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1.
Oreochromis karongae, one of the “chambo” tilapia species from Lake Malawi, has a karyotype of 2n = 38, making it one of the few species investigated to differ from the typical tilapia karyotype (2n = 44). The O. karongae karyotype consists of one large subtelocentric pair of chromosomes, four medium-sized pairs (three subtelocentric and one submetacentric) and 14 small pairs. The five largest pairs could be distinguished from each other on the basis of size, morphology and a series of fluorescence in situ hybridisation (FISH) probes. The largest pair is easily distinguished on the basis of size and a chromosome 1 (linkage group 3) bacterial artificial chromosome (BAC) FISH probe from Oreochromis niloticus. BAC clones from O. niloticus chromosome 2 (linkage group 7) hybridised to one of the medium-sized subtelocentric chromosome pairs (no. 5) of O. karongae, distinguishing the ancestral medium-sized pair from the three other medium-sized chromosome pairs (nos. 2, 3 and 4) that appear to have resulted from fusions. SATA repetitive DNA hybridised to the centromeres of all 19 chromosome pairs and also revealed the locations of the relic centromeres in the three fused pairs. Telomeric (TTAGGG)n repeats were identified in the telomeres of all chromosomes, and an interstitial telomeric site (ITS) was identified in three chromosomal pairs (no. 2, 3 and 4). Additionally, two ITS sites were identified in the largest chromosome pair (pair 1), confirming the origin of this chromosome from three ancestral chromosomes. SATA and ITS sites allowed the orientation of the fusions in pairs 2, 3 and 4, which all appear to have been in different orientations (q–q, p–q and p–p, respectively). One of these fusions (O. karongae chromosome pair no. 2) involves a small chromosome (equivalent to linkage group 1), which in O. niloticus carries the main sex-determining gene. 4′,6-Diamidino-2-phenyloindole staining of the synaptonemal complex in male O. karongae revealed the presumptive positions of the kinetochores, which correspond well to the centromeric positions observed in the mitotic karyotype.  相似文献   

2.
There are only a few reports on the chromosomal location of DNA sequences in bivalve species, none of them using meiotic chromosomes. Mitotic chromosomes of the clam Dosinia exoleta were analysed by means of Giemsa, silver and fluorochrome staining and fluorescent in situ hybridization (FISH) with 18S + 28S rDNA and telomeric probes. A technique for surface spreading of synaptonemal complexes (SCs) of Dosinia exoleta was developed for the first time in a bivalve species. Silver and DAPI/PI staining and SC-FISH were also applied to the study of the meiotic chromosomes of this clam. The diploid chromosome number in this species is 38 and the karyotype is composed of 11 pairs of metacentric and eight pairs of submetacentric chromosomes. 18S + 28S rDNA clusters map to the subtelomeric region of the short arm of one metacentric chromosome pair whereas telomeric signals appear at both ends of every chromosome.  相似文献   

3.
Karyotype and other chromosomal characteristics in the Adriatic brook lamprey Lampetra zanandreai, representative of one of the most ancestral group of vertebrates, were examined using conventional (Ag-staining, C-banding as well as CMA3 and DAPI fluorescence) and molecular (FISH with 18/28S rDNA and EcoRI satDNA as probes) protocols with metaphase chromosomes derived from whole blood cultures. The chromosome complement had a modal diploid chromosome number of 2n = 164, as in other petromyzontid lamprey species. Ag-staining and CMA3 fluorescence, as well as FISH with 18/28S rDNA probes, detected nucleolar organizer regions (NORs) close to the centromeres of the biarmed chromosomes of pairs 1 and 2, the largest chromosome pairs of the complement. In addition to NORs, CMA3 fluorescence revealed positive signals in approximately 40 other chromosomes. DAPI stained mostly centromeric regions of many chromosomes as well as conspicuously massive blocks overlapping NOR sites. C-banding evidenced a large amount of constitutive heterochromatin in somatic chromosomes, with approximately 40 C-positive acrocentric elements completely heterochromatic, corresponding with the 40 CMA3+ chromosomes and positive heterochromatic blocks in pericentromeric regions of chromosome pairs 1 and 2. Polymerase chain reaction (PCR)-based cloning of satellite DNA with primers derived from Petromyzon marinus centromeric sequences was successful for L. zanandreai genomic DNA. The sequence was AT-rich (59%) and characterized by short consensus motifs similar to other centromeric satellite motifs. FISH using satDNA clones as a probe produced a fluorescent signal on a single pair of small chromosomes. This sequence was PCR-amplified also in L. planeri and P. marinus genomic DNA, and the evolution of this repetitive element in the above species was analysed.  相似文献   

