Genetic differences between the wild and hatchery-produced populations of Korean short barbeled grunter (Hapalogenys nitens) determined with microsatellite markers.

Short barbeled grunter, Hapalogenys nitens, is an economically important fishery resource. In Korea, this fish is in the early stage of domestication, and it has been regarded as the candidate marine fish species for prospective aquaculture diversification. This study presents a preliminary investigation of the future viability of sustainable fry production from short barbeled grunter. We used 12 polymorphic nuclear microsatellite DNA loci to analyze the possible genetic variability between the wild and hatchery-produced populations of short barbeled grunter from Korea and identified 91 alleles. Compared to the wild population, significant genetic changes including reduced genetic diversity (average allele number: 7.42 vs 3.75; average expected heterozygosity: 0.713 vs 0.598, Wilcoxon signed-rank test; P < 0.05) and differentiation [overall fixation index (FST) = 0.088, P < 0.01] occurred in the hatchery-produced population, as indicated by the observation of allele richness, unique allele, heterozygosity, FST, and results of molecular analysis of variance. These findings indicate that genetic drift may have promoted the differentiation between these 2 populations, which may have negative effects on sustainable fry production. Therefore, genetic variations of the wild and hatchery-produced populations should be monitored and subjected to control inbreeding through a commercial breeding program. The information presented by this paper would provide a useful genetic basis for future sustainable culturing planning and management of H. nitens.

Comparison of genetic diversity between wild-caught broodstock and hatchery-produced offspring populations of the vulnerable Korean kelp grouper (Epinephelus bruneus) by microsatellites.

The kelp grouper Epinephelus bruneus (Perciformes: Haemulidae), is one of the most economically important fishery resources in Korea. This fish is regarded as a target for prospective aquaculture diversification; therefore, maintenance of stock quality is important. To investigate the effects of current artificial reproduction in a hatchery facility, genetic variation in wild-caught broodstock and hatchery-produced offspring of kelp grouper was analyzed using eight polymorphic nuclear microsatellite DNA loci; 77 alleles were identified. Allelic variability ranged from 2 to 22 in the broodstock and from 1 to 10 in the offspring. The average observed and expected heterozygosities were 0.620 and 0.623 in the broodstock and 0.600 and 0.513 in the offspring, respectively. The possibility of a recent genetic bottleneck was suggested in both populations of E. bruneus. The minor, but significant, genetic differentiation (FST = 0.047, P < 0.05) observed was mainly due to statistically significant reductions in the number of alleles in the offspring compared with the broodstock, suggesting that these genetic changes could be related to genetic drift. Our results demonstrate the usefulness of microsatellite markers to monitor genetic variation and raise concerns about potential harmful genetic effects of inappropriate hatchery procedures. Therefore, genetic variation between broodstock and offspring in a hatchery should be monitored in both breeding and release programs as a routine hatchery operation, and inbreeding should ideally be controlled to improve kelp grouper hatchery management. Our data provide a useful genetic basis for future planning of sustainable culture and management of E. bruneus in fisheries.

Fibrinolysis in glomerulonephritis treated with ancrod: renal functional, immunologic and histopathologic effects.

The effects of a 14-day course of ancrod on fibrinolysis, renal function and structure, and immunologic findings are reported in 37 patients with glomerulonephritis. Patients were divided into two groups. In the first, the level of fibrin degradation products within 48 h was relatively low (less than 1 mg/ml). In these patients there was a linear relationship between changes in levels of fibrin degradation products and fibrinogen, suggesting that fibrin degradation products derived from ancrod-cleaved-fibrinogen in the circulating pool; in most, level of plasma alpha 2-antiplasmin before treatment was elevated. In the second, the level of fibrin degradation products within 48 h was high (greater than 1 mg/ml). Compared with the change in fibrinogen, a disproportionate increase in levels of fibrin degradation products suggested that a significant amount derived from sources other than plasmin digested ancrod-cleaved-fibrinogen, thus reflecting effective fibrinolysis, perhaps also in tissues; in most, the level of plasma alpha 2-antiplasmin was normal before treatment. In those with initial high levels of fibrin degradation products, higher levels persisted throughout treatment, changes in other fibrinolysis components were greater, and plasminogen activator inhibitor levels became normal. In patients with initial high but not with initial low response in fibrin degradation products renal function improved within 24 to 48 h and continued to improve thereafter; there was an immediate but temporary increase in proteinuria. Microvascular thrombosis decreased significantly, indicating effective removal of fibrin from glomeruli. The relation of early fibrinolysis to changes in immunologic and histopathologic findings was analyzed in patients with lupus nephritis. With ancrod, there was an increase toward normal of serum C3 and C4, a decrease in serum Igs, gamma globulin and anti-dsDNA antibody and in glomerular C3 and Ig deposits, suggesting that ancrod had favorable effects on immunologic factors. There were no clinical differences in patients with initial high and low responses, but the relationship of microvascular and inflammatory indexes before treatment differed. Initial renal biopsies and those after treatment were carried out on average 28 days apart. Inflammatory and microvascular indexes and glomerular thrombi decreased in patients with initial high levels of fibrin degradation products; fibrosclerosis index and glomerular sclerosis increased in patients with initial low levels of fibrin degradation products. Fibrinolysis expressed as the 48 h (fibrin degradation products/fibrinogen) ratio, correlated inversely with change in fibrosclerosis index and glomerular sclerosis in the whole group, and especially in those with initial high levels of fibrin degradation products.(ABSTRACT TRUNCATED AT 400 WORDS)