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1.
Allozyme variability in ten polymorphous loci and three samples of the chiton Ischnochiton hakodadensis from Peter the Great Bay, Sea of Japan, was examined by gel electrophoresis. The samples were collected in different areas of the Bay: clean, heavily polluted with petroleum hydrocarbons and detergents, and heavily polluted with heavy metal combinations. It was established that the genetic similarity of the samples was very high, but their differences in allele frequencies, observed heterozygosity, and heterozygote deficiency in some loci were statistically significant. We suppose that allozyme differences between the studied chiton samples are the result of selection to resist anthropogenic pollution of the habitat.  相似文献   

2.
Eight polymorphic loci were surveyed in three samples of the gastropodTegula rustica collected in a clean area of Peter the Great Bay and in three samples from a heavily polluted area of the bay. Macrospatial, microspatial, and temporal differences in allele frequencies and heterozygosity were found at some of the loci; however, the genetic similarity among the samples was very high. It is concluded that allozyme variability at the surveyed loci ofT. rustica cannot be used in pollution monitoring of Peter the Great Bay.  相似文献   

3.
Allozyme variability was investigated at 18 polymorphic loci in 9 samples of the bivalveMytilus trossulus (Gould, 1850) from Vostok Bay, Sea of Japan. Significant differences in allele frequencies at some loci were found between samples from different age cohorts and different depths. Genetic distances between samples were as great as (and often exceeded) those typically found between geographically separate populations in Peter the Great Bay. Some practical recommendations for experimental researchers are proposed.  相似文献   

4.
The allozyme variability for 15 loci in two samples of the Pacific mussel Mytilus trossulus collected from a single giant cluster was investigated using the method of gel electrophoresis. One sample was subjected to short-term anaerobic stress and then to a longer aerobic stress, leading to the death of about 85% of the individuals. At some of the loci, significant differences in the genotypic and allele frequencies were found between the samples. The results are suggestive of the differential survival of mussels with different genotypes and alleles at some of the surveyed loci under stress. Our data are in agreement with the hypothesis of the adaptive significance of allozyme polymorphism.  相似文献   

5.
The physiological state of littoral and sublittoral microbial communities in a marine shallow-water hydrothermal ecosystem (Kraternaya Bight) was studied using lipid biomarkers. The ratio trans/cis (n-7) isomers of monoenic fatty acids (FAs) of polar lipids in intertidal and subtidal algobacterial and bacterial mats of the bight exceeded 0.1 significantly; this indicated a stress state in bacteria. No concomitant increase was found in the ratio of cyclopropane fatty acids to 16: 1 and 18: 1 (n-7) cis monoenic fatty acids. In bottom sediments, the ratio trans/cis (n-7) isomers of monoenic fatty acids was below 0.1. A positive correlation (r = 0.71) was revealed between the ratio trans/cis isomers of (n-7) monoenic fatty acids and the content of saturated fatty acids.  相似文献   

6.
The intentional introduction of red king crab, Paralithodes camtschatica (Tilesius, 1815) in the Barents Sea represent one of a few successful cases and one that now supports a commercial fishery. Introductions of alien species into new environments are often associated with genetic bottlenecks, which cause a reduction in the genetic variation, and this could be important for the spreading potential of the species in the Atlantic Ocean. Red king crab samples collected in the Varangerfjord located on the Barents Sea (northern Norway) were compared with reference crab samples collected from the Bering Sea and Kamchatka regions in the Pacific Ocean. All samples were screened for eleven microsatellite loci, based on the development of species-specific primers. The observed number of alleles per locus was similar, and no reduction in genetic variation, including gene diversity and allelic richness, was detected between the Varangerfjord sample and the reference sample from Okhotsk Sea near Kamchatka, indicating no genetic bottlenecking at least for the microsatellite loci investigated. The same results were found in comparison with the sample from Bering Sea. The level of genetic differentiation among the samples, measured as overall F ST across all loci, was relatively low (0.0238) with a range of 0.0035–0.1000 for the various loci investigated. The largest pairwise F ST values were found between the Bering Sea and Varangerfjord/Barents Sea samples, with a value of 0.0194 across all loci tested. The lowest value (0.0101) was found between the Varangerfjord and Kamchatka samples. Genetic differentiation based on exact tests on allele frequencies revealed highly significant differences between all pairwise comparisons. The high level of genetic variation found in the Varangerfjord/Barents Sea sample could be of significance with respect to further spreading of the species to other regions in the North Atlantic Ocean.  相似文献   

