Line x tester analysis for fixed effect model in cotton (Gossypium hirsutum L.)

Summary The data from an experiment in cotton consisting of three testers and 12 lines selected deliberately have been analysed. The investigation showed higher specific combining ability variance for yield of seed cotton and number of bolls, indicating the predominance of non-additive gene action. Of parental lines, H777 was found to possess high g.c.a. effects for seed cotton yield, number of bolls and number of sympodes. Parent H842 contributed only for boll weight, whereas H655 was good general combiner for number of monopodes. There appeared to be better chances for increasing the yield by exploiting hybrid vigour for the number of bolls and boll weight. The presence of marked non-additive gene effects, in addition to additive gene effects, indicated the need for exploiting both the fixable and non-fixable components of genetic variance for increasing productivity in cotton.     

Abscisic-acid-induced turion formation in Spirodela polyrrhiza L. IV. Comparative ion flux characteristics of the turion and the vegetative frond and the effect of ABA during early turion development

Abstract Using the method of compartmental analysis, the ion fluxes and compartment concentrations of Ca²⁺, K⁺ and Cl^- have been compared in the untreated vegetative frond and the abscisic acid (ABA) induced turion of Spirodela polyrrhiza. The ABA-induced turion is characterized by reduced Ca²⁺ exchange across the tonoplast and low vacuolar Ca²⁺ concentration relative to the vegetative frond. In addition the turion exhibits a higher plasmalemma flux with a correspondingly high Ca²⁺ concentration in the cytoplasm. The concentration of K⁺ and Cl^- is much lower in the cytoplasm of the ABA-induced turion than in the vegetative frond with the influx/efflux ratio at both the plasmalemma and the tonoplast being less than 1, a finding exhibited also in dormant storage tissue. Treatment of vegetative fronds with ABA for 18 h resulted in a reduced K⁺ plasmalemma efflux relative to untreated vegetative fronds and a concomitant increase in the cytoplasmic concentration. There was no rapid effect of ABA on Ca²⁺, K⁺ or Cl^- fluxes through either membrane. These results are consistent with the notion that drastic changes in ion fluxes and concentrations in the turion are a secondary consequence of ABA-induced development, possibly due to prior regulation by ABA of enzymes inherent to processes involved in membrane transport.     

Calcium fluxes at plasmalemma and tonoplast

Abstract. An account is given of the characterization of calcium fluxes across plasmalemma and tonoplast membranes of root cortical cells, using compartmental analysis. Some of the assumptions associated with the method are discussed. Recent evidence regarding the concentration of free Ca²⁺ in plant cells, and the mechanisms driving active calcium transport across cell membranes, is reviewed. It is proposed that the evidence from whole cell studies and work at the molecular level is mutually supportive, and some speculation is ventured about the general pattern of calcium transport in higher plant cells.     

In vitro autoradiographic localization of vasoactive intestinal peptide (VIP) binding sites in the rat central nervous system

This paper describes the autoradiographic distribution of VIP binding sites in the rat central nervous system using monoiodinated ¹²³I-labeled VIP. High densities of VIP binding sites are observed in the granular layer of the dorsal dentate gyrus of the hippocampus, the basolateral amygdaloid nucleus, the dorsolateral and median geniculate nuclei of the thalamus as well as in the ventral part of the hypothalamic dorsomedial nucleus.     

Relationship of alpha MSH-specific neurons to the arcuate opiocortin neuronal system as determined by dual antigen immunocytochemical procedures

The cross-immunoreactivity, topography, and fiber projections of the alpha MSH-immunoreactive specific neurons in the forebrain of the rat appear to be distinctly different from that of the neurons in the hypothalamic arcuate opiocortin system. The cell bodies, immunoreactive only to -MSH, have a specific pattern of distribution in the dorsal and lateral hypothalamic regions from the level of the retrochiasmatic region to the premammillary area of the posterior hypothalamus. Immunoreactive fibers of these cells appear to extend into regions of the cerebral cortex and hippocampus. An antomical relationship between the immunostained fibers and/or terminals of the arcuate opiocortin pool of neurons and the -MSH-immunoreactive perikarya is described utilizing the ABC (Avidin-Biotin-Peroxidase Complex) and ABC-GO (Glucose Oxidase) or glucose oxidase-antiglucose oxidase complex methods of immunocytochemistry in which two tissue antigens with contrasting colors are demonstrated in the same tissue section.     

Stimulus coding in crayfish antennal mechanoreceptors estimated by noise analysis

Two different kinds of mechanoreceptive hairs (smooth and feathered) on the second antennae of the freshwater crayfish, Orconectes virilis, have been investigated for their stimulus coding propertics. These mechanoreceptors show a great deal of non-linear behaviour both in threshold and in directionality. An effective appraoch for the investigation of such systems is noise analysis in the frequency domain. This method has been used here to calculate zero-, first- and second-order kernels. Sensory cells reveal different first- and second-order kernels, depending on which type of hair is being stimulated. The first-order kernel has a pronounced peak in the frequency response at 110 Hz if a feathered hair is stimulated and at 60 Hz if a smooth hair is stimulated. The second-order kernel shows a number of pronounced peaks in the frequency response between 40 and 110 Hz, but only if a feathered hair is stimulated. Smooth hair stimulation results in less sharp peaks but in higher gain for the same range of stimulus frequencies.     

