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Effect of cholesterol-loaded cyclodextrins on bull and goat sperm processed with fast or slow cryopreservation protocols
No full textCholesterol-loaded cyclodextrins (CLC) added to the sperm before cryopreservation enhance sperm quality after freeze-thawing in several cold shock-sensitive species, including cattle and goats. However, all studies conducted to date have used conventional protocols, in which sperm are cooled slowly to 5 degrees C before freezing. As cholesterol plays a significant role in sperm cold shock resistance, it is possible that CLC-treated sperm can withstand cooling damage when the sperm are not cooled slowly to 5 degrees C before freezing. In this study, we determined whether CLC-treated goat (1 mg CLC/120x10(6) sperm) and bull (2 mg CLC/120x10(6) sperm) sperm quality, after thawing, was different for sperm frozen using conventional protocols (including a slow cooling phase to 5oC) and protocols in which the sperm were frozen from room temperature, without cooling the sperm slowly to 5 degrees C before freezing. CLC-treated sperm exhibited higher percentages of plasma membrane-intact sperm than control sperm when cryopreserved using conventional protocols. In addition, CLC treatment enhanced both sperm motility and plasma membrane integrity when sperm were frozen directly from room temperature. However, this treatment did not fully prevent the damage of the sperm after cooling rapidly and subsequent freezing, as the sperm quality was lower than that presented by the samples frozen using the conventional protocol. The results are promising, but studies to optimize the protocols for freezing sperm directly from room temperature need to be conducted, as well as studies to determine how cryopreserving sperm in this manner affects other sperm functions
Microbial examination of anaerobic sludge adaptation to animal slurry
No full textThe objective of this study was to evaluate changes in the microbial population of anaerobic sludge digesters during the adaptation to pig slurry (PS) using quantitative real-time polymerase chain reaction (qPCR) and qualitative scanning electron microscopy (SEM). Additionally, the relationship between microbial parameters and sludge physicochemical composition and methane yield was examined. Results showed that the addition of PS to an unadapted thermophilic anaerobic digester caused an increase in volatile fatty acids (VFA) concentration, a decrease in removal efficiency and CH4 yield. Additionally, increases in total bacteria and total archaea were observed using qPCR. Scanning electron micrographs provided a general overview of the sludge's cell morphology, morphological diversity and degree of organic matter degradation. A change in microbial morphotypes from homogeneous cell morphologies to a higher morphological diversity, similar to that observed in PS, was observed with the addition of PS by SEM. Therefore, the combination of qPCR and SEM allowed expanding the knowledge about the microbial adaptation to animal slurry in thermophilic anaerobic digesters
Aplicaciones potenciales de los residuos orgánicos en viveros de especies forestales mediterráneas
Get PDFLa creciente actividad de reforestación en el área mediterránea, fruto de la necesidad de reducir la importante degradación medioambiental de esta zona, ha disparado la demanda de plantas en los viveros forestales. Como consecuencia, grandes cantidades de materiales no renovables como turba o suelo natural están siendo utilizadas para la fabricación de sustratos. En horticultura y viverismo ornamental, el aprovechamiento de residuos y subproductos orgánicos es una práctica cada vez más extendida, que tiene el doble efecto de ser beneficiosa para el desarrollo de las plantas y respetuosa con el medio ambiente. El objetivo de este estudio fue explorar el uso potencial de composts y residuos orgánicos fácilmente disponibles en la producción de Pinus halepensis en viveros forestales del área mediterránea. Se realizaron tres ensayos poniendo especial interés en su adaptación a las necesidades locales del sector y a las características de los materiales orgánicos existentes en la zona: 1) Evaluación del uso de fibra de coco, de huesecillo de aceituna y de compost de residuos urbanos como componentes de sustratos 2) Estudio de la aplicación de vermicompost como promotor del crecimiento radicular 3) Uso de harinas cárnicas y compost de lodos de depuradora como fertilizantes alternativos a la fertilización mineral. Pese al carácter exploratorio de este ensayo, se han obtenido resultados prometedores respecto al uso de residuos orgánicos como fertilizantes y como sustratos en viverismo forestal en condiciones mediterráneas. Así, el empleo como sustrato de cultivo de fibra de coco reciclada, sola o en combinación con compost de residuos urbanos o huesecillo de aceituna, produjo plantas de biomasa igual o incluso en ciertos casos superiores, a aquellas crecidas en el mantillo comercial normalmente utilizado en los viveros de la zona. Los índices morfológicos de calidad y el contenido de nutrientes fueron similares, por lo que estos materiales se presentan como una firme alternativa a los sustratos habitualmente empleados. La aplicación de vermicompost, en cambio, no estimuló el desarrollo de las raíces, ni siquiera con la dosis superior de las cinco ensayadas. La fertilización orgánica con harinas de carne y compost de lodos de depuradora produjo plantones de calidad similar a los obtenidos con la fertilización mineral
