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1.
Three populations (Azov, Caspian, and Black Sea) of Russian sturgeon Acipenser queldenstaedtii were tested for polymorphism at nuclear (RAPD and microsatellites) and mitochondrial (PCR identification of two mitotypes) markers. In addition, morphometric analysis of he representatives of Azov population was carried out. According to the morphological characters, the Black Sea population occupied an intermediate position between the Caspian and Azov populations, reflecting the phylogeography of this species. In agreement with the morphometric data, genetic distances (the data of STR analysis) also placed the Black Sea population between the Caspian and Azov populations (F ST = 0.058 and 0.043). The genetic distance between the Azov and Caspian population was somewhat higher (F ST = 0.070). The highest allelic polymorphism at four microsatellite loci was found observed in Caspian population, while the lowest polymorphism was in the Sea of Azov. RAPD analysis distinguished high polymorphism within the populations, although it was not feasible for interpopulation analysis. Using the method differentiating the “baerii-like” and typical “gueldenstaedtii” mitotypes, the absence of the “baerii-like” marker in the Black Sea population was demonstrated. The frequency of this marker in Caspian and Azov populations constituted 31.1 and 1.8%, respectively. Possible evolutionary reasons for the interpopulation differences observed are discussed.  相似文献   

2.
Nautilus species are the only remaining cephalopods with an external shell. Targeted heavily by the shell trade across their distribution area, these species have a poorly known population structure and genetics. Molecular techniques have been used to assess levels of inter- and intra-population genetic diversity in isolated populations of Nautilus in the northern sections of the Great Barrier Reef (GBR), Australia and in the Coral Sea. Distinct populations, physically separated by depths in excess of 1,000 m were examined. RAPD analysis of genetic differences showed limited differentiation of the “Northern GBR” populations and the “Coral Sea” populations. Discrimination between the two geographic groups was observed from these data. In addition, partial sequencing of the CoxI gene region, yielded 575 bp of sequence, which was aligned for 43 samples and phylogenetic trees constructed to examine genetic relationships. Two distinct clades were resolved in the resulting trees, representing the “Northern GBR” and “Coral Sea” population groups. Inter- and intra-population relationships are presented and discussed. The differentiation of the Nautilus populations from the Northern section of the Great Barrier Reef and those from the Coral Sea were supported by two distinctly different methodologies and the significance of this separation and the potential evolutionary divergence of these two population groups is discussed.  相似文献   

3.
The randomly amplified polymorphic DNA (RAPD) markers were used to detect interspecific genetic variability and genetic relatedness among five Indian sciaenids namely Otolithes cuvieri, Johnieops sina, Johnieops macrorhynus, Johnieops vogleri and Protonibea diacanthus for the first time. Eight RAPD primers (OPA01, OPA06, OPA07, OPA18, OPP12, OPP14, OPP16 and OPP11) generated 40 species specific diagnostic bands. The highest genetic divergence was detected between J. macrorhynus and P. diacanthus (0.586) where as the lowest one was observed between J. sina and J. vogleri (0.274). Handling editor: C. Strumbauer  相似文献   

4.
The family Channidae is represented by 26 species, out of which 23 species are found in Asia. However, the taxonomy and phylogeny of the Channid fishes found in India are poorly understood. In the present study, eight species of Channa (Channa striata, Channa punctatus, Channa marulius, Channa gachua, Channa stewartii, Channa aurantimaculata, Channa barca and Channa bleheri) were investigated using partial sequences of 16S rRNA and Cytochrome c Oxidase subunit I (COI) of mitochondrial genes to differentiate among the eight species and study their relationships. The sequence analysis of the genes revealed two distinct groups, which are genetically distant from each other and exhibit identical phylogenetic resolution. The partial sequences of both the genes provided sufficient phylogenetic information to distinguish all the eight species of Channa.  相似文献   

