Y chromosome haplotype diversity of domestic sheep (Ovis aries) in northern Eurasia

Variation in two SNPs and one microsatellite on the Y chromosome was analyzed in a total of 663 rams representing 59 breeds from a large geographic range in northern Eurasia. SNPA‐oY1 showed the highest allele frequency (91.55%) across the breeds, whereas SNPG‐oY1 was present in only 56 samples. Combined genotypes established seven haplotypes (H4, H5, H6, H7, H8, H12 and H19). H6 dominated in northern Eurasia, and H8 showed the second‐highest frequency. H4, which had been earlier reported to be absent in European breeds, was detected in one European breed (Swiniarka), whereas H7, which had been previously identified to be unique to European breeds, was present in two Chinese breeds (Ninglang Black and Large‐tailed Han), one Buryatian (Transbaikal Finewool) and two Russian breeds (North Caucasus Mutton‐Wool and Kuibyshev). H12, which had been detected only in Turkish breeds, was also found in Chinese breeds in this work. An overall low level of haplotype diversity (median h = 0.1288) was observed across the breeds with relatively higher median values in breeds from the regions neighboring the Near Eastern domestication center of sheep. H6 is the dominant haplotype in northwestern and eastern China, in which the haplotype distribution could be explained by the historical translocations of the H4 and H8 Y chromosomes to China via the Mongol invasions followed by expansions to northwestern and eastern China. Our findings extend previous results of sheep Y chromosomal genetic variability and indicate probably recent paternal gene flows between sheep breeds from distinct major geographic regions.     

The resistance to heat of thermo-resistant streptococci attached to stainless steel in the presence of milk

Skim milk residues had a significant impact on the sensitivity to heat of a dairy isolate of the thermo-resistant, Streptococcus thermophilus. Cells of S. thermophilus (H) suspended in water or in milk had D values at 60°C of 2.0 and 14 min, respectively. Cells of S. thermophilus (H) attached to stainless steel in the presence of water or milk had D values at 60°C of 2.2 and 8.1 min, respectively. The attached cells in both experiments were heat-treated in the presence of water. The increase in heat resistance could not be fully attributed to individual components (caseinate or whey) in the milk. The potential for thermo-resistant streptococci to survive heat treatment in a dairy manufacturing plant is therefore greater than may be expected for the organism in less complex environments. Journal of Industrial Microbiology & Biotechnology (2002) 28, 134–136 DOI: 10.1038/sj/jim/7000229 Received 06 September 2001/ Accepted in revised form 17 November 2001     

Investigation of alkane biodegradation using the microtiter plate method and correlation between biofilm formation, biosurfactant production and crude oil biodegradation

Among 25 crude oil-degrading bacteria isolated from a marine environment, four strains, which grew well on crude oil, were selected for more study. All the four isolated had maximum growth on 2.5% of crude oil and strain BC (Pseudomonas) could remove crude oil by 83%. The drop collapse method and microtiter assay show that this strain produces more biosurfactant, and its biofilm formation is higher compared to other strains. Bacterial adhesions to crude oil for strains CS-2 (Pseudomonas), BC, PG-5 (Rhodococcus) and H (Bacillus) were 30%, 46%, 10% and 1%, respectively. Therefore, strain H with a low production of biosurfactant and biofilm formation had showed the least growth on these compounds. PCR analysis of these four strains showed that all isolates had alk-B genes from group (III) alkane hydroxylase. All isolate strains could utilize cyclohexan, octane, hexadecane, octadecan and diesel fuel oil; however, the microtiter plate assay showed that strain BC had more growth, respiration and biofilm formation on octadecan.     

Substance P-Induced Reduction in the Initial Accumulation of Cytosolic myo-[3H]Inositol in Rat Parotid Acinar Cells Mediated by the NK1 Tachykinin Receptor

