Inheritance of Anthracnose Resistance in the Common Bean Differential Cultivar G 2333 and Identification of a New Molecular Marker Linked to the Co-42 gene

The inheritance of anthracnose resistance of the common bean ( Phaseolus vulgaris L.) differential cultivar G 2333 to Colletotrichum lindemuthianum races 73 and 89 was studied in crosses with the susceptible cultivar Rudá. The segregation ratios of 15 : 1 in the F₂ and 3 : 1 in the backcrosses to Rudá indicate that for each of the races tested there are two independent resistance loci in G 2333. A random amplified polymorphic DNA (RAPD) molecular marker (OPH18_1200C) linked in resistance to race 73 was identified in a BC₃F_2:3 population derived from crosses between Rudá and G 2333. A RAPD molecular marker OPAS13_950C, previously identified as linked to gene Co-4² , was also amplified in this population. Co-segregation analyses showed that these two markers are located at 5.6 (OPH18_1200C) and 11.2 (OPAS13_950C) cM of the Co-4² gene. These markers were not present in BC₁F_2:3 plants resistant to race 89 indicating that this population carries a different resistance gene. DNA amplification of BC₁F_2:3 plants with RAPD molecular marker OPAB_450C, previously identified as linked to gene Co-5 , indicated that this gene is present in this population.     

Allozyme, mitochondrial-DNA, and morphometrie variability indicate cryptic species of anchovy (Engraulis encrasicolus)

Previous surveys of population structure in the Atlantic-Mediterranean anchovy Engraulis encrasicolus L. have reported heterogeneity in morphology, allozyme frequencies, and mitochondrial DNA haplotype frequencies at a regional scale. In particular, two stocks of anchovy have been detected in the Adriatic Sea. In this paper, the available data is reviewed with the aim to relate genetic variation to geography at the widest possible geographical scale, for investigating the evolutionary mechanisms underlying stock structure in anchovy. Correspondence analysis of allozyme frequencies (24 samples, three polymorphic loci) compiled from the literature indicates three distinct entities in the Mediterranean Sea. Open-sea or oceanic anchovy populations are genetically different from inshore-water populations within a region (Nei's ^ G _ST = 0.035–0.067), while broadscale geographical variation is weak for each of these two habitat-specific forms (^ G _ST = 0.005–0.006). Mitochondrial-DNA haplotype frequencies support the distinction between an inshore form and an oceanic form (^ G _ST = 0.067–0.107), with virtually no genetic differences among oceanic populations across the Gulf of Biscay, the western Mediterranean and the Ionian Sea (^ G _ST = −0.001). If natural selection on marker loci is unimportant, these results indicate the occurrence of two parapatric, genetically distinct, habitat-specific forms that are widely distributed throughout the Mediterranean Sea. Persistent allele and haplotype-frequency differences between these forms indicate reproductive isolation and the presence of an E. encrasicolus species complex in the Mediterranean. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society 75 : 261–269.     

Occurrence of aminopropylcadaverine and its aminopropyl derivatives aminopentylnorspermidine and N, N' -bis(3-aminopropyl)cadaverine in Halococcus acetoinfaciens

Abstract Besides putrescine, cadaverine, spermidine, spermine and thermospermine, three novel polyamines were detected in a slightly halophilic eubacterium Halococcus acetoinfaciens (IAM 12094, ATCC 25861). These novel polyamines were found to be N -3-aminopropylcadaverine [NH₂(CH₂)₃NH(CH₂)₅NH₂] and its aminopropyl derivatives: aminopentylnorspermidine [NH₂(CH₂)₃NH(CH₂)₃NH(CH₂)₅NH₂] and N , N ' -bis(3-aminoprophyl)cadaverine [NH₂(CH₂)₃ NH(CH₂)₅NH(CH₂)₃NH₂]. Aminopropylcadaverine was also detected in two other species, Halococcus agglomeratus (IAM 12095, ATCC 25862) and Halococcus nondenitrificans (IAM 12096, ATCC 25863).     

