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1.
Elizabeth S. MacAvoy Lorna M. McGibbon James P. Sainsbury Hayley Lawrence Carol A. Wilson Charles H. Daugherty Geoffrey K. Chambers 《Conservation Genetics》2007,8(2):305-318
Tuatara (Sphenodon spp) populations are restricted to 35 offshore islands in the Hauraki Gulf, Bay of Plenty and Cook Strait of New Zealand.
Low levels of genetic variation have previously been revealed by allozyme and mtDNA analyses. In this new study, we show that
six polymorphic microsatellite loci display high levels of genetic variation in 14 populations across the geographic range
of tuatara. These populations are characterised by disjunct allele frequency spectra with high numbers of private alleles.
High F
ST (0.26) values indicate marked population structure and assignment tests allocate 96% of all individuals to their source populations.
These genetic data confirm that islands support genetically distinct populations. Principal component analysis and allelic
sequence data supplied information about genetic relationships between populations. Low numbers of rare alleles and low allelic
richness identified populations with reduced genetic diversity. Little Barrier Island has very low numbers of old tuatara
which have retained some relictual diversity. North Brother Island’s tuatara population is inbred with fixed alleles at 5
of the 6 loci. 相似文献
2.
This study bridges two conchological approaches to model the growth characteristics of freshwater pearl mussel shell: size-at-age
and sclerochronology. We demonstrate a simple numerical model that transfers sclerochronological data into realistic estimates
of ontogenetic shell sizing. This model was constructed for a subset of shell growth data dealing with morphometrics and annual
shell growth increments. Further, validation of the model was performed using a dataset that was withheld from the calibration.
Both subsets of data showed significant correlations between the observed (measured by vernier callipers) and reconstructed
size-at-age data, indicating a successful model. The practical applicability of the model was exemplified for the studied
Finnish freshwater pearl mussel populations. In accordance with the previously set theory about the plasticity of life history
traits of the species, the southern mussels showed higher growth rates than the northern mussels.
Handling editor: K. Martens 相似文献
3.
Abdul Muneer PM Gopalakrishnan A Musammilu KK Mohindra V Lal KK Basheer VS Lakra WS 《Molecular biology reports》2009,36(7):1779-1791
Random amplified polymorphic DNA (RAPD) and microsatellite markers were applied to evaluate the genetic variation in endemic
and endangered yellow catfish, Horabagrus
brachysoma sampled from three geographic locations of Western Ghat, South India river systems. In RAPD, of 32 10-mer RAPD primers screened
initially, 10 were chosen and used in a comparative analysis of H. brachysoma collected from Meenachil, Chalakkudy and Nethravathi River systems. Of the 124 total RAPD fragments amplified, 49 (39.51%)
were found to be shared by individuals of all 3 populations. The remaining 75 fragments were found to be polymorphic (60.48%).
In microsatellites, six polymorphic microsatellite loci were identified by using primers developed for Pangasius
hypophthalmus, Clarias
macrocephalus and Clarias
gariepinus. The identified loci were confirmed as microsatellite by sequencing after making a clone. The nucleotide sequences of 6 loci
were published in NCBI genbank. The number of alleles across the six loci ranged from 4 to 7 and heterozygosities ranged from
0.07 to 0.93. The mean number of alleles and effective number of alleles per locus were 5.00 and 3.314, respectively. The
average heterozygosity across all investigated samples was 0.72, indicating a significant deficiency of heterozygotes in this
species. RAPD and microsatellite methods reported a high degree of gene diversity and genetic distances depicted by UPGMA
dendrograms among the populations of H. brachysoma. 相似文献
4.
Jer Pin Chong Jayne C. Brim Box Jeanette K. Howard David Wolf Terry L. Myers Karen E. Mock 《Conservation Genetics》2008,9(5):1303-1309
The surprising diversity and recent dramatic decline of freshwater mussels in North America have been well documented, although
inventory efforts to date have been concentrated in the eastern United States. Unlike their eastern counterparts, western
freshwater mussels have received comparatively little attention. The accurate identity of western lineages is a necessary
component for future inventory, monitoring, and ecological work involving these taxa. Here we initiate a study involving the
most speciose genus (Anodonta) in western North America, incorporating information about type localities and type specimen morphology and describing the
discovery of three highly divergent lineages among four western Anodonta species. In a limited phylogenetic analysis, we find (1) that A. californiensis/nuttalliana and A.oregonensis/kennerlyi are distinct, highly divergent clades, and (2) that A. beringiana is more closely allied with A. woodiana, an Asian species, than either of the other two western North American clades. We were largely unable to resolve the placement
of these three clades with respect to other anodontines, and suggest the need for a broader phylogenetic framework. We recommend,
however, that the existence of these three deeply divergent groups be considered in the development of regional monitoring,
conservation and research plans despite the taxonomic uncertainty. 相似文献
5.