Abstract: Stimulation of rat parotid acinar cells by the tachykinin neurokinin (NK) 1 receptor agonist substance P (SP) resulted in a significant reduction in the initial accumulation of cytosolic myo-[³H]inositol. This effect was rapid, because a reduction of ～15% could be seen already at 30 s, with the maximal effect (～45%) being observed at 15 min. The response to SP stimulation Was temperature dependent, because at 4°C no reduction was found, jln addition, at 4°C, cytosolic myo-[³H]inositol represented only 10% of the labeled inositol accumulated at 37°C. The SP-induced reduct on in cytosolic ravo[³H]inositol accumulation was concentration dependent; the EC₅₀ obtained for SP was 5.8 ± 2.5 nM. Spantide [N Arg¹, D-Trp⁷⁹, Leu]SP), a SP antagonist, used at a concentration oif 10⁵ A/, gave a competitive shift of the dose-response curve to SP. Various tachykinins and their analogs were evaluated for their ability to reduce cytosolic mvo-[³H]inositol. [L-Pro⁹]SP and SP methyl ester, two highly selective agonists of NK1 receptors, reduced the initial accumulation of myo-H]inositol with EQo values of 2.3 and 67.0 nM, respectively. Long SP C-terminal fragments were more potent than shorter ones. SP N-terminal fragments and SP free acid were -without effect. [Pro⁷]NKB, a selective NKB analog, had no effect. The rank order of potency of mammalian tachykinins was SP > NKA > NKB. These findings and the close correlation between EC50 values and IC₅₀ values obtained in binding studies implicate the NK 1 receptor. In addition, stimulation of muscarinic receptors by carbachol alscp resulted in a reduction in level of cytosolic mjw-[³H]inositol, with this effect being reversed by atropine. Moreover, atropine was unable tjo alter the SP-induced reduction in cytosolic myo-[³H]inositol accumulation. Other neurotransmitters, such as glutamic acid, serotonin, chplecystokinin, neurotensin, bradykinin, and neuropeptide Y, were without effect on initial cytosolic myo-[³H]inositol accumulation. In conclusion, NK1 and muscarinic receptors seem to regulate the membrane transport of inositol in acinar cells of the rat parotid gland. Measurement of the initial accumulation of cytosolic myo-[³H]inositol in this tissue could profitably be adopted as a very simple, rapid, [sensitive, and specific biochemical procedure for screening the activity of potential agonists and antagonists at NK1 receptors.     

Biopotential of Fleuggea leucopyrus (Koen.) Willd. against Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

In the past five decades, agricultural pests are controlled by synthetic pesticides which caused ill effects on non-target organisms and environment; also insect pests developed resistance and minor pests became major pests. By keeping this in mind, the present study was selected. Antifeedant and larvicidal activities and growth inhibitory effects of hexane, chloroform and ethyl acetate leaf extracts of Fleuggea leucopyrus (Koen.) Willd. against Helicoverpa armigera (Hbn.) were studied. Antifeedant and larvicidal activities were evaluated at 0.5, 1, 2.5 and 5% concentrations at laboratory conditions. Hexane and chloroform extracts at 5% concentration recorded significant antifeedant activity of 82.41 and 74.45%, respectively. Hexane extract recorded the least LC₅₀ and LC₉₀ values of 1.37 and 4.80%, respectively. Hexane extract recorded maximum larvicidal activity of 85.78% with LC₅₀ and LC₉₀ values of 1.69 and 4.94%, respectively. Ethyl acetate extract also had notable amount of larvicidal activity of 81.77% at 5% concentration. Hexane extract at 5 and 2.5% and ethyl acetate extract at 5% concentrations completely prevented the adult emergence of H. armigera. This plant could be further exploited to identify the active principle(s) responsible for the activities and to develop a novel pesticidal formulation. This is the first report of F. leucopyrus is studied for its bioefficacy against H. armigera.     

New national and regional bryophyte records, 23

Abstract

We recorded evidence for herbivory in the mosses Hypopterygium tamarisci and Lopidium concinnum in a tropical rainforest (São Paulo State, Brazil). We described this herbivory quantitatively, measured the protein and phenol abundance, and identified potential herbivores in the laboratory. We sampled plants from 10 colonies of each species in the years 2007 and 2008. To quantify herbivory, we used an index of damage (ID), with six categories of injury from 0 (0%) to 5 (50–100%). Air-dried moss samples were weighed (100 mg) and used for protein and phenol detection by the Bradford and Folin-Ciocalteau methods, respectively. The plants were cultivated under controlled laboratory conditions and the identification of herbivores was performed from photographs. Injury was higher in H. tamarisci than in L. concinnum (68% and 38% in 2007 and 35% and 23% in 2008, respectively). H. tamarisci had higher mean ID (1·70 in 2007 and 1·09 in 2008); however, the ID values were low compared with ID values detected in angiosperms from tropical forests. Proteins were more abundant than phenol compounds for both species. H. tamarisci had the highest levels of protein and phenols. The phenol/protein ratios (ph/pt ratio) from H. tamarisci (0·42) and L. concinnum (0·40) were similar to those of other terrestrial plants. No correlation between ID and ph/pt ratio, proteins or phenols was detected. Lepidoptera larvae (Geometridae) and micro-snails (Charopidae) were found feeding mainly on the leaves of these mosses. Thus, H. tamarisci and L. concinnum are food sources for herbivores in the field, mainly as alternative food sources for some small and less mobile herbivores.     