7.
A single-species environmental DNA (eDNA) method was developed to sample for a small, benthic rare species, Eastern Sand Darter (Ammocrypta pellucida Putnam, 1863) in two large Lake Ontario embayments. Summer water sampling allowed for: (a) surveys of habitats (Wellers Bay) where traditional fish sampling gear could not be used; and, (b) a comparison between eDNA and seining-based detection probabilities at known occupied habitats (West Lake). In 2018, replicate (n = 3) 1 L water samples were collected from 90 Wellers Bay sites and 71 West Lake sites. A site-occupancy model, a hierarchical logistic regression model, was fitted to determine site occupancy, sample occupancy (presence of Eastern Sand Darter DNA in a water sample) and probability of detection (p) based on replicate quantitative polymerase chain reaction (qPCR) results for each water sample. Eastern Sand Darter was detected at 10 West Lake sites, but not from Wellers Bay. Mean site occupancy was 0.31 (0.12–0.70; 95% CLs), mean sample occupancy was 0.28 (0.09–0.58; 95% CLs), and mean detection probability in a subsample (i.e., successful qPCR amplification) given it was present was 0.40 (0.25–0.55; 95% CLs). While the eDNA method successfully detected Eastern Sand Darter from known occupied areas in West Lake, it was not more effective for assessing local site occupancy than traditional sampling methods, such as the seine.  相似文献   

8.
The results of microbiological analysis of a number of microorganisms of various ecological–trophic groups in plankton microbial communities of some water areas of the Sea of Okhotsk and Avacha Bay are presented. The data were compared to the hydrochemical parameters (temperature, salinity, BOD5, dissolved oxygen, phosphates, organic phosphate, detergents) determined simultaneously. The microbian indication method is used for express assessment of water pollution of the surveyed areas. The data demonstrated that Avacha Bay was subjected to heavier anthropogenic impact than the water areas of the ports of Kholmsk and Magadan.  相似文献   

9.
The temporal diversity of 11 morphological features of both shell valves in eight cultivated samples of the Japanese scallop M. yessoensis from Alexeev Bay (Popov Island, Sea of Japan) at different ages and from different generations was analyzed. The sample diversity with respect to each investigated feature was observed. The sample differences in the studied features as well as shell valve variability within the sample were demonstrated to be determined by both mollusk age and sample generation. This phenomenon is considered to be the result of differences in the environmental influence on each mollusk generation under constant technological conditions.  相似文献   

10.
Abstract. Allozyme electrophoresis was used to investigate the structure of genetic variation in the rhizomatous coastal sedge, Carex arenaria, throughout its European range — from the SW Iberian peninsula to the Baltic region. Material was sampled from 77 sites in five geographic regions. Nine of the 13 investigated loci were polymorphic in the total material and there were interregional differences in the number of polymorphic loci per site and the percentage of variable sites. In the Scandinavia/Baltic region only 61% of the sites contained at least one locus with more than one allele, whereas all the British and SW Iberian sites were variable. There was a general tendency for the regional frequencies of the less common alleles at individual loci to decline from SW to NE. The mean (over loci and sites) within‐site gene diversity (H site) was 0.064 (in calculations based on the number of observed multilocus allozyme genotypes within each sampling site). Although there was considerable variation between geographically adjacent sites, within‐site diversity showed a general decrease from SW to NE in Europe. There were significant differences in within‐region gene diversity (Hreg) for the four most variable loci between the five regions. Hreg generally decreased from SW to NE Europe and most loci showed the highest diversity in the SW Iberian peninsula and the Bay of Biscay regions. The mean (over loci) gene diversity in the total material (Htot) was 0.070 and the levels of diversity in Carex arenaria are substantially lower than is usual in rhizomatous sedges. The within‐site, between‐site and between‐regional components of the total diversity were 92.4%, 2.5% and 5.1%, respectively. The low levels of overall gene diversity in C. arenaria and the successive decrease in diversity from SW to NE are interpreted in terms of the species’ history of postglacial spread into northern Europe. Despite the overall northwards decrease in diversity, the widespread occurrence of less common alleles and the lack of regional deviations from Hardy–Weinberg genotype frequency expectations suggest that C. arenaria is not predominantly self‐fertilized.  相似文献   