The blue mussel Mytilus trossulus occurs in the Pacific and in the North Atlantic. We developed and characterized six microsatellite loci for Baltic M. trossulus. Seventeen microsatellite loci were screened, of which six were polymorphic. The number of alleles among 50 individuals ranged
from 3 to 13 and the observed and expected heterozygosity were 0.09–0.46 and 0.34–0.86, respectively. The loci were also tested
for cross amplification in M. edulis, in which four of the six microsatellite loci were successfully amplified. 相似文献
6.
Na Chen Yan-Zhuo Yang Xiao-li Yang Xing-xu Zhang Chun-jie Li 《Conservation Genetics》2008,9(4):961-963
Microsatellites are often highly variable and abundant in most complex genomes, therefore are widely used in population genetic
studies. In this study, twelve polymorphic microsatellite loci were isolated and characterized for the Achnatherum inebrians, a plant abundant in grasslands of Northwest China. Characterization of 24 A. inebrians individuals form four geographically distant populations (Gansu, Qinghai, Xinjiang and Inner Mongolia provinces) showed moderate
to high allelic diversity ranging from 3 to 13 alleles per locus, and the expected heterozygosity ranging from 0.41 to 0.67.
No evidence of linkage disequilibrium was found for any locus pairwise comparisons. The markers described here will be useful
for investigating the genetic diversity, genetic structure and gene flow of this species.
Na Chen and Yan-Zhuo Yang contributed equally to this work. 相似文献
7.
Robainas-Barcia A Blanco G Sánchez JA Monnerot M Solignac M García-Machado E 《Genetica》2008,133(3):283-294
We analyzed the spatiotemporal genetic structure of Farfantepenaeus notialis populations using five microsatellites loci in order to understand the influence of natural events such as hurricanes on the genetic drift/migration balance as the main cause for the variation of allele frequencies over time. The results were compared with the previous ones obtained from allozymes and mtDNA. High and stable genetic diversity levels (He=0.879+/-0.0015) were found over eight years for the populations that inhabit the south Cuban platform, however significant changes of allele frequencies were detected over time. The F(ST) estimates, albeit low, revealed significant differences among populations inside the Ana Maria Gulf for 1995 but not for the 1999 and 2003 samples. The F(ST), AMOVA and the genetic distance analysis revealed the instability of the genetic structure over time in accordance with allozymes results. The correspondence of the microsatellite results with those obtained from allozymes confirm the effects of migration enhanced by natural events as the main cause of the temporal variation of allele frequencies. The genetic drift effect was discarded through the evaluation of Ne and the M ratio, while natural selection effects were rejected because of the lowest probability of microsatellite loci being under selective pressures. The microsatellite data are also consistent with the results obtained with mtDNA in detecting significant and persistent genetic differences between the Gulfs of Ana María and Batabanó for the years 1995 and 2003. 相似文献
8.
Stratikopoulos EE Augustinos AA Petalas YG Vrahatis MN Mintzas A Mathiopoulos KD Zacharopoulou A 《Genetica》2008,133(2):147-157
A genetic map based on microsatellite polymorphisms and visible mutations of the Mediterranean fruit fly (medfly), Ceratitis capitata is presented. Genotyping was performed on single flies from several backcross families. The map is composed of 67 microsatellites and 16 visible markers distributed over four linkage groups. Fluorescence in situ hybridization of selected microsatellite markers on salivary gland polytene chromosomes allowed the alignment of these groups to the second, fourth, fifth and sixth chromosome. None of the markers tested showed segregation either with the X or the third chromosome. However, this map constitutes a substantial starting point for a detailed genetic map of C. capitata. The construction of an integrated map covering the whole genome should greatly facilitate genetic studies and future genome sequence projects of the species. 相似文献
9.
P. Olofsson 《Biology Bulletin》2017,44(1):74-80
A total of 16 freshwater pearl mussel Margaritifera margaritifera rivers out of 64 known freshwater pearl mussel rivers are included in the Administrative County of Norrbotten regional monitoring program. First surveys were done in 1994 and the results show that only three rivers have viable populations according to national criteria despite little visible human impact and that juvenile mussels (<50 mm in length) have been found in all rivers at every occasion. The results also indicate that there might be “missing years” for juvenile recruitment suggesting that freshwater pearl mussel populations at the extreme end of the species range might be dependent on “golden moments” in order to keep up viable populations. Deeper knowledge and better tools for determining viable populations might be necessary in order to make the right decisions on how to manage the rivers and the freshwater pearl mussel populations. 相似文献
10.