Flow cytometric DNA analysis of nurse shark, Ginglymostoma cirratum (Bonaterre) and clearnose skate, Raja eglanteria (Bosc) peripheral red blood cells

Flow cytometric DNA analysis was used to determine the DNA content of red blood cells from Ginglymostoma cirratum (Bonaterre) and Raja eglanteria (Bosc). The DNA content/nucleus was calculated to be 7.6 and 7.1 pg/nucleus, respectively. Peripheral red blood cells obtained both from G. cirratum and from R. eglanteria were demonstrated to be actively cell cycling. Percentages of red blood cells in the phases of the cell cycle ( G ₀/ G ₁, S , and G ₂/ M ) not only varied considerably between different fishes but also were quite variable in weekly samples obtained from individual animals.     

Two tertiary branched tetraamines, N4-aminopropylnorspermidine and N4-aminopropylsperimidine, are the major polyamines in thermophilic eubacteria, Thermoleophilum

Abstract Two novel polyamines were found as major polyamines of Thermoleophilum album and Thermoleophilum minutum , which are Gram-negative eubacteria obligate for thermophily and n -alkane substrates. They were identified as tertiary branched tetraamines, N⁴-aminopropylnorspermidine ( tris (3-aminopropyl)amine) [NH₂(CH₂)₃N-((CH₂)₃NH₂)(CH₂)₃NH₂ or N(CH₂CH₂CH₂NH₂)₃] and N⁴-aminopropylspermidine [NH₂(CH₂)₃N((CH₂)₃NH₂)(CH₂)₄NH₂] by high-performance liquid chromatography and gas chromatography-mass spectrometry.     

Seasonal variability in growth of larval Japanese anchovy Engraulis japonicus driven by fluctuations in sea temperature in the Kii Channel, Japan

Seasonal variability in the growth of larval Japanese anchovy Engraulis japonicus was examined through otolith microstructure analysis based on the samples collected from the northern side (inner area, IA) and the southern side (outer area, OA) of the Kii Channel from April 2006 to March 2007. Growth trajectories (otolith backcalculated mean standard length of 5 day intervals from 5 days after hatch to 24 days) as well as the most recent 5 day mean growth rate of larvae before capture ( G ₅) differed among months. Growth trajectories showed the same pattern as G ₅. In IA, mean ± s.d. G ₅ ranged from 0·31 ± 0·04 mm day⁻¹ (January) to 0·73 ± 0·06 mm day⁻¹ (October). In OA, mean ± s.d. G ₅ ranged from 0·36 ± 0·05 mm day⁻¹ (January) to 0·79 ± 0·11 mm day⁻¹ (August). G ₅ values declined from November to January and then started to increase. In general, the seasonal patterns of growth were similar between IA and OA, and a clear seasonal pattern in growth was identified. When the relationships among larval growth rate, sea temperature, zooplankton density and larval density were examined, growth rate was positively related with sea temperature in both areas and not related with the other factors. The similar pattern in growth observed between IA and OA was probably due to the low spatial variability in sea temperature compared to its seasonal variability.     

The Subunit Composition of a GABAA/Benzodiazepine Receptor from Rat Cerebellum

Abstract: The pentameric subunit composition of a large population (36%) of the cerebellar granule cell GABA_A receptors that show diazepam (or clonazepam)-insensitive [³H]Ro 15-4513 binding has been determined by immunoprecipitation with subunit-specific antibodies. These receptors have α₆, α₁, γ_2S, γ_2L, and β₂ or β₃ subunits colocalizing in the same receptor complex.     

LEAF INFECTION OF COTTON BY XANTHOMONAS MALVACEARUM (E.F.SM.) DOWSON

Xanthomonas malvacearum spread more rapidly along vascular tissue than into mesophyll when inoculated to the main veins of susceptible cotton leaves. The extent of spread varied with the concentrations of inocula, tissue age and cotton variety.
Increasing concentrations of inocula accelerated the initial spread of disease.
Bacteria spread more rapidly in young leaves than in old—increasing age greatly decreased disease in the mesophyll. The initial invasion was quicker in young leaves of young plants than in young leaves of old plants.
Three types of behaviour, according to the host's reaction, distinguish Knight's resistance factors: ( a ) where X. malvacearum spread extensively along veins and into mesophyll of plants containing factors B₃ and B₅; ( b ) where it was restricted to the point of inoculation in plants containing B ₄, B₉ and combinations with B _6m; and ( c ) where it spread along veins but not appreciably into mesophyll in varieties containing B ₂ and B ₂ B ₃.
From this and four other different types of tests, factors B ₂ and B ₃ seem to increase mesophyll resistance but only B ₂ gives appreciable vascular resistance. Further, the vascular bundles in varieties with B ₂ seem to be surrounded by an additional 'barrier' which resists X. malvacearum.     

