Intermediary metabolic response and gene transcription modulation on the Sub-Antarctic notothenioid Eleginops maclovinus (Valenciennes, 1930) injected with two strains of Piscirickettsia salmonis

Pathogen interactions with cultured fish populations are well studied, but their effects on native fishes have not been characterized. In Chile, the disease caused by bacterial species Piscirickettsia salmonis represents one of the main issues and is considered to be one of the important pathogens in the field of aquaculture. They have been found to infect native fish. Therefore, it is necessary to understand the impact of P. salmonis on native species of local commercial value, as well as the potential impact associated with the emergence of antibiotic-resistant strains of P. salmonis. Due to this purpose, the native fish Eleginops maclovinus was used in our study. Fish were randomly distributed in tanks and intraperitoneally inoculated with two strains of P. salmonis. No mortality was recorded during the experiment. Cortisol, glucose and total α-amino acid levels increased in fish injected with AUSTRAL-005 strain compared to sham-injected and LF-89-inoculated fish. Moreover, results showed an increase in the activity of carbohydrates and lipids metabolism in liver; and an increase in the carbohydrates, lipids and total α-amino acid metabolism in muscle after injection with AUSTRAL-005. Our results suggest that P. salmonis modulates the physiology of E. maclovinus and the physiological impact increase in the presence of the antibiotic-resistant strain AUSTRAL-005.     

Evaluation of a multi-parent advanced generation inter-cross (MAGIC) introgressed line population for Verticillium wilt resistance in Upland cotton

Verticillium wilt (VW, caused by Verticillium dahliae Kleb) is a destructive fungal soil-borne disease in Upland cotton (Gossypium hirsutum L.). High levels of VW resistance can be transferred into Upland from Pima cotton (G. barbadense L.) through interspecific introgression breeding. In this greenhouse study, VW resistance was evaluated in a multi-parent advanced generation inter-cross (MAGIC) introgressed line (IL) population, derived from a random mated Barbadense Upland population with five generations of intermating (called RMBUP-C4) between three Upland cotton cultivars and 18 CS-B Upland lines each carrying a pair of G. barbadense chromosome or arm in the TM-1 background. The objectives of this study were to, (1) evaluate VW resistance of 530 MAGIC ILs in the greenhouse; and (2) to identify lines with VW resistance in the MAGIC population based on a total of three replicated greenhouse tests. Approximately 8 plants for each line in each replicate were grown and screened for VW resistance using three parameters i.e., disease leaf severity rating, percentage defoliated leaves, and percentage infected plants, with a total of ~?25,190 plants evaluated. A correlation analysis indicated that the three parameters were significantly and positively correlated with one another in each test. The disease leaf severity rating was the best parameter to assess VW resistance due to its relatively low coefficient of variation and its higher resolution to differentiate resistant genotypes from susceptible ones. Of the 530 genotypes, 5 showed resistance to VW, namely, NMIL348, NMIL518, NMIL405, NMIL290, NMIL307 and had higher levels of resistance to VW with mean disease leaf severity ratings, percentage of defoliated leaves, and percentage of infected plants across three tests ranging from 0.58–1.46, 9.46–26.74, and 25–95%, respectively. These lines can be used as parental lines to improve VW resistance in cotton breeding programs.     

Quality assessment of newly hatched mud crab,Scylla serrata,larvae

Starvation and exposure to formalin were investigated as possible stress tests for evaluating the quality of mud crab, Scylla serrata, larvae. For the starvation stress test, newly hatched zoeae stocked in 150‐ml containers were either starved or fed rotifers. Similarly, newly hatched zoeae were stocked in containers with seawater of 0 (control), 20, 30 and 40 mg/L formalin for the formalin stress test. The zoeae from the same batches were used for seed production to monitor their performance and validate the results of stress tests. Starvation was found to be unsuitable for larval quality evaluation. However, the impact of initial food deprivation on the newly hatched larvae indicates that feeding immediately after hatching is necessary for mud crab larvae. Exposure of larvae to 40 mg/L formalin for 3 hr appeared to be a reliable and practical method for larval quality assessment as the survival of larvae in the mass production tanks validated the classification of good and poor quality batches in the stress tests. On this basis, a hatchery operator can decide which batch should be cultured further. Finally, there appears to be a link between the quality of larvae and the performance at the megalopa and early juvenile crabs.     

Changes in Gut Microbiota Linked to a Reduction in Systolic Blood Pressure in Spontaneously Hypertensive Rats Fed an Extra Virgin Olive Oil-Enriched Diet

Fat type in diet is responsible for specific changes in gut microbiota (GM). Extra virgin olive oil (EVOO) has been shown to be beneficial for blood pressure and to produce effects on GM. To analyze the cause-effect relationship between intestinal microbial changes and blood pressure, we studied the effect of EVOO on fecal microbiota and systolic blood pressure (SBP) levels in spontaneously hypertensive rats (SHR). SHR were fed either an enriched EVOO diet or a standard diet for a period of 12 weeks. At the end of the experimental period, the microbial profiles in the feces were studied in both groups by using PCR-denaturing gradient gel electrophoresis. Real-time PCR was used to quantify the selected bacterial groups. The results demonstrated significant differences when using Lactobacillus (p<0.05), clostridia XIV (p<0.01) and universal (p<0.05) primers. A significant (r=?0.475; p=0.04) inverse correlation between the abundance of clostridia XIV and SBP, which depends on the type of diet, was also observed. Finally, the results suggested an increase in the microbial diversity of the feces of the animals fed the EVOO diet. These results strongly connect the pattern of GM in SHR fed a diet enriched with EVOO to the lower levels of SBP observed in these animals at the end of the feeding period.