Garrett DL, Pietsch TW, Utter FM, Hauser L. (2007) The hybrid sole, Inopsetta ischyra (Teleostei: Pleuronectiformes: Pleuronectidae): hybrid or biological species? Trans. Am. Fish. Soc. 136:460-468.
Hauser L, Newton, L, LeClair, L, Buckley, R. (2007) Genetic identification of progeny of reef-resident brown rockfish (Sebastes auriculatus). Pages 99-119 in Heifetz, J, Dicosimo, J, Gharrett, AJ, Love, MS, O'Connell, VM, Stanley, RD (eds), Biology, Assessment, and Management of Pacific Rockfishes, Proceedings of the Lowell Wakefield Fisheries Symposium, Anchorage, Sept. 2005. Alaska Sea Grant.
The extent of larval retention and natal homing in demersal fish is a topic central to the design and the efficacy of Marine Protected Areas (MPAs). Unfortunately, little is known about effective larval dispersal in many marine species. The duration of the pelagic phase in many species suggests extensive dispersal, and population genetic studies indicate large-scale exchange of migrants, though there is also recent evidence for surprisingly limited realized dispersal. Here, we use genetic markers (microsatellites) to identify the offspring of resident adult brown rockfish (Sebastes auriculatus) among incoming settling juveniles on an isolated artificial reef at Point Heyer in Puget Sound, thus directly estimating rates of self-recruitment on the reef. Due to low marker variability, unambiguous identification of these offspring from empirical data was not possible. Nevertheless, comparison between parent-offspring matches in observed and simulated genetic data suggested that self-recruitment was less than 10%. One of the juveniles genetically matching an adult was confirmed as its offspring by larval otolith marking, which confirms that self-recruitment does occur. Our data suggested some, but limited, self-recruitment, that corresponded well to expectations at this scale from mean dispersal distances in brown rockfish.
Weetman DW, Ruggerio A, Mariani S, Shaw PW, Lawler AR, Hauser L. (2007) Hierarchical population structure in the commercially exploited shrimp Crangon crangon identified by AFLP analysis. Mar. Biol. 151:565-575.
The coastal shrimp Crangon crangon is an ecologically and commercially important species but there is limited knowledge of its genetic population structure. We utilised Amplified Fragment Length Polymorphisms (AFLPs) to investigate population differentiation among eight sampling locations comprising paired sites from north- and south-western Britain, the eastern English Channel and the Baltic Sea. Initial AMOVA and cluster analysis suggested strong differentiation, but outlier analysis identified three loci that might be subject to selection, one of which showed significant latitudinal variation in allele frequencies. Following exclusion of these outlier loci, and also of a divergent, genetically-impoverished sample from the UK Bristol Channel, cluster analysis revealed three major groupings, corresponding to geographical regions: western Britain, the eastern English Channel and the Baltic Sea. AMOVA identified significant differentiation both within and among these regions, with similar variation explained by each hierarchical level. C. crangon shows greater genetic structuring than has been found in many decapod crustaceans studied to date, and our results are consistent with unstable population sizes and gene flow restricted by distance and probably also hydrographic features. Further investigation of temporal stability in population structure is required, but broad-scale homogeneity of fishery stocks should not be assumed.
Chambers, MD, VanBlaricom GR, Hauser L, Utter F, Friedman CS. (2006) Genetic structure of black abalone (Haliotis cracherodii) populations in the California islands and central California coast: impacts of larval dispersal and decimation from withering syndrome. J. Exp. Mar. Biol. Ecol. 331:173-185.