Reduced Development of Grey Mould (Botrytis cinerea) in Bean and Tomato Plants by Calcium Nutrition

Fertilization of bean plants grown in perlite with 1 and 3 mM CaCl₂ or Ca(NO₃)₂ reduced severity of grey mould as compared with control plants or plants fertilized with 5 mM of the compounds. Fertilization with Ca(NO₃)₂ reduced severity leaf grey mould and fruit ghost spots of tomato plants grown in perlite by 70 and 45%, respectively. The rate of decrease varied with the position of the fruits on the plants. Leaves from plants treated with calcium or otherwise [KNO₃, (NH₄)₂SO₄] produced less ethylene than leaves of nontreated plants. Rate of growth of B. cinerea was lower on growth medium prepared from washings from leaves of calcium fertilized plants than from leaves from other treatments. The fertilizer combination Ca(H₂PO₄)₂+ CaSO₄ (1 and 3 g/kg soil) applied once to tomato plants grown in soil reduced severity of leaf grey mould by 80 % (significant at P = 0.05) but 1–3 g CaSO₄/kg soil only tended to reduce disease severity (30–40 %, not significant) as compared with the control. The compounds CaCl₂ and Ca(NO₃)₂ increased significantly ( P = 0.05) the growth of B. cinerea on synthetic medium when applied at rates of 1 0–10.0 mM whereas reduction of growth was observed with 0.1 mM of the compounds and of CaSO₄.     

Towards a general rule for estimating the stage of pregnancy in field-caught tsetse flies

Abstract. Ovarian dissections were performed on the tsetse flies Glossina morsitans morsitans Westwood and G.pallidipes Austen of known ages, maintained in the laboratory or on an island in Lake Kariba, Zimbabwe. The lengths ( l ₂ and l _u) of the second largest oocyte and of the larva in utero were found to increase approximately exponentially during pregnancy. The length ( l ₁) of the largest oocyte increased exponentially for about the first 80% of pregnancy. Linear relationships between the log values of l ₁, l ₂ and l _u in field-caught flies, of unknown chronological age, are consistent with the idea that growth patterns are similar in laboratory, island and open field situations. The egg phase takes up c. 45% of pregnancy in both species, regardless of season and the absolute duration of pregnancy. The changes in the log values of l ₁, l ₂ and l _u, over the ranges within which they change linearly, can be used to assign flies to their stage of pregnancy. When applied to field data the rule showed that G.pallidipes caught in odour-baited traps, and on a mobile electric net, exhibited major activity peaks shortly before and after parturition. Flies from the trap (but not the net) showed a smaller peak of activity near the middle of pregnancy. The egg and the three larval phases in utero take up c. 45%, 25%, 20% and 10% of pregnancy respectively.     

Alcohol dehydrogenase isozymes in the mouse: Genetic regulation, allelic variation among inbred strains and sex differences of liver and kidney A2 isozyme activity

Genetic analysis of a proposed cis-acting temporal locus ( Adh-3t ), which regulates alcohol dehydrogenase C₂ (ADH-C₂) acitivity in mouse epididymis extracts, among F₁ (ddN × BALB/c) × ddN male backcross progeny provided evidence for genetic distinctness between the structural ( Adh-3 ) and temporal ( Adh-3t ) loci on chromosome 3. Genetic analysis also confirmed the close, linkage of Adh-1 (encoding liver and kidney ADH-A₂) and Adh-3 (encoding stomach ADH-C₂) to within 0.3 centimorgans on the mouse genome. Evidence is presented for a proposed closely linked cis-acting temporal locus (designated Adh-1t ) for the A₂ isozyme (encoded by Adh-1 ) controlling the activity of this enzyme in mouse kidney extracts, but having no apparent affect on liver and intestine ADH-A₂ activities. An extensive survey of the distribution of Adh-1, Adh-3 and Adh-3t alleles among 65 strains of mice is reported — with the exception of two Japanese strains (ddN and KF), linkage disequilibrium between Adh-3 and Adh-3t was observed. Sex differences in mouse liver and kidney ADH-A₂ activities were observed, with male/female ratios of approximately 0.6 and 3 respectively for these tissue extracts.     