4.
Isolates of Dicrocoelium dendriticum (n = 150) from sheep and cattle bred in southern Italy and isolates (n = 5) of D. hospes from a Bos indicus from Senegal were characterized genetically. The 28S region and the second internal transcribed spacer (ITS-2) plus flanking 5.8S and 28S sequences (ITS-2+) of ribosomal DNA (rDNA) were amplified by polymerase chain reaction and sequenced from individual flukes. Regarding the 28S rDNA, sequences of 568 and 581 bp were obtained for D. dendriticum and D. hospes, respectively. No intraspecific variation was observed between the 28S rDNA of all the D. dendriticum specimens studied and the D. dendriticum 28S rDNA sequence present in GenBank™. However, intraspecific variation was observed in the 28S rDNA of the D. hospes specimens compared to the sequence present in GenBank™. Regarding the ITS2+ rDNA, sequences of 402 and 428 bp were obtained for D. dendriticum and D. hospes, respectively; both sequences were deposited in GenBank™. Variations intra- and interpopulation were observed for D. dendriticum, whereas 100% identity was observed in all the ITS2+ sequences of D. hospes. With respect to the interspecific variations, the ITS-2+ of D. dendriticum and D. hospes differed in 33 positions. The findings of the present study showed an ITS2+ sequence variability (8.2–8.5%) between D. dendriticum and D. hospes, thus demonstrating the utility of this sequence to discriminate the two species.  相似文献   

5.
The cytogenetic characterization of the carrot genome (Daucus carota L., 2n = 18) has been limited so far, partly because of its somatic chromosome morphology and scant of chromosome markers. Here, we integrate the carrot linkage groups with pachytene chromosomes by fluorescent in situ hybridization (FISH) mapping genetically anchored bacterial artificial chromosomes (BACs). We isolated a satellite repeat from the centromeric regions of the carrot chromosomes, which facilitated the study of the pachytene-based karyotype and demonstrated that heterochromatic domains were mainly confined to the pericentromeric regions of each chromosome. Chromosome-specific BACs were used to: (1) physically locate genetically unanchored DNA sequences, (2) reveal relationships between genetic and physical distances, and (3) address chromosome evolution in Daucus. Most carrot BACs generated distinct FISH signals in 22-chromosome Daucus species, providing evidence for syntenic chromosome segments and rearrangements among them. These results provide a foundation for further cytogenetic characterization and chromosome evolution studies in Daucus.  相似文献   

6.
The diagnostic reliability and prognostic implications of procalcitonin (PCT) (ng/ml) on admission in patients with community-acquired pneumonia (CAP) due to Legionella pneumophila are unknown. We retrospectively analysed PCT values in 29 patients with microbiologically proven Legionella-CAP admitted to the University Hospital Basel, Switzerland, between 2002 and 2007 and compared them to other markers of infection, namely, C-reactive protein (CRP) (mg/l) and leukocyte count (109/l), and two prognostic severity assessment scores (PSI and CURB65). Laboratory analysis demonstrated that PCT values on admission were >0.1 in over 93%, >0.25 in over 86%, and >0.5 in over 82% of patients with Legionella-CAP. Patients with adverse medical outcomes (59%, n = 17) including need for ICU admission (55%, n = 16) and/or inhospital mortality (14%, n = 4) had significantly higher median PCT values on admission (4.27 [IQR 2.46–9.48] vs 0.97 [IQR 0.29–2.44], p = 0.01), while the PSI (124 [IQR 81–147] vs 94 [IQR 75–116], p = 0.19), the CURB65 (2 [IQR 1–2] vs 1 [1–3], p = 0.47), CRP values (282 [IQR 218–343], p = 0.28 vs 201 [IQR 147–279], p = 0.28), and leukocyte counts (12 [IQR 10–21] vs 12 [IQR 9–15], p = 0.58) were similar. In receiver operating curves, PCT concentrations on admission had a higher prognostic accuracy to predict adverse outcomes (AUC 0.78 [95%CI 0.61–96]) as compared to the PSI (0.64 [95%CI 0.43–0.86], p = 0.23), the CURB65 (0.58 [95%CI 0.36–0.79], p = 0.21), CRP (0.61 [95%CI 0.39–0.84], p = 0.19), and leukocyte count (0.57 [95%CI 0.35–0.78], p = 0.12). Kaplan-Meier curves demonstrated that patients with initial PCT values above the optimal cut-off of 1.5 had a significantly higher risk of death and/or ICU admission (log rank p = 0.003) during the hospital stay. In patients with CAP due to Legionella, PCT levels on admission might be an interesting predictor for adverse medical outcomes. Jeannine Haeuptle, Roya Zaborsky, and Rico Fiumefreddo contributed equally to this article.  相似文献   

