segments (base). These results show (1) that the functions of mesophyll and bundle sheath chloroplasts differ during development of the maize leaf (2) that the amount of chlorophyll protein complexes present varies along the maize leaf from base to tip.

Effects of growth regulators on light‐dependent anthocyanin production in Zea mays seedlings

Rengel, Z. and Kordan, H. A. 1987. Effects of growth regulators on light‐dependent anthocyanin production in Zea mays seedlings.The effects of ethylene, indolyl‐ and naphthylacetic acids, zeatin, benzyladenine, gib‐berellic acid and triiodobenzoic acid on anthocyanin production in seedlings of Zea mays L. cv. Golden Bantam were investigated. Endogenously produced and exogen‐ously supplied ethylene, as well as the other growth regulators tested markedly suppressed anthocyanin formation. Except for triiodobenzoic acid, the other growth regulators stimulated ethylene production, the amounts produced in the light being larger than those in the dark. Absorption of ethylene by permanganate as well as inhibition of ethylene production or action by Co2+ or Ag+ increased anthocyanin formation in maize seedlings above the level found in the control plants. The inhibiting effect of auxins and cytokinins on anthocyanin production was reversed by Co2+ or Ag+. In contrast, decreased anthocyanin formation caused by gibberellic acid or triiodobenzoic acid seemed unrelated to ethylene and could not be alleviated by Co2+ or Ag+.

Reversal of Abscisic Acid-Induced Stomatal Closure by trans-Cinnamic and p-Coumaric Acid

Abscisic acid (ABA)-induced increase in stomatal diffusive resistance (SDR) in excised leaves of bean (Phaseolus vulgaris L. cv Pencil Pod) and maize (Zea mays L. cv Golden Bantam) is inhibited by low concentrations of trans-cinnamic acid (TCA) (1 micromolar) and p-coumaric acid (PCA) (10 micromolar) when given together with ABA (10 micromolar) in the transpiration stream through the cut end of the petiole or leaf blade. A concentration effect is observed both in the ABA action and its reversal by phenolic acids. Leaves having attained a high diffusive resistance in ABA solution recover rapidly when transferred to water. ABA (10 micromolar) induced closure of the stomata in onion, Allium cepa L. and Vicia faba epidermal peels. This is associated with loss of K(+) from guard cells. In the presence of TCA (10 micromolar) and PCA (10 micromolar) K(+) is retained in the guard cells with open stomata. The dark closure of stomata is also inhibited by TCA and PCA. It is suggested that these phenolic acids may inhibit the ABA effect by competing with or acting on some ABA-specific site, probably located on the plasma membrane, regulating flux of K(+) ions. A weak association of ABA with the plasma membrane is envisaged because of the rapid recovery obtained upon transferral of the leaves to water.

5-Azacytidine and sodium butyrate induce expression of aromatase in fibroblasts from chickens carrying the henny feathering trait but not from wild-type chickens.

Male chickens with the henny feathering trait have a female feathering pattern. In two henny-feathered breeds, the Sebright bantam and the Golden Campine, the synthesis of estrogen is increased as a consequence of increased activity of aromatase, a cytochrome P-450 enzyme that converts androgen to estrogen. The activity of the enzyme is elevated in tissue slices and in cultured fibroblasts from heterozygous and homozygous birds of both breeds. In contrast, aromatase activity is very low in extraglandular tissues from control chickens and is undetectable in fibroblasts cultured from these tissues. The current studies show that two agents known to alter gene expression--5-azacytidine and sodium butyrate--markedly induce expression of aromatase activity in Sebright and Campine fibroblasts but have no effect on aromatase activity in fibroblasts from wild-type chickens. Induction of aromatase is specific since two other microsomal enzymes in chicken fibroblasts--one, a component of the aromatase enzyme complex and the other a cytochrome P-450 oxidase distinct from the aromatase--are not significantly affected by these agents. Further study of this unique mutation should provide insight into the mechanisms by which genes are switched to an uninducible state during differentiation.