PHOTOSYNTHETIC PATHWAYS OF HESPERALOE FUNIFERA AND H. NOCTURNA (AGAYACEAE): NOVEL SOURCES OF SPECIALTY FIBERS

Hesperaloe funifera and H. nocturna are currently being studied as potential new sources of fibers for specialty papers. This study investigated canopy architecture and light interception in H. funifera, and gas exchange in both species. H. funifera is an acaulescent rosette species with stiff, upright leaves. Mean leaf angle for 3-year-old plants was 70° from horizontal, and more than 90% of the leaf surface was at angles greater than 50°. Vertical orientation of leaves reduced seasonal variation in light interception and midday light interception during summer months. High leaf angles are interpreted as an adaptation to arid habitats that could reduce this species' suitability for cultivation in more humid areas. Both H. funifera and H. nocturna had leaf-tissue water contents and mesophyll-succulence values intermediate between previously investigated Agavaceae known to be either C₃ or Crassulacean acid metabolism (CAM) plants. Both species proved to have CAM, however. Gas exchange characteristics varied with leaf age, with older leaves having higher assimilation rates, greater water-use efficiency, and a higher proportion of nighttime CO₂ uptake. Interestingly, these older leaves had mesophyll succulence values closer to those of typical C₃ species. These Hesperaloe species can thus be characterized as nonsucculent CAM plants. Both species showed CO₂ uptake rates of 5–8 μmol m^-2 sec^-1 expressed on a total-surface-area basis and 10–18 μmol m^-2 sec^-1 expressed on a projected-leaf-area basis. Expanded cultivation of species possessing CAM in marginal areas has been recommended recently; the physiological studies reported here along with previous studies of their economic botany identify these Hesperaloe species as good crop candidates for dry regions.     

Host specificity of <Emphasis Type="Italic">Ischnodemus variegatus</Emphasis>, an herbivore of West Indian marsh grass (<Emphasis Type="Italic">Hymenachne amplexicaulis</Emphasis>)

West Indian marsh grass, Hymenachne amplexicaulis Rudge (Nees) (Poaceae), is an emergent wetland plant that is native to South and Central America as well as portions of the Caribbean, but is considered invasive in Florida USA. The neotropical bug, Ischnodemus variegatus (Signoret) (Hemiptera: Lygaeoidea: Blissidae) was observed feeding on H. amplexicaulis in Florida in 2000. To assess whether this insect could be considered as a specialist biological control agent or potential threat to native and cultivated grasses, the host specificity of I. variegatus was studied under laboratory and field conditions. Developmental host range was examined on 57 plant species across seven plant families. Complete development was obtained on H. amplexicaulis (23.4% survivorship), Paspalum repens (0.4%), Panicum anceps (2.2%) and Thalia geniculata (0.3%). Adults survived 1.6 times longer and laid 6.6 times more eggs on H. amplexicaulis than the other species. Oviposition on suboptimal host species was positively related to I. variegatus density under multiple choice conditions. Results from field experiments indicated that H. amplexicaulis had higher densities of I. variegatus than other species. Spill-over to suboptimal hosts occurred in an area where H. amplexicaulis was growing in poor conditions and there was a high density of I. variegatus. Thus, laboratory and field studies demonstrate that I. variegatus had higher performance on H. amplexicaulis compared to any other host, and that suboptimal hosts could be colonized temporarily. Handling Editor: John Scott. An erratum to this article can be found at     

MOLECULAR TESTS OF THE HYPOTHESIZED HYBRID ORIGIN OF TWO DIPLOID HELIANTHUS SPECIES (ASTERACEAE)