5.
A portion of the mitochondrial 16S rRNA gene was compared between two color morphotypes of Gerres erythrourus, viz. “yellow type” and “white type,” obtained from Ryukyu Islands, Japan, and various areas of the Indo-Pacific, respectively. Phylogenetic analyses showed that the haplotypes of each color morph were reciprocally monophyletic, supported by high bootstrap values. The degree of sequence difference between the two color morphs was comparable to that existing between species of the same complex as well as other distinct gerreid species. The genetic results together with their geographic range indicated that the two color morphs represent two distinct species. Supplementary material to this paper is available in electronic format at http://dx.doi.org/10.1007/s10228-005-0324-0  相似文献   

6.
Mobile genetic elements constitute a substantial part of eukaryotic genome and play an important role in its organization and functioning. Co-evolution of retrotransposons and their hosts resulted in the establishment of control systems employing mechanisms of RNA interference that seem to be impossible to evade. However, “active” copies of endogenous retrovirus gypsy escape cellular control in some cases, while its evolutionary elder “inactive” variants do not. To clarify the evolutionary relationship between “active” and “inactive” gypsy we combined two approaches: the analysis of gypsy sequences, isolated from G32 Drosophila melanogaster strain and from different Drosophila species of the melanogaster subgroup, as well as the study of databases, available on the Internet. No signs of “intermediate” (between “active” and “inactive”) gypsy form were found in GenBank, and four full-size G32 gypsy copies demonstrated a convergence that presumably involves gene conversion. No “active” gypsy were revealed among PCR generated gypsy ORF3 sequences from the various Drosophila species indicating that “active” gypsy appeared in some population of D. melanogaster and then started to spread out. Analysis of sequences flanking gypsy variants in G32 revealed their predominantly heterochromatic location. Discrepancy between the structure of actual gypsy sites in G32 and corresponding sequences in database might indicate significant inter-strain heterochromatin diversity. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

7.
Sequence-characterized amplified regions markers (SCARs) were developed from six randomly amplified polymorphic DNA (RAPD) markers linked to the major QTL region for powdery mildew (Uncinula necator) resistance in a test population derived from the cross of grapevine cultivars “Regent” (resistant) × “Lemberger”(susceptible). RAPD products were cloned and sequenced. Primer pairs with at least 21 nucleotides primer length were designed. All pairs were tested in the F1 progeny of “Regent” × “Lemberger”. The SCAR primers resulted in the amplification of specific bands of expected sizes and were tested in additional genetic resources of resistant and susceptible germplasm. All SCAR primer pairs resulted in the amplification of specific fragments. Two of the SCAR markers named ScORA7-760 and ScORN3-R produced amplification products predominantly in resistant individuals and were found to correlate to disease resistance. ScORA7-760, in particular, is suitable for marker-assisted selection for powdery mildew resistance and to facilitate pyramiding powdery mildew resistance genes from various sources.  相似文献   

8.
Candidatus Liberobacter,” the uncultured bacterium associated with citrus Huanglongbing (HLB) disease, is an α-Proteobacteria, and two species, “Candidatus L. africanum” and “Candidatus L. asiaticum,” have been characterized by sequence analysis of the 16S rDNA and β operon (rplKAJL-rpoBC) genes. These genes were isolated by PCR and random cloning of DNA from infected plants. However, this strategy is laborious and allowed selection of only three Liberobacter DNA fragments. In this paper, we described isolation of additional genes using Random Amplified Polymorphic DNA (RAPD). In total, 102 random 10-mer primers were used in PCR reactions on healthy and Liberobacter-infected plant DNA. Eight DNA bands amplified from infected plant DNA were cloned and analyzed. Six of them were found to be part of the Liberobacter genome by sequence and hybridization experiments. On these DNA fragments, four genes were identified: nusG, pgm, omp, and a hypothetical protein gene. These results indicate that RAPD can be used to clone DNA of uncultured organisms. Received: 14 September 1998 / Accepted: 6 October 1998  相似文献   

