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1.
Despite almost a hundred years of studies on the Pacific cod’s biological and ecological peculiarities, many of them and especially population structure remain poorly understood. The variability of DNA microsatellite loci Gmo3, Gmo34, Gmo35, Pgmo32, and Gmo 19 was analyzed for the cod sampled in different areas of the North Pacific. The cod sampled nearby the Southern Kurils, differed significantly by Gmo3 and Pgmo32 compared to the populations inhabiting the Bering Sea, the Sea of Okhotsk and the coastal waters off Canada. Further, Pacific cod of the three latter populations demonstrated high similarity (I = 0.996) in spite of considerable geographic remoteness of these areas from one another.  相似文献   

2.
Variation of microsatellite loci Gmo8, Gmo-G12, Gmo-G18, Gmo19, PGmo32, Gmo34, and Gmo35 is investigated in Kildin cod Gadus morhua kildinensis. The investigated loci are characterized by a low level of variation: five loci are represented by two-allele systems and three loci are monomorphic. Mean value of heterozygosity calculated by all investigated loci is lower in Kildin cod than in Atlantic Gadus morhua—0.2854 vs. 0.5667.  相似文献   

3.
Incubation of pacific cod eggs was divided into eight series, in which temperatures were set at −0.04°C to +4.03°C and warm and cold conditions alternated. The morphological changes that took place during the embryogenesis were described in detail using the results of the incubation. Twenty-two morphological characters that could be identified easily and that characterized the morphogenesis were defined in the course of development. The results of the incubation and data from the literature showed that the duration of the embryonic period in the Pacific cod’s lifecycle grew exponentially as water temperature decreased. It was found during the experiment that developing cod eggs survived low water temperatures up to freezing, as well as abrupt warming or cooling (over 3°C). According to the widely accepted Rass scale, the first stage of the Pacific cod embryogenesis takes 21% of its total duration, the second stage 23%, the third, 17%, and the fourth, 39%. However, at a temperature below 0°C, the relative duration of the stages of cleavage and embryonic shield was slightly shortened, whereas the mature embryo stage extended to almost half of the embryogenesis period. A more comprehensive analysis of temperature effects on embryogenesis revealed that the reduction of the rate of embryogenesis upon a temperature decrease occurred mostly at later stages of embryo growth. Modeling of development using defined morphological characters showed that the duration of embryogenesis grew linearly as the incubation temperature dropped in the first half of the embryogenesis and exponentially in the second half. A function was selected that described the obtained results most satisfactorily and that could be used for estimating the duration of the entire embryogenesis or any its stages within the range of water temperatures typical for Pacific cod.  相似文献   

4.
Variability of microsatellite DNA loci Gmo3, Gmo34, and Gmo35 is studied in samples of Pacific cod Gadus macrocephalus and Atlantic cod G. morhua. The results show high values of identity of the samples within the North Pacific basin (0.9766–0.9924) and within the Northeast Atlantic basin (0.9580). Based on the pairwise assessment of genetic differentiation, the F ST values are significantly different in all variants between the samples of Pacific and Atlantic cod (F ST = 0.5235–0.6719, p < 0.001). Within the basins, the significant differences in the frequencies of main alleles are revealed in the loci Gmo3 and Gmo34 for the samples from the Pacific and Atlantic oceans, respectively.  相似文献   

5.
According to the results of analysis of genetic differentiation and Bayesian hierarchical cluster analysis of polymorphism in microsatellite loci, it was demonstrated that the development of marginal groups represented by subspecies level taxa (Greenland (Gadus macrocephalus ogac) and White Sea (Gadus morhua marisalbi) cod) occurred in the Late Holocene in a similar scenario, but in different regions and from different initial forms. The development of these reproductively independent cod groups was a result of physiological adaptations to arctic conditions in coastal northern water areas that developed under global cooling in the Subboreal.  相似文献   

6.
The Australian freshwater cod genus, Maccullochella is represented by three species: Murray cod, M. peelii peelii, eastern freshwater cod, M. ikei, and trout cod, M.macquariensis. Seven novel microsatellite loci from M. ikei and six previously published loci from M. peelii peelii were tested on wild populations of Murray, eastern and trout cod. Levels of polymorphism varied between species with 13 loci polymorphic in Murray cod, 9 in trout cod and 7 in eastern cod. Observed heterozygosities ranged from 0.053 to 0.842. This suite of microsatellite loci will facilitate future studies of the genetic status of wild and hatchery bred populations of Maccullochella.  相似文献   