11.
以泸州老窖1、50、100和400年窖泥为研究对象,采用变性梯度凝胶电泳(DGGE)研究浓香型白酒窖泥放线菌的群落结构及其多样性。DGGE图谱显示,除1年样品外,其余窖底泥多样性指数(H)均低于同窖龄窖壁泥,但均匀度指数(EH)较高。不同窖池相同部位窖泥的群落结构变化趋势为:随窖龄的延长,窖壁泥H值逐渐上升,为1.74—2.28;窖底泥下降,为1.73—2.07。EH值均为波动下降,分别在0.986—0.991和0.971—0.994之间。窖底泥相似性系数(SC)逐渐上升,为0.46—0.82;窖壁泥为0.31—0.62。DGGE条带测序结果显示,窖泥放线菌归于Olsenella、Atopobium、Streptomyces和Corynebacterium 4个属。Olsenella和Atopobium属为共有的优势属,且在窖壁泥中的优势度(di)均随窖龄延长而降低,在窖底泥中升高。实验结果表明,浓香型白酒窖泥蕴藏着丰富的放线菌资源,群落结构和多样性存在差异,菌群演替呈现一定规律性。  相似文献   

12.
Allozyme variability was assessed, using starch gel electrophoresis, at 15 polymorphic loci in two samples of the Pacific mussel Mytilus trossulus collected from local populations in heavily (Golden Horn Bay) and slightly polluted areas (Sukhoputnaya Bay) of Peter the Great Bay. Significant differences between samples were found in the genotypic frequencies at nine loci and in allele frequencies, at six loci. The results are suggestive of the differential survival of individuals having different genotypes and alleles at some of the surveyed loci under conditions of pollution. Our data are not in conflict with the hypothesis of the adaptive significance of allozyme polymorphism.  相似文献   

13.
The genetic diversity among spawning groups of herring from different parts of the White Sea was assessed using ten microsatellite loci. All loci were polymorphic with the expected heterozygosity estimates varying in the range of 12.7–94.1% (mean was 59.5%). The degree of genetic differentiation displayed by White Sea herring was statistically significant (θ = 2.03%). The level of pairwise genetic differentiation F ST was 0–0.085, and it was statistically significant in most of the comparison pairs between the herring samples. A hierarchical analysis of molecular variance (AMOVA) revealed the statistically significant differentiation of White Sea herring. 96.59% genetic variation was found within the samples and 3.41% variation was found among the populations. The main component of interpopulation diversity (1.85%) falls at the differences between two ecological forms of herring, spring- and summer-spawning. Within the spring-spawning form, the presence of local stocks in Kandalaksha Bay, Onega Bay, and Dvina Bay was demonstrated.  相似文献   

14.
Brewer  Robert H. 《Hydrobiologia》1991,(1):471-477
Two populations of Cyanea, one in the Niantic River estuary and the other in the adjacent Niantic Bay portion of Long Island Sound, were studied for more than a decade. The estuary and the bay are connected by a narrow channel: this and hydrographic features constrain transport between them. Specimens from each site exhibit morphological and seasonal differences comparable to those which distinguish C. capillata from C. lamarckii in European waters. Reproducing River medusae never cooccurred with reproducing Bay medusae. Estuarine jellyfish are sometimes found in the Bay, but reproducing individuals have not been seen there. Reproductively mature Bay jellyfish occasionally appear in the River, but benthic samples show that they do not deposit planulae at this site and thus do not contribute to the next generation of medusae in the River. Such differences suggest an absence of gene flow between these two populations, indicating that the River medusae and Bay medusae might be separate species.  相似文献   

15.
Five sympatric colour varieties of the hoplonemertean Tetrastemma nigrifrons (var. pallidum, var. bicolor, var. purpureum, var. punctata, var. albino) were found in Vostok Bay (the Sea of Japan). The taxonomic status of the varieties, some of which have been known for almost a century, was uncertain. Starch gel electrophoresis was used to compare allele frequencies of these varieties at 19 isozyme loci. Neither fixed allelic differences nor statistically significant differences in allele frequencies between different colour varieties was revealed. It was concluded therefore that all the colour varieties studied are conspecific. As estimated from the electrophoretic screening of 24 isozyme loci, the species is highly variable at the molecular level. It has high mean values of observed and expected heterozygosity estimates, H o =0.313 ± 0.049 and H e =0.323 ± 0.050, and is one of the most variable species among invertebrates.  相似文献   

16.
Fifteen microsatellite loci were developed for pink ling (Genypterus blacodes), a fish of significant commercial importance to Australasia. Nine loci were examined in samples from five regions of Australia’s South East Fishery. All nine were highly polymorphic; numbers of alleles per locus ranged from 11 to 52 in total samples of 270–306 individuals. The average observed heterozygosity per locus per sample (0.823) was a little lower than the average Hardy–Weinberg expected heterozygosity per sample (0.895), perhaps reflecting the possible presence of null alleles at two loci. There was no significant evidence of genetic stock heterogeneity.  相似文献   