Enzyme electrophoresis and restriction-fragment analysis of chloroplast DNA (cpDNA) and nuclear ribosomal DNA (rDNA) were used to test the hypothesis that both Helianthus neglectus and H. paradoxus are stabilized hybrid derivatives of H. annuus and H. petiolaris. The four species are annuals, diploid outcrossers, and have the same chromosome number. Helianthus annuus and H. petiolaris had the same allele in highest frequency for 16 of the 18 isozyme loci examined and had different majority alleles for only 6-Pgd3 and Pgi2. The two species had divergent rDNAs that could be distinguished by seven diagnostic restriction site mutations and three length mutations, and their cpDNAs could be differentiated by three diagnostic restriction site mutations. The alleles observed in H. neglectus were not a combination of those observed in H. annuus and H. petiolaris. Although H. neglectus had only one unique allele, it possessed none of the three alleles specific to H. annuus. In contrast, it had four of the seven alleles specific to H. petiolaris. Furthermore, H. neglectus had the same rDNA type as H. petiolaris and had the same cpDNA as that found in two populations of H. petiolaris ssp. fallax. These data allowed us to speculate that H. neglectus may be a recent derivative of H. petiolaris ssp. fallax, rather than a stabilized hybrid derivative as originally proposed. In contrast, H. paradoxus combined the alleles of H. annuus and H. petiolaris and had no unique alleles. At Adh2, H. paradoxus was monomorphic for an allele found only in H. petiolaris ssp. fallax, whereas at 6-Pgd3 and Pgi2, it was monomorphic for high frequency H. annuus alleles. Furthermore, H. paradoxus combined the rDNA repeat types of both proposed parents and had the chloroplast genome of H. annuus. These data provide compelling evidence that H. paradoxus, in contrast to H. neglectus, was derived via hybridization.     

Duodenal ulcer relapse is not always associated with recurrence of H. pylori infection: a prospective three-year follow-up study

Background. Long-term data concerning the reappearance of Helicobacter pylori infection and duodenal ulcer (DU) recurrence after successful eradication are still few and conflicting. Inadequate histological assessment or use of indirect tests for the determination of H. pylori and bias in the selection of patients to be controlled can influence reported results. The aim of this study was to determine the rate of recurrence of H. pylori infection and ulcer relapse in a population of cured DU patients followed up for 3 years irrespective of their symptomatology. Methods. Between 1992 and 1994, 126 patients with DU disease were treated with double or triple therapy. Patients using nonsteroidal antiinflammatory drugs or aspirin or receiving maintenance antisecretory therapy were excluded. H. pylori infection was assessed by three bioptic tests from both the antrum and the body (culture, urease, histopathological examination). After 2 months from cessation of treatment, DU had healed and H. pylori infection was cured in 102 of 126 patients (81%). These patients were endoscopically followed up after 1 and 3 years, respectively, and were advised to contact us at symptom recurrence. At 1 and 3 years, we studied 95 (93.2%) and 79 (77.4%) patients, respectively, of the 102 who were cured. The other patients were untraceable or refused endoscopy because they were asymptomatic. Results. After 1 year, no patient had H. pylori recurrence, whereas three patients had a relapse of DU without evidence of infection. After 3 years, recurrence of H. pylori occurred in six patients (annual rate, 2.5%), DU relapsed in five H. pylori–positive patients (6.3%) and in two H. pylori–negative patients (annual rate, 1.9%). Fasting gastrin and acid secretion values studied in all relapsed patients were within the normal range except for one H. pylori–positive patient. Conclusions. Recurrence of H. pylori infection is very low where treatment is effective, but a DU relapse, not related to acid hypersecretion, can occur in a small percentage of cured patients.     

加勒比松种源苗期DNA甲基化多样性分析

为了解加勒比松(Pinus caribaea)种源的遗传多样性,利用甲基化敏感扩增多态性技术对加勒比松3个变种17个种源的DNA甲基化多样性进行了研究。结果表明,56对引物组合共扩增出425条谱带,其中多态性谱带422条,多态性百分率为99.25%。加勒比松种源幼苗半甲基化比率比全甲基化比率稍高,洪都拉斯加勒比松、古巴加勒比松和巴哈马加勒比松的DNA甲基化率分别为22.39%、22.29%和22.35%,差异不显著。加勒比松的DNA序列遗传多样性(H=0.4376)高于DNA甲基化多样性(H=0.3274),Mantel检验表明,基因组遗传变异与表观遗传变异不存在相关性(r=-0.171,P=0.16)。表观聚类与遗传聚类间存在较大差异,两种聚类分析结果均未将3个加勒比松变种分开。这表明加勒比松变种间的表观遗传变异极为丰富,能为加勒比松遗传改良提供优良种质资源。     

