Qingyin Wang

Sequence characterized amplified regions (SCAR) reveal candidate markers linked to growth traits in the Chinese shrimp Fenneropenaeus chinensis

Growth traits in 150 Chinese shrimps Fenneropenaeus chinensis were analyzed by the sequence characterized amplified regions (SCAR) technique in two populations of sixth-generation cultured shrimps with different ranges of body lengths (CP-a and CP-b) and in the wild-type population (WP). First, 240 random primers were used to screen polymorphic fragments by random amplified polymorphic DNA (RAPD). Population analysis revealed nine RAPD markers correlated with growth traits, including seven positively and two negatively correlated ones. The sequences of the RAPD markers were then used to design longer primers for SCAR. Six primer pairs were obtained, and two of these produced polymorphic fragments among the three groups. One amplified 39, 26 and 27 polymorphic fragments, with band frequencies of 78, 52 and 54% in the CP-a, CP-b and WP groups, respectively. The distributions of polymorphic fragments in the three groups were significantly different (Pxa0<xa00.05) according to a χ2 test, indicating that they may be candidate markers linked to growth traits. Another primer pair amplified three alleles, resulting in six combinations of genotypes among three groups. Since allele A1 was only found in the population of shorter shrimps, it may be a negative growth marker.

Effects of BPA and E2 on expression profiles of genes related to hypothalamic-pituitary-gonadal axis of half-smooth tongue sole Cynoglossus semilaevis

Endocrine disrupting chemicals (EDCs) are increasingly viewed as persistent pollutants, similar to natural hormones in function. This paper describes the expression profiles of 7 genes (DMRT, VTG GnRHR FSHR CYP17A CYP19A, and CYP19B) involved in sex steroid synthesis and action as well as sexual development in adult male and female Cynoglossus semilaevis, after exposure to different concentrations of Bisphenol A (BPA) and 17β-estradiol (E2). Both BPA (1, 10, 50, 125, and 250 mg/kg) and E2 (0.5, 5, and 10 mg/kg) induced changes in target gene expression, although the estrogenic effects of E2 as a model estrogen were stronger. Among the 7 genes, VTG CYP17A and CYP19 responded strongly to BPA or E2 exposure and can thus serve as reference biomarkers for estrogenic EDCs exposure in marine teleosts. These data will provide a window to establish a hypothalamic-pituitary-gonadal model in C. semilaevis to better understand the effect pathways of EDCs.

Mechanical stress induces neuroendocrine and immune responses of sea cucumber (Apostichopus japonicus)

Grading procedure in routine sea cucumber hatchery production is thought to affect juvenile sea cucumber immunological response. The present study investigated the impact of a 3-min mechanical perturbation mimicking the grading procedure on neuroendocrine and immune parameters of the sea cucumber Apostichopus japonicus. During the application of stress, concentrations of noradrenaline and dopamine in coelomic fluid increased significantly, indicating that the mechanical perturbation resulted in a transient state of stress in sea cucumbers. Coelomocytes concentration in coelomic fluid increased transiently after the beginning of stressing, and reached the maximum in 1 h. Whereas, coelomocytes phagocytosis at 3 min, superoxide anion production from 3 min to 0.5 h, acid phosphatase activity at 0.5 h, and phenoloxidase activity from 3 min to 0.5 h were all significantly down-regulated. All of the immune parameters recovered to baseline levels after the experiment was conducted for 8 h, and an immunostimulation occurred after the stress considering the phagocytosis and acid phosphatase activity. The results suggested that, as in other marine invertebrates, neuroendocrine/immune connections exist in sea cucumber A. japonicus. Mechanical stress can elicit a profound influence on sea cucumber neuroendocrine system. Neuroendocrine messengers act in turn to modulate the immunity functions. Therefore, these effects should be considered for developing better husbandry procedures.

Cytological observations on fertilization and early embryonic development in sea cucumber Apostichopus japonicus

A series of characteristic cytological events during fertilization and early embryonic development in Apostichopus japonicus were studied by the fluorescence microscope with HOECHST 33258 stained.The results indicated that unfertilized mature eggs of A.japonicus were globular and remained at the metaphase of meiosis Ⅰ.At water temperature of 22-23 ℃ and salinity 29,sperms quickly attached to the surface of the egg after mixing of sperms and eggs.At 12 min after insemination,the first meiosis is finished,with release of the first polar body.Most of fertilized eggs released the second polar bodies at 20 min after insemination.About 35 min,the male and the female pronuclei associated with each other after their chromosomes formed respectively in the center of egg.The first and second cleavages finished at 80 min and 100 min respectively in fast developing fertilized eggs.Polyspermy phenomena were observed in the fertilization process in A.japonicus.