7.
The early fourth instar larvae of Culex quinquefasciatus, reared in the laboratory were used for larvicidal assay with leaf extracts of Vitex negundo, Vitex trifolia, Vitex peduncularis and Vitex altissima. The methanol extracts of the four species possessed varying levels of larvicidal nature. The highest larvicidal activity was found with the extract of V. trifolia (LC50 = 41.41 ppm) followed by V. peduncularis (LC50 = 76.28 ppm), V. altissima (LC50 = 128.04 ppm) and V. negundo (LC50 = 212.57 ppm).  相似文献   

8.
The process of isolation of the 27-kDa glycoprotein from the somatic antigen of Fasciola gigantica was standardized and the diagnostic potentiality was evaluated for the detection of bubaline fasciolosis by indirect enzyme-linked immunosorbent assay. Initially, the test was standardized using the sera from experimentally noninfected(n = 20) and infected (n = 5)animals. Further, the sensitivity and the specificity of the test were evaluated through the sera of buffaloes with different natural infections, i.e., F. gigantica (n = 8 animals), F. gigantica and Gastrothylax crumenifer(n = 15), F. gigantica and Gigantocotyle explanatum (n = 6), trematode infections other than F. gigantica (n = 9), only G. crumenifer (n = 36), only G. explanatum (n = 18), G. crumenifer and G. explanatum positive (n = 39), and PM negative (n = 102). All animals came from the slaughterhouses of Bareilly (Uttar Pradesh, India) and Patna (Bihar, India). The level of sensitivity observed in the present study was 81.0%, while 97–98% specificity against G. crumenifer, G. explanatum, or a mixed infection with both parasites was noted. The study showed F. gigantica prevalence rate of 18–20% in the buffaloes of the study area. Enzyme-linked immunosorbent assay with a 27-kDa glycoprotein could be a feasible diagnostic method for the early detection of bovine fasciolosis.  相似文献   

9.
Chromosomal characteristics, i.e., number, size, morphology, and location of ribosomal DNA (rDNA) clusters were examined in two medically important liver flukes, Fasciola hepatica and Fascioloides magna (Fasciolidae), using conventional Giemsa staining and fluorescent in situ hybridization (FISH) with ribosomal 18S rDNA probe. A comparison of F. magna and F. hepatica karyotypes confirmed significant differences in all chromosomal features. Whilst the karyotype of F. hepatica comprised ten pairs of chromosomes (one metacentric and nine medium-sized subtelocentrics and submetacentrics; 2n = 20, n = 1 m + 5 sm + 4 st; TCL = 49.9 μm), the complement of F. magna was composed of 11 pairs of medium-sized subtelocentrics and submeta-metacentrics (2n = 22, n = 9 st + 1 sm + 1 sm-m; TCL = 35.2 μm). Noticeable differences were found mainly in length and morphology of first chromosome pair. It was metacentric and 9.0 μm long in F. hepatica while subtelocentric and 4.7 μm long in F. magna. Although FISH with rDNA probe revealed a single cluster of ribosomal genes in both species, conspicuous interspecific differences were displayed by chromosomal location of ribosomal loci (i.e., NORs). The signals were found on short arms of fifth homologous pair in F. hepatica; however, they were detected in pericentromeric regions of the long arms of tenth pair in F. magna. The observed cytogenetic differences were interpreted in terms of karyotype evolution of fasciolid flukes; F. hepatica may be regarded phylogenetically younger than F. magna. The present paper provides a pilot study on molecular cytogenetics within a group of hermaphroditic digenetic flukes.  相似文献   

10.
We investigated by fluorescence in situ hybridization (FISH) the synteny between Brachypodium distachyon with a small genome (1C = 320 Mb) and barley with a large genome (1C = 5,100 Mb) at the chromosome level. Reciprocal genomic in situ hybridization (GISH) between B. distachyon and barley labeled mainly 45S ribosomal DNA loci, indicating that most high copy DNA is weakly conserved between both grasses. Of 13 BAC clones with inserts from different B. distachyon chromosomes, only two belonging to chromosome 1 yielded hybridization signals on a barley metaphase chromosome (on 7HS and 7HL, respectively), confirming synteny between both chromosomes. FISH experiments to characterize the synteny of single-copy loci were performed. Two of four Brachypodium sylvaticum BACs spanning a 223-kb interval homologous to the region of barley that harbors a gibberellic-acid-insensitive semi-dwarfing gene, sdw3, hybridized specifically to a central position of B. distachyon chromosome 1 short arm but not to the homologous region of the barley genome. Repeat-free sequences PCR amplified from four non-overlapping barley BACs linked to the core of Sdw3 region yielded signals at distinct positions in the middle of barley chromosome arm 2HS. Together, these results (1) confirmed the synteny between B. distachyon chromosome 1 and barley chromosomes 2H and 7H at the cytological level, (2) indicated mid-arm position for the Sdw3 locus genetically mapped at the centromere of barley chromosome 2H, and (3) proved that the sdw3 core interval of <100 kb in B. distachyon corresponds to a megabase-sized syntenic region in barley.  相似文献   