Behavioural and physiological adaptations to a burrowing lifestyle in the snake blenny, Lumpenus lampretaeformis, and the red band-fish, Cepola rubescens

Observations have been made on the mode of burrow construction in the snake blenny, Lumpenus lampretaeformis , under laboratory conditions. It appears that head probing and lateral oscillations of the body are principally responsible for the excavation of the burrow which is completed within 24 h. The burrow structure has been analysed in detail, showing a mean depth of 7.2 cm with a maximum observed length of 73 cm, with most systems between 20 and 35 cm in length. Initially linear burrows with two openings are usually provided with a small side tunnel, giving the system a characteristic Y-shape.
Burrow irrigation was investigated for the first time in L. lampretaeformis. The mean duration of burrow irrigation, by flexions of the tail of the fish, was 21 s with over 13 min h⁻¹ spent in irrigating the burrow. The mean water displacement per irrigation period was 3.1 ml. The PO ₂ and PCO ₂ were measured in both surface water and within the burrow system of L. lampretaeformis. Surface water values for PO ₂ were high (> 150 Torr) and PCO ₂ low (<0.4 Torr). Hypoxic and hypercapnic conditions were measured in the burrow system itself, with PO ₂ values ranging between 57 and 129 Torr and PCO ₂ rising to > 1.3 Torr in some burrows.
A comparative study of Cepola rubescens burrows indicated similar surface water PO ₂ and PCO ₂ values as in L. lampretaeformis. Burrow water PO ₂ values ranged between 60 and 94 Torr, with PCO ₂ values as high as 1.5 Torr being recorded. These results are discussed in relation to the adaptation of both species to a burrowing lifestyle.     

Long-term stability and effective population size in North Sea and Baltic Sea cod (Gadus morhua)

DNA from archived otoliths was used to explore the temporal stability of the genetic composition of two cod populations, the Moray Firth (North Sea) sampled in 1965 and 2002, and the Bornholm Basin (Baltic Sea) sampled in 1928 and 1997. We found no significant changes in the allele frequencies for the Moray Firth population, while subtle but significant genetic changes over time were detected for the Bornholm Basin population. Estimates of the effective population size ( N _e ) generally exceeded 500 for both populations when employing a number of varieties of the temporal genetic method. However, confidence intervals were very wide and N _e 's most likely range in the thousands. There was no apparent loss of genetic variability and no evidence of a genetic bottleneck for either of the populations. Calculations of the expected levels of genetic variability under different scenarios of N _e showed that the number of alleles commonly reported at microsatellite loci in Atlantic cod is best explained by N _e 's exceeding thousand. Recent fishery-induced bottlenecks can, however, not be ruled out as an explanation for the apparent discrepancy between high levels of variability and recently reported estimates of N _e  << 1000. From life history traits and estimates of survival rates in the wild, we evaluate the compatibility of the species' biology and extremely low N _e / N ratios. Our data suggest that very small N _e 's are not likely to be of general concern for cod populations and, accordingly, most populations do not face any severe threat of losing evolutionary potential due to genetic drift.     