7.
Genetic diversity of 13 species of the genus Vincetoxicum Wolf found in Ukraine with the use of four of eight nuclear microsatellite markers previously developed for Vincetoxicum atratum from Japan was studied. The number of alleles in studied loci varied in the range from 8 to 25. The expected heterozygosity was 0.690–0.938; the observed heterozygosity varied in the range from 0.205 to 0.806. The total rate of genetic variability of studied species was found to be comparable to the rate of variability of Vincetoxicum atratum from Japan. Microsatellite loci Vinc5, Vinc104, Vinc123, and Vinc124 can be successfully used for estimating the intra- and interspecific polymorphism of the species of genus Vincetoxicum Wolf in Ukraine.  相似文献   

8.
The transferability of microsatellite markers developed for olive cultivars (Olea europaea L.) has been tested and confirmed in the Olea complex. Thirty two genotypes, belonging to different taxa of the genus Olea, have been analyzed with four olive SSRs. Positive amplifications at all loci were obtained in 13 taxa (at least one accession per species). Sixty seven different alleles have been detected at the four loci analyzed. Polymorphic products have been observed at the inter- and intra-species level. Some SSR loci have shown multiple amplification products in some species. The high number of unique alleles has allowed the unambiguous discrimination of most accessions. Similarity coefficients and relationships among the Olea taxa have been calculated based on SSR amplification results. The reliability of SSRs as markers for intra-species variability evaluation has been confirmed while their use to explore relationships at the inter-species level is discussed, being dependent on the locus analyzed.Communicated by H.F. Linskens  相似文献   

9.
Experimental data on the molecular structure and variability of microsatellite loci in unisexual and bisexual lizard species of the genus Darevskia were analyzed. The allelic variants of Du281 and Du47 were found to differ in the number of monomers, the structure of microsatellite clusters, and point mutations in these clusters and flanking DNA. Interspecific comparison of alleles of these loci revealed both variable regions in the microsatellite clusters and allele-specific evolutionarily conserved nucleotide groups. In general, the results of comparative structural analysis of allelic variants testify to a high genetic similarity of the unisexual and bisexual lizard species studied and reveals the characteristic features of their interspecies variability.  相似文献   

10.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

11.
A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and hypothetical lipoprotein (LpnB) sequences. A comparison between GM2212 and the type strain of Francisella philomiragia were performed by DNA–DNA hybridization and fatty acid analysis. The DNA–DNA hybridization showed a 70% similarity. The fatty acid analysis showed only minor differences between the Francisella isolates. Due to the inconclusive result from the DNA–DNA hybridisation, major emphasis concerning the status of this isolate is made on previously published molecular, phenotypic and biochemical characters. All characteristics taken together support the establishment of GM2212 as a novel species, for which the name Francisella piscicida sp. nov. is proposed (=CNCM I-3511T = DSM 18777T = LMG registration number not yet available).  相似文献   

12.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

13.
The variable microsatellite repeat BM224 has been revealed in the genomes of eight species of green frogs (Rana ridibunda, R. cf. bedriagae, R. cretensis, R. esculenta, R. lessonae, R. shquiperica, R. saharica, R. nigromaculata). Previously, this repeat was observed in members of the genus Bufo. In this paper, the possibility of using this genetic marker for species identification is discussed.  相似文献   

14.
Limpets (Patella spp.) are suitable organisms to investigate the effects of climate change in marine systems. They are widespread over NE Atlantic intertidal rocky shores and have been extensively studied in terms of population dynamics and ecology. Within genus Patella, microsatellites have only been developed for Patella caerulea and cross-species tests are unknown. In this work, we describe 11 primer pairs for Patella depressa and the results of cross-species testing on Patella candei and Patella rustica.  相似文献   

15.
Embryonic and early larval development of White Sea cod Gadus morhua marisalbi are described. The study is conducted on live material obtained after spawning of fishes in the tanks and based on artificial insemination of eggs. Dynamics of contact and mobility properties of cells in vivo and in vitro (in cell culture) is assessed. Discrete chronological parameters of the morphogenetic movements are determined. Early ontogeny of the White Sea cod is very similar to that in G. morhua of the Northeast Atlantic. However, the former subspecies differs in larger egg diameter (on average, 1.50 mm), larger buoyancy (at a salinity up to 24.22‰), and a resistance to negative temperature (?1.8°C).  相似文献   

