Lipid composition of the mantle and digestive gland of <Emphasis Type="Italic">Octopus vulgaris</Emphasis> juveniles (Cuvier, 1797) exposed to prolonged starvation

Lipid composition of the mantle and digestive gland of Octopus vulgaris that were not fed for 27 days were determined. Every 3 days, three octopuses were killed and samples of the mantle and the digestive gland (DG) were taken, in order to determine total lipids as well as lipid classes and fatty acids. Composition in total lipids (TL) for the mantle was similar until day 21, then decreased and remained similar until the end of the experiment. Composition in total lipids for the DG decreased significantly after 3 days, then remained similar until day 21, and then decreased until the end of the experiment. As for the lipid classes, in the DG the main components were triglycerides and sterol esters. Sterol esters suffered strong reductions after 10 days of starvation, while triglycerides remained similar until day 21 and then decreased until the end of the experiment. Cholesterol decreased gradually throughout the experimental period. For polar lipids, phosphatidylcholine and phosphatidylethanolamine increased during the first 3 days and then decreased throughout the experiment. In the mantle, the only neutral classes that decrease were triacylglycerols and sterol esters, while no polar lipid classes decreased in this organ. It was noticeable the decrease in almost all fatty acids in the DG after 3 days of starvation, while in the mantle there were no differences in fatty acid concentrations during the experiment.     

Comparison between haplotype-based and individual snp-based genomic predictions for beef fatty acid profile in Nelore cattle

The aim of this study was to evaluate the genomic predictions using the single-step genomic best linear unbiased predictor (ssGBLUP) method based on SNPs and haplotype markers associated with beef fatty acids (FAs) profile in Nelore cattle. The data set contained records from 963 Nelore bulls finished in feedlot (±90 days) and slaughtered with approximately 24 months of age. Meat samples from the Longissimus dorsi muscle were taken for FAs profile measurement. FAs were quantified by gas chromatography using a SP-2560 capillary column. Animals were genotyped with the high-density SNP panel (BovineHD BeadChip assay) containing 777,962 markers. SNPs with a minor allele frequency and a call rate lower than 0.05 and 0.90, respectively, monomorphic, located on sex chromosomes, and with unknown position were removed from the data set. After genomic quality control, a total of 469,981 SNPs and 892 samples were available for subsequent analyses. Missing genotypes were imputed and phased using the FImpute software. Haplotype blocks were defined based on linkage disequilibrium using the Haploview software. The model to estimate variance components and genetic parameters and to predict the genomic values included the random genetic additive effects, fixed effects of the contemporary group and the age at slaughter as a linear covariate. Accuracies using the haplotype-based approach ranged from 0.07 to 0.31, and those SNP-based ranged from 0.06 to 0.33. Regression coefficients ranged from 0.07 to 0.74 and from 0.08 to 1.45 using the haplotype- and SNP-based approaches, respectively. Despite the low to moderate accuracies for the genomic values, it is possible to obtain genetic progress trough selection using genomic information based either on SNPs or haplotype markers. The SNP-based approach allows less biased genomic evaluations, and it is more feasible when taking into account the computational and operational cost underlying the haplotypes inference.     

Fatal coccidiosis by Isospora icterus (Upton & Whitaker, 2000) in captive Campo Troupial (Icterus jamacaii) in Brazil

An outbreak of coccidiosis by Isospora icterus (I. icterus, Upton & Whitaker, 2000) in captive Campo Troupial (Icterus jamacaii) (Gmelin, 1788) at the Wild Animals Triage Center (IBAMA, Belo Horizonte, Brazil) is described. Clinical history and the necropsy findings documented diarrhea with diffuse necrotic enteritis. Sporulated oocysts (n = 100) had a bilayered wall, were subspherical, and measured 30.1 (27.5-32.5) microm in length and 28.5 (26.2-30.0) microm in width. A polar body but no micropyle was present and the length/width ratio was 1.1 (1.00-1.2). Each oocyst contained two ellipsoidal sporocysts measuring 17.6 (15.0-20.0) microm in length and 12.9 (12.5-15.0) microm in width, with a length/width ratio of 1.4 (1.2-1.5), and with Stieda and sub-Stieda bodies. Each sporocyst contained four sporozoites with granular sporocyst residuum. Oocysts were compatible with those from I. icterus, previously described in Campo Troupial.     

Quantitative studies on downy mildew (<Emphasis Type="Italic">Peronospora destructor</Emphasis> Berk. Casp.) affecting onion seed production in southern Uruguay