Three parameters comprehensively describe the temperature response of respiratory oxygen reduction

Using an exponential model that relies on Arrhenius kinetics, we explored Type I, Type II and dynamic (e.g. declining Q ₁₀ with increasing temperature) responses of respiration to temperature. Our Arrhenius model provides three parameters: R _REF (the base of the exponential model, nmol g⁻¹ s⁻¹), E ₀ (the overall activation energy of oxygen reduction that dominates its temperature sensitivity, kJ mol⁻¹) and δ (that describes dynamic responses of E ₀ to measurement temperature, 10³ K²). Two parameters, E ₀ and δ , are tightly linked. Increases in overall activation energy at a reference temperature were inversely related to changes in δ . At an E ₀ of ca. 45 kJ mol⁻¹, δ approached zero, and respiratory temperature response was strictly Arrhenius-like. Physiologically, these observations suggest that as contributions of AOX to combined oxygen reduction increase, E ₀( REF ) decreases because of different temperature sensitivities for V _max, and δ increases because of different temperature sensitivities for K _1/2 of AOX and COX. The balance between COX and AOX activity helps regulate plant metabolism by adjusting the demand for ATP to that for reducing power and carbon skeleton intermediates. Our approach enables determination of respiratory capacity in vivo and opens a path to development of process-based models of plant respiration.     

Non-association between Rfp-Y major histocompatibility complex-like genes and susceptibility to Marek's disease virus-induced tumours in 63× 72 F2 intercross chickens

Marek's disease (MD) is a lymphoproliferative disease caused by a member of the herpesvirus family, and the best understood genetic resistance to MD involves the chicken major histocompatibility complex (MHC) B -complex. Preliminary observations have suggested that MHC-like Rfp-Y genes might also influence the incidence of MD. This study describes the differentiation and definition of unique Rfp-Y genes in inbred lines 6₃ and 7₂, lines that possess identical B -complex genes, but that are resistant or susceptible to MD, respectively. To assess if Rfp-Y genes affect susceptibility to MD, 265 6₃× 7₂ F₂ chickens were challenged with the JM strain of MD virus at 1 week of age and were evaluated for MD lesions at up to 10 weeks of age. Genotyping of the F₂ chickens for Rfp-Y haplotypes was performed by restriction fragment length polymorphism analysis of genomic DNA using Taq I and a B-FIV probe. Analysis of variance and interval mapping procedures were used to determine association between the Rfp-Y haplotypes and the phenotypic MD values of the F₂ chickens. The cosegregation analysis of 265 F₂ chickens indicated that there was no association between Rfp-Y haplotypes and MD susceptibility. Furthermore, the fact that the Rfp-Y haplotypes fit the 1:2:1 segregation ratio and the Rfp-Y allele frequencies did not differ significantly from 0·5 in the full population or in selected subpopulations (of either 40 MD-resistant or 39 MD-susceptible chickens) also indicated that Rfp-Y haplotypes do not significantly influence MD susceptibility. We conclude that Rfp-Y haplotypes do not play a major role in determining the genetic susceptibility to MD in 6₃× 7₂ F₂ White Leghorn chickens.     

Association mapping of cadmium, copper and hydrogen peroxide tolerance of roots and translocation capacities of cadmium and copper in Arabidopsis thaliana

Association mapping analysis of Cd, Cu and H ₂O ₂ tolerance, judged by relative root length (RRL: % of root length in stress condition relative to that in control condition), and Cd and Cu translocation ratios (amount of metal in the shoot to the total) were performed using 90 accessions of Arabidopsis thaliana . Using 140 SNPs that were distributed across the genome, association mapping analysis was performed with a haploid setting by the Q + K method, which minimizes detection of false associations by combining the Q-matrix of the structured association (Q) with kinship (K) to control for the population structure. Six, five and five significant (−log ₁₀ P -value is 1.3 ≥) linkages were detected between the SNPs and Cd, Cu and H₂O₂ resistant RRLs, respectively. In addition, six significant linkages were identified with translocation capacities of Cd and Cu. Among those detected loci, two each of Cu and Cd tolerance RRLs were collocated with those of H₂O₂ tolerance RRL, while one locus each was detected by Cu and Cd tolerance RRLs that collocated with their translocation ratios. These results suggested that these factors might partly explain the phenotypic variation of tolerance RRLs to Cd and Cu of Arabidopsis thaliana . Finally, using a different approach to analyze interactions between individual phenotypes, namely clustering analysis, we found an expected segregation of resistant SNPs (single-nucleotide polymorphisms) of the multiple RRLs in the typical accession groups carrying multiple traits. Almost none of the loci detected by association mapping analysis were linked to the loci of previously identified critical genes regulating the traits, suggesting that this could be useful to identify complex architecture of genetic factors determining variation among multiple accessions.     

