Heritability of cortisol response to confinement stress in European sea bass dicentrarchus labrax

Background

In fish, the most studied production traits in terms of heritability are body weight or growth, stress or disease resistance, while heritability of cortisol levels, widely used as a measure of response to stress, is less studied. In this study, we have estimated heritabilities of two growth traits (body weight and length) and of cortisol response to confinement stress in the European sea bass.

Findings

The F1 progeny analysed (n = 922) belonged to a small effective breeding population with contributions from an unbalanced family structure of just 10 males and 2 females. Heritability values ranged from 0.54 (±0.21) for body weight to 0.65 (±0.22) for standard body length and were low for cortisol response i.e. 0.08 (±0.06). Genetic correlations were positive (0.94) between standard body length and body weight and negative between cortisol and body weight and between cortisol and standard body length (−0.60 and −0.55, respectively).

Conclusion

This study confirms that in European sea bass, heritability of growth-related traits is high and that selection on such traits has potential. However, heritability of cortisol response to stress is low in European sea bass and since it is known to vary greatly among species, further studies are necessary to understand the reasons for these differences.     

Treatment of stress urinary incontinence with duloxetine hydrochloride

Currently, there are no approved medications for the treatment of stress urinary incontinence (SUI) in the United States. The effectiveness of duloxetine in the treatment of SUI is linked to its inhibition of presynaptic neuronal reuptake of serotonin and norepinephrine in the central nervous system, resulting in elevated levels of serotonin and norepinephrine in the synaptic cleft. In animal studies, this agent leads to an increase in nerve stimulation to the urethral striated sphincter muscle. A similar mechanism in women is believed to result in stronger urethral contractions, with improved sphincter tone during urine storage and physical stress. In 3 randomized, placebo-controlled clinical trials, patients receiving duloxetine had a statistically significant and clinically relevant reduction in the number of incontinence episodes and a corresponding improvement in quality of life. If this use of duloxetine is approved by the U.S. Food and Drug Administration, as it has been by the European regulatory agencies, it will be the first drug indicated for the treatment of SUI. This pharmacologic therapy is an additional option for women and is likely to become an integral component of patient management.     

Preliminary evaluation of non-native rainbow trout (Oncorhynchus mykiss) impact on the Cederberg ghost frog (Heleophryne depressa) in South Africa’s Cape Fold Ecoregion

We evaluated the impact of non-native rainbow trout Oncorhynchus mykiss on a population of endemic Cedarberg ghost frog Heleophryne depressa in the upper Krom River (Olifants-Doring River Catchment, Cape Fold Ecoregion). We compared H. depressa abundance (using kick-sampling and underwater video analysis) and environmental conditions between sites above and below a waterfall that marks the upper distribution limit of O. mykiss. Heleophryne depressa abundance was significantly greater above the waterfall than that below it, and, because there was no significant difference in measured environmental variables, O. mykiss presence is identified as the most likely explanation for the observed decrease in H. depressa abundance.     

Cell-to-cell and phloem-mediated transport of potato virus X. The role of virions

Movement-deficient potato virus X (PVX) mutants tagged with the green fluorescent protein were used to investigate the role of the coat protein (CP) and triple gene block (TGB) proteins in virus movement. Mutants lacking either a functional CP or TGB were restricted to single epidermal cells. Microinjection of dextran probes into cells infected with the mutants showed that an increase in the plasmodesmal size exclusion limit was dependent on one or more of the TGB proteins and was independent of CP. Fluorescently labeled CP that was injected into epidermal cells was confined to the injected cells, showing that the CP lacks an intrinsic transport function. In additional experiments, transgenic plants expressing the PVX CP were used as rootstocks and grafted with nontransformed scions. Inoculation of the PVX CP mutants to the transgenic rootstocks resulted in cell-to-cell and systemic movement within the transgenic tissue. Translocation of the CP mutants into sink leaves of the nontransgenic scions was also observed, but infection was restricted to cells close to major veins. These results indicate that the PVX CP is transported through the phloem, unloads into the vascular tissue, and subsequently is transported between cells during the course of infection. Evidence is presented that PVX uses a novel strategy for cell-to-cell movement involving the transport of filamentous virions through plasmodesmata.     

The movement protein of cucumber mosaic virus traffics into sieve elements in minor veins of nicotiana clevelandii

The location of the 3a movement protein (MP) of cucumber mosaic virus (CMV) was studied by quantitative immunogold labeling of the wild-type 3a MP in leaves of Nicotiana clevelandii infected by CMV as well as by using a 3a-green fluorescent protein (GFP) fusion expressed from a potato virus X (PVX) vector. Whether expressed from CMV or PVX, the 3a MP targeted plasmodesmata and accumulated in the central cavity of the pore. Within minor veins, the most extensively labeled plasmodesmata were those connecting sieve elements and companion cells. In addition to targeting plasmodesmata, the 3a MP accumulated in the parietal layer of mature sieve elements. Confocal imaging of cells expressing the 3a-GFP fusion protein showed that the 3a MP assembled into elaborate fibrillar formations in the sieve element parietal layer. The ability of 3a-GFP, expressed from PVX rather than CMV, to enter sieve elements demonstrates that neither the CMV RNA nor the CMV coat protein is required for trafficking of the 3a MP into sieve elements. CMV virions were not detected in plasmodesmata from CMV-infected tissue, although large CMV aggregates were often found in the parietal layer of sieve elements and were usually surrounded by 3a MP. These data suggest that CMV traffics into minor vein sieve elements as a ribonucleoprotein complex that contains the viral RNA, coat protein, and 3a MP, with subsequent viral assembly occurring in the sieve element parietal layer.     

Female grooming markets in a population of gray-cheeked mangabeys (Lophocebus albigena)

Primate female allogrooming models based on biological marketstheory predict that grooming is "time matched" within bouts,that is, the amount of time the first female grooms predictsthe amount of time the second one grooms. The models also predictthat when female–female contest competition is weak, groomingis traded for grooming, but when female–female contestcompetition is strong, grooming may be traded for other commoditiessuch as feeding tolerance, and grooming discrepancy betweenmembers of dyads is rank related. We tested these predictionsusing data collected from adult and subadult female gray-cheekedmangabeys (Lophocebus albigena) (N = 26) in 5 groups in KibaleNational Park, Uganda. We found that, overall, females reciprocatedin 33% of grooming bouts. Among reciprocated bouts, femalesin all 5 groups showed time matching. In 2 groups, we also foundrank-related grooming discrepancies but showing opposite patternsto each other. Consistent with predictions based on biologicalmarkets theory, these groups may have been under greater feedingcompetition, revealed more by adjustments in ranging behaviorthan increased agonistic rates. Although these results supportcurrent allogrooming models, they also suggest that the modelsmay become more robust if the influence of scramble competitionis incorporated. In addition, they emphasize the flexibilityand dynamic nature of female competitive relationships withinthe same population of primates.