The Nuclear Endoreduplication Cycle in Metaxylem Cells of Primary Roots of Zea mays L.

The nuclear DNA content of metaxylem cells in roots of Zea mays cv. Golden Bantam reaches 16C or 32C by successive rounds of DNA endoreduplication. Each phase of endoreduplication (endo-S) is separated by a non-DNA synthetic phase (endo-G). These phases seem to occur in zones at fixed distances from the root tip. The duration of the phases in two of the endoreduplication cycles (4C–8C, 8C–16C) has been estimated in two ways. The first makes use of the rate of movement of cells through the positions along the root where the different phases of the cycle are occurring, the second uses labelling with methyl-[3H]thymidine and autoradiography. Both methods indicate that the endo-S phases which cause the nuclear DNA content to rise from 4C to 8C and from 8C to 16C last 8–10 h, and that the intervening endo-G phase lasts 8–12 h. DNA endoreduplication keeps pace with the increase of nuclear volume; cell volume increases at a more rapid rate, however. Comparison of the endoreduplication cycle in the metaxylem with the mitotic cycle in the adjoining files of parenchyma cells shows that the mitotic cells complete their cycle more slowly.

Pyruvate Orthophosphate Dikinase mRNA Organ Specificity in Wheat and Maize

Polyadenylated RNA was isolated from leaves and seeds of a C(3) plant (Triticum aestivum L. cv Cheyenne, CI 8885) and from a C(4) plant (Zea mays L. cv Golden bantam). Each polyadenylated RNA preparation was translated in vitro with micrococcal nuclease-treated reticulocyte lysate. When the in vitro translation products were probed with antibodies to pyruvate orthophosphate dikinase (PPDK) (EC 2.7.9.1), two sizes of polypeptide were identified. A 110 kilodalton polypeptide was found in the in vitro translation products of mRNA isolated exclusively from leaves of both wheat and maize. A 94 kilodalton polypeptide, similar to the PPDK polypeptide which can be extracted after in vivo synthesis in maize and wheat leaves and seeds, was found in the in vitro translation products obtained from wheat seeds and maize kernels.These results indicate that the mRNAs for PPDK polypeptides are organ-specific in both a C(4) and a C(3) plant. Hague et al. (1983 Nucleic Acids Res 11: 4853-4865) proposed that the larger size polypeptide of the in vitro translation polypeptide from maize leaf RNA contains a ;transit sequence' which permits entry into the chloroplasts of a polypeptide synthesized in vivo in maize leaf cell cytoplasm. It appears that in wheat leaves also the transit of synthesized PPDK polypeptide through an intracellular membrane may be required, while such a transit sequence seems not to be required within cells of wheat and maize seeds.

Antifeeding potency of neem formulations

Abstract Ethanolic extracts of fresh neem seeds were formulated as aqueous suspensions and defatted ground neem kernels were formulated as non‐wettable dusts for greenhouse studies with fall army‐worm larvae, Spodoptera frugiperda (J. E. Smith). First stage larvae of the fall armyworm were fed neem‐treated Golden Bantam sweet corn. The antifeeding potency of 0.2 and 0.4% aqueous solutions of the neem seed extract was maintained for at least 21 days. Tests with formulated dusts showed moderate activity against 1st stage fall armyworm larvae.

Inheritance of the henny-feathering trait of the Sebright bantam chicken.