Onion downy mildew (Dm) symptoms and damage on seed production fields in southern Uruguay were quantified during two seasons as the progress of incidence, severity, and as the effect of the level of seed-stalks infections on seed yield and quality. In addition, the effects of two plantation dates and two plant densities on Dm were studied in a factorial experiment. Maximum incidence along the season ranged from 15 to 65% in four commercial fields in 2005 and two fields in 2006. Maximum severity ranged from 4.5 to 9.3% of leaf area affected in 2005, and 0.35 to 1.17% in 2006. Whereas Dm incidence varied among studied fields, disease progress as Dm severity varied mainly between studied years. Crop rotation, crop vigour and plant density were identified as major factors affecting Dm variation in the field. Intensive fungicide schedules did not control Dm when other conditions favoured the disease. A high level of Dm severity defined as large necklace spots on seed-stalks significantly reduced seed yield in comparison with healthy seed-stalks in 2005, as well as seed yield and germination in 2006. Weight of 1,000 seeds was not significantly reduced by Dm infections on seed-stalks. Six genera of fungi were recovered from seeds harvested on highly infected seed-stalks (Stemphylium, Fusarium, Alternaria, Penicillium, Aspergillus and Botrytis), but not Peronospora. Late planting date and low plant density had significantly lower Dm incidence and severity. This finding questioned the early planting dates and high densities previously recommended in order to achieve high yielding crops. The combination of several practices to reduce initial inoculum, susceptibility status of the host, and environmental conditions promoting the disease is discussed as forming a basis for effective disease control.     

PCR-RFLP analysis of the whole chloroplast DNA from three cultivated species of cotton (Gossypium L.)

Variations of the chloroplast DNA (cpDNA) from three of the four cultivated species of cotton (Malvaceae); Gossypium barbadense L., Gossypium hirsutum L., Gossypium arboreum L. and its synonym Gossypium nanking Meyen., were analyzed. Using specific set of primers, the whole circular cpDNAs from the four test species were amplified. These were subsequently digested with the use of seven restriction enzymes. The amplified fragments of the whole cpDNAs of the diploid cultivated cotton G. arboreum and its synonym G. nanking did not show any differences. However, the allotetraploid cultivated cottons G. barbadense and G. hirsutum, showed some fragment length differences directly visible after amplification and two types of restriction fragment length polymorphism (RFLP), the first appeared as slightly lengthened bands and the other as gain or loss of a restriction site. The results also showed that the chloroplast genomes of the allotetraploid cultivated cottons are highly similar to the diploid cultivated cottons tested in terms of length and digestion patterns. The detected amplified length differences, RFLPs and the restriction sites can be considered as species specific markers for the allotetraploid cultivated cottons, which could be a useful tool for future studies of the cpDNA of the genus Gossypium L.     

Structure and genetic diversity of macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] approached by SNP markers to assist breeding strategies

Genetic Resources and Crop Evolution - Macauba palm [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] is a perennial oil, it stands out for having several characteristics of commercial interest, mainly...     

Shade tolerance, photoinhibition sensitivity and phenotypic plasticity of Ilex aquifolium in continental Mediterranean sites

Shade tolerance, plastic phenotypic response to light and sensitivity to photoinhibition were studied in holly (Ilex aquifolium L.) seedlings transported from the field to a greenhouse and in adult trees in the field. All plants were growing in, or originated from, continental Mediterranean sites in central Spain. Seedlings tolerated moderate but not deep shade. Mortality was high and growth reduced in 1% sunlight. Survival was maximal in 12% sunlight and minimal in full sunlight, although the relative growth rate of the seedlings surviving in high light was similar to that of plants in moderate shade. Maximum photochemical efficiency at predawn was significantly lower in sun plants than in shade plants in the field, revealing chronic photoinhibition that was most pronounced in winter. Plasticity in response to available light varied according to the variable studied, being low for photosynthetic capacity and stomatal conductance, and high for specific leaf area, root:shoot ratio and leaf area ratio, particularly in seedlings. Differences in water relations and hydraulic features between sun and shade plants in the field were marginal. High water potential at the turgor loss point of field-grown plants suggested that holly is sensitive to drought during both the seedling and the adult stage. Low relative growth rates in both high and low light with low physiological plasticity in response to light indicate the existence of a stress-tolerance mechanism. We conclude that holly is a facultative understory plant in areas of oceanic and relatively mild climate, but an obligate understory plant in dry continental areas such as the study site. The impact of abandonment of traditional management practices and climate change on these Mediterranean populations is discussed.     

Long‐lasting Effect Against White Spot Syndrome Virus in Shrimp Broodstock,Litopenaeus vannamei,by LvRab7 Silencing

The white spot syndrome virus (WSSV) remains the most devastating viral pathogen of shrimp culture worldwide. Gene silencing by RNA interference (RNAi) using double stranded RNA (dsRNA) has been considered a powerful tool for conferring protection against WSSV when viral genes are silenced, as documented in several shrimp species. However, this effect is not long lasting. Our results provide the first evidence that long‐term silencing of the LvRab7 endogen produced antiviral effect against WSSV, which endured at least 21 d after dsRNA treatment (dat). Until now, the most efficient way to implement RNAi with dsRNA into the shrimp is by injection. Consequently, its application to broodstock in hatcheries is possible, minimizing the risk of vertical transmission of the virus. We show that the expression of Rab7 in hemocytes is lowest at 2 dat and finally recovers to basal status. In contrast, in gills and pleopods, gene expression silencing continued for at least 21 d. We challenged Litopenaeus vannamei broodstock with WSSV at 7, 14, or 21 dat reaching mortality rates of 0, 40, and 27%, respectively. In conclusion, the LvRab7 gene silencing is progressive and effective against WSSV. However, further studies are necessary to elucidate the functions of Rab7 in shrimp cells before applying this methodology at a commercial level.