11.
Recent studies have shown that hormones could induce anti-parasitic functions of the host immune system; thus, the aim of the present study was to estimate the seroprevalence of Toxoplasma gondii antibodies by an enzyme-linked immunosorbent assay in a Polish population of women and men with hyperprolactinaemia (n = 234) and hypoprolactinaemia (n = 41) and in a control group (n = 281) with the physiological level of prolactin (PRL). Women with hyperprolactinaemia revealed lower seroprevalence than those with normal PRL level (33.90% and 45.58%, respectively; p = 0.025). Detailed analysis of the results showed that twofold, threefold, fourfold and fivefold increase of the PRL concentration above the normal was correlated to the decrease of the T. gondii seroprevalence, but only in the group of women with a very high PRL level (>86 ng/ml) seroprevalence (12.50%) was significantly lower (p = 0.0004) than in the control subjects. These results confirm previously described suggestions on the relationship between hyperprolactinaemia and parasitic infection frequency. We postulate that a high level of PRL may be one of the important factors preventing T. gondii infection in women.  相似文献   

12.
Even if Panton–Valentine leukocidin (PVL), toxic shock syndrome toxin-1 (TSST-1), staphylococcal enterotoxins (SEB and SEC), and exfoliative toxins (ETA and ETB) may be associated with severe infections, the clinical significance of their presence in clinical isolates of Staphylococcus aureus remains poorly documented. In this study, we evaluated the prevalence of toxin genes and the relationship between their presence and the severity of infection. We screened for the presence of these six toxin genes among 186 consecutive S. aureus clinical isolates (resistant or not to methicillin) during a two-month period. We compared the toxin gene profile between strains recovered from patients presenting uncomplicated infections (n = 151) and from patients suffering from severe infections (n = 35). At least one toxin gene was detected in 55 (29.6%) isolates as follows: pvl (n = 1), tst + sec (n = 5), seb (n = 19), seb + sec (n = 1), sec (n = 28), and eta (n = 1). The proportion of toxin-producing strains among patients with uncomplicated infections (27.8%) and patients with severe infections (37.1%) was not statistically different (p = 0.3044), even if the severity of infection tended to be associated with the presence of sec (p = 0.0655). Although the prevalence of toxin genes was relatively high herein, no statistically significant association between the severity of infection and the presence of toxin genes was observed.  相似文献   

13.
This retrospective case–control study was undertaken to review the clinical features associated with heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) infections and the local impact they have on clinical outcome. Compared with vancomycin-susceptible S. aureus (n = 30), hVISA and VISA infections (n = 10) are found to be associated with a longer period of prior glycopeptide use (P = 0.01), bone/joint (P < 0.01) and prosthetic infections (P = 0.04), as well as treatment failure, as evidenced by longer bacteremic (P < 0.01) and culture positivity (P < 0.01) periods. This was observed to have resulted in longer hospital length of stay (P < 0.01) and total antibiotic therapy duration (P = 0.01). There was, however, no significant difference in the overall patient mortality or the hospitalization cost (P = 0.12) in both groups. Clinicians should be cognizant of the association between hVISA/VISA with high bacterial load deep-seated infections. We recommend targeted and even universal screening for hVISA/VISA in methicillin-resistant S. aureus (MRSA) infections.  相似文献   

14.
The acetone, chloroform, ethyl acetate, hexane and methanol extracts of peel and leaf extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) and feeding deterrence to nymphs of cotton pest, Aphis gossypii Glover (Homoptera: Aphididae). The larval and nymph mortality were observed after 24 h of exposure. All extracts showed moderate larvicidal and nymphicidal effects; however, the highest mortality was found in peel chloroform extract of C. sinensis, leaf ethyl acetate extracts of O. canum and O. sanctum and leaf chloroform extract of R. nasutus against the larvae of A. subpictus (LC50 = 58.25, 88.15, 21.67 and 40.46 ppm; LC90 = 298.31, 528.70, 98.34 and 267.20 ppm), peel methanol extract of C. sinensis, leaf methanol extract of O. canum, ethyl acetate