Replacement of histidine in position 105 in the α₅ subunit by cysteine stimulates zolpidem sensitivity of α₅β₂γ₂ GABA(A) receptors

Zolpidem is a positive allosteric modulator of GABA_A receptors with sensitivity to subunit composition. While it acts with high affinity and efficacy at GABA_A receptors containing the α₁ subunit, it has a lower affinity to GABA_A receptors containing α₂, α₃, or α₅ subunits and has a very weak efficacy at receptors containing the α₅ subunit. Here, we show that replacing histidine in position 105 in the α₅ subunit by cysteine strongly stimulates the effect of zolpidem in receptors containing the α₅ subunit. The side chain volume of the amino acid residue in this position does not correlate with the modulation by zolpidem. Interestingly, serine is not able to promote the potentiation by zolpidem. The homologous residues to α₅H105 in α₁, α₂, and α₃ are well-known determinants of the action of classical benzodiazepines. Other studies have shown that replacement of these histidines α₁H101, α₂H101, and α₃H126 by arginine, as naturally present in α₄ and α₆, leads to benzodiazepine insensitivity of these receptors. Thus, the nature of the amino acid residue in this position is not only crucial for the action of classical benzodiazepines but in α₅ containing receptors also for the action of zolpidem.     

Isoform-Specific Effects of Apolipoproteins E2, E3, and E4 on Cerebral Capillary Sequestration and Blood-Brain Barrier Transport of Circulating Alzheimer's Amyloid β

Abstract: Cerebral capillary sequestration and blood-brain barrier (BBB) permeability to apolipoproteins E2 (apoE2), E3 (apoE3), and E4 (apoE4) and to their complexes with sAβ_1–40, a peptide homologous to the major form of soluble Alzheimer's amyloid β, were studied in perfused guinea pig brain. Cerebrovascular uptake of three apoE isoforms was low, their blood-to-brain transport undetectable, but uptake by the choroid plexus significant. Binding of all three isoforms to sAβ_1–40 in vitro was similar with a K _D between 11.8 and 12.9 n M . Transport into brain parenchyma and sequestration by BBB and choroid plexus were negligible for sAβ_1–40-apoE2 and sAβ_1–40-apoE3, but significant for sAβ_1–40-apoE4. After 10 min, 85% of sAβ_1–40-apoE4 taken up at the BBB remained as intact complex, whereas free sAβ_1–40 was 51% degraded. Circulating apoE isoforms have contrasting effects on cerebral capillary uptake of and BBB permeability of sAβ. ApoE2 and apoE3 completely prevent cerebral capillary sequestration and blood-to-brain transport of sAβ_1–40. Conversely, apoE4, by entering brain microvessels and parenchyma as a stable complex with sAβ, reduces peptide degradation and may predispose to cerebrovascular and possibly enhance parenchymal amyloid formation under pathological conditions.     

Effects of sulfate and nitrate on K+ uptake and growth of wheat and cucumber

The uptake of K⁺ ion was studied in the roots of wheat ( Triuicum aestivum L. cv. GK Szeged) and cucumber ( Cucumis sativus L. cv. Budai csemege) seedlings grown in nutrient solution under nitrogen and sulfate stress conditions. Seedlings pretreated with 1 or 10 m M NaNO₃, absorbed more K⁺ than those treated with 0.1 m M NaNO₃. However, the posteffect of NaNO₃ was considerably influenced by the Na₂SO₄, treatment. The results suggest that, at least partly, a feed-back regulation of K⁺ uptake may occur. However, due to the high Na⁺ contents of the roots, a Na⁺ effect in this process cannot be excluded. The growth and dry matter yields of the roots and shoots were strongly influenced by the SO²⁻/₄ and NO⁻/₃ supply of the plants. Appreciable differences were experienced between wheat and cucumber seedlings. The optimum SO²⁻/₄ concentration of the growth solution for maximal growth varied considerably between the species, and was also different for the roots and the shoots in a given species.