Leaf growth in the fast-growing Holcus lanatus and the slow-growing Deschampsia flexuosa: tissue maturation

Inherent variation in the relative growth rate of grasses is negatively correlated with that in leaf mass per unit leaf area (LMA). To scrutinize this correlation, the LMA of two grass species was analysed. Changes in LMA and cell wall synthesis in leaf blades of the fast-growing grass Holcus lanatus and the slow-growing grass Deschampsia flexuosa were investigated above the elongation zone of the leaf blade. After the leaf had obtained its final length, in H. lantus final LMA values of 40-44 gm^-2 were obtained at full leaf length, whereas in D. flexuosa LMA values continued to rise to 110 gm^-2. During this period of tissue maturation the LMA value doubled in H. lanatus, whereas in D. flexuosa an increase of 30% was measured. Most of the cell walls could be hydrolysed with driselase, the residue was hydrolysed with sulphuric acid. Driselase hydrolysates were identical in sugar composition, whereas the sugars released by sulphuric acid treatment changed gradually in composition as the tissue matured. The major sites of cell wall deposition during cell maturation were the outer walls of epidermal cells, fibres adjacent to the epidermis and the mestome ring around the vascular bundles. Lignin deposition was restricted to the vascular bundles and lignin levels of the leaf blade did not exceed 0.9% of the total amount of cell wall polysaccharides. Lignin accumulation occurred mainly after the increase in LMA and is unlikely to affect measurably the growth of these leaves.     

Karyotypes,nucleoli, and amphiplasty in hybrids between Hordeum vulgare L. and H. bulbosum L.

Chromosome measurements were carried out in Hordeum vulgare, H. bulbosum, and their diploid, triploid, and tetraploid hybrids. The chromosomes were classified by using relative values, and thus karyotypes were established. For comparison of these karyotypes both relative and absolute values were used. It was concluded that differential amphiplasty occurred, whereas neutral amphiplasty could not be demonstrated. In the hybrids the relative length of the parts of the chromosomes (long arm, short arm, satellite) was not changed in comparison with these lengths in the pure species. The karyotypes of both species had considerable similarities. From comparing the mean absolute genome lengths, it was, however, concluded that in the pure species, as well as in all hybrid types, the chromosomes of H. vulgare were longer than those of H. bulbosum. In the diploid and tetraploid hybrids the mean genome lengths were shorter than those in the pure species and the triploid hybrids. The differential amphiplasty was such that the secondary constriction of chromosome 6 of H. bulbosum, did not show up in the hybrids. This could be related to the suppression of nucleolar formation in the genome of H. bulbosum, because the maximum number of nucleoli in root tip cells equalled the number of satellite chromosomes. Finally it was found that the pattern of nucleolar fusion in diploid and triploid hybrids deviated from the expectation. The results were discussed in relation to chromosomal disturbances that occurred in the hybrid tissues and that resulted in elimination of chromosomes and other effects.     

Effects of X-irradiation induced loss of cerebellar granule cells on the synaptosomal levels and the high affinity uptake of amino acids.

Abstract— Crude synaptosomal (P₂) preparations were obtained from the cerebella of rats in which the granule cell population had been selectively reduced by X-irradiation treatment and from the cerebella of control animals. In the P₂ fraction from control cerebella, the level of glutamate was greater than any other of the 5 amino acids measured and was 2-fold higher than taurine, which was present at the next highest level. The content of taurine was slightly higher than that found for aspartate and was 3-fold greater than that observed for GABA. Alanine and glycine were present in the lowest amounts. The levels of glutamate and aspartate were significantly (P < 0.05) lower by 25 and 15%, respectively, in the P₂ fraction isolated from the X-irradiated cerebella in comparison to control values. The content of taurine, GABA, glycine, and alanine were not changed by the X-irradiation treatment. The uptake of 1.0 μm -l -[³H]glutamate and l -[³H]aspartate was reduced approx 20% by X-irradiation treatment, whereas the uptake of 1.0 μm -[³H]GABA and [³H]taurine was unchanged. A more detailed kinetic analysis of l -[³H]glutamate uptake revealed there was a 20% decrease in the V_max value with X-irradiation treatment and no change in the apparent K_m value. In a second study, the uptake of l -[³H]glutamate, l -[³H]aspartate and [³H]GABA was measured using P₂ fractions obtained from the cerebella of rats in which the population of granule, stellate and basket cells had been reduced by X-irradiation treatment. The uptake of 1.0μm -l -[³H]glutamate, l -[³H]aspartate and [³H]GABA was significantly (P < 0.05) reduced to 57, 68, and 59%, respectively, of control values. A more detailed kinetic analysis of [³H]GABA uptake revealed no significant change in the apparent K_m and a 35% decrease in the V_max value. The data are discussed in terms of glutamate being the excitatory neurotransmitter released from granule cells and GABA being the inhibitory neurotransmitter released from basket cells.     

