Effect of nitrogen application on growth and photosynthetic nitrogen use efficiency in two ecotypes of wild strawberry, Fragaria chiloensis

The relationships between increasing nitrogen fertilization and growth, maximum CO₂ assimilation and the initial slope of the CO₂ response curve were studied in 2 ecotypes of wild strawberry, Fragaria chiloensis (L.) Duchn. Nitrogen accumulation of CA11, an ecotype from a low-nutrient dune site, was greater at all nitrogen concentrations than that of RCP37, an ecotype from a higher-nutrient strand site. Maximum CO₂ assimilation, total Rubisco activity, dry weight, and initiation of leaves and crowns were higher in CAI1 than RCP37 as nitrogen treatment was increased from 0 to 200 mg ^l-1, whereas these parameters were lower in CAl1 when fertilized at 300 mg T¹, but not in RCP37. The mean leaf area of CA11 was greater than RCP37 when grown with no supplemental nitrogen, but mean leaf area of the 2 lines was similar under nitrogen fertilization. Maximum CO₂ assimilation and carboxylation efficiency increased with increasing leaf nitrogen in both clones. At equivalent concentrations of leaf nitrogen, RCP37 had higher CO₂ assimilation and carboxylation efficiency than CA11 and the difference between the 2 clones increased as ieaf nitrogen increased. Thus, RCP37 had a higher photosynthetic nitrogen use efficiency than CA11. However, at a given applied nitrogen level, CA11 allocated more nitrogen to a unit of leaf area so that photosynthetic rates were higher than RCP37, except at the highest application of 300 mg ^l-1. The high nitrogen accumulation capacity and resource allocation to fruiting structures (crowns) in CA11 leads us to suggest that this clone may possess genes that could increase fruit yield in cultivated strawberry.     

Use of hydrogen cyanamide for apple and plum thinning

Effects of various concentrations of Dormex (a.i. 49% hydrogen cyanamide) on fruit thinning of Rome Beauty apple (Malus domestica Borkh.), Friar and Simka plums (Prunus salicina Lindley) were studied. A full bloom application of Dormex at all tested concentrations decreased Rome Beauty apple fruit set and yield, and increased fruit weight. Dormex at 0.25% (v/v) resulted in adequate apple thinning, indicated by production of an optimum fruit weight (320 g). Prebloom and full bloom applications of Dormex at greater than 0.75% reduced plum fruit set and yield in Friar. Full bloom application of Dormex at 0.50% showed a satisfactory fruit set, yield, and fruit weight in Friar plum. Prebloom Dormex application had no significant effect on `Simka' plum fruit set or yield, but full bloom application decreased fruit set and yield.     

Antibodies recognizing specific Mycobacterium avium subsp. paratuberculosis’s MAP3738c protein in type 1 diabetes mellitus children are associated with serum Th1 (CXCL10) chemokine

Recently Mycobacterium avium subsp. paratuberculosis (Map) was associated to type 1 diabetes mellitus (T1DM). In this study we investigated for Map presence in children affected by T1DM compared to healthy children. A pool of 212 sera from T1DM children at onset was compared to sera from 57 healthy children for humoral immune response towards the Map specific protein MAP3738c by ELISA. Serum concentrations of CXCL10 (pro-Th1) and CCL2 (pro-Th2) chemokines were also measured in both sera pool. Results showed that T1DM children had a stronger seropositivity towards MAP3738c protein compared to healthy children. Data highlighted also the correlation between serum activity of T1DM patients towards the specific protein of Map and the increase of CXCL10 concentration if compared to non-diabetic subjects. In conclusion, an immune response to Map in T1DM patients at onset was observed and this may indicate a role of the bacterium in triggering or precipitating the disease.     