9.
The genetic diversity and relationship among four morphotypes of Rhinogobius sp. OR, Gobiidae (“Tōshoku,” “Shinjiko,” “Gi-tōshoku,” and “Shimahire”) were investigated with seven microsatellite DNA loci, and amphidromy of these morphotypes was verified by strontium (Sr) and calcium (Ca) deposition in the otolith. Samples of “Tōshoku,” “Shinjiko,” “Gi-tōshoku,” and “Shimahire” were collected from, respectively, three, three, two, and four locations in Japan. Microsatellite analysis detected high genetic diversity (based on the number of alleles, allelic richness, and average observed heterozygosity) in the “Tōshoku” and “Shinjiko” morphotypes relative to the “Shimahire” morphotype; the “Gi-tōshoku” morphotype had an intermediate level of variation. Almost all pairwise F ST values were significantly different from zero (P < 0.001), except between two populations of “Tōshoku.” Clear genetic independence was observed between the “Shinjiko” and “Shimahire” morphotypes in the Maruyama River. A principle component analysis based on microsatellite data indicated that the “Tōshoku,” “Shinjiko,” and “Gi-tōshoku” morphotypes were genetically similar. Furthermore, the three populations of “Tōshoku” were closely related each other, and two of those collected from the Lake Biwa system were a single population. There was, however, a high degree of genetic differentiation between “Shimahire” and the other morphotypes; moreover, there was high genetic divergence among four populations of the “Shimahire” morphotype. Amphidromous migratory histories were indicated by Sr:Ca ratios in two of three populations of the “Shinjiko” morphotype and in one of two “Gi-tōshoku” morphotypes, whereas all populations of the “Shimahire” morphotype were freshwater residents. The large genetic divergence and low genetic diversity in “Shimahire” are likely related to migration history.  相似文献   

10.
The genetic diversity and genetic relatedness of mei (Prunus mume; 2n = 16) were studied using amplified fragment length polymorphism (AFLP) markers. Eight EcoRI–PstI AFLP primer combinations were applied to 121 distinct genotypes of mei cultivars and related species. A total of 508 AFLP product bands were produced, of which 382 were polymorphic. The unweighted pair group method with arithmetic averages analysis was carried out based on these AFLP markers. From this analysis, “Qugeng Mei,” “Yan Mei,” “Chaodou Mei,” and mei cultivars were seen to share the same P. mume genetic stem. The AFLP data were able to clearly discriminate P. mume from other species in the genus Prunus, with P. armeniaca aligning as its closest related species. Two major groups and nine subgroups of mei flower were identified, and there was a strong coincidence of these AFLP-based groupings with the respective morphological characters of the accessions. The genetic diversity of mei accessions was greatest in the Yunnan Province and decreased toward Eastern China and Japan, so supporting the hypothesis that the southwest of China represents the genetic diversity center of the species.  相似文献   

11.
The Mediterranean fan mussel Pinna nobilis is an endangered invertebrate due to overexploitation and habitat deterioration. In this species, two distinctive morphs, the “combed” and “straight and wide” forms, have been recorded and it is not known whether this morphometric variability is attributed to genetic or environmental factors. In this study, we used mitochondrial COI sequences to describe the genetic variability of five Pinna nobilis populations sampled along the northern, eastern, and southern Tunisian coastline, and to examine whether there is a genetic differentiation between the two forms of this species. DNA sequences of 675 bp from the mitochondrial COI gene have revealed 10 different haplotypes among 49 examined specimens. Haplotype diversity was high, ranging between 0.40441 and 0.80952, and showed a decreasing North-East gradient, which seems to be explained by the hydrogeography of the study area. The mitochondrial COI marker did not suggest a genetic distinctiveness between the two Pinna nobilis shell forms, “combed” and “straight and wide”. Although the morphometric plasticity of the fan mussel could be due to the influence of environmental factors, further genetic studies using nuclear markers are envisaged to investigate whether this differentiation is associated to gene flow restrictions.  相似文献   

12.
The systematics and taxonomy of Kappaphycus and Eucheuma (Solieriaceae) is confused and difficult due to morphological plasticity, lack of adequate characters to identify species and commercial names of convenience. These taxa are geographically widely dispersed through cultivation. Commercial, wild and herbarium sources were analysed; molecular markers provided insights into taxonomy and genetic variation, and where sources of genetic variation may be located. The mitochondrial cox2-3 and plastidal RuBisCo spacers were sequenced. There is a clear genetic distinction between K. alvarezii (“cottonii”) and K. striatum (“sacol”) samples. Kappaphycus alvarezii from Hawaii and some samples from Africa are also genetically distinct. Our data also show that all currently cultivated K. alvarezii from all over the world have a similar mitochondrial haplotype. Within Eucheuma denticulatum (“spinosum”) most African samples are again genetically distinct. Our data also suggest that currently cultivated E. denticulatum may have been “domesticated” several times, whereas this is not evident for the cultivated K. alvarezii. The present markers used do not distinguish all the morpho-types known in cultivation (e.g. var. tambalang, “giant” type) but do suggest that these markers may be useful to assess introductions and species identification in samples.  相似文献   