EFFECTS OF SIMULATED ACID RAIN ON PHASEOLUS VULGARIS L. (FABACEAE)

Experiments were performed to determine the effects of simulated acid rain on Phaseolus vulgaris L. At pH values below 3, plants exhibited a failure to attain normal height, had necrotic and wrinkled leaves, excessive and adventitious budding, and premature abscission of primary leaves. Histologically, leaves had smaller cells, less intercellular space, and smaller starch granules within the chloroplasts. Respiration rates of the treated plants increased only slightly at low pH values. Apparent rates of photosynthesis, however, increased dramatically. Both carbohydrate production and root biomass were reduced by low pH treatments, and application of Congo red indicator to the acid-treated leaf tissue showed that the cell contents were acidified to a pH of below 4.0.     

Variations in the Ability of Ruminal Gram-Negative Prevotella Species to Resist Monensin

Gram-negative, ruminal Prevotella strains (n = 15) differed greatly in their sensitivity to the feed additive monensin. Strains that were repeatedly transferred with sublethal doses tolerated more monensin than those that were unadapted, but growth experiments indicated that the sensitivity range was as great as 2000-fold. Prevotella bryantii B₁4 grew with monensin concentrations as high as 20 μM, but P. ruminicola H15a, D31d, 20-63, E40a, and D42f never initiated growth if monensin was greater than 0.01 μM. Washed cell preparations that were energized with glucose lost intracellular potassium when monensin was added, and potassium depletion could also be used as an index of monensin sensitivity. Adapted cells of P. bryantii B₁4 had a half-maximal potassium depletion constant (K _d) of 3.2 μM, but the K _d values of P. ruminicola strains H15a, D31d, 20-63, E40a, and D42f were less than 0.04 μM. Maximal potassium depletion (K _max) values range from 90% to 40%, and monensin-adapted cells always had lower K _max values than unadapted cells. A linear regression of log K _d/K _max versus percentage decrease in optical density divided by monensin concentration had an r² of 0.75, and this regression indicated that potassium depletion from washed cells closely correlated with growth inhibition. P. bryantii B₁4 had a K _d/K _max ratio that was sevenfold greater than other Prevotella strains, and this result indicated that P. bryantii may be unusual in its ability to grow with very high concentrations of monensin. Received: 13 August 1999 / Accepted: 5 October 1999     

THE GENETIC ARCHITECTURE OF A COMPLEX ECOLOGICAL TRAIT: HOST PLANT USE IN THE SPECIALIST MOTH,HELIOTHIS SUBFLEXA

We used genetic mapping to examine the genetic architecture of differences in host plant use between two species of noctuid moths, Heliothis subflexa, a specialist on Physalis spp., and its close relative, the broad generalist H. virescens. We introgressed H. subflexa chromosomes into the H. virescens background and analyzed 1462 backcross insects. The effects of H. subflexa‐origin chromosomes were small when measured as the percent variation explained in backcross populations (0.2–5%), but were larger when considered in relation to the interspecific difference explained (1.5–165%). Most significant chromosomes had effects on more than one trait, and their effects varied between years, sexes, and genetic backgrounds. Different chromosomes could produce similar phenotypes, suggesting that the same trait might be controlled by different chromosomes in different backcross populations. It appears that many loci of small effect contribute to the use of Physalis by H. subflexa. We hypothesize that behavioral changes may have paved the way for physiological adaptation to Physalis by the generalist ancestor of H. subflexa and H. virescens.     

