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Asian seabass (Lates calcarifer) is an important foodfish species. It has been cultured in Singapore since the 1980s. A selective breeding program to improve growth, meat quality and disease resistance has been ongoing in Singapore since 2004. In 2012, outbreaks of the big belly disease (BBD) occurred in two batches of offspring generated by a mass-cross among F1 brooders in a hatchery. After the outbreaks, only 437 survived in 6000 F2 juveniles. Molecular parentage analysis with 10 microsatellites revealed that four parents (F1) produced high percentage of offspring that survived the BBD outbreaks. Eighty-two BBD survivor offspring (F2) were selected based on their growth performance at 90 days post hatch (dph), family origin and allelic diversity. They were used as brooders to generate F3. In a period of five years, these F2 brooders produced six batches of offspring, where no outbreak of BBD occurred. In the same period, outbreaks of BBD occurred in 4 out of 18 batches produced by F2 brooders selected for growth, with mortality rates ranging from 85.1% to 95.4%. In F3, the average body weight (57.1 ± 1.09 g, n = 3068) of the line for BBD survival was slightly lower than that (60.6 ± 2.29 g, n = 4280) of the line for growth at 90 dph. In both lines, the body weight of F3 was much higher than that (46.90 ± 0.19 g, n = 12117) of F2. The genetic diversity in the line for BBD survival (F3) was much lower than that in F3 line for growth due to small founder population. These data indicate that the selection of BBD survival during BBD outbreaks using molecular parentage analysis is effective to reduce BBD outbreaks. Avoiding further reduction of genetic diversity is essential in the line selected for increased survival against BBD. [ABSTRACT FROM AUTHOR]

In aquaculture species, maintaining pedigree information and genetic variation in each generation is essential, but very difficult. In this study, we used nine microsatellites to genotype 2,520 offspring from four independent full-factorial crosses (10 males × 10 females) of Asian seabass to reconstruct pedigree and monitor the change of genetic variations. In all four crosses, over 96.8% of the offspring could be assigned to their parents, indicating the high power of the nine microsatellites for parentage assignment. This study revealed several interesting results: (1). In all four crosses, the contribution of parents to offspring was significantly uneven, and some dominant breeding fishes (i.e. brooders) were found; (2). In two mass crosses where the brooders were carefully checked for reproductive status, a majority (⩾90%) of brooders contributed to offspring, whereas in another two crosses, where the brooders were randomly picked without checking reproductive status, only a few brooders (40.0-45.0%) produced offspring; (3). Females had more problems in successful spawning compared to males; and (4). In the two crosses where a few brooders produced offspring, there was a substantial loss in allelic (24.1- 34.3%) and gene (20.5-25.7%) diversities in offspring, while in the other two crosses, the majority of allelic (96.8-97.0%) and gene diversities (94.8-97.1%) were maintained. These observations suggest that a routine molecular parentage analysis is required to maintain both allelic and gene diversity in breeding Asian seabass. [ABSTRACT FROM AUTHOR]

AbstractAim:The aim of this study was to investigate the effect of the squamosamide derivative FLZ (N-2-(4-hydroxy-phenyl)-ethyl-2-(2,5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide) on lipopolysaccharide (LPS)-induced inflammatory mediator production and the underlying mechanism in RAW264.7 macrophages.Methods:RAW264.7 cells were preincubated with non-toxic concentrations of compound FLZ (1, 5, and 10 μmol/L) for 30 min and then stimulated with 10 μg/L LPS. The production of nitric oxide (NO), the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), and the activation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways were examined.Results:FLZ significantly inhibited the LPS-induced production of NO, as well as the expression of iNOS and COX-2 at both the RNA and the protein levels in RAW264.7 cells. The LPS-induced increase in the DNA binding activity of NF-κB and activator protein 1 (AP-1), the nuclear translocation of NF-κB p65, the degradation of the inhibitory κBα protein (IκBα) and the phosphorylation of IκBα, IκB kinase (IKK) α/β, c-Jun NH2-terminal kinase (JNK) and p38 MAPKs were all suppressed by FLZ. However, the phosphorylation of extracellular signal-regulated kinase (ERK) was not affected. Further study revealed that FLZ inhibited the phosphorylation of transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1), which is an upstream signaling molecule required for IKKα/β, JNK and p38 activation.Conclusion:FLZ inhibited the LPS-induced production of inflammatory mediators at least partly through the downregulation of the TAK-IKK and TAK-JNK/p38MAPK pathways.Acta Pharmacologica Sinica (2009) 30: 209–218; doi: 10.1038/aps.2008.29; published online 26th January 2009 [ABSTRACT FROM AUTHOR]