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1.
The effects of t-haplotypes on embryonic morphology in house mouse Mus musculus were described. Lethal mutations, t-haplotypes, in homozygotes induce abnormal embryogenesis and zygotic death at different developmental stages, which depends on the time of their action in ontogeny. Death commonly occurs in the first semester of pregnancy from the morula to the mature embryo stage (day 9–10), and the embryogenetic abnormalities and their timing were Specific for each t-haplotype. Such mutations were analyzed to identify the gene products (proteins) affecting the nervous system development. The t-complex proved to contain tandem repeats coding for regulatory factors modulating the expression of specific structural genes in mouse neurons.  相似文献   

2.
Pinus massoniana is one of the important afforestation and pioneer tree species, which is widely distribute in southern China. Chloroplast simple sequence repeat markers (cpSSRs) have been widely used in studies of tree genetics, phylogenetic and breeding. We sequenced the whole chloroplast genome sequences of P. massoniana using PCR and Sanger sequencing. A total of 71 cpSSRs were identified, among which mononucleotide repeats were predominant (70.42%). Seventeen primer pairs were developed and amplification tests were conducted with 15 P. massoniana individuals. Also, cross-species amplification tests were conducted among 15 individuals per Pinus species, including P. elliottii, P. bungeana, P. armandii, P. caribaea, P. tabulaeformis, P. taiwanensis and P. yunnanensis which revealed polymorphic information content ranging from 0.2 to 0.8 and average of haploid diversity (h) ranging from 0.29 to 0.63. In addition, the polymorphic cpSSRs were useful in distinguishing the sampled pine species, and could be powerful tool in phylogenetic studies.  相似文献   

3.
Chloroplasts contain several copies of their DNA, and intra-individual haplotypic variation (heteroplasmy) is common in plants, but unexplored in the cosmopolitan genus Phragmites. The aims of this study were to assess if heteroplasmy due to paternal leakage of the chloroplast occurs in Phragmites and which new insights into the evolutionary history of Phragmites australis in North America can be identified from the heteroplasmic variation. Eight non-native P. australis haplotypes occur in North America and can interbreed with P. australis ssp. americanus and P. australis var. berlandieri, creating opportunities for biparental inheritance of distinctive haplotypes. The polymorphism in the trnT-trnL sequence length revealed seventeen cases of heteroplasmy worldwide, in contact zones of distantly related haplotypes and in known hybrid populations, nine of which occurred in North America. In America, the cloned sequences, combined with nuclear markers, identified recombined haplotypes between native P. australis ssp. americanus and invasive P. australis haplotype M, and between the species P. mauritianus and P. australis, due to chloroplast paternal leakage. The occurrence of heteroplasmy and recombined haplotypes suggest a local origin for some of the rare non-native haplotypes occurring in North America, and plastid leakage events in the evolutionary histories of P. australis ssp. americanus and P. australis var. berlandieri.  相似文献   

4.
Jayson GC et al. remarked in Lancet that nearly 100% of mucinous ovarian cancer cases have Kras mutation as well as a high frequency of Her2 amplification. Using the Abbott PathVysion Her2 DNA Probe Kit and Kras mutant-enriched PCR Kits (FemtoPath®), 21 samples of primary ovarian mucinous cystadenocarcinomas from Taiwanese patients were examined to determine the status of Her2 amplification and Kras mutations. Our results showed the Her2 amplification rates were 33.33%, while the Kras mutation rates were 61.90%. We present here our results in order to enlighten the readership that the ~100% Kras mutant frequency and the high Her2 amplification rate reported by Jayson et al. may be too exaggerated to be applicable into all populations. Additionally, we report another 2 novel Kras mutations (A11V, V14I).  相似文献   

5.
The structure of the D-loop region in mitochondrial DNA (mtDNA) of Russian sturgeon Acipenser gueldenstaedtii from the Azov Sea population was studied with the method of direct sequencing. Interindividual heteroplasmy of the length of mtDNA in the region of D-loop realized by the presence of a different number of tandem repeats (82 pairs of bases) was found. Analysis of tandem repeats in the D-loop region in mtDNA in the studied sample (28 individuals) revealed eight mitotypes differed in the pattern of nucleotide substitution and in the number of tandem repeats (2, 3, and 4 repeats). Revealed mitotypes can be considered as potential genetic markers for different biological groups, schools, or seasonal races of A. gueldenstaedtii.  相似文献   