17.
We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and Uummannaq samples with the samples from Inglefield Bredning and Scoresby Sound using three different multivariate techniques for each sex. None of the results were significant. Seven of the non-metric variables were independent of age and sex and were used in comparing samples from the six localities. No differences were found among the four localities in West Greenland, but differences were found in two of the non-metric variables between the combined West Greenland sample and the one from Scoresby Sound. A major shortcoming of the analysis based on metric data was the small sample size from several of the areas, which resulted in low statistical power. Genetic as well as environmental factors could explain the differences detected here between narwhals living along the west and the east coasts of Greenland.  相似文献   

18.
Allozyme variability in 16 polymorphic loci in two size cohorts of large (30.0 ± 6.3 mm) and small (9.8 ± 2.3 mm) spat of the mussel Mytilus trossulus (Gould) coinhabiting the intertidal zone in Brazhnikov Bay (Amursky Bay, Sea of Japan) was studied 1988–1989. It was determined that the size cohorts compared were highly similar genetically; Nei's minimum distances were 0.014 and 0.016 in 1988 and in 1989. However, statistically significant differences in allele frequencies were found at 2 loci, both in 1988 and in 1989. The loci differing by allele frequencies in 1988 did not coincide with those in 1989. Significant differences by heterozygosity between the cohorts were found only at the Idg-1 and Est-3 loci, 1988; and at the Aat-1, 6-Fgd, Est-3 loci, 1989; but the average heterozygosity was not significantly different in the cohorts for both years. A deficiency of heterozygotes (Dg) was observed almost at all loci in both cohorts. The mean Dg values were significantly higher in the cohort of small size individuals. Since the environmental conditions for both cohorts were similar, the allozyme differences between them were not a result of natural selection. A possible cause of the allozyme and size differences among the mussel cohorts is the gap in the settling time of larvae, which entails the formation of two size cohorts of mussels. Such a gap was caused by protraction of spawning period of M. trossulus and by the formation of segregate larval pools from various mussel populations differing in allele frequencies.  相似文献   

19.
Diatom assemblages of sediments obtained from Kushu Lake and Akkeshi were analyzed in order to clarify the local Holocene sedimentary history. The results revealed the following: 1) Sometime before about 9000 yr B.P., Kushu Lake was originally a freshwater environment. 2) The first marine diatom zone (MD1 Zone) was deposited on the bottom of the paleo-Kushu Bay between 8500 and 6000 yr B.P. 3) This site changed to become the bottom of the paleo-Kushu Lagoon around 6000 yr B.P. owing to the formation of a bay-mouth bar across the paleo-Kushu Bay and the first Holocene regression resulted in a freshwater lake at about 4500 yr B.P. 4) At this time, the Akkeshi site changed from a sublittoral shore in a drowned valley to a peat moor. 5) The second Holocene transgression at about 3000 yr B.P. was detected at the Akkeshi site. 6) At Kushu Lake site the occurrence ofMastogloia elliptica between 7000 and 5000 yr B.P. suggested the influx of the Tsushima warm current into the Japan Sea.  相似文献   

20.
Most industrial and agricultural enterprises of the Kamchatsky district are situated along the coast of the Avacha Bay and its river drainage. Intensive water pollution resulted in extreme deterioration of the bay's ecology. The destruction of macrophytobenthos under the influence of pollution was investigated. Materials were regularly collected at the same sampling sites in different seasons of the year from 1988 up to 1999. Analysis of our data allowed us to determine directions of long‐term changes of species composition and macrophytobenthos structure, speed of degradation of different types of vegetational communities and reasons for all these processes. The Avacha Bay's flora consisted of more than 160 species up to 1970s, including species belonged to 104 genera, 47 families, 23 orders, 3 divisions (30 Chlorophyta, 48 Phaeophyta, 82 Rhodophyta). Flora of the internal part of the bay differed from that of the bay's mouth and consisted of 143 and 146 species, respectively. Presently, the whole flora of the bay (internal part+ throat) includes only 94 species. Along the urban coast 18 poly‐ and mesosaprobious species are found only. They are characterized by small sizes, low productivity and short life cycles. Most of them are ephemeral with a primitive morphology. The responsive reaction of algae to pollution resulted in decreases in size and weight of the thalli, and appearance of anomalies of development. Laminaria bongardiana was used as a bioindicator. The changes of weight and sizes of its plants allow us to determine degree of the pollution in different parts of the coast of the Avacha Bay.  相似文献   

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