The genetic structure of black abalone populations in the southern California Islands and central California coast was investigated by protein electrophoresis. Detailed sampling of San Nicolas Island (SN) permitted investigation of microgeographic genetic differentiation among local geomorphological features. In addition, temporal genetic differentiation was assessed by comparing juveniles and adults at three islands, San Miguel (SM), Santa Cruz (SC) and San Nicolas (SN). Mainland and island locations were genetically differentiated based on allele frequency differences and the presence of private alleles in some island populations. Although microgeographic genetic structure among sites on SN was weak and not statistically significant, heterozygosity varied among sites, with diversity decreasing from west to east. In addition, investigation among cohorts showed that adults were genetically differentiated among island locations, whereas no differences among juveniles were detected. Genetic differentiation between adult and juvenile abalones was detected at SC but not SM or SN. These data are generally consistent with local recruitment augmented by relatively more gene flow among island populations than among island and mainland populations, and possible selection acting on immigrant recruits.
Hauser, L, Seamons, TR, Dauer, M, Naish, KA, Quinn, TP. 2006. An empirical verification of population assignment methods by marking and parentage data: hatchery and wild steelhead (Oncorhynchus mykiss) in Forks Creek, Washington, USA. Mol. Ecol. 15:3157-3173.
Assignment tests are increasingly applied in ecology and conservation, though empirical comparisons of methods are still rare or are restricted to few of the available approaches. Furthermore, the performance of assignment tests in cases with low population differentiation, violations of Hardy-Weinberg equilibrium and unbalanced sampling designs has not been verified. The release of adult hatchery steelhead to spawn in Forks Creek in 1996 and 1997 provided an opportunity to compare the power of different assignment methods to distinguish their offspring from those of sympatric wild steelhead. We compared standard assignment methods requiring baseline samples (frequency, distance and Bayesian) and clustering approaches with and without baseline information, using six freely available computer programs. Assignments were verified by parentage data obtained for a subset of returning offspring. All methods provided similar assignment success, despite low differentiation between wild and hatchery fish (FST=0.02). Bayesian approaches with baseline data performed best, while the results of clustering methods were variable and depended on the samples included in the analysis and the availability of baseline information. Removal of a locus with null alleles and equalizing sample sizes had little effect on assignments. Our results demonstrate the robustness of most assignment tests to low differentiation and violations of assumptions, as well as their utility for ecological studies that require correct classification of different groups.
Weetman DW, Hauser L, Bayes MK, Ellis JR, Shaw PW (2006) Population structure and its determinants in the commercially exploited marine gastropod Buccinum undatum at different spatial scales. Marine Ecology Progress Series 317, 157-169.
Marine invertebrates are exploited increasingly as food resources worldwide, but knowledge of genetic population structure is limited for most commercially valuable taxa. We investigated genetic structure in the widely distributed, subtidal gastropod Buccinum undatum by screening samples from 28 locations at 5 microsatellite loci. Multidimensional scaling and cluster analysis were applied to study macrogeographic structure, and revealed 4 well-supported groupings of populations: Canada, Iceland, Swedish Skaggerak, and a cluster containing most samples from the European continental shelf (hereafter ‘Shelf’). A fifth cluster comprising all 5 samples from the Solent (UK) relied on exceptional differentiation of just 2 alleles, which is consistent with significant evidence for recent bottlenecks in this area. Within the Shelf cluster most pairwise tests of differentiation were significant, although the global FST of 0.014 was very low for a direct-developing species. Our data suggest that use of highly polymorphic markers caused a relatively minor downward bias to FST, although historical connectivity of populations that are not in migration-drift equilibrium might be more important. However, significant isolation by distance among British North Sea coast samples (FST = 0.010) is consistent with approach to equilibrium and suggests recent gene flow, probably between semi-continuous populations. At a microgeographic scale, we found migration to be consistently higher from inshore to offshore within 3 separate areas; a factor that may underpin the lower diversity and greater differentiation observed for bay and inlet populations. Such populations might serve as important sources of genetic diversity, but are likely to be particularly vulnerable to exploitation.
Weetman DW, Hauser L, Carvalho GR (2006) Heterogeneous evolution of microsatellites revealed by reconstruction of recent mutation history in an invasive apomictic snail, Potamopyrgus antipodarum. Genetica 127, 285-293.