6.
Chloroplast rpS16 gene intron sequences were determined and characterized for twenty-five Lemnaceae accessions representing nine duckweed species. For each Lemnaceae species nucleotide substitutions and for Lemna minor, Lemna aequinoctialis, Wolffia arrhiza different indels were detected. Most of indels were found for Wolffia arrhiza and Lemna aequinoctialis. The analyses of intraspecific polymorphism resulted in identification of several gaplotypes in Lemna gibba and Lemna trisulca. Lemnaceae phylogenetic relationship based on rpS16 intron variability data has revealed significant differences between Lemna aequinoctialis and other Lemna species. Genetic distance values corroborated competence of Landoltia punctata separations from Spirodela into an independent generic taxon. The acceptability of rpS16 intron sequences for phylogenetic studies in Lemnaceae was shown.  相似文献   

7.

Background

Polymorphic tandem repeat typing is a new generic technology which has been proved to be very efficient for bacterial pathogens such as B. anthracis, M. tuberculosis, P. aeruginosa, L. pneumophila, Y. pestis. The previously developed tandem repeats database takes advantage of the release of genome sequence data for a growing number of bacteria to facilitate the identification of tandem repeats. The development of an assay then requires the evaluation of tandem repeat polymorphism on well-selected sets of isolates. In the case of major human pathogens, such as S. aureus, more than one strain is being sequenced, so that tandem repeats most likely to be polymorphic can now be selected in silico based on genome sequence comparison.

Results

In addition to the previously described general Tandem Repeats Database, we have developed a tool to automatically identify tandem repeats of a different length in the genome sequence of two (or more) closely related bacterial strains. Genome comparisons are pre-computed. The results of the comparisons are parsed in a database, which can be conveniently queried over the internet according to criteria of practical value, including repeat unit length, predicted size difference, etc. Comparisons are available for 16 bacterial species, and the orthopox viruses, including the variola virus and three of its close neighbors.

Conclusions

We are presenting an internet-based resource to help develop and perform tandem repeats based bacterial strain typing. The tools accessible at http://minisatellites.u-psud.fr now comprise four parts. The Tandem Repeats Database enables the identification of tandem repeats across entire genomes. The Strain Comparison Page identifies tandem repeats differing between different genome sequences from the same species. The "Blast in the Tandem Repeats Database" facilitates the search for a known tandem repeat and the prediction of amplification product sizes. The "Bacterial Genotyping Page" is a service for strain identification at the subspecies level.
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8.
Centaurin β5, a protein with a yet unknown function, belongs to the centaurin family. It is encoded by CENTB5, whose expression pattern has been studied insufficiently. Intron 14–15 of human CENTB5 contains a lowly variable minisatellite repeat UPS29, while the mouse Centb5 contains an imperfect microsatellite repeat (CATG)19. The shorter UPS29 alleles have previously been associated with certain forms of Parkinson’s disease and epilepsy. Moreover, both human and murine CENTB5 are syntenic with SCNN1D and ACOT7, which are active primarily in the nervous system, and whose aberrations are associated with epilepsy and neurodegenerative processes. As intronic sequences can modulate the expression of not only those genes that harbor them, but also of neighboring and remote genes, the CENTB5, SCNN1D, and ACOT7 expression levels were all analyzed by RT-PCR. The potential of intronic tandem repeats UPS29 and (CATG)19 to regulate/modulate the expression of CENTB5, SCNN1D, and ACOT7 has been assessed in silico. CENTB5, SCNN1D, and ACOT7 expression was detected in all human and murine tissues studied, suggestive of their physiologic importance. The putative role of UPS29 in the regulation of CENTB5, SCNN1D, and ACOT7 activity in the nerve tissue is discussed.  相似文献   

