Monitoring of genetically close Tsaiya duck populations using novel microsatellite markers with high polymorphism.

OBJECTIVE: A set of microsatellite markers with high polymorphism from Tsaiya duck were used for the genetic monitoring and genetic structure analysis of Brown and White Tsaiya duck populations in Taiwan. METHODS: The synthetic short tandem repeated probes were used to isolate new microsatellite markers from the genomic DNA of Tsaiya ducks. Eight populations, a total of 566 samples, sourced from Ilan Branch, Livestock Research Institute were genotyped through novel and known markers. The population genetic variables were calculated using optional programs in order to describe and monitor the genetic variability and the genetic structures of these Tsaiya duck populations. RESULTS: In total 24 primer pairs, including 17 novel microsatellite loci from this study and seven previously known loci, were constructed for the detection of genetic variations in duck populations. The average values for the allele number, the effective number of alleles, the observed heterozygosity, the expected heterozygosity, and the polymorphism information content were 11.29, 5.370, 0.591, 0.746, and 0.708, respectively. The results of analysis of molecular variance and principal component analysis indicated a contracting Brown Tsaiya duck cluster and a spreading White Tsaiya duck cluster. The Brown Tsaiya ducks and the White Tsaiya ducks with Pekin ducks were just split to six clusters and three clusters when K was set equal to 6 and 3 in the Bayesian cluster analysis. The individual phylogenetic tree revealed eight taxa, and each individual was assigned to its own population. CONCLUSION: According to our study, the 24 novel microsatellite markers exhibited a high capacity to analyze relationships of inter- and intra-population in those populations with a relatively limited degree of genetic diversity. We suggest that duck farms in Taiwan could use the new (novel) microsatellite set to monitor the genetic characteristics and structures of their Tsaiya duck populations at various intervals in order to ensure quality breeding and conservation strategies.

In vitro culture and characterization of duck primordial germ cells.

This study aimed to isolate, culture, and characterize duck primordial germ cells (PGCs) and to compare these cells with chicken PGCs. We first cultured Muscovy duck (Cairina moschata) circulating PGCs and gonadal PGCs (gPGCs) in the modified serum-containing medium used to amplify chicken PGCs. gPGCs were found to proliferate better in serum-free chemically defined medium than in serum-containing medium. Thereafter, gPGCs were similarly isolated from 2 other duck breeds, the Pekin duck (Anas platyrhynchos) and the hybrid mule duck (C. moschata × A. platyrhynchos), and amplified for a limited period of time in the chemically defined culture condition, but sufficiently to be characterized and transplanted. Cultured gPGCs of all 3 duck breeds were characterized by Periodic acid-Schiff staining, immunocytochemical staining, and expression analysis of germline-specific and pluripotency genes. Cultured duck gPGCs colonized the gonads after being genetically labeled and injected into recipient embryos. Taken together, these results demonstrate that duck PGCs retain their germline characteristics after being isolated, expanded in vitro, and genetically modified. Further studies are required to establish the optimal conditions for long-term culture of duck PGCs, which may involve supplementing the culture medium with other growth factors or compounds.

Treatment of duck house wastewater by a pilot-scale sequencing batch reactor system for sustainable duck production.

The objective of this study is trying to solve water pollution problems related to duck house wastewater by developing a novel duck house wastewater treatment technology. A pilot-scale sequencing batch reactor (SBR) system using different hydraulic retention times (HRTs) for treating duck house wastewater was developed and applied in this study. Experimental results showed that removal efficiency of chemical oxygen demand in untreated duck house wastewater was 98.4, 98.4, 87.8, and 72.5% for the different HRTs of 5, 3, 1, and 0.5 d, respectively. In addition, removal efficiency of biochemical oxygen demand in untreated duck house wastewater was 99.6, 99.3, 90.4, and 58.0%, respectively. The pilot-scale SBR system was effective and deemed capable to be applied to treat duck house wastewater. It is feasible to apply an automatic SBR system on site based on the previous case study of the farm-scale automatic SBR systems for piggery wastewater treatment.

Sperm Quality Parameters and Reproductive Efficiency in Muscovy Duck (Cairina moschata).

The in vitro sperm quality parameters (motility, M; viability, V; normal morphology, NM; plasma membrane integrity, PMI; mitochondrial function, MF) in Muscovy drakes (Cairina moschata) were evaluated by using microscopy and flow cytometry, the correlation among sperm quality parameters and results of artificial insemination was also assessed in present study. M, V and NM were detected by phase contrast microscopy assisted with eosinnigrosin staining, and PMI and MF were detected by using flow cytometry within appropriate fluorescence staining (SYBR-14/PI and R123/PI, respectively). Fertility (F), early embryonic mortality (EEM) and the survival embryo rate (SER) were assessed after the artificial insemination of Muscovy or Kaiya duck (Anas platyrhynchos) females. Sperm PMI and MF, the parameters detected by flow cytometry were positively correlated with sperm M, V, and NM, those were detected by phase contrast microscopy (P<0.05). Sperm V and PMI were negatively correlated with the percentage of early embryo mortality of Muscovy duck fertile eggs (P<0.05). The results of the present study showed the relationships among the AI results and the sperm quality parameters detected by microscopy as well as flow cytometry. In conclusion, flow cytometry assisted with microscopy can be an effective tool to evaluate in vitro sperm quality and may contribute to predict the reproductive performances of individual Muscovy drakes, which helps to improve duck production efficiency.

Freshwater clam extract inhibits inflammatory responses in LPS-activated macrophages by reducing the activation of mitogen-activated protein kinases and NF-kappaB.

Recent studies demonstrated that freshwater clam (Corbicula fluminea) has lipid-lowering and hepatoprotective activities, but its effect on immune responses has not yet been addressed. Here we showed that ethanol extracts of C. fluminea (ECF) reduced nitrite oxide, interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha in lipopolysaccharide-activated macrophages. Further, ECF was fractionated into n-hexane, ethyl acetate, ethanol, and water soluble fractions. Of these, the ethyl acetate soluble fraction (EACF) had the highest capacity to inhibit pro-inflammatory mediators expression. The underlying mechanisms for the anti-inflammatory activity of EACF were demonstrated as down-regulation of ERK1/2, JNK1/2, and p38 phosphorylation and NF-kappaB activity. Using gas chromatography-mass spectrometric analysis EACF was found to be composed mainly of fatty acids and steroids. Our results provide evidence that freshwater clam has anti-inflammatory activity, and support the possibility for the development of freshwater clam as a health supplement or adjuvant therapeutic agent for either preventing or treating inflammation related diseases.