Possible antagonism of (Z)‐2‐hexenyl (E)‐3‐hexenoate against the attractiveness of (E)‐2‐hexenyl (Z)‐3‐hexenoate to Ooencyrtus nezarae (Hymenoptera: Encyrtidae)

Ooencyrtus nezarae (Hymenoptera: Encyrtidae) is an egg parasitoid of bean bug Riptortus pedestris (Hemiptera: Alydidae) which is a major pest of beans. Females of O. nezarae are attracted to (E)‐2‐hexenyl (Z)‐3‐hexenoate (EZ), one of the components of aggregation pheromone of R. pedestris. Effects of three isomers (ZE, EE and ZZ) of EZ on the attractiveness of O. nezarae were tested using electroantennography (EAG) and field bioassays. EAG analyses revealed that the response of O. nezarae to ZE was significantly higher than those to air, hexane and two other isomers, even though the response was lower than that to EZ. ZE affected the attractiveness of EZ dose‐dependently in the field. Addition of ZE (100 mg) to EZ (10 mg) caused a significant reduction in the catches of O. nezarae females. Single or binary addition of two other isomers (EE and ZZ) to EZ could not decrease or increase significantly the number of O. nezarae catches of EZ. Even though addition of ZZ (10, 50 or 100 mg) to EZ (10 mg) caused dose‐dependent reduction in the number of O. nezarae female catches, the reductions were not significantly different from that of EZ. EZ and its three isomers were not attractive to O. nezarae males at all.     

Helix coil transitions of d (A)n·d(T)n,d(A-T)n·d(A-T)n,and d(A-A-T)n·d(A-T-T)n; evaluation of parameters governing DNA stability

The thermally induced helix-coil transitions of three A-T DNAs, d(A)_n·d(T)_n, d(A-T)_n·d(A-T)_n, and d(A-A-T)_n·d(A-T-T)_n, were studied. Experimental transition curves of the DNAs were analyzed using the loop entropy model of DNA melting. The calculation of the melting curve of d(A-A-T)_n·d(A-T-T)_n is presented using the integral equation formalism of Goel and Montroll. The aim of this work was to evaluate thermodynamic parameters which govern DNA stability and to test the theoretical model employed in the analysis. Our results show (1) an excellent over-all agreement between theory and experiment, (2) a loop entropy exponent k = 1.55 ± 0.05 provided the best fit to all the polymer transition curves, (3) the evaluated stacking free energies reflect the relative stability of the DNAs, and (4) the stacking energies of the ApA·TpT dimer evaluated from d(A)_n·d(T)_n and d(A-A-T)_n·d(A-T-T)_n differ. The last result is consistent with different conformations for the dimer in these two polymers.     

Interaction of poly(I)·poly(C) with trans-dichloro-diammine-platinum (II)

The covalent binding of trans-Pt (NH₃)₂Cl₂ to the double-stranded poly(I)·poly(C) follows three types of reactions, depending on r_b and the concentration of polynucleotide in the reaction mixture. At r_b ? 0.1, the principal reaction is coordination to poly(I), giving rise to some destabilization of the double strand, as shown by uv and CD spectra, and a decrease in T_m values, giving rise to free loops of poly(C). At higher r_b and low polynucleotide concentration, the free cytidine bases react with platinum bound on the complementary strand to form intramolecular (interstrand) crosslinks that restabilize the double-stranded structure. At high r_b and high polynucleotide concentration, while the above reaction still occurs, the predominant one is the formation of intermolecular crosslinks. Under no conditions has strand separation been observed.     

Synthesis by Ring‐Closing Alkyne Metathesis with Selective Hydrogenation,and Olfactory Comparison of (7E)‐ and (7Z)‐Cyclohexadec‐7‐enone (Aurelione®)