16.
Analysis of variation of biological and morphometric characteristics of cod Gadus morhua from the Gulf of Ura-a water area in the composition of Motovskii Bay of the Barents Sea was performed. The material was collected from 1999 to 2006 during spawning of the Atlantic cod. Parameters such as length, weight, sex composition, maturity stage, age, otolith structure, and variation of plastic characters were analyzed. It was shown that the Gulf of Ura, parallel to individuals of junior age groups, is inhabited by cod in the spawning state aged 5–6 months and older with coastal and Atlantic types of otolith.  相似文献   

17.
A Francisella sp., isolate GM2212T, previously isolated from diseased farmed Atlantic cod Gadus morhua in Norway is characterized. The complete 16S rDNA, 16S–23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and a hypothetical lipoprotein (LpnB) is sequenced and compared with Francisella tularensis and Francisella philomiragia. All these sequences support a close relationship between GM2212T and F. philomiragia. The bacterium grows at 10–25°C with an optimum at about 20°C, a temperature range clearly different from F. tularensis and F. philomiragia. GM2212T is catalase-positive, indole positive, oxidase-negative, do not produce H2S in Triple Sugar Iron agar, and does not hydrolyze gelatin, is resistant to erythromycin and susceptible to ceftazidime, the latter five characteristics separating it from F. philomiragia. Cysteine enhances growth. Acid is produced from d-glucose, maltose, sucrose (weak) but not from lactose or glycerol. GM2212T grows on both MacConkey agar and in nutrient broth (6% NaCl). The bacterium is resistant to trimethoprim-sulfamethoxazole, penicillines, cefuroxime and erythromycin; but is susceptible to ceftazidime, tetracycline, gentamicin, ciprofloxacin. Based on the molecular and phenotypical characteristics, we suggest that this GM2212 isolate, may represent a new species of Francisella. Isolate GM2212T (=CNCM I-3481T = CNCM I-3511T = DSM 18777T).  相似文献   

18.
The results of the studies on morpho-biological characteristics of Pacific cod Gadus macrocephalus of Bering Island coastal waters (Komandor Islands) are presented. As assessed by several morphometric indices, the studied cod differs from the cod of the Bering Sea.  相似文献   

19.
The aim of this study was to determine if individual ticks among the progeny of a single female Rhipicephalus (Boophilus) microplus tick removed from cattle under natural conditions are the result of mating with one or several males. To this end, simulations were run using an existing dataset of genotypes from 8 microsatellite loci to predict the number of samples required and the best locus. Subsequently, 14–22 progeny from each of 15 engorged female ticks removed from three cows, and the engorged females themselves, were genotyped for the BmM1 locus and the minimum number of potential male parents was determined for each progeny group. Of the 15 progeny groups, 10 must have been sired by more than one male, as indicated by the presence of five unique alleles among the progeny or three unique alleles that could not have been contributed by the female. This finding demonstrates multiple paternity in R. microplus.  相似文献   

20.
Caulerpa spp. are clonal green marine algae which often act as invasive species when growing outside their native biogeographical borders. Over the two past decades, Caulerpa taxifolia has spread along the Mediterranean coast, presently occurring at 70 sites and covering nearly 3,000 ha of subtidal area. New genetic markers (microsatellites) have been developed to assess clonal structure and genetic diversity of recently established populations of the invasive species C. taxifolia and Caulerpa racemosa in comparison with populations of the native Caulerpa prolifera in the Mediterranean. Our results show that nine polymorphic markers have been developed for C. prolifera, seven for C. taxifolia, and three for C. racemosa. Genetic diversity in Caulerpa was assessed in two geographical scales: one at a population scale where 40 thalli units were collected from C. prolifera in Cala d’Or, Mallorca, Spain, and another at a species scale, where 30 sample units were analyzed for C. prolifera, 24 for C. taxifolia, and 24 for C. racemosa from different sites in the Mediterranean, Atlantic, and Pacific Ocean. Number of alleles, expected heterozygosity, and marker amplification success are provided in each case.  相似文献   

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