Localisation and measurement of VIP in the genitourinary system of man and animals

VIP is present in the genitourinary system of man and animals. In man the highest concentrations are found in the penis, the uterus and vagina and in the urinary bladder. VIP nerves heavily innervate the erectile tissue of the male external genitalia, the uterine smooth muscle and blood vessels, the seromucous glands of the cervix, and the lamina propria and vaginal epithelium. In the urinary bladder, VIP nerves are located beneath the transitional epithelium, in the lamina propria and in the smooth muscle. Other areas well innervated by VIP nerves include the prostate, seminal vesicles and vasa deferentia. Chemical (phenol- and 6-OHDA) or surgical (hypogastric or pelvic nerve section) extrinsic denervation fail to deplete the genitourinary system of its VIP content, supporting the view that VIP-containing nerves originate from local ganglion cells. Indeed, neuronal cell bodies containing VIP are seen in the paracervical ganglia of the female genitalia, the para- or intramural bladder ganglia and scattered through the base of the cavernosum body, the neck of the bladder and the prostate. The finding of elevated levels of VIP in the local circulation after induced penile erection in man and mammals and the ability of VIP to relax the detrusor muscle of the bladder suggests that the peptide may be involved in penile erection and bladder relaxation, as does the marked VIP depletion in the penis or bladder in patients suffering from diabetic impotence or bladder instability.     

A circular waveguide irradiation system for nonhuman primates: design and dosimetry

A 275-MHz exposure system, consisting of a circular waveguide irradiator and a transparent plastic animal cage, has been developed to accommodate rhesus monkeys weighing up to 15 kg. The vertically oriented waveguide is composed primarily of stainless steel and is fitted with an inner cage fabricated from a tubular section of acrylic plastic. Circularly polarized electromagnetic energy at 275 MHz, either pulsed or continuous wave (CW), can be propagated from the removable top section of the waveguide. The cage is designed to function as the monkey's permanent home. It is fitted with a lever-actuated behavioral performance device on which the monkey responds according to a predetermined schedule to obtain a daily food ration. The system can be adapted to provide for the collection of metabolic and physiologic data as well. Dosimetric measurements were conducted with six rhesus monkeys weighing 3.0-7.2 kg and with a 4-kg model. The dosimetric results show that about one-third of the net incident energy is absorbed by a subject in this system at a normalized specific absorption rate (SAR) of 0.33 (W/kg)/(mW/cm2).     

The chloride requirement for photosynthetic oxygen evolution. Analysis of the effects of chloride and other anions on amine inhibition of the oxygen-evolving complex

In the presence of Cl^?, the severity of ammonia-induced inhibition of photosynthetic oxygen evolution is attenuated in spinach thylakoid membranes (Sandusky, P.O. and Yocum, C.F. (1983) FEBS Lett. 162, 339–343). A further examination of this phenomenon using steady-state kinetic analysis suggests that there are two sites of ammonia attack, only one of which is protected by the presence of Cl^?. In the case of Tris-induced inhibition of oxygen evolution only the Cl^? protected site is evident. In both cases the mechanism of Cl^? protection involves the binding of Cl^? in competition with the inhibitory amine. Anions (Br^? and NO^?₃) known to reactive oxygen evolution in Cl^?-depleted membranes also protect against Tris-induced inhibition, and reactivation of Cl^?-depleted membranes by Cl^? is competitively inhibited by ammonia. Inactivation of the oxygen-evolving complex by NH₂OH is impeded by Cl^?, whereas Cl^? does not affect the inhibition induced by so-called ADRY reagents. We propose that Cl^? functions in the oxygen-evolving complex as a ligand bridging manganese atoms to mediate electron transfer. This model accounts both for the well known Cl^? requirement of oxygen evolution, and for the inhibitory effects of amines on this reaction.     

Purification and characterization of two essential cytochromes of the thiosulphate-oxidizing multi-enzyme system from Thiobacillus A2 (Thiobacillus versutus)

Four c-type cytochromes were purified by several procedures including chromatography on DEAE-Sepharose CL-6B, Phenyl-Sepharose CL-4B and Sephadex G-75, G-100 and G-200 and chromatofocusing. Cytochrome c-551 had a pI value of 5.2 and an M_r of 260 000 consisting of six non-covalently bound polypeptides each with an M_r of 43 000, and contained four to five haems. Cytochrome c-552.5 had a pI value of 4.8 and an M_r of 56 000 consisting of two polypeptides with the same M_r 29 000, and contained two haems. Cytochromes c-551 and c-552.5 were reduced by ascorbate to about 70 and 60% of the fully dithionite-reduced values, respectively, and both were essential components in the thiosulphate-oxidizing multi-enzyme system (other components of the system were ‘enzyme A’, ‘enzyme B’ and sulphite: cytochrome c oxidoreductase). These two cytochromes functioned as electron carriers and effectors in the oxidation of thiosulphate. Some evidence suggested that cytochrome c-551 might be a specialized electron transfer component for sulphonate-sulphur oxidation. Both cytochromes could be reduced by thiosulphate in the presence of enzymes A and B. Cytochrome c-550 (basic) and cytochrome c-550 (acidic) were small proteins with M_r 15 000 and 14 000 and pI values of over 8 and 5, respectively. Their physiological role is uncertain.