Heterogeneous patterns of microsatellite evolution present a major challenge for the development of mutation models, and an improved understanding of the determinants of variation in mutation rates and patterns among loci, alleles and taxa is required. A 19th Century bottleneck associated with the introduction of clones of the snail Potamopyrgus antipodarum to Britain presented an opportunity to reconstruct recent microsatellite evolution within the most common apomictic lineage. There was significant variation in both the number and step size of mutations among the seven loci studied. Patterns of mutability were consistent with higher mutation rates for di- than trinucleotides and for longer alleles at a locus. Mutation size was influenced in a more complex way, decreasing with relative allele length much more strongly for tri-, than dinucleotides. We found support for this latter, highly novel result in the literature via reanalysis of data in a recent genome-scan study of human microsatellites, which showed a similarly disparate pattern of length-dependence between di- and trinucleotides. In spite of the apomictic form of reproduction and an unusually strong excess of microsatellite contractions in P. antipodarum, there were notable similarities with mutation processes of human microsatellites, supporting the wider taxonomic generality of such evolutionary mechanisms.
Chambers MD, von Blaricom GR, Hauser L, Utter FM, Friedmann CS (2006) Genetic structure of black abalone (Haliotis cracherodii) populations in the California islands and central California coast: impacts of larval dispersal and decimation from Withering Syndrome. Journal of Experimental Marine Biology and Ecology 331, 173-185.
The genetic structure of black abalone populations in the southern California Islands and central California coast was investigated by protein electrophoresis. Detailed sampling of San Nicolas Island (SN) permitted investigation of microgeographic genetic differentiation among local geomorphological features. In addition, temporal genetic differentiation was assessed by comparing juveniles and adults at three islands, San Miguel (SM), Santa Cruz (SC) and San Nicolas (SN). Mainland and island locations were genetically differentiated based on allele frequency differences and the presence of private alleles in some island populations. Although microgeographic genetic structure among sites on SN was weak and not statistically significant, heterozygosity varied among sites, with diversity decreasing from west to east. In addition, investigation among cohorts showed that adults were genetically differentiated among island locations, whereas no differences among juveniles were detected. Genetic differentiation between adult and juvenile abalones was detected at SC but not SM or SN. These data are generally consistent with local recruitment augmented by relatively more gene flow among island populations than among island and mainland populations, and possible selection acting on immigrant recruits.
Case RAJ, Hutchinson WF, Hauser L, Buehler V, Clemmesen C, Dahle G, Kjesbu OS, Moksness E, Otterå H, Paulsen H, Svåsand T, Thorsen A, Carvalho GR (2006) Association between growth and Pan I genotype within Atlantic cod (Gadus morhua) full sib families. Transactions of the American Fisheries Society 135, 241-250.
Studies of the pantophysin (Pan I*) locus in Atlantic cod Gadus morhua and other marine gadoids indicate that the locus is under positive selection; in Atlantic cod, genotypic variation at this locus has been linked to differences in growth. Here, we present preliminary data comparing the growth and condition of different Atlantic cod Pan I* genotypes within families held under seminatural mesocosm conditions. Larvae from three full-sibling families carrying Pan I*bb or Pan I*ab genotypes were reared for 10 weeks in two mesocosms. Multivariate analysis of variance indicated that larvae carrying the Pan I*ab genotype exhibited significantly higher standard length, dry weight, and RNA: DNA ratio (condition factor) than did larvae that carried the Pan I*bb genotype, potentially indicating selection. The influence of linked loci cannot be excluded; indeed, the absence of a significant correlation between genotype and growth in one family may substantiate this. The lack of differences in survival among genotypes indicates that moderate selective effects are acting primarily through size-specific mortality and fecundity. The proposed putative fitness effects, together with documented marked geographic differentiation in the wild, have implications for Atlantic cod population structure, effective migration rates, recruitment, and local adaptation, which are of particular relevance in a species threatened by continuing exploitation and rising sea temperatures.