Both C?C‐bond isomers of cyclohexadec‐7‐enone ( 6 , Aurelione^®) were selectively synthesized via cyclohexadec‐7‐ynol ( 16 ) by ring‐closing alkyne metathesis of icosa‐2,18‐diyn‐9‐ol ( 15 ), employing an in situ‐formed catalyst from Mo(CO)₆ and 4‐(trifluoromethyl)phenol. Pyridinium chlorochromate (PCC) oxidation and subsequent Lindlar hydrogenation afforded the (7Z)‐configured isomer (7Z)‐ 6 , while hydrosilylation of the intermediate cyclohexadec‐7‐ynone ( 17 ), followed by desilylation, provided the (7E)‐configured cyclohexadec‐7‐enone ((7E)‐ 6 ). The substrate for the alkyne metathesis was prepared from cycloheptanone ( 7 ) by cycloaddition of chloromethylcarbene to its trimethylsilyl enol ether 8 , and subsequent ring enlargement of the adduct 9 under rearrangement to 2‐methylcyclooct‐2‐enone ( 10 ), which was subjected to Weitz? Scheffer epoxidation and Eschenmoser? Ohloff fragmentation to non‐7‐ynal ( 12 ). Its reaction with the Grignard reagent of 11‐bromoundec‐2‐yne ( 14 ), prepared from the corresponding alcohol 13 by Appel? Lee bromination, furnished the icosa‐2,18‐diyn‐9‐ol ( 15 ). While both isomers of cyclohexadec‐7‐enone ( 6 ) possess warm and powdery musk odors with tobacco‐type ambery accents, (7Z)‐ 6 is more animalic and waxy, whereas (7E)‐ 6 was found to be more floral, sweet, and hay‐like in tonality. Interestingly, however, with odor detection thresholds of 2.0 ng/l air and 2.3 ng/l air, respectively, both (7Z)‐ 6 and (7E)‐ 6 were found to be almost identical in their odor strength, with the (7Z)‐ 6 being only very slightly more powerful.     

Identification of interleukin‐16 (IL‐16) and interleukin‐17D (IL‐17D) genes from Dabry's sturgeon (Acipenser dabryanus)

Dabry's sturgeon (Acipenser dabryanus) represents an ancient Actinopterygian lineage that are termed “living fossils”. Many diseases have been found in Dabry's sturgeon. In the present study, genes encoding interleukin (IL)‐16 and IL‐17D in Dabry's sturgeon were identified by RNA‐sequencing. Phylogenetic tree analysis suggested that they clustered together with the corresponding pro‐IL‐16 proteins and IL‐17D proteins from other fish. Sequence analysis revealed that IL‐17D protein was more conserved than pro‐IL‐16. Dabry's sturgeon pro‐IL‐16 contains four putative PDZ domains and do not include signal peptides, while IL‐17D only possesses signal peptides (1–25 aa). The expression patterns of IL‐16 and IL‐17D genes were investigated in Dabry's sturgeon to reveal their functions in disease. The expression level of IL‐16 showed no significant changes in embryos; however, the high expression level of IL‐17D at 0–14 hpf (hours post fertilization) implied the existence of maternal expression in the oocyte and an association with embryonic development. Tissue distribution analysis revealed that IL‐16 and IL‐17D proteins have potential functions in immune and non‐immune tissue compartments. IL‐16 and IL‐17D had different fold changes in primary spleen leukocytes after polyinosinic:polycytidylic acid (poly I:C) and lipopolysaccharide (LPS) administration, which suggested that IL‐16 has a stronger antiviral capability compared with its antibacterial response, and IL‐17D has a stronger antibacterial capability compared with its antiviral response. IL‐16 showed an earlier response to virus compared with IL‐17D, and IL‐17D showed earlier and shorter response to bacteria compared with IL‐16. Our findings suggested the roles of IL‐16 and IL‐17D in Dabry's sturgeon, and provided the theoretical basis for the prevention and control of diseases of Dabry's sturgeon.     

Interferon induction by platinum(II)-poly(I)·poly(C) complexes

The effect of the interaction between poly(I)·poly(C) and cis-dichloro-diammineplatinum(II) (cis-Pt), its trans analogue and chloro-diethylene-triamminoplatinum(II) (dien-Pt) on interferon induction activity was investigated. The covalent monodentate fixation of the three compounds on N⁷ of inosine has different effects on the structure and thermostability of poly(I)·poly(C) which is well reflected by the interferon induction activity of the samples. Thus, the sandwich stabilization by dien-Pt at low binding ratios is manifested by an increased interferon induction and a high resistance towards RNAase degradation. The destabilization of the duplex by cis-Pt decreases interferon induction, accompanied by an increase in RNAase sensitivity of the complexes. In the case of trans-Pt the duplex structure is little perturbed and interferon induction is essentially maintained.     