茶树品种(品系)芽叶色泽表型遗传数量分类研究

为探讨茶树春梢芽叶色泽的数量遗传特性,应用色差仪测定68份茶树品种(品系)春梢芽叶的色泽表型值并进行数量分类研究。结果表明,对叶色差异度较高的第1叶位L~*、a~*、b~*、C、H值进行分层聚类分析,可将芽叶色泽划分为紫色系、黄色系和绿色系等7个色系。色系分类与CIELab颜色体系的对应性较强,色系划分符合茶树品种(品系)叶色表型特点。茶树品系的叶色表型较丰富,叶色在L~*、a~*、b~*值三维坐标空间整体呈带域分布,色系由紫色系、紫红色系、紫绿色系向黄色系、黄绿色系、绿色系变化。春梢芽叶色泽表型数据的遗传数量分类与色系判定为茶树特异芽叶色泽育种提供科学依据。     

Epigenetic modulation of BRCA-1 and MGMT genes,and histones H4 and H3 are associated with breast tumors

Aberrant patterns in promoter methylation of tumor-suppressor genes and posttranslational modifications of histone proteins are considered as major features of malignancy. In this study, we aimed to investigate promoter methylation of three tumor-suppressor genes (BRCA-1, MGMT, and P16) and three histone marks (H3K9ac, H3K18ac, and H4K20me3) in patients with breast tumors. This case-control study included 27 patients with malignant breast tumors (MBT) and 31 patients with benign breast tumors (BBT). The methylation-specific PCR was used for determining promoter methylation of BRCA-1, MGMT, and P16 genes. Western blot analysis was performed to detect histone lysine acetylation (H3K9ac and H3K18ac) and lysine methylation (H4K20me3). BRCA-1 promoter methylation was detected in 44.4% of the MBT whereas this alteration was found in 9.7% of BBT (P = 0.005). The Kaplan-Meier analysis indicated that hypermethylation in BRCA-1 promoter was significantly associated with poor overall survival of patients with breast cancer (P = 0.039). MGMT promoter methylation was identified in 18.5% of MBT and 0.0% of the BBT (P = 0.01). The frequency of P16 promoter methylation was 25.8% in BBT and 11.1% in MBT (P = 0.12). As compared with BBT, MBT samples displayed the aberrant patterns of histones marks with hypomethylation of H4K20 and hypoacetylation of H3K18 (P = 0.03 and P = 0.04, respectively). There was a negative significant correlation between H3K9ac levels and tumor size in MBT group (r = −0.672; P = 0.008). The present findings suggest that promoter hypermethylation of MGMT and BRCA-1 genes along with alterations in H3K18ac and H4K20me3 levels may have prognostic values in patients with breast cancer. Moreover, the detection of these epigenetic modifications in breast tumors could be helpful in finding new methods for breast cancer therapy.     

Comparative studies on the nutrition of two species of abalone,Haliotis tuberculata Linnaeus and Haliotis discus hannai Ino I. Effects of algal diets on growth and biochemical composition

Summary

This study was conducted to examine the nutritional value of eight algal diets for two species of abalone, Haliotis tuberculata and Haliotis discus hannai, by measuring biochemical composition of the algae and relating this to feeding rate, growth and biochemical composition of the animals. Nutritional value of algal diets can be divided into three categories for each species of abalone. For H. tuberculata the best performance was on the mixed diet and Palmaria palmata intermediate was Alaria esculenta, Ulva lactuca and Laminaria digitata, and lowest growth was on Laminaria saccharina and Chondrus crispus. For H. discus hannai, best performance was on A. esculenta, P. palmata and the mixed diet; intermediate was on L. saccharina and L. digitata and lowest was on U. lactuca. It is generally accepted that high “balanced” levels of protein (>15%), lipid (3–5%) and carbohydrate (20–30%), with no detrimental substances in natural algae are essential for optimal growth performance of these abalone. The fact that A. esculenta, L. saccharina and U. lactuca had different dietary values for the two abalone species indicates specific nutritive requirements and/or digestive physiology. Overall, H. tuberculata grew faster, had higher food conversion efficiencies and muscle yield than H. discus hannai. Generally abalone fed on the highest category diets, had higher muscle yields and levels of protein, visceral lipids and muscle carbohydrate. Viscera and foot muscle are reservoirs for lipid and carbohydrate, respectively. The effect of algal diet on sexual maturation is similar to that on somatic growth.