Canino MF, Spies I, Hauser L (2005) Development and characterization of novel di- and tetranucleotide microsatellite markers in Pacific cod (Gadus macrocephalus). Molecular Ecology Notes 5, 908-910.
The Pacific cod (Gadus macrocephalus) supports large commercial fisheries in the northern Pacific Ocean and the Bering Sea. Here we characterize 10 polymorphic microsatellite loci isolated from enriched genomic libraries. Loci were screened on a sample of 96 spawning adults. The average number of alleles per locus was 25.3 (range 12–44), with expected heterozygosities (HE) ranging from 0.54 to 0.97. No significant deviations of genotypic proportions from Hardy–Weinberg equilibrium or linkage equilibrium were detected. These markers will be used in future studies of population structure and mixed stock analysis of this important gadid species.
Hauser AC, Hauser L, Pabinger-Fasching I, Quehenberger P, Derfler K, Horl WH. (2005) The course of anticardiolipin antibody levels under immunoadsorption therapy. American Journal of Kidney Diseases 46, 446-454.
Case RAJ, Hutchinson WF, Hauser L, van Oosterhout C & Carvalho GR (2005) Macro- and microgeographic variation in pantophysin (PanI) allele frequencies in NE Atlantic cod (Gadus morhua). Marine Ecology Progress Series 301, 267-278.
Using samples of Atlantic cod Gadus morhua L. from the North Sea, and previously published genetic data from the Irish and Celtic Seas, Iceland, and Norwegian fjord and offshore populations, we describe striking macro- and micro-geographic patterns in pantophysin (PanI) allele frequencies. The relatively abrupt discontinuity in PanI allele frequency distribution at 2 different locations is not congruent with standard patterns of isolation by distance and could arise from population admixtures, historical or contemporary natural selection, behavioural segregation or a combination of these factors. Here, we examined the relationships between the distributions of PanI alleles and temperature, salinity and depth. In the northeast Atlantic, temperature was highly correlated with PanI allele frequency, even when the effect of geographic distance was removed. In the Norwegian fjords, partial Mantel tests indicated that temperature, salinity and depth all had a significant effect on PanI allele frequency in juvenile fish. However, a sample from the brackish waters of the eastern Baltic Sea suggested that salinity may be linked to PanI allele frequency distribution and that the relationship with temperature was weaker in areas of low salinity. Strong correlations between PanI allele frequencies and key environmental variables, together with evidence from the available literature, suggested that environmental conditions play an important role in determining the distribution of different PanI genotypes. The combined use of environmental data, PanI genotyping and neutral markers may provide a valuable approach to examine local adaptation, levels of gene flow and stock structuring.
Canino MF, O’Reilly PTO, Hauser L, Bentzen P (2005) Genetic differentiation in walleye pollock (Theragra chalcogramma) in response to selection at the pantophysin (Pan I) locus. Canadian Journal of Fisheries and Aquatic Sciences 62, 2519-2529.
Samples of walleye pollock (Theragra chalcogramma) from the North Pacific Ocean and Bering Sea were screened for variation at the pantophysin (PanI) locus. Global genetic differentiation across samples (FST = 0.038) was considerably greater than reported in previous population studies using allozymes, mtDNA, or microsatellite loci and significantly greater than FST distributions of neutral loci simulated over a large range of locus heterozygosity. PanI allele frequencies varied over a broad latitudinal gradient and were correlated with estimated mean surface temperatures, resulting in the greatest levels of genetic divergence between the northern Bering Sea and the southernmost locations in the temperate Pacific Ocean (Puget Sound, Japan). The discordance between estimates of population differentiation estimated from PanI and other neutral marker classes, both in magnitude and in geographic patterns, could arise from temperature-mediated effects of natural selection over broad geographic scales. Our empirical results suggest that loci subject to directional selection may prove to be useful markers for stock identification in weakly structured marine fishes.