We determined the concentration of glutathione (GSH) and the activity of glutathione S-transferase (GST) in the gills and hepatopancreas of the freshwater pearl mussel Margaritifera margaritifera L. It was found that the concentration of GSH in the gills decreases with a decrease in temperature, which indicates that metabolic processes in these ectothermic animals are decelerated. It was also found that changes in the concentration of GSH and in the activity of GST do not depend on age; thus, these biochemical markers can be used as bioindicators regardless of age. No substrate-specific activity of GST was observed, which means that freshwater pearl mussels have limited ability to metabolize compounds with different chemical structures. 相似文献
11.
S. J. Välilä K. E. Knott E. P. Ieshko A. E. Veselov J. K. Taskinen 《Biology Bulletin》2017,44(1):92-98
The freshwater pearl mussel Margaritifera margaritifera L. is one of the most endangered freshwater mussels in the world. Effective conservation of threatened species requires not only ecological, but also genetic information from the target species and populations. Since low genetic diversity can reduce the ability of a species to adapt to environmental changes, maintaining genetic diversity has been identified as one of the key elements in successful conservation programs. We examined genetic variation of the freshwater pearl mussel from the River Vuokkijoki, Karelia, Russia. We sequenced a fragment of the cytochrome c oxidase subunit I gene (COI) from 22 individuals and compared the data to 32 previously published COI sequences available in GenBank. We identified 10 different COI haplotypes in the sequenced samples, three of which had not been previously reported. Our results show that the River Vuokkijoki has high genetic diversity and suggest that the colonization of this northern freshwater pearl mussel population might have occurred from multiple and even distant refugia. Therefore, the freshwater pearl mussel population of the River Vuokkijoki is valuable for the conservation of the whole species. 相似文献
12.
Garrulax morrisonianus, an endemic avian species of Taiwan, inhabits evergreen forests at high elevations of 2,000–3,952 m. In this study, we developed
15 microsatellite primer pairs for genetic study. These markers were screened for 52 samples collected from wild populations
of different geographical regions. The number of alleles ranged from 4 to 13. The expected (H
E) and observed (H
O) heterozygosities were 0.430–0.725 and 0.000–0.500, respectively. All loci were significantly deviated from Hardy-Weinberg
equilibrium due to the heterozygote deficiency.
The authors Tzen-Yuh Chiang, Sao-Cheng Lao, Ya-Fu Lee contributed to the study equally. 相似文献
13.
Manja U. Böhme Norbert Schneeweiß Uwe Fritz Martin Schlegel Thomas U. Berendonk 《Conservation Genetics》2007,8(3):555-563
Edge and central populations can show great differences regarding their genetic variation and thereby also in their probability
of extinction. This fact might be of great importance for the conservation strategies of endangered species. In this study
we examine the level of microsatellite variability within three threatened edge populations of the green lizard subspecies
Lacerta viridis viridis (Laur.) in Brandenburg (Germany) and compare the observed variation to other edge and central populations within the northern
species range. We demonstrate that the northernmost edge populations contain less genetic variation in comparison to the central
population. However, there were no observable significant differences to the other edge population included in this study.
Surprisingly, we observed a high genetic differentiation in a small geographical range between the three endangered populations
in Brandenburg, which can be explained by processes like fragmentation, isolation, genetic drift and small individual numbers
within these populations. We also detected unique genetic variants (alleles), which only occurred in these populations, despite
a low overall genetic variation. This study demonstrates the potential of fast evolving markers assessing the genetic status
of endangered populations with a high resolution. It also illustrates the need for a comparative analysis of different regions
within the species range, achieving a more exact interpretation of the genetic variation in endangered populations. This will
aid future management decisions in the conservation of genetic diversity in threatened species. 相似文献
14.
Achnatherum sibiricum is a threaten and toxic perennial bunchgrass mainly in the north of China. We developed 11 polymorphic microsatellite loci
from A. sibiricum by combining biotin capture method. After validating and scoring, these loci were polymorphic in a test population with the
range of alleles from four to 13 per locus. The observed and expected heterozygosities ranged from 0.1649 to 0.5624 and from
0.3071 to 0.8826, respectively. All 11 microsatellite markers were in Hardy–Weinberg equilibrium. These polymorphic microsatellites
will be useful for genetic diversity analysis and population structure construction for A. sibiricum. 相似文献
15.