Polymer‐Supported Optically Active fac(S)‐Tris(thiotato)rhodium(III) Complex for Sulfur‐Bridging Reaction With Precious Metal Ions

The optically active mixed‐ligand fac(S)‐tris(thiolato)rhodium(III) complexes, Δ_L‐fac(S)‐[Rh(aet)₂(L‐cys‐N,S)]^? (aet = 2‐aminoethanethiolate, L‐cys = L‐cysteinate) ( 1 ) and Δ_LL‐fac(S)‐[Rh(aet)(L‐cys‐N,S)₂]^2? were newly prepared by the equatorial preference of the carboxyl group in the coordinated L‐cys ligand. The amide formation reaction of 1 with 1,10‐diaminodecane and polyallylamine gave the diamine‐bridged dinuclear Rh(III) complex and the single‐chain polymer‐supported Rh(III) complex with retention of the Δ_L configuration of 1 , respectively. These Rh(III) complexes reacted with Co(III) or Co(II) to give the linear‐type trinuclear structure with the S‐bridged Co(III) center and the two Δ‐Rh(III) terminal moieties. The polymer‐supported Rh(III) complex was applied not only to the CD spectropolarimetric detection and determination of a trace of precious metal ions such as Au(III), Pt(II), and Pd(II) but also to concentration and extraction of these metal ions into the solid polymer phase. Chirality 28:85–91, 2016. © 2015 Wiley Periodicals, Inc.     

The crystal structures of 4,4′-bipyridinium μ-(4,4′-bipyridine)bis[diaquatetranitratoneodymate(III)]-tris(4,4′-bipyridine) and a second monoclinic form of triaquatrinitratoholmium(III) – bis (4,4′-bipyridine)

The structures of (4-bipyH)₂[(μ-4-bipy)Nd₂(NO₃)₈(H₂O)₄]·3(4-bipy) (4-bipy = 4,4′-bipyridine; P2₁/c, a = 18.723(10), b = 10.720(6), c = 18.027(10) Å, β = 94.43(5)°, Z = 2; R = 0.066 for 4931 (diffractometer data) and of a second monoclinic form of [Ho(NO₃)₃(H₂O)₃]·2(4-bipy) (P2₁/c, a = 15.830(10), b = 21.44(3), c = 15.70(3) Å, β = 100.4(2)°, Z = 8; R = 0.091 for 2335 film data) are reported. In the first compound pairs of Nd atoms are bridged across a crystal inversion centre by a 4-bipy ligand, and 10-coordination is completed by one monodentate NO₃, three bidentate NO₃, and two H₂O ligands, with bond lengths Nd---N 2.70, Nd---OH₂(av.) 2.44, Nd---O(NO₃, av.) 2.56 Å. The second compound has a variant of the previously-reported monoclinic [Y(NO₃)₃(H₂O)₃]·2(4-bipy) structure, with doubling of the unit cell on a but with essentially no change in the geometry and orientation of the nine-coordinate complex. In both compounds the non-coordinated, non-protonated 4-bipy N atoms form hydrogen bonds with ligand H₂O.     

Interaction of poly(I) and poly(I)·poly(C) with chlorodiethylenetriamino platinum(II) chloride

The fixation of dien-Pt on poly(I)·poly(C) leads to only minor changes in the uv and CD spectra at ambient temperature, showing that there is little perturbation of the secondary structure in the r_b range studied (up to 0.30). However, the melting profiles show two steps. The T_m for strand separation increases linearly from 61°C (r_b = 0) to 80°C (r_b = 0.18), after which it declines on further increasing the r_b. The second melting step is not complete at 100°C, and the magnitude of the absorbance change in this second step also appears to be at a maximum at r_b = 0.18. Although dien-Pt can only coordinate to one base, the nmr spectra at 80°C also show a second type of interaction with the adjacent bases, which is only destroyed in the presence of a strong denaturing agent, 5M guanidinium hydrochloride. From these results and the spectrophotometric data, we observe that dien-Pt forms a triple sandwich by hydrogen bonding of the platinum amino groups to the adjacent hypoxanthine bases (N⁷). The presence of these hydrogen bonds accounts for the increased stability (maximal at one Pt to three hypoxanthine bases) and their rupture is seen in the second melting step. No interaction has been observed with poly(C) strand. Reaction of dien-Pt with poly(I) shows the formation of the same triple sandwich structure in the nmr spectra.     