Effect of Antioxidants on Enzymatic Browning of Eggplant Extract and Fresh-Cut Tissue
No full textThe effect of antioxidants controlling enzymatic browning of eggplants was studied in extract and fresh-cut tissue. Initially, the effect of ascorbic acid (AA), citric acid (CA), peracetic acid (PA), calcium chloride, cyclodextrin, cysteine (Cys), hexametaphosphate and 4-hexylresorcinol (Hexyl) at different concentrations was studied in extracts and precipitates of eggplant. Cys and Hexyl were effective at 10 mM in both the extract and pellet. Higher concentrations were needed to have an effective control of enzymatic browning in samples treated with AA (20 mM), CA (50 mM) and PA (50 mM). Next, the application of AA, CA, PA, Cys and Hexyl at different concentrations was studied on fresh-cut eggplant tissues during storage at 5C. Cys was effective as antioxidant, extending the shelf life till 9 days of storage at 5C when applied at a concentration of 1%. Tissue browning increased as AA and Hexyl concentrations increased
Effect of the addition of calcium to freezing extender on boar sperm quality after cryopreservation
No full textEffect of lanosterol on the in vitro maturation in semi-defined culture system of prepubertal ewe oocytes
No full textThe choice of medium and supplements can affect meiotic regulation and may have an impact on the regulation of mammalian oocyte growth and embryonic cell function. The aim of the present study was to assess the effects of oxygen concentration and endogenous lanosterol on the in vitro maturation (IVM) media without serum and based on recombinant human chorionic gonadotrophin in prepubertal ewe oocytes. Firstly, the effect of varying oxygen concentrations (5% and 20%) during IVM in TCM-199 supplemented (4 mg/ml bovine serum albumin (BSA), 100 M cysteamine, 0.3 mM sodium pyruvate, 0.1 UI/ml recombinant follicle-stimulating hormone (r-FSH; Gonal-F (R) 75 UI, Serono, Italy), 0.1 UI/ml recombinant leuteinizing hormone (r-LH; Lhadi (R) 75 UI, Serono, Italy) and 1 g/ml estradiol-17) on subsequent nuclear maturation of oocytes examined under ultraviolet light following staining with bisbenzimide (Hoechst 33342) was investigated. Secondly, two concentrations of lanosterol (0, 10 and 50 M) were added to the IVM medium. Nuclear maturation of oocytes was examined as previously. Lipid content in oocytes, an important indicator of cytoplasmic maturity, was also measured using Nile red fluorescent stain. The results showed that low oxygen concentration affected the nuclear maturation. Similarly, a significantly higher rate of meiosis resumption was observed with 10 M (72.3%) of lanosterol compared with the control (51.8%) or 50 M of lanosterol (59.4%). A significantly higher content of lipids was also observed with 10 and 50 M of lanosterol (7.3 +/- 0.2 x 10(6) and 7.4 +/- 0.2 x 10(6) arbitrary units of fluorescence) compared with the control (6.7 +/- 0.2 x 10(6) arbitrary units of fluorescence). The results indicate that 10 M lanosterol during IVM in medium without serum and based on recombinant human chorionic gonadotrophin has a positive effect on maturation of prepubertal ewe oocytes
Current impact and future directions of high throughput sequencing in plant virus diagnostics
No full textThe ability to provide a fast, inexpensive and reliable diagnostic for any given viral infection is a key parameter in efforts to fight and control these ubiquitous pathogens. The recent developments of high-throughput sequencing (also called Next Generation Sequencing - NGS) technologies and bioinformatics have drastically changed the research on viral pathogens. It is now raising a growing interest for virus diagnostics. This review provides a snapshot vision on the current use and impact of high throughput sequencing approaches in plant virus characterization. More specifically, this review highlights the potential of these new technologies and their interplay with current protocols in the future of molecular diagnostic of plant viruses. The current limitations that will need to be addressed for a wider adoption of high-throughput sequencing in plant virus diagnostics are thoroughly discussed. (C) 2014 Elsevier B.V. All rights reserved
Plum pox virus and sharka: a model potyvirus and a major disease
Get PDFTaxonomic relationships:
Plum pox virus (PPV) is a member of the genus Potyvirus in the family Potyviridae. PPV diversity is structured into at least eight monophyletic strains.