Genetic diversity and differentiation within and among nine G. morsitans morsitans populations from East and southern Africa was assessed by examining variation at seven microsatellite loci and a mitochondrial
locus, cytochrome oxidase (COI). Mean COI diversity within populations was 0.63 ± 0.33 and 0.81 taken over all populations. Diversities averaged over microsatellite
loci were high (mean number of alleles/locus ≥7.4; mean H
E ≥ 65%) in all populations. Diversities averaged across populations were greater in East Africa (mean number of alleles = 22 ± 2.6;
mean h
e = 0.773 ± 0.033) than in southern Africa (mean number of alleles = 18.7 ± 4.0; mean h
e = 0.713 ± 0.072). Differentiation among all populations was highly significant (R
ST = 0.25, F
ST = 0.132). Nei’s G
ij
statistics were 0.09 and 0.19 within regions for microsatellites and mitochondria, respectively; between regions, G
ij
was 0.14 for microsatellites and 0.23 for mitochondria. G
ST among populations was 0.23 for microsatellite loci and 0.40 for mitochondria. The F, G and R statistics indicate highly restricted gene flow among G. m. morsitans populations separated over geographic scales of 12–917 km. 相似文献
16.
The analysis of 135 mitochondrial D-loop sequences of the Iberian autochthonous red-legged partridge (Alectoris rufa) from wild population hunting bags from various locations and fowl runs in Spain yielded 37 different haplotypes. Among these,
three haplotypes correspond to chukar partridges (Alectoris chukar), indicating genetic introgression from birds illegally introduced for restocking: three individuals carrying such haplotypes
where found in natural populations, one appeared among those sampled on a mass reproduction farm and the remaining 10 in another
fowl-run. The geographical origin of the contaminating chukar haplotypes could be assigned to the most easterly area of the
chukar partridge geographical distribution in China. Molecular diversity parameters in the A. rufa samples indicate a considerable amount of genetic variation. ΦST showed significant differences among populations that are not explained by geographical distance alone. Particularly, one
northern population (Palencia) shows a certain degree of genetic differentiation that could reflect a previously suggested
subspecies division.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Endangered freshwater pearl mussels Margaritifera margaritifera reveal a complex life cycle with an obligate host-dependent phase. Only two species, Atlantic salmon Salmo salar and brown trout S. trutta, are important hosts in Europe, indicating a high degree of specialization. Whilst freshwater pearl mussels with their filtering activity can provide important ecosystem services and indirectly improve the habitat quality for their salmonid hosts, their direct effects on physiological stress, reduced swimming performance, and increased mortality at high rates of infestation all support a parasitic character of the mussel during its hostdependent phase. From an evolutionary perspective, both the much greater generation time of the parasite compared to the host, as well as the great distribution ranges of M. margaritifera and its hosts should favour local adaptation patterns. The variable suitability of different salmonid strains and species as hosts for M. margaritifera and the resulting differences in the performance of larvae during the host-dependent phase indicate that host-management strategies should focus on maintaining high quality hosts at a regional scale to avoid selection or genetic drift effects which could erode the genetic and evolutionary potential for adaptation to changing environmental conditions. 相似文献
18.
An understanding of the variation pattern in disease resistance (R) genes is essential for its use in breeding programs aimed at neutralizing the threat of pathogens. Although the variation
between populations is well known, there is little research about R-gene variation patterns within populations. Here, we investigate the polymorphism at three R-gene loci of 39 individual plants from nine populations of Arabidopsis thaliana. Our data suggest that alleles of each locus from individuals within a local population were either nearly identical, or
highly diverse as ones between populations. The vast majority (92.5%) of within-population variation was shared globally,
with high levels of allelic diversity (up to 11.7%) and abundant diverse-alleles. This unique pattern of within-population
variation at R-loci suggests that individual plants within a population had the great potential to maintain a high level of globally-shared
polymorphisms, and that the diversifying selection was the major force maintaining such polymorphisms. Consequently, the shared-polymorphism
became recyclable for new R-genes, as the corresponding avirulence re-emerges in pathogen populations.
Nucleotide sequence data reported are available in the GenBank databases under the accession numbers EF368054-EF368158. 相似文献
19.
Bernhard C. Stoeckle Rafael Araujo Juergen Geist Ralph Kuehn Carlos Toledo Annie Machordom 《Conservation Genetics》2017,18(1):147-157
Genetic diversity of European freshwater pearl mussel, Margaritifera margaritifera (L.), appears exceptional with highest genetic variability found in the northernmost European populations of Scandinavia and lower genetic variability in central and southern Europe. The objective of this study was to investigate genetic diversity and differentiation of 14 southernmost populations on the Iberian Peninsula which greatly differ in terms of life span and habitat conditions from the rest of central and northern European populations. The analyses of ten microsatellite loci revealed a pronounced level of genetic divergence and very low genetic diversity. These results match the expectations of geographically peripheral populations with respect to their genetic composition. The life history strategy, the narrow ecological niche of the species, and anthropogenic habitat modifications have most likely shaped the genetic pattern of Iberian pearl mussel populations. The peripheral position with less optimal habitat conditions may increase the extinction risk of these populations and thus effective conservation strategies for the Iberian M. margaritifera are needed. The successful conservation of the species at its southwestern margin requires inclusion of genetically different conservation units which may reveal local adaptation. 相似文献