Weetman D, Hauser L, Shaw PW & Bayes MK (2005) Microsatellite markers for the whelk Buccinum undatum. Molecular Ecology Notes 5, 361-362.
Five microsatellite loci are described for the commercially exploited marine gastropod, Buccinum undatum . Levels of polymorphism were variable with three to 19 alleles per locus and expected heterozygosities of 0.26–0.94 in 60 individuals of the population from which the loci were isolated. Homozygote excess at two of the loci might be attributable to null alleles, and these loci should not be used in, for example, parentage analysis. Nevertheless, because null allele frequencies can be estimated and their effects partitioned, all are useful markers for studies of population differentiation.
Clemmesen C, Bühler V, Carvalho GR, Case RAJ., Evans G, Hauser L, Hutchinson WF, Kjesbu WF, Mempel H, Moskness E, Otteraa H, Paulsen H, Thoresen A, Svaasand T (2003) Variability in condition and growth of Atlantic cod larvae and juveniles reared in mesocosms: environmental and maternal effects. Journal of Fish Biology 62, 706-723.
Standard length, dry mass and RNA:DNA ratio measurements of 3876 Atlantic cod Gadus morhua larvae and juveniles from 26 families of recruit (fish during their first year of spawning) and repeat spawners (fish which were in their subsequent spawning season) reared in two mesocosms (2500 and 4400m3) under semi-natural conditions were analysed over a period of 10 weeks using microsatellites. Larvae from recruit spawners were significantly longer and heavier at hatch and throughout the 10 weeks. RNA:DNA ratios from recruit spawner offspring were only significantly higher at week 1. The smaller (2500m3) mesocosm was characterized by low plankton density during the transition from endogenous to exogenous feeding followed by a higher density during the metamorphosis period (weeks 4 and 5), with the reverse pattern evident in the 4400m3 mesocosm. Patterns of larval growth followed patterns of zooplankton density. Significant differences in RNA:DNA ratios between the mesocosms at all comparable sampling dates were found and within each mesocosm individual fish exhibited a wide range of growth and condition responses under the same environmental conditions. RNA:DNA ratios as a function of size differed in the amount of variability between mesocosms, indicating that the higher food density led to a higher proportion of well-conditioned larvae in the first 3 weeks. Food availability probably has a major role in determining offspring growth and condition, with limited effects due to maternal effects in cases where the broodstock females are approximately of similar size and condition.
Gomez-Uchida D, Weetman DW, Hauser L, Galleguillos R & Retamal M (2003) Allozyme and AFLP analysis of genetic population structure in the hairy edible crab Cancer setosus from the Chilean coast. Journal of Crustacean Biology, 23, 486-494.
Management plans and stock assessment of exploited marine invertebrates should consider information on the genetic population structure of the species. In this context, the genetic diversity within and between populations of the commercially exploited hairy edible crab Cancer setosus was investigated using allozyme and AFLP (Amplified Fragment Length Polymorphism) markers, covering a range of approximately 2500 km along the Chilean coast. Genetic diversity estimates within populations, such as polymorphism and average expected heterozygosity, were low from two polymorphic allozyme loci, PGM-1 and EST-1 (P0.99 = 8.7 %; HE = 2.5 %) but much higher for 190 AFLP loci (P0.99 = 52 %; HE = 18.7 %). Nevertheless, differentiation among samples was statistically significant for allozymes (FST = 0.026; P < 0.001), but not for AFLPs (AMOVA φPT = 0.007; P = 0.118). Several possible causes of these differences are discussed in an evolutionary and oceanographic framework. AFLP also identified a sex-linked marker, present in 96 % of females but only 9 % of males. Relatively little is known about sex-determination in decapods, but these data suggest that in C. setosus, the mechanism is primarily genetic and that females may be the heterogametic sex.