The henny -feathering trait of the Sebright bantam chicken is the result of an enhanced rate of estrogen synthesis (aromatase activity) in skin and other peripheral tissues of this bird. To gain insight into the underlying nature of this mutation, we examined the inheritance of this trait using a sensitive isotopic assay for aromatase activity. All birds of the F1 generation obtained by crossing homozygous henny X non- henny chickens expressed increased aromatase in the skin, and the males exhibited henny -feathering plumage. The average rate of aromatase activity in the skin of F1 chicks was approximately half that of homozygous henny chicks. The distribution of increased aromatase activity in the F2 generation and in the backcrosses of F1 to the two types of parental strains suggest that the enzyme activity in extragonadal tissues is regulated predominantly by one autosomal gene. Attempts to demonstrate linkage to several known loci by backcrossing F1 heterozygotes with parental chickens carrying a variety of genetic markers were unsuccessful. We conclude that the enhanced estrogen synthesis in extragonadal tissues in chickens carrying this gene is inherited as an autosomal codominant but that a half maximal level of the enzyme is sufficient to allow full development of female feathering in affected male birds so that henny -feathering is transmitted as a dominant trait.

Responses of Selected Plant Species to Elevated Carbon Dioxide in the Field

AbstractIt has become of interest to study long‐term effects of CO2 concentration on plant growth, because intensive burning of fossil fuels and destruction of forests promise to continue the recent rise in atmospheric partial pressures of CO2 into the next century (Bolin, 1977; Stuiver, 1978). Effects of CO2 enrichment on growth of crop and forest species were therefore studied for the first time in the field in open top exposure chambers at daytime mean CO2 concentrations of 612, 936, 1292, and 1638 mg m−3, and in ambient control plots. Increased growth of plant parts of corn (Zea mays L. ‘Golden Bantam’), soybean [Glycine max L. (Merr.) ‘Ransom’], loblolly pine (Pinus taeda L.), and sweetgum (Liquidambar styraciflua L.) were recorded. Growth increases for soybean and sweetgum in elevated CO2 atmospheres were due to increases in leaf area and photosynthesis per unit leaf area, and decreases in conductance and, therefore, water use. For corn, however, photosynthesis was unaffected by CO2 enhancement, and growth stimulation appeared to be due to lowered conductance and increased water use efficiency alone.

Characterization of the increased estrogen synthesis in skin fibroblasts from the sebright bantam

We have utilized the Sebright bantam chicken as a model system to explore the regulation of estrogen formation in peripheral tissues. As the result of a gene mutation, Sebright males develop a female feathering pattern associated with an increase in estrogen synthesis in skin and in fibroblasts cultured from skin. To provide insight into the mechanisms by which estrogen synthesis is increased we examined several parameters of the aromatase reaction in homogenates from control ovaries, Sebright ovaries and fibroblasts grown from Sebright skin: the pH optima; the apparent f m 's for testosterone, 19-nortestosterone, androstenedione, 16-hydroxyandrostenedione, and NADPH; the apparent K i 's for 4-hydroxyandrostenedione, aminoglutethimide, dehydroepiandrosterone, and 19-hydroxytestosterone; and the inactivation of the reaction by heating. No qualitative differences were identified in the enzyme from Sebright and control birds.

Developmental Pattern of Increased Aromatase Activity in the Sebright Bantam Chicken*

Feathers in the male Sebright bantam chicken are feminized as the result of a mutation that causes an increase in the capacity for estrogen synthesis (aromatase activity) in skin. To determine when during development the increased aromatase activity is expressed, we measured the enzyme in tissue slices of Sebright bantam and control bantam chickens of days 3, 12, and 18 of embryogenesis, on day 1 after hatching, and in mature birds. An assay was used that measures the release of 3H2O from [1 beta-3H]testosterone during the aromatization process. Aromatase activity was expressed in the 3-day-old Sebright embryos, but was not detectable in control embryos of the same age. In older embryos and birds, aromatase activity was assayed in multiple tissues. Enzyme activity was detectable in all tissues examined from day 12 and day 18 Sebright embryos. In control embryos, aromatase was detectable in ovarian but not in extraglandular tissues. The enzyme activity in most tissues of the Sebright decreased within 1 day after hatching and continued to decrease thereafter so that in the adult Sebright, aromatase activity was high only in skin (and skin appendages) and ovary. We conclude that the normal allele of this gene acts to limit the rate of estrogen formation in extraglandular tissues.