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American shad Alosa sapidissima, an anadromous clupeid, exhibits variation in reproductive strategies, including semelparity and iteroparity. It provides an excellent model for studying the behaviour of germ cells in anadromous fish during their migration from sea to river. The vasa gene was characterized in A. sapidissima as a germ-cell marker to elaborate the process of germ-cell development and differentiation in anadromous species. A complementary (c)DNA fragment of 819 bp, partial open reading frame (ORF), was cloned by degenerate PCR and named as ASvas. In adult A. sapidissima, vasa transcript was exclusively detected in gonads by reverse-transcription (RT)-PCR. Through chromogenic in situ hybridization, the vasa messenger (m)RNA was specifically detected in primordial germ cells (PGC) in embryos and germ cells at early stages in ovary and testis. Besides, the cellular distribution profile of Vasa protein also proved that vasa gene could be used as a germ-line marker to trace the PGCs migration during embryogenesis and the germ-cell differentiation during gametogenesis in A. sapidissima. During embryogenesis, the migrating PGCs were clearly detected at tail-bud stage and the PGCs reached the genital ridge at the stage of pre-hatching stage in A. sapidissima embryos. During gametogenesis, the Vasa protein was dynamically expressed in differentiating germ cells at different stages in adult gonads. As far as we know, this is the first report to demonstrate the PGCs migration and germ-cell differentiation through vasa gene expression in the anadromous species. The findings will pave a way for investigating germ-cell development and maturation in the A. sapidissima and other anadromous fish.

In this study, we developed a multiplex microsatellite polymerase chain reaction (PCR) assay that consisted of 13 pairs of primers selected from previously developed microsatellite markers in mud carp data obtained in our laboratory. We adjusted the number of cycles, the time of extension, and the primer ratios to make the multiplex PCR system as valuable as possible. Using this system, we performed a genetic analysis and parentage assignment for 2 male and 5 female mud carps and 146 of their progeny. The results showed a range of alleles of 2

The voltage-dependent anion channel (VDAC) is a highly conserved integral protein of mitochondria in different eukaryotic species. It forms a selective channel in the mitochondrial outer membrane that serves as the controlled pathway for small metabolites and ions. In this study, a VDAC gene, EcVDAC1, was isolated from orange-spotted grouper (Epinephelus coioides). The EcVDAC1 exhibits ubiquitous expression in various tissues of orange-spotted grouper and is upregulated in liver, gill, and spleen after stimulation with lipopolysaccharides (LPS). Subcellular localization analysis shows that the EcVDAC1 protein colocalized with the mitochondria. A caspase-3 assay demonstrates that overexpression of the EcVDAC1 induced apoptotic cell death in fathead minnow cells. The data presented in this study provide new information regarding the relationship between LPS and the EcVDAC1 gene, suggesting that the fish VDAC1 gene may play an important role in antibacterial immune response.

The American Shad Alosa sapidissima was introduced into China for aquaculture in 2003. The histological characteristics of the digestive tract of American Shad larvae were examined from hatching to 33 d after hatching (DAH) with the aim of cultivating the larvae efficiently. The fertilized American Shad eggs were imported from Oregon and incubated in barrels with spring water maintained at 20.3–21.9°C in Qingyuan, Guangdong Province, China. The larvae were transferred to cement pools (water temperature at 24.0–25.0°C) at 13 DAH. Larvae were fed Artemia nauplii starting at 3 DAH, Artemia nauplii supplemented with gradually increasing proportions of commercial formulated feed after 18 DAH, and then only the formulated feed by 30 DAH. Based on the source of nutrition and structural changes in the digestive tract, larval development was divided into three stages: (1) lecitotrophic (0–2 DAH), (2) lecitoexotrophic (3 DAH), and (3) exotrophic (4–33 DAH). At 0 DAH of the lecitotrophic stage, the digestiv...