Hauser L, Hemingway KL, Wedderburn RJ, Lawrence AJ (2003) Links Between Genetic Damage and Cellular/Molecular Responses to Pollution and the Population Genetics of the Species. In Effects of Pollution on Fish: Molecular Effects and Population Responses (Lawrence A.J. & Hemingway K.L. eds.). Blackwell Science, pp. 256-288.
Cajaraville M.P., Hauser L., Carvalho G., Hylland K. Olabarrieta I, Lawrence A.J., Lowe D. & Goksøyr A. (2003) Genetic damage and the molecular / cellular response to pollution. In Effects of Pollution on Fish: Molecular Effects and Population Responses (Lawrence A.J. & Hemingway K.L. eds.). Blackwell Science, pp. 14-82.
Goksøyr A., Arukwe A., Larsson J., Cajaraville M.P., Hauser L., Nilsen B.M., Lowe D., Mathiessen P. (2003) Molecular / cellular processes and the impact on reproduction. In Effects of Pollution on Fish: Molecular Effects and Population Responses (Lawrence A.J. & Hemingway K.L. eds.). Blackwell Science, pp. 179-220
Carvalho G.R., van Osterhout C., Hauser L., Magurran A.E. (2003) Measuring genetic variation in wild populations: from molecular markers to adaptive traits. In Genes in the Environment (Hails R, Beringer J, Godfray HC, eds.). Blackwell Science, pp. 91- 111.
Bernal-Ramírez JH, Adcock GJ, Hauser L, Carvalho GR, Smith PJ (2002) Temporal stability of genetic population structure in the New Zealand snapper, Pagrus auratus, and relationship to coastal currents. Marine Biology 142, 567-574.
Genetic diversity and population structure of snapper (Pagrus auratus, Bloch and Schneider), a coastal demersal sparid fish, were determined using six nuclear microsatellite loci and SSCP (single strand conformational polymorphism) analysis of the mitochondrial (mt) DNA D-loop in samples collected across the range of the species in New Zealand. Microsatellite data showed similar results to allozyme data collected in the late 1970s that found differentiation between the north-east and southern populations. In addition, an isolated population of snapper in Tasman Bay was identified. The two data sets provide evidence for the temporal stability of the genetic population structure of snapper over 22 years, with differentiation over relatively small spatial scales separated by oceanographic boundaries rather than isolation by distance. In contrast to nuclear markers, mtDNA did not reveal any significant genetic heterogeneity among samples.
van Oosterhout C, Trigg RE, Carvalho GR, Magurran AE, Hauser L, Shaw PW (2002) Inbreeding depression and genetic load of sexually selected traits: How the guppy lost its spots. Journal of Evolutionary Biology 16, 273-281.
To date, few studies have investigated the effects of inbreeding on sexually selected traits, although inbreeding depression on such traits can play an important role in the evolution and ecology of wild populations. Sexually selected traits such as ornamentation and courtship behaviour may not be primary fitness characters, but selection and dominance coefficients of their mutations will resemble those of traits under natural selection. Strong directional selection, for instance, through female mate-choice, purges all but the most recessive deleterious mutations, and the remaining dominance variation will result in inbreeding depression once populations undergo bottlenecks. We analysed the effects of inbreeding on sexually selected traits (colour pattern and courtship behaviour) in the male guppy, Poecilia reticulata, from Trinidad, and found a significant decline in the frequency of mating behaviour and colour spots. Such effects occurred although the genetic basis of these traits, many of which are Y-linked and hemizygous, would be expected to leave relatively little scope for inbreeding depression. Findings suggest that these sexually selected traits could reflect the genetic condition or health of males, and thus may be informative mate-cue characters for female choice as suggested by the ‘good genes’ model.
Weetman D, Hauser L & Carvalho GR (2002) Reconstruction of microsatellite mutation history reveals a strong and consistent deletion bias in invasive clonal snails, Potamopyrgus antipodarum. Genetics 162, 813-822.
