Genetics In Fisheries Research Articles

Assessment of Needs for Education Opportunities in Fisheries Genetics

Although many fisheries management activities affect the genetics of managed populations, most fishery managers have not received education or training in fisheries genetics. In this study, I assessed opportunities and perceived needs for education and training in fisheries genetics. A survey of university fisheries science programs revealed more than half of the fisheries curricula in North America offer students little or no opportunity for coursework in fisheries genetics, but many departments were interested in establishing or expanding offerings in fisheries genetics. A survey of administrators of state, provincial, and federal fisheries management agencies documented a shortfall of in-house agency expertise in genetics relative to perceived needs. Agency heads indicated strong support for sending key individuals to continuing education short courses in areas of relevance to agency missions. Development of teaching support materials and more extensive offering of continuing education short courses are important measures for improving education opportunities in fisheries genetics.

Application of DNA Fingerprinting to Confirmation of Clone in Ayu

In order to determine the effectiveness of DNA fingerprinting as a tool for confirmation of clonal nature and identity, we applied a DNA fingerprinting method to three genetically different groups of ayu Plecoglossus altivelis: clonal diploid, mitotic gynogenetic diploid (mitotic-G2N) and normal diploid. Genomic DNA extracted from blood was digested by Pst I restriction endonuclease and was hybridized with repetitive sequence in bacteriophage M13 DNA labelled with [α-32P] isotope. DNA fingerprints of P. altivelis were detected over the whole effective fraction range from 0.5-25 Kilobase pairs, and more than 42 fragment patterns were detected. The DNA fingerprints of clonal fish consisted of at least 21 distinguishable bands which showed identical patterns within a clone. Mitotic-G2N consisted of 12-18 bands, and an individual fingerprint of this group hardly shared the bands of the other individuals. A trend of markedly low levels of band sharing in the DNA fingerprint among individuals of mitotic-G2N fish would be useful as a powerful genetic marker for their respective clonal lines. In N-CONT, 9 of the 18-24 distinguishable bands were shared. These results suggest the usefulness of DNA fingerprinting in fisheries genetics as a marker for the assessment of inbreeding rates, and also for the identification of individuals and families.

Detection of Intraspecific.DNA Sequence Variation in the Mitochondrial CytochromebGene of Atlantic Cod (Gadus morhua) by the Polymerase Chain Reaction

We determined the DNA sequence of a portion of the mitochondrial cytochrome b gene for 55 Atlantic cod (Gadus morhua) from Norway and from 10 locations within the Northern Cod complex and adjacent stocks off Newfoundland. DNA was prepared for sequencing by the polymerase chain reaction (PCR). Eleven variable nucleotide positions within a 298 base region defined 12 genotypes. Genotype proportions differed significantly between Newfoundland and Norwegian populations: the majority genotype among Newfoundland populations was present in a minority of Norwegian cod. Newfoundland cod showed less genotypic diversity than those from the eastern Atlantic: nine genotypes were found among all 10 Newfoundland populations, as compared with seven genotypes within the single Norwegian population. An exception was an overwintering, inshore Newfoundland population that showed four genotypes among five fish. As in other vertebrates, third position synonymous transitions predominate over other types of nucleotide changes. However, two amino acid replacement substitutions occur among cod, and the ratio of purine transitions to pyrimidine transitions is significantly higher than in other species. The existence of DNA sequence polymorphism permits the various hypotheses of the distribution and differentiation of Newfoundland cod stocks to be tested, and points to the utility of PCR technology in fishery genetics.

Two linked loci with a null allele for leucine aminopeptidase isozymes in apple snail Pomacea canaliculata.

Because of its short life-cycle, the apple snail Pomacea canaliculata is useful as a pilot organism for shellfish studies in fishery genetics and breeding. Four electrophoretically different phenotypes of leucine aminopeptidase (LAP) were found in the apple snail. The zymogram shows to be under the control of two alleles, A and a, at the two variant loci, Lap-2 and Lap-3, respectively. In both, a stands for the null allele. Different phenotypic frequencies at Lap-2 and Lap-3 were observed among the different egg lumps. Analyzing the presumed parental phenotypes and the phenotypic segregation of their offsprings, the existence of linkage between both loci, Lap-2 and Lap-3, were revealed. Calculating the recombination frequency between both 5.7% was obtained.

Fisheries Genetics: Issues and Priorities for Research and Policy Development

Abstract Following the recent establishment of an AFS North Central Division Fisheries Genetics Technical Committee, a workshop on fisheries genetics was held at the 1987 Midwest Fish and Wildlife Conference. The workshop provided a forum for information transfer on techniques, issues, and priorities for research and policy development. The workshop opened with invited presentations on stock identification methods, the effects of hatcheries and breeding programs in fisheries management, the potential for genetic engineering in fisheries management, and an overview of current issues in fisheries genetics. Participants were then divided into discussion groups which were instructed to answer specific questions and to define the highest priority research or policy need for assigned issues. In total, six major issues in fisheries genetics were addressed, including: application of stock identification methods in management, use of the stock concept in management, impacts of man-induced selection on fisheries re...