13.
Leech taxonomy is based on unstable morphological characters. The overall level of genetic variability and species differentiation is unknown. Using the RAPD assays genetic diversities and genetic similarities were estimated in twelve species collected in North-Eastern Poland and representing three families and five subfamilies. Ten primers revealed 204 reproducible bands. Genetic diversities varied from 0.099 to 0.219 classifying studied species among variable invertebrates. Total 45 markers comprised 22% of all amplified bands were unique for species thus enabling their identification. Genetic similarities among species (0.528–0.811) evidenced several stages of differentiation, which is mirrored in the current taxonomy. The UPGMA and multidimensional scaling (nMDS) based on our RAPDs are congruent and reflected traditional division into “Rhynchobdellida” and Arhynchobdellida. The RAPD approach proved to be an effective tool in population and evolutionary studies of leeches. For the first time, genetic parameters were estimated enabling to compare leeches with outcomes from other animals.  相似文献   

14.
Genetic diversity of the isolates of Fusarium oxysporum f. sp. ciceris causing chickpea wilt collected from 12 states representing different agro-ecological regions of India was determined through randomly amplified polymorphic DNA (RAPD) markers. The UPGMA cluster analysis grouped the isolates into eight categories showing high magnitude of genetic diversity. Each group had the isolates from different states present in various agro-ecological regions of India. Therefore, the groups generated through the RAPD analysis were not corresponding to area of the origin of the isolates. The RAPD primers, namely, OPA 7 and OPA 11 produced Foc specific fragment of ≈1.3 kb and ≈1.4 kb, respectively in all the isolates. These fragments were eluted, purified, cloned in pGEM-T Easy vector and sequenced. Primers were designed with sequence information of these two fragments using primer.3 software. Two sets of sequence characterized amplified region markers (SC-FOC 1 and SC-FOC 2) developed from the sequences of these fragments were found to be specific to Foc and produced an amplicon of 1.3 and 1.4 kb, respectively. These set of markers were validated against the isolates of the pathogen collected from different locations of India representing various races of the pathogen. They are non-specific to the other Fusarium species, Rhizoctonia solani and R. bataticola.  相似文献   

15.
Traditional Knowledge and Management of Feijoa (Acca sellowiana) in Southern Brazil. This paper investigates traditional knowledge of the use and management of Acca sellowiana in southern Brazil. Fifty-six informants from three rural communities were assigned to one of four subgroups (“maintainers,” “managers,” “cultivators,” or “users”) based on their responses regarding management and use of A. sellowiana. Traditional knowledge related to use of this species is widespread among rural residents, but traditional knowledge related to management is fragmented depending on whether one uses, manages, or cultivates the species. Knowledge held in rural communities suggests that A. sellowiana could play an expanded role in local economies as well as biodiversity conservation. We suggest that participatory research could stimulate greater local use as well as on-farm conservation of A. sellowiana.  相似文献   

16.
Interactions between plants and herbivores are considered “diffuse” if the ecological interactions between two species, or their evolutionary responses, differ depending on the presence of a third species. I looked for evidence of diffuse interactions among horsenettle (Solanum carolinense) and two common herbivores. Plants experimentally protected from lace bugs (Gargaphia solani) were twice as susceptible to attack from flea beetles (Epitrix fuscula) once transplanted into the field. Thus, the selective benefit to horsenettle of resistance against lace bugs in nature would likely be diminished by increased attack from flea beetles. Moreover, the relative rank among horsenettle genotypes for resistance against flea beetles was changed by prior exposure to lace bugs. Thus, the genetic expression of resistance to flea beetles would depend on the “lace bug environment.” By affecting selective pressures or response to selection, these sorts of diffuse interactions in a plant-herbivore community can slow the host plant’s evolution of resistance to its herbivores.  相似文献   