Direct observations of mutations and comparative analyses suggest that nuclear microsatellites show a tendency to expand, with reports of deletion biases limited to very long alleles or a few loci in multilocus studies. Here we investigate microsatellite evolution in clonal snails, Potamopyrgus antipodarum, since their introduction to Britain in the 19th century, using an analysis based on minimum spanning networks of multilocus microsatellite genotypes. British populations consist of a small number of highly distinct genotype groups with very few outlying genotypes, suggesting clonal lineages containing minor variation generated by mutation. Network patterns suggest that a single introduced genotype was the ancestor of all extant variation and also provide support for wholly apomictic reproduction within the most common clonal lineage (group A). Microsatellites within group A showed a strong tendency to delete repeats, with an overall bias exceeding 88%, irrespective of the exact method used to infer mutations. This highly unusual pattern of deletion bias is consistent across populations and loci and is unrelated to allele size. We suggest that for persistence of microsatellites in this clone, some change in the mutation mechanism must have occurred in relatively recent evolutionary time. Possible causes of such a change in mechanism are discussed.
Hauser L, Adcock GJ, Smith PJ, Bernal Ramirez JH, Carvalho GR (2002) Loss of microsatellite diversity and low effective population size in an overexploited population of New Zealand snapper (Pagrus auratus). Proceedings of the National Academy of Sciences 99, 11742-11747.
Although the effects of overfishing on species diversity and abundance are well documented, threats to the genetic diversity of marine fish populations have so far been largely neglected. Indeed, there seems to be little cause for concern, as even ‘‘collapsed’’ stocks usually consist of several million individuals, whereas population genetics theory suggests that only very small populations suffer significant loss of genetic diversity. On the other hand, in many marine species the genetically effective population size (Ne), which determines the genetic properties of a population, may be orders of magnitude smaller than the census population size (N). Here, microsatellite analyses of a time series of archived scales demonstrated a significant decline in genetic diversity in a New Zealand snapper population during its exploitation history. Effective population sizes estimated both from the decline in heterozygosity and from temporal fluctuations in allele frequency were five orders of magnitude smaller than census population sizes from fishery data. If such low Ne/N ratios are commonplace in marine species, many exploited marine fish stocks may be in danger of losing genetic variability, potentially resulting in reduced adaptability, population persistence, and productivity.
Hauser L, Turan C, Carvalho GR (2001) Haplotype frequency distribution and discriminatory power of two mtDNA fragments in a marine pelagic teleost (Atlantic herring, Clupea harengus). Heredity, 87¸ 621-630.
Two regions of the mtDNA of Atlantic herring (Clupea harengus), ND3/4 and ND5/6, were surveyed by RFLP analysis to assess the effects of marker variability on the power of statistical tests. Although haplotype diversity was similar, marked differences in the number of common haplotypes were observed between the two regions, with ND3/4 having a more even distribution of haplotype frequencies. ND3/4 also revealed higher differentiation among samples than ND5/6, similar to previously published microsatellite data of the same samples. The data suggested that the highly skewed haplotype distribution of many mtDNA markers may be one of the reasons for the less frequent detection of population differentiation compared to microsatellites. Pooling (`binning') of related haplotypes did not increase differentiation revealed by each mtDNA region individually, but greatly strengthened geographical patterns shown by both regions combined. The data provided evidence for genetic differentiation of Icelandic herring from other north-eastern Atlantic stocks, and indicated genetic differences between Baltic and Celtic Sea herring. However, mtDNA data failed to confirm previously reported differences between Barents Sea herring, Norwegian fjord populations and Norwegian spring spawners.
Weetman D., Hauser L., Carvalho G.R. (2001) Isolation and characterization of di- and trinucleotide microsatellites in the freshwater snail Potamopyrgus antipodarum. Molecular Ecology Notes, 1, 185-187.