Proton NMR study of the interaction of cis-dichloro-diamine-platinum(II) with poly(I) and poly(I)·poly(C)

The fixation of cis (NH₃)₂Cl₂Pt(II) to poly(I)·poly(C) leads to the formation of two complexed species. One involves coordination to a single base (accounting for about 70% of the total platinum bound over the r_b range 0.07–0.25) and the other to two bases which are not adjacent to each other but may be on the same strand and separated by a loop. Reaction of the platinum compound with poly(I) gives in addition to the above two species a minor one (about 15%, independent of r_b over the range 0.05–0.30) in which the platinum is bound to two adjacent bases. The availability of such coordination reduces the dominance of the 1:1 species, which, however, remains the major one (ca. 55%).     

Biosynthesis of (1→3),(1→4)-β-glucan in developing endosperms of barley (Hordeum vulgare)

A (1→3),(1→4)-β-glucan synthase catalysing the synthesis of (1→3),(1→4)-β-glucan (mixed-linkage glucan) was investigated using microsomal membranes prepared from developing barley (Hordeum vulgare L. cv. Shikokuhadaka 97) endosperms harvested 21 days after flowering. The microsomal fraction produced (1→3),(1→4)-β-glucan by incorporation of [¹⁴C]Glc from UDP-[¹⁴C]Glc. The production of (1→3),(1→4)-β-glucan was ascertained by specific enzymatic digestion with endo-(1→3),(1→4)-β-glucanase (lichenase; EC 3.2.1.73) from Bacillus amyloliquefaciens, which released a radiolabelled trisaccharide (3-O-β-cellobiosyl-glucose) and a tetrasaccharide (3-O-β-cellotriosyl-glucose), the diagnostic oligosaccharides for the identification of (1→3),(1→4)-β-glucan. Digestion of the products with exo-(1→3)-β-glucanase (EC 3.2.1.58) from Basidiomycete QM806 released radiolabelled Glc, indicating that not only (1→3),(1→4)-β-glucans but also (1→3)-β-glucans (callose) had been formed due to the presence of (1→3)-β-glucan (callose) synthase (EC 2.4.1.34) in the microsomal fraction. The activity of (1→3),(1→4)-β-glucan synthase was maximal at pH 9.0 and at 25°C and in the presence of at least 2 mM Mg²⁺. The apparent K_m and V_max values for UDP-Glc were 0.33 mM and 480 pmol min⁻¹ mg protein⁻¹, respectively. Investigating the dependence of enzyme activity on developmental stage (7–35 days after flowering) of the endosperms, we found an increase of activity during the initial development reaching a maximum at 19 days, followed by a gradual decrease as the endosperms matured. The amount of (1→3),(1→4)-β-glucan in the cell walls of the endosperms, however, increased gradually towards maturation, even after 19 days. Analysing the relationship between enzyme activity and (1→3),(1→4)-β-glucan deposition in cell walls of endosperms prepared from 12 different barley varieties harvested 11–22 days after flowering showed that some varieties had both low activity and low glucan content, and in some both were high. But for several other varieties, the availability of donor substrate and other factors seem to influence the production of (1→3),(1→4)-β-glucan as well.     

Year‐round movements of sympatric Fork‐tailed (Oceanodroma furcata) and Leach's (O. leucorhoa) storm‐petrels

Long‐distance movements are characteristic of most seabirds in the order Procellariiformes. However, little is known about the migration and foraging ranges of many of the smaller species in this order, especially storm‐petrels (Hydrobatidae). We used Global Location Sensors to document the year‐round movements of sympatrically breeding Fork‐tailed Storm‐Petrels (Oceanodroma furcata) and Leach's Storm‐Petrels (O. leucorhoa) from the Gillam Islands located northwest of Vancouver Island, British Columbia, Canada. In 2016, breeding Fork‐tailed (N = 5) and Leach's (N = 2) storm‐petrels traveled maximum distances of ~1550–1600 km from their colony to a region that has a wide shelf with major canyons creating a highly productive foraging area. After the breeding season, Fork‐tailed Storm‐Petrels (N = 2) traveled to similar areas west of the Gillam Islands, a maximum distance of ~3600 km from the breeding colony, and remained in the North Pacific Ocean and north of the Subarctic Boundary for an average of 5.4 mo. Post‐breeding Leach's Storm‐Petrels (N = 2) moved south to the Eastern Tropical Pacific, west of central Mexico, Ecuador, and northern Peru, an estimated maximum distance of ~6700 km from their breeding colony, and remained there for an average of 7.2 mo. Carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope analyses of feathers revealed niche separation between Fork‐tailed (N = 21) and Leach's (N = 53) storm‐petrels. The wide range of δ¹⁵N values in the feathers of Leach's Storm‐Petrels (N = 53) suggests that they foraged at a variety of trophic levels during the non‐breeding season. Our results demonstrate that storm‐petrels have large core foraging areas and occupy vast oceanic areas in the Pacific during their annual cycle. However, given the coarse precision of Global Location Sensors, additional study is needed to identify the specific areas used by each species during both breeding and non‐breeding periods.     