Circulating chemokine (CXC motif) ligand (CXCL)9 is increased in aggressive chronic autoimmune thyroiditis, in association with CXCL10

Chemokine (CXC motif) ligand (CXCL)9 (CXCL9) has been shown to be involved in autoimmune thyroid disorders, however no data are present about CXCL9 circulating levels in chronic autoimmune thyroiditis (AT) vs controls. Serum CXCL9 (and for comparison CXCL10) has been measured in patients with AT vs normal control and nontoxic multinodular goiter, and this parameter has been related to the clinical phenotype. For this study we selected 189 consecutive patients with newly diagnosed AT, 63 euthyroid controls, 30 patients with nontoxic multinodular goiter. The three groups were similar in gender distribution and age; 26% of AT patients had subclinical hypothyroidism. Serum CXCL9 was significantly higher in AT (148±110 pg/mL) than in controls (71±34 pg/mL) or patients with multinodular goiter (87±35 pg/mL) (p<0.0001). Among AT patients, CXCL9 levels were significantly higher in patients older than 50 years, those with a hypoechoic ultrasonographic pattern or with hypothyroidism. Also CXCL10 was confirmed to be associated with AT, overall in presence of hypothyroidism. In a multiple linear regression model of CXCL9 (ln[pg/mL]) vs age, thyroid volume, TSH, AbTg, AbTPO, hypoechoic pattern, the presence of hypervascularity, and CXCL10 (ln[pg/mL]), only TSH and CXCL10 (ln[pg/mL]) were significantly related to serum CXCL9 levels. We show that circulating CXCL9 is increased in patients with aggressive thyroiditis and hypothyroidism. A strong relation between circulating CXCL9 and CXCL10 has been first shown, underlining the importance of a T helper 1 immune attack in the initiation of AT.     

Structural model of the amino propeptide of collagen XI alpha1 chain with similarity to the LNS domains

Fibrillar collagens are the principal structural molecules of connective tissues. The assembly of collagen fibrils is regulated by quantitatively minor fibrillar collagens, types V and XI. A unique amino-terminal propeptide domain of these collagens has been attributed this regulatory role. The structure of the amino terminal propeptide has yet to be determined. Low sequence similarity necessitated a secondary structure-based method to carry out homology modeling based upon the determined structure of LNS family members, named for a common structure in the laminin LG5 domain, the neurexin 1B domain and the sex hormone binding globulin. Distribution of amino acids within the model suggested glycosaminoglycan interaction and calcium binding. These activities were tested experimentally. Sequence analyses of existing genes for collagens indicate that 16 known collagen alpha chains may contain an LNS domain. A similar approach may prove useful for structure/function studies of similar domains in other collagens with similar domains. This will provide mechanistic details of the organization and assembly of the extracellular matrix and the underlying basis of structural integrity in connective tissues. The absolute requirement for collagen XI in skeletal growth is indicated by collagen XI deficiencies such as chondrodystrophies found in the cho/cho mouse and in humans with Stickler syndrome.     

A comprehensive mouse IBD database for the efficient localization of quantitative trait loci

Traditional fine-mapping approaches in mouse genetics that go from a linkage region to a candidate gene are very costly and time consuming. Shared ancestry regions, along with the combination of genetics and genomics approaches, provide a powerful tool to shorten the time and effort required to identify a causative gene. In this article we present a novel methodology that predicts IBD (identical by descent) regions between pairs of inbred strains using single nucleotide polymorphism (SNP) maps. We have validated this approach by comparing the IBD regions, estimated using different algorithms, to the results derived using the sequence information in the strains present in the Celera Mouse Database. We showed that based on the current publicly available SNP genotypes, large IBD regions (>1 Mb) can be identified successfully. By assembling a list of 21,514 SNPs in 61 common inbred strains, we inferred IBD regions between all pairs of strains and confirmed, for the first time, that existing quantitative trait genes (QTG) and susceptibility genes all lie outside of IBD regions. We also illustrated how knowledge of IBD structures can be applied to strain selection for future crosses. We have made our results available for data mining and download through a public website ( ). Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users.     