17.
This study reviews the nominal taxa within the species “Nemachilus” stoliczkae and “N.” dorsonotatus, described by Herzenstein (1888). N. dorsonotatus, N. d. retropinnis, and N. plagiognathus are reviewed within the species Triplophysa stoliczkae; it is suggested that this species is represented by at least 5 subspecies. N. stoliczkae brevicauda, N. s. leptosoma (synonym, N. s. productus), and N. s. crassicauda are considered as valid species, the last 2 are related to the group including the species T. tenuis, T. choprai, T. tenuicauda, and T. yasinensis rather than with T. stoliczkae. It was shown that the “stoliczkae” species group (sensu Prokofiev, 2001) should be divided into three species groups: “stoliczkae” (s. str.), “tenuis,” and “robusta”; their diagnoses and the species composition are presented. A new species from the “stoliczkae” group is described (T. scapanognatha sp. nova), related to T. tanggulaensis (Zhu, 1982). Original Russian Text ? A.M. Prokofiev, 2007, published in Voprosy Ikhtiologii, 2007, Vol. 47, No. 1, pp. 5–25.  相似文献   

18.
Snakehead species belonging to Channidae are primary group of freshwater air breathing fishes having their confined distribution in African and Asian continents. ISSR – PCR was used to investigate the phylogenetic relationship among five Channidae species viz. Channa striatus, Channa marulius, Channa punctatus, Channa diplogramme and Channa gachua. In addition, morphometric and meristic characters were subjected to principal component analysis (PCA) and the bootstrap values within the species were also calculated. The genetic identity between the species ranged from 0.5526 to 0.7632 and the genetic distance ranged from 0.2703 to 0.5931. The Nei's gene diversity (H) was calculated as 0.2653 and the Shannon's information index (I) was 0.3842. UPGMA dendrogram arrived by the morphological and molecular markers revealed the closeness between C. striatus and C. marulius among the five species.  相似文献   

19.
Den sharing by conspecific spiny lobsters (aggregation) is modulated by chemical attraction but may confer several, not necessarily mutually exclusive, antipredator byproduct benefits: a “guide effect”, which only benefits the individual attracted to a sheltered conspecific; a “dilution effect”, which reduces per-capita risk of predation simply through aggregation; or active “group defense”. Each potential benefit has a different set of predictors (relationships between aggregation and conspecific or predator densities), but conflicting results could suggest the simultaneous operation of more than one benefit. These predictions were tested for coexisting Panulirus guttatus (a reef-obligate) and Panulirus argus (a temporary reef-dweller) using data collected during 11 surveys on fixed sites over a coral reef in Mexico. P. guttatus greatly outnumbered P. argus, but P. argus showed a greater tendency to aggregate. All three benefits of den sharing operated for the more social P. argus, with “group defense” being of the most benefit for larger individuals, and the “guide” and “dilution” effects for smaller individuals recently immigrating into the reef habitat and sharing dens with larger conspecifics. P. guttatus did not display “group defense” and its aggregations appeared to be modulated by the interplay between attraction and aggressive behaviors. This species relied more on solitary crypticity, especially at larger sizes, but appeared to benefit from a “guide effect” at high conspecific densities. In experimental tanks, each species tended to aggregate when tested separately, but when tested jointly, aggregation among P. guttatus was significantly reduced. The experimental results reflect the differential patterns of aggregation between the fore-reef, where P. guttatus dominated, and the back-reef, where coexistence of both species was greater.  相似文献   

20.
Length–weight relationships (LWRs) and length–length relationships (LLRs) of two endemic Channid fish species, Channa aurantimaculata Musikasinthorn, 2000 and C. stewartii (Playfair, 1867) were studied from Brahmaputra River basin in Assam, India. Sampling was done from May to December, 2017 and a total of 81 fish specimens were collected using bamboo traps. In the LWRs, b value for C. aurantimaculata and C. stewartii were 3.0456 and 2.9172 respectively. Maximum size recorded for C. aurantimaculata in the present study (34.1 cm) was higher than previous record in FishBase (19.1 cm).  相似文献   

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