Genetic variation of <Emphasis Type="Italic">Oplopanax elatus</Emphasis> (Nakai) Nakai (Araliaceae)

Using allozyme analysis, genetic and genotypic variation of rare relict species, a member of one of ancient angiosperm families, Araliaceae, the clonal plant Oplopanax elatus (Nakai) Nakai, was evaluated. Electrophoretic separation of the enzymes is described, and genetic interpretation of the enzymes variation patterns is presented. The values of genetic variation indices obtained were low (P = 25%; A = 1.45: H _o = 0.131; H _e = 0.113) and comparable with the data reported for the rare plant species and the representatives of the family Araliaceae. The main factors responsible for the polymorphism level observed might be the evolutionary history of the species and gene drift. The level of genotypic diversity (G/N = 0.76; D = 0.97) was substantially higher, compared to the values reported for species with vegetative reproduction (D = 0.62). These results suggest certain contribution of the propagation by seeds in the formation of the species of interest.     

Dorlodotia and related genera (Rugosa) from the Visean (Mississippian; Carboniferous) of Zonguldak and Bartin (North‐Western Turkey)

Abstract: A rich and diverse coral fauna collected from the Livian (Viséan, Mississippian) of Zonguldak and Bart?n (North‐western Turkey) contains numerous specimens of Dorlodotia and related forms. The most common species, D. delepinei Charles, 1933 , is redetermined as Dorlodotia briarti, an European species. A new species of Dorlodotia is described for very large, phaceloid forms: D. euxinensis. The genus Ceriodotia is created for species close to Dorlodotia with a cerioid habit. It comprises two species: C. bartinensis and C. petalaxoides, both common in the Viséan of Zonguldak and Bart?n. Based on comparison of morphological characters and features of the astogeny, a phylogenetic lineage is proposed for Dorlodotia and the new taxa. The evolution of D. euxinensis from D. briarti is peramorphic. Subsequent paedomorphosis resulted in the lineage D. euxinensis–C. bartinensis–C. petalaxoides. Ceriodotia probably includes Viséan taxa from Asia previously described as ‘Acrocyathus’.     

Chromosomal Analysis of Neohydrocoptus jaechi (Wewalka) and Canthydrus diophthalmus (Reiche & Saulcy) (Coleoptera: Noteridae)

Neohydrocoptus jaechi (Wewalka) is recorded for the first time in Egypt. It is very similar to N. angolensis (Peschet), but there are aedeagal differences. The karyotype consists of 6 pairs of autosomes and sex chromosomes which are neo-XY (♂) and neo-XX (♀). C-banding shows that the sex chromosomes of Canthydrus diophthalmus (Reiche & Saulcy) are not the small pair suggested by Bilton (1992), but are one of the largest pairs, with the Y-chromosome totally heterochromatic. The implications of these findings are considered in the light of Belkaceme's (1991) work on the phylogeny of Noteridae. Neohydrocoptus is placed among the group of more primitive genera, outside the closely-knit group of higher Noteridae, while Canthydrus is placed right at the top of the higher Noteridae. The neo-XY sex chromosomes of Neohydrocoptus could be a primitive condition for the family, while the system found in Canthydrus is derivable from that of Synchortus Sharp (Saleh Ahmed et al., 1997) (one of Belkaceme's basal genera of the higher Noteridae) by loss of the mainly heterochromatic X₂-chromosome, leaving the more normal X₁-chromosome and the Y, which is almost entirely heterochromatic in Synchortus and completely so in Canthydrus.     