Geographical distribution:
First discovered in Bulgaria, PPV is nowadays present in most of continental Europe (with an endemic status in many central and southern European countries) and has progressively spread to many countries on other continents.
Genomic structure:
Typical of potyviruses, the PPV genome is a positive-sense single-stranded RNA (ssRNA), with a protein linked to its 5′ end and a 3′-terminal poly A tail. It is encapsidated by a single type of capsid protein (CP) in flexuous rod particles and is translated into a large polyprotein which is proteolytically processed in at least 10 final products: P1, HCPro, P3, 6K1, CI, 6K2, VPg, NIapro, NIb and CP. In addition, P3N-PIPO is predicted to be produced by a translational frameshift.
Pathogenicity features:
PPV causes sharka, the most damaging viral disease of stone fruit trees. It also infects wild and ornamental Prunus trees and has a large experimental host range in herbaceous species. PPV spreads over long distances by uncontrolled movement of plant material, and many species of aphid transmit the virus locally in a nonpersistent manner.
Sources of resistance:
A few natural sources of resistance to PPV have been found so far in Prunus species, which are being used in classical breeding programmes. Different genetic engineering approaches are being used to generate resistance to PPV, and a transgenic plum, ‘HoneySweet’, transformed with the viral CP gene, has demonstrated high resistance to PPV in field tests in several countries and has obtained regulatory approval in the USA
The effect of epistasis between linked genes on quantitative trait locus analysis
No full textThe effect of epistasis between linked genes on quantitative trait locus (QTL) analysis was studied as a function of their contribution to the phenotypic variance and their genetic distance by simulation of F2 (at least 200 individuals) and recombinant inbred line (RIL) populations. Data sets were replicated 100 times. For F2 populations, the presence of epistasis improves the detection of QTLs having effects in opposite directions. Epistasis between linked QTLs (26.5 cM) was poorly detected even when its contribution was relatively high compared to the main effects, and was null for heritabilities lower than 0.10. The detection of false-positive main effects is strongly affected by the distance between epistatic QTLs. The closer they are (a parts per thousand currency sign11.5 cM), the higher the probability of detecting false-positive main-effect QTLs and the lower the probability of detecting epistatic effects. In this case, the presence of main-effect QTLs is due to the deviation of the heterozygote from the homozygotes at each linked interacting QTL and is algebraically explained by the joint effect of the linkage and the additive-by-additive interaction, resulting in a heterosis at a single genomic region in the absence of simulated dominant genetic effects. The number of false-positive main effects only reached nominal levels at about 100 cM. For RIL populations, the number of false positives or the detection of existing epistasis does not depend on the distance, and the power to detect epistatic QTLs is much higher even with small sample sizes and low contributions to the trait. RIL populations are highly recommended to detect epistatic QTLs and to better infer the genetic architecture of a quantitative trait
Effect of the holding time at 15 degrees C prior to cryopreservation, the thawing rate and the post-thaw incubation temperature on the boar sperm quality after cryopreservation
No full textThe aim of the present study was to evaluate the effect of the holding time at 15 degrees C prior to cryopreservation (2,4 and 8 h), thawing rate (37 degrees C for 20 s or 70 degrees C for 8 s) and post-thaw incubation temperature (15 degrees C or 37 degrees C) on the post-thaw boar sperm quality. These are important time periods in the freezing-thawing process which have been less studied. Sperm-rich ejaculate fractions from three healthy boars were collected once a week for five consecutive weeks and were cryopreserved with the lactose-egg yolk extender (LEY). Sperm quality was determined by assessing the motility, the acrosome status, and the sperm plasma membrane integrity at 30, 150 and 240 min of incubation. The results show that with the holding time at 15 degrees C prior to cryopreservation there was not a clear effect until at least 24 h of holding time. The thawing rate and the post-thaw incubation temperature, however, had a marked effect on sperm quality. When the samples were thawed at 70 degrees C for 8 s, the sperm viability, motility and some kinetic variables (VCL, VSL, VAP and ALH) were greater than with results observed when the samples were thawed at 37 degrees C for 20 s. In addition after thawing the sperm samples incubated at 15 degrees C had a sustained sperm quality for longer, up to 4 h post-thawing. (C) 2014 Elsevier B.V. All rights reserved