9.
Sequence polymorphism of the mitochondrial DNA cytochrome b gene fragment was analyzed in 21 specimens of subspecies Luscinia calliope calliope (Pallas, 1776) and two specimens of L. c. anadyrensis (Portenko, 1939). On sequence chromatograms, in 19 specimens of L. c. calliope, double peaks of heteroplasmy type in the taxon-specific positions were revealed. Moreover, two clone variants were identified. The first variant was the calliope mitochondrial cyt b gene and the second was the nuclear cyt b pseudogene, similar to the mitochondrial haplotype anadyrensis-camtschatkensis. In L. c. anadyrensis, four clone variants, represented by the mitochondrial calliope and anadyrensis-camtschatkensis cyt b genes and nuclear calliope and sachalinensis cyt b pseudogenes, were identified. Some nuclear cyt b pseudogenes were highly similar (98–99%) to the mitochondrial genes of the subspecies L. c. anadyrensis, L. c. camtschatkensis, and L. c. sachalinensis. In the same time, the majority of nuclear pseudogene sequences were characterized by a high level of polymorphism, caused by nonsynonymous substitutions (up to five substitutions per sequence), the presence of indels in some of the clones, and TAA and TGA stop codons. In our opinion, the mitochondrial haplotypes anadyrensis-camtschatkensis and sachalinensis occurred as a result of intergenomic homologous recombination. This finding provides a new insight into the colonization history of the northeastern part of the range by L. calliope, according to which populating the territory of Chukotka, Kamchatka, and Sakhalin took place at different times and along the independent pathways.  相似文献   

10.
Comparison of ORFs between H. pylori strains 26695 and J99 showed that transitions (more than 3%) prevail over transversions (less than 1%). The predominance of transitions was explained by the high rates of cytosine replacement by thymine in the coding (3.5–5.3%) and noncoding (2.9–3.9%) DNA strands. The proportion of transversion-type correspondences (A → C, A → T, C → A, C → G, G → C, G → T, T → A, and T → G) did not exceed 0.84%. The highest proportion (28.3%) was observed for correspondences between C and T in ACGT-ATGT, the target site of active methyltransferase of H. pylori J99 (M.Hpy99XI). It was assumed that C → T mutations due to cytosine methylation-deamination are prevalent in H. pylori.  相似文献   

11.
Using monolocus PCR analysis with the pairs of primers designed for the Du215 locus of Darevskia unisexualis, allelic polymorphism at the orthologous locus in the populations of the related parthenospecies D. armeniaca was investigated. It was demonstrated that Du215 (arm) locus was polymorphic and in the populations of parthenospecies D. armeniaca (n = 127) represented by at least three allelic variants, differing from each other by the size and composition of microsatellite cluster, and by single nucleotide substitutions in flanking DNA. Unlike the Du215 locus, Du215 (arm) was shown contain not only GATA, but also (GACA) repeats, which were absent in D. unisexualis. Thus, in this study, the data on the molecular nature of allelic polymorphism at one of the microsatellite loci of the parthenospecies D. armeniaca were reported.  相似文献   

12.
Infertility and hypercytolipidemic utero-ovarian involution are recognized consequences of the diabetes-obesity syndrome (DOS) in C57BL mice with either obese (ob/ob) or diabetes (db/db) single gene mutations. We have evaluated the interdependent deleterious influences of both mutation types and differences in the genomic background on utero-ovarian dysfunction in C57BL mice. Control (+/?) C57BL mice were matched with littermate ob/ob and db/db mutants expressed on either the /KsJ or /6 background. Both ob/ob and db/db mutations increased body weights of /KsJ and /6 background strains relative to +/? groups. In contrast, uterine and ovarian weights were depressed by ob/ob and db/dbmutations relative to +/?, regardless of the background strain, but especially when expressed on the /KsJ background. Functionally, both ob/ob and db/db mutations induced hyperglycemic-hyperinsulinemic states coupled with depressed serum estradiol-17-β and progesterone concentrations when expressed on a /KsJ background. Microscopic analysis of utero-ovarian tissue samples revealed marked hypercytolipidemia in the follicular granulosa and endometrial epithelial tissue layers of both ob/oband db/db mutant groups relative to normal +/? cytoarchitecture. The db/db mutation consistently promoted more severe hypercytolipidemic profiles than the ob/obmutation, regardless of background strain. Thus, the severity of utero-ovarian hypercytolipidemia following the expression ofob/ob and db/db mutations in C57BL mice is influenced, or moderated, by the genomic background on which the mutation is expressed.  相似文献   