<Emphasis Type="Italic">Siderocelis irregularis</Emphasis> (Chlorophyta,Trebouxiophyceae) in Lake Tanganyika (Africa)

Siderocelis irregularis Hindák, representing a genus Siderocelis (Naumann) Fott that is known from European temperate waters, was identified as a common phytoplankter in Lake Tanganyika. It was found aposymbiotic as well as ingested (possibly endosymbiotic) in lake heterotrophs, mainly Strombidium sp. and Vorticella spp. The morphology and ultrastructure of the species, studied with LM, SEM and TEM, are described with emphasis on the structure of the cell wall and the pyrenoid. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Cytotaxonomy of Dubyaea glaucescens (Compositae–Cichorieae)

Recent molecular phylogenetic analyses indicate that Dubyaea glaucescens (Compositae–Cichorieae) should be transferred to the genus Faberia as F. glaucescens. Here, we present cytological evidence for this transfer. Dubyaea glaucescens comprises two ploidy levels, 2n = 34 (diploid) and 2n = 51 (triploid), making the basic chromosome number x = 17. The chromosomes vary in length from 5.82 μm to 2.11 μm, and the karyotypes are 2n = 20m + 14sm (3sat) for the diploid cytotype and 2n = 30m + 21sm (3sat) for the triploid cytotype. Karyological characters of D. glaucescens, including chromosome number, size, morphology, and karyotype asymmetry, all agree remarkably with those reported previously in Faberia, but are distinct from those in other species of Dubyaea. The transfer of D. glaucescens to Faberia is thus strongly corroborated.     

Feather mites (Astigmata: Psoroptidia) parasitising the rock ptarmigan <Emphasis Type="Italic">Lagopus muta</Emphasis> (Montin) (Aves: Galliformes) in Iceland

Four new species of feather mites are described from the Icelandic rock ptarmigan Lagopus muta islandorum (Faber) in Iceland. These are Metamicrolichus islandicus n. sp., Myialges borealis n. sp. (Epidermoptidae), Strelkoviacarus holoaspis n. sp. (Analgidae) and Tetraolichus lagopi n. sp. (Pterolichidae). This is the first report on feather mites associated with the Icelandic rock ptarmigan. Brief comments on the systematics and biology of corresponding feather mite genera are given. For two species, originally described in Pterolichus Robin, 1868 (Pterolichidae), new combinations are proposed, i.e. Tetraolichus gaudi (Černy, 1971) n. comb. and T. microdiscus (Trouessart, 1887) n. comb.     

Synthesis and hypoglycemic activity of <Emphasis Type="Italic">Bis</Emphasis>(L-malato)oxovanadium(IV)

In order to create new oral vanadyl organic complexes-based drugs for the treatment of diabetes mellitus we have originally synthesized a biligand vanadyl derivative of L-malic acid (bis(L-malato)oxovanadium(IV)) and investigated its potential as a novel hypoglycemic agent using the experimental streptozotocin-induced diabetes in rats. The oral administration of bis(L-malato)oxovanadium(IV) with drinking water significantly reduced blood and urinary glucose concentrations and also the level of glycated proteins in the streptozotocin-diabetic rats.     

Raman spectroscopic measurements in self‐pressurized aqueous solutions above 100°C: The melting of poly(G) and poly(G) · poly(C)

We have studied by Raman spectroscopy the thermal behavior of associated polyguanylic acid [poly(G)] and polyguanylic–polycytidylic acid [poly(G) · poly(C)] in self‐pressurized aqueous solutions contained in sealed capillary tubes. The associated polynucleotides were found to be very resistant to heat, but evidence of thermal degradation was observed after melting of the helical structures. The cooperative melting transition of the four‐stranded complex of poly(G) was located at 141°C in 0.5M KCl, 135°C in 0.5M NaCl, 129°C in 0.5M LiCl, 123°C in 0.1M tetramethylammonium perchlorate, and 105°C in 0.1M tetraethylammonium bromide solutions. The transition was observed at 130°C in poly(G) · poly(C) (in 0.5M NaCl). The results in this case show that a four‐stranded poly(G) complex is formed following the melting of the double helix. © 1999 John Wiley & Sons, Inc. Biopoly 49: 21–28, 1999