The freshwater prosobranch snail Potamopyrgus antipodarum is an important model system for studying the maintenance of sexual reproduction in its native New Zealand. Since introduction to the UK in the 1850s, the species has spread throughout Europe and recently the USA. We present the first microsatellites for P. antipodarum . Using two isolation protocols, which are qualitatively compared, we have developed PCR primers for three di- and four trinucleotide microsatellites. All loci proved to be polymorphic, when screened for variability in several UK populations. These markers should be of considerable utility in future population and ecological genetics studies of this species.
Adock GJ, Bernal Ramirez JH, Hauser L, Smith P & Carvalho GR (2000) Screening of DNA polymorphisms in samples of archived scales from New Zealand snapper. Journal of Fish Biology 56, 1283-1287.
Primers and protocols were developed to screen efficiently DNA sequence polymorphism of nuclear and mitochondrial loci in samples of dried archived scales collected over the last 50 years from the New Zealand snapper Pagrus auratus (Sparidae).
Carvalho G.R. & Hauser L. (1999) Molecular markers and the species concept: new techniques to resolve old disputes? Reviews in Fish Biology and Fisheries 9, 379-382.
Hauser L. & Ward R.D. (1998) Population identification in pelagic fish: the limits of molecular markers. In Advances in Molecular Ecology (Carvalho G.R., ed.). IOSPress, Amsterdam. pp. 191-224
Hauser L., Carvalho G.R. & Pitcher, T.J. (1998) Genetic population structure in the Lake Tanganyika sardine, Limnothrissa miodon. Journal of Fish Biology 53 (Suppl. A), 413-429.
Hauser L., Carvalho G.R., Pitcher, T.J. & Ogutu-Ohwayo R. (1998) Genetic affinities of an introduced predator: Nile perch in Lake Victoria, East Africa. Molecular Ecology 7, 849-857.
Hauser L., Carvalho G.R. & Pitcher, T.J. (1998) Genetic similarity of a phenotypically divergent population of the clupeid Limnothrissa miodon, following introduction into man-made lake. In Stocking and Introductions of Fish (Cowx I.G., ed.). Fishing News Books, Blackwell Scientific Ltd. pp. 338-354.
Carvalho G.R. & Hauser L. (1998) Advances in the molecular analysis of fish population structure. Italian Journal of Zoology, Suppl. S, 21-33.
Carvalho G.R., Shaw P.W., Hauser L., Seghers B.H. & Magurran A.E. (1996) Artificial introductions, evolutionary change and population differentiation in Trinidadian guppies (Poecilia reticulata: Poeciliidae). Biological Journal of the Linnean Society 57, 219-234.
Hauser L., Carvalho G.R. & Pitcher T.J. (1995) Morphological and genetic differentiation of a clupeid (Limnothrissa miodon) 34 years after introduction into Lake Kivu, East Africa. Journal of Fish Biology 47, 127-144.
Carvalho G.R. & Hauser L. (1995) Genetic effects of fish introductions: a perspective on African lakes. In: Pitcher, T.J. and Hart, P.J.B. (eds) Impact of Species Changes in African Lakes. Chapman and Hall, London. pp. 457-585.
Carvalho G.R. & Hauser L. (1994) Molecular genetics and the stock concept in fisheries. Reviews in Fisheries and Fish Biology, 4, 326-350.
Hauser L., Carvalho G.R., Hughes R.N. & Carter R.E. (1992) Clonal structure of the introduced freshwater snail, Potamopyrgus antipodarum (Prosobranchia: Hydrobiidae), as revealed by DNA fingerprinting. Proceedings of the Royal Society, London, B, 249, 19-25.
Hauser L., Beaumont A.R., Marshall G.T.H. & Wyatt R.J. (1991) Effects of sea trout stocking on the population genetics of landlocked brown trout, Salmo trutta L., in the Conwy River system, North Wales, U.K. Journal of Fish Biology, 39 (A), 109-116.
