Heritability estimation of silver carp (Hypophthalmichthys molitrix) harvest traits using microsatellite based parentage assignment

Silver carp accounts for the largest biomass production of any finfish aquaculture species in the world. In spite of its great importance as an aquacultural species, very little is known about the genetic parameters of its commercially important traits. As an initial step towards developing a selective breeding programme, heritability of harvest weight and length was estimated for a silver carp stock maintained in the NFRDMP (North West Fisheries Resource Development and Management Project) hatchery in Bangladesh. Three sets of partial factorial matings were performed (12 sires and 12 dams in each set) to produce full and half-sib families for this study. Offspring from all families produced in a set were reared communally for six months and then weighed and measured upon harvesting. Ten silver carp microsatellite markers were included in two multiplex PCR systems and were used to assign parentage to the individuals. Out of 331 offspring, 96.3% could be assigned to a single family. Statistical analyses to partition the variance components for weight and length data were carried out by the REML (Restricted Maximum Likelihood) method. Heritability for harvest weight was estimated to be 0.67 (confidence interval: 0.42-0.93) and for harvest length 0.51 (confidence interval: 0.29-0.78). Despite the limited sample size, the moderate to high heritability estimates suggest that this population should respond rapidly to selective breeding for increased harvest size. In addition to this first report of quantitative genetic parameters in silver carp, this paper also describes two novel multiplexes of silver carp microsatellite markers for parentage assignment and discusses the effects of the partial factorial mating design in maintaining effective population size in this species

Detection of hybridization between Chinese carp species (Hypophthalmichthys molitrix and Aristichthys nobilis) in hatchery broodstock in Bangladesh, using DNA microsatellite loci

Hybridization between silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) has been reported to occur fairly frequently in commercial aquaculture hatcheries in Bangladesh. The consequences of hybridization for broodstock purity had not previously been investigated. Allelic variation at three microsatellite DNA loci isolated from silver carp routinely distinguished between silver carp and bighead carp. These markers were used in the analysis of samples collected from hatcheries in different regions of Bangladesh. Of 422 hatchery broodstock that were morphologically identified as silver carp, 8.3% had bighead allele(s) at one or more of the three microsatellite loci, while 23.3% of the 236 fish morphologically identified as bighead carp had silver carp allele(s) at one or more loci. The results suggested that while some of these fish might be F1 hybrids, others had more complex genotypes, suggesting further generations of hybridization or introgression between the species in hatcheries, with potentially damaging consequences for the integrity of these stocks and their performance in aquaculture

Aquaporin 1 regulates GTP-induced rapid gating of water in secretory vesicles

The swelling of secretory vesicles has been implicated in exocytosis, but the underlying mechanism of vesicle swelling remains largely unknown. Zymogen granules (ZGs), the membrane-bound secretory vesicles in exocrine pancreas, swell in response to GTP mediated by a G(α)(i3) protein. Evidence is presented here that the water channel aquaporin-1 (AQP1) is present in the ZG membrane and participates in rapid GTP-induced vesicular water gating and swelling. Isolated ZGs exhibit low basal water permeability. However, exposure of granules to GTP results in a marked potentiation of water entry. Treatment of ZGs with the known water channel inhibitor Hg(2+) is accompanied by a reversible loss in both the basal and GTP-stimulatable water entry and vesicle swelling. Introduction of AQP1-specific antibody raised against the carboxyl-terminal domain of AQP1 blocks GTP-stimulable swelling of vesicles. Our results demonstrate that AQP1 associated at the ZG membrane is involved in basal as well as GTP-induced rapid gating of water in ZGs of the exocrine pancreas

Acetaminophen as a renoprotective adjunctive treatment in patients with severe and moderately severe falciparum malaria : a randomized, controlled, open-label trial

Background: Acute kidney injury independently predicts mortality in falciparum malaria. It is unknown whether acetaminophen’s capacity to inhibit plasma hemoglobin-mediated oxidation is renoprotective in severe malaria. Methods: This phase 2, open-label, randomized controlled trial conducted at two hospitals in Bangladesh assessed effects on renal function, safety, pharmacokinetic (PK) properties and pharmacodynamic (PD) effects of acetaminophen. Febrile patients (>12 years) with severe falciparum malaria were randomly assigned to receive acetaminophen (1 g 6–hourly for 72 hours) or no acetaminophen, in addition to intravenous artesunate. Primary outcome was the proportional change in creatinine after 72 hours stratified by median plasma hemoglobin. Results: Between 2012 and 2014, 62 patients were randomly assigned to receive acetaminophen (n = 31) or no acetaminophen (n = 31). Median (interquartile range) reduction in creatinine after 72 hours was 23% (37% to 18%) in patients assigned to acetaminophen, versus 14% (29% to 0%) in patients assigned to no acetaminophen (P = .043). This difference in reduction was 37% (48% to 22%) versus 14% (30% to −71%) in patients with hemoglobin ≥45000 ng/mL (P = .010). The proportion with progressing kidney injury was higher among controls (subdistribution hazard ratio, 3.0; 95% confidence interval, 1.1 to 8.5; P = .034). PK–PD analyses showed that higher exposure to acetaminophen increased the probability of creatinine improvement. No patient fulfilled Hy’s law for hepatotoxicity. Conclusions: In this proof-of-principle study, acetaminophen showed renoprotection without evidence of safety concerns in patients with severe falciparum malaria, particularly in those with prominent intravascular hemolysis.Published versio