13.
Molecular markers derived from the complete chloroplast genome can provide effective tools for species identification and phylogenetic resolution. Complete chloroplast (cp) genome sequences of Capsicum species have been reported. We herein report the complete chloroplast genome sequence of Capsicum baccatum var. baccatum, a wild Capsicum species. The total length of the chloroplast genome is 157,145 bp with 37.7 % overall GC content. One pair of inverted repeats, 25,910 bp in length, was separated by a small single-copy region (17,974 bp) and large single-copy region (87,351 bp). This region contains 86 protein-coding genes, 30 tRNA genes, 4 rRNA genes, and 11 genes contain one or two introns. Pair-wise alignments of chloroplast genome were performed for genome-wide comparison. Analysis revealed a total of 134 simple sequence repeat (SSR) motifs and 282 insertions or deletions variants in the C. baccatum var. baccatum cp genome. The types and abundances of repeat units in Capsicum species were relatively conserved, and these loci could be used in future studies to investigate and conserve the genetic diversity of the Capsicum species.  相似文献   

14.
15.
A total of 26,685 unutilized public domain expressed sequence tags (ESTs) of Arachis hypogaea L. were analyzed to give a total of 4442 EST-SSRs, in which 517 ESTs contained more than one simple sequence repeat (SSR). Of these EST-SSRs, 2542 were mononucleotide repeats (MNRs), 803 were dinucleotide repeats (DNRs), 1043 were trinucleotide repeats (TNRs), 40 were tetranucleotide repeats (TtNRs), six were pentanucleotide repeats (PNRs) and eight were hexanucleotide repeats (HNRs). Out of these 4442 EST-SSRs, only 1160 were found to be successful in non-redundant primer design; 1060 were simple SSRs, while the remaining 100 were compound forms. Among all the motifs, MNRs were abundant, followed by TNRs and DNRs. The AAG/CTT motif was the most abundant (~33 %) TNR, while AG/CT was the most abundant DNR. For redundancy and novelty, a stringent criterion deploying three different strategies was used and a total of 782 novel EST-SSRs were added to the public domain of peanut. These novel EST-SSR markers will be useful for qualitative and quantitative trait mapping, marker-assisted selection and genetic diversity studies in cultivated peanut as well as related Arachis species. A subset of 30 novel EST-SSRs was further randomly selected for validation and genotyping studies with eight well-known cultivars and 32 advanced breeding lines (ADBX lines, ADBY lines and ADBZ lines) from Odisha state, India. The number of polymorphic markers among accessions of A. hypogaea was low; however, a set of informative EST-SSR markers detected considerable levels of genetic variability in peanut cultivars and uncharacterized breeding lines collected from Odisha. The 30 newly developed EST-SSRs from Arachis spp. showed ~97 % amplification in Cicer arientinum and 93 % in pigeon pea. Thus, the EST-SSRs developed in this study will be a very useful asset for genetic analysis, comparative genome mapping, population genetic structure and phylogenetic inferences among wild and allied species of Arachis.  相似文献   

16.
Morphological and quantitative characteristics of the growth variability of two Parvancorina species were analyzed based on new abundant material from the Vendian of the White Sea. Growth variability in this problematic taxon appears to be wider than previously suggested. We found allometric growth in the White Sea population of P. minchami Glaessner, 1958, in contrast to isometric growth in Australian representatives of the species. Another White Sea species, P. sagitta Ivantsov, 2004, shows gradual formation of anchor-shaped structure in juveniles. Based on Australian material, it was previously believed that this structure did not change during ontogeny. These two distinctive features together with a strong variability of age-related measurements distinguish Parvancorina from other early arthropods (Scania, Primicaris), and cast doubt on the growth pattern as an argument in favor of the arthropodan nature of Parvancorina.  相似文献   