Analysis of chromosome damage in circulating lymphocytes of radiological workers affected by thyroid nodules

The aim of our study was to assess whether or not thyroid nodularity in combination with occupational exposure to low levels of ionising radiation would be correlated with chromosome damage in peripheral lymphocytes. Conventional chromosome-aberration analysis was performed on a group of 92 hospital workers with or without thyroid nodules. On the basis of measurements of their exposure levels, the workers were classified into a low (mean total level=0.03 mSv), medium (mean total level=1.04 mSv) or high (mean total level=8.60 mSv) exposure category. Our results indicate that among workers with thyroid nodules, the high-exposed workers showed significantly higher levels of both total (2.35+/-0.34 per 100 cells) and chromosome-type aberrations (1.46+/-0.20 per 100 cells) than medium-exposed (0.98+/-0.42 and 0.68+/-0.25 per 100 cells, respectively) or low-exposed workers (1.11+/-0.29 and 0.58+/-0.17 per 100 cells, respectively). Workers without thyroid nodules had comparable frequencies of chromosome aberrations among the three exposure categories. To our knowledge, this is the first study revealing a slight, but significant increase of chromosome damage in peripheral lymphocytes from hospital workers who developed thyroid nodules under conditions of occupational exposure to radiation well below the threshold limit for the workplace. The existence of a possible association between chromosome aberrations and development of thyroid nodularity will be discussed.     

Persistent degenerative changes in thymic organ function revealed by an inducible model of organ regrowth

The thymus is the most rapidly aging tissue in the body, with progressive atrophy beginning as early as birth and not later than adolescence. Latent regenerative potential exists in the atrophic thymus, because certain stimuli can induce quantitative regrowth, but qualitative function of T lymphocytes produced by the regenerated organ has not been fully assessed. Using a genome-wide computational approach, we show that accelerated thymic aging is primarily a function of stromal cells, and that while overall cellularity of the thymus can be restored, many other aspects of thymic function cannot. Medullary islet complexity and tissue-restricted antigen expression decrease with age, representing potential mechanisms for age-related increases in autoimmune disease, but neither of these is restored by induced regrowth, suggesting that new T cells produced by the regrown thymus will probably include more autoreactive cells. Global analysis of stromal gene expression profiles implicates widespread changes in Wnt signaling as the most significant hallmark of degeneration, changes that once again persist even at peak regrowth. Consistent with the permanent nature of age-related molecular changes in stromal cells, induced thymic regrowth is not durable, with the regrown organ returning to an atrophic state within 2 weeks of reaching peak size. Our findings indicate that while quantitative regrowth of the thymus is achievable, the changes associated with aging persist, including potential negative implications for autoimmunity.     

Effect of two microalgae concentrations on body size and egg size of the rotifer <Emphasis Type="Italic">Brachionus calyciflorus</Emphasis>

The rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 10⁶ cells ml⁻¹). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed on higher densities of Chlorella sp. (10 × 10⁶ cells ml⁻¹) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 10⁶ cells ml⁻¹). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size.     

Reciprocal Hemizygosity Analysis of Mouse Hepatic Lipase Reveals Influence on Obesity

Objectives: We previously demonstrated coincident quantitative trait loci (QTLs) for percentage body fat, plasma hepatic lipase (HL) activity, and plasma cholesterol on mouse chromosome 7. In the present study, we investigated whether hepatic lipase (Lipc) is an obesity gene, whether Lipc interacts with an unknown gene on chromosome 7, and how HL activity is linked to the chromosome 7 locus. Research Methods and Procedures: BSB mice are a model of complex obesity due to interactions among genes from C57BL/6J and Mus spretus (SPRET) in (C57BL/6J × SPRET) × C57BL/6J backcross mice. Five crosses tested the impact on obesity of combinations of inactive (knockout) and wild‐type Lipc alleles from C57BL/6J or SPRET in a reciprocal hemizygosity analysis. Results: The combined data from this allelic series suggest that Lipc alleles, and not alleles from a gene linked to Lipc, influence obesity. No interaction between Lipc and chromosome 7 was demonstrated. We confirmed the chromosome 7 QTLs for obesity, HL activity, and cholesterol. Because obesity and HL activity are not consistently associated in the BSB model, linkage of HL activity to chromosome 7 is not secondary to obesity per se. We also report, for the first time to our knowledge, a QTL in mammals for food intake. Discussion: This use of reciprocal hemizygosity analysis in mammals, which, to our knowledge, is the first reported, reveals its power to detect previously unknown effects of Lipc on obesity.