17.
The abnormal pistils widely occur in Japanese apricot (Prunus mume Sieb. et Zucc) and seriously affect the fruit production. In this study, a CCoAOMT homologue, PmCCoAOMT, was cloned in Japanese apricot and the bioinformatics software analyzed the structural characteristics. The PmCCoAOMT protein was detected to be located in the cell cytoplasm by onion transient expression experiment. Analysis of the real-time PCR data showed that PmCCoAOMT gene expressed in the prophase development of pistil and the expression level in ‘Daqiandi’ was higher than ‘Longyan.’ The expression level in ‘Longyan’ was higher than ‘Daqiandi’ in the late period development of pistil, and the expression level of perfect flower (perfect pistil) was higher than imperfect flower (pistil deformity and no pistil). Compared with the control, the over-expression of PmCCoAOMT transgenic tobacco lines showed bigger flowers, darker petals. The lignin monomer composition in transgenic tobacco lines was also measured, and the results showed that transgenic tobacco lines had a higher S (Syringyl)/G (Guaiacyl) ratio (22.3 %) than control lines (11.8 %). Also, the perfect flower buds contained more S/G ratio (92.62 %) than imperfect flower buds (83.55 %) in ‘Daqiandi.’ Our results indicated that the PmCCoAOMT gene might have function in lignin accumulation, which contributed to pistil development in Japanese apricot.  相似文献   

18.
It is well known that dopaminergic genes affect the development of attention deficit hyperactivity disorder (ADHD) in various populations. Many studies have shown that variable number tandem repeats (VNTRs) located within the 3′-untranslated region of DAT1 and in exon 3 of DRD4 are associated with ADHD development; however, these results were inconsistent. Therefore, we investigated the genetic association between two VNTRs and ADHD in Korean children. We determined the VNTRs using PCR. We examined genotype and allele frequency differences between the experimental and control groups, along with the odds ratios, using Chi square and exact tests. We observed a significant association between the children with ADHD and the control group in the 10R/10R genotype of DAT1 VNTRs (p?=?0.025). In addition, the 11R allele of DAT1 VNTRs showed a higher frequency in the control group than in the ADHD group (p?=?0.023). Also, the short repeat (without 11R) and long repeat alleles (including 11R) were associated with ADHD (p?<?0.05). The analysis of DRD4 VNTRs revealed that the 2R allele is associated with ADHD (p?=?0.025). A significant result was also observed in long and short repeats (p?<?0.05). Additionally, ADHD subtypes showed that the DRD4 VNTRs are associated with combined and hyperactive-impulsive subtype groups (p?<?0.05). Therefore, our results suggest that DAT1 VNTRs and DRD4 VNTRs play a role in the genetic etiology of ADHD in Korean children.  相似文献   

19.
Steady growth in the degree of antimicrobial resistance in Neisseria gonorrhoeae calls for the control of the spreading of resistance mutations. Here we present the data describing drug resistance mutations, the results of antimicrobial susceptibility tests, and molecular genotypes of 128 recent N. gonorrhoeae isolates collected across 9 regions of the Russian Federation. The mutations in chromosome genes penA, ponA, rpsJ, gyrA, parC, which determine the susceptibility of N. gonorrhoeae to penicillins, tetracyclines, and fluoroquinolones were detected by multiplex amplification followed by hybridization on a hydrogel microarray. The most frequent mutation was an insertion of an aspartate at position 345 of penA gene (76.6%), whereas mutations Leu421Pro in ponA gene, Val57Met in rpsJ gene, Ser91Phe in gyrA gene, Asp95Gly in gyrA gene, and Ser87Arg in parC gene were detected in 32.8–36.7% of strains. One third of studied N. gonorrhoeae isolates harbored multiple drug resistance mutations in bacterial chromosome, resulting in the bimodal distribution of mutation profiles and related patterns of antimicrobial susceptibility. The spread of multiple resistance could be explained by the vertical transfer of the mutations resulting in the clonality of the N. gonorrhoeae population.  相似文献   

20.
We have studied the molecular characteristics of the yellow locus (y; 1–0.0), which determines the body color of phenotypically wild-type and mutant alleles isolated in different years from geographically distant populations of Drosophila melanogaster. According to the Southern blot, data restriction maps of the yellow locus of all examined strains differ from one another, as well as from Oregon stock. FISH analysis shows that, in the neighborhood of the yellow locus in the X chromosome, neither P nor hobo elements are found in y1–775 stock, while only hobo is found in these region in y1–859 and y1–866 stocks, only the P element is found in y+sn849 stock, and both elements are found in y1–719 stock. Thus, all yellow mutants studied are of independent origin. Locus yellow located on the end of X chromosome (region 1A5–8 on the cytologic map) carries significantly more transposon than retrotransposon induced mutations compared to the white locus (region 3C2). It is possible that, at the ends of Drosophila melanogaster chromosomes, transposons are more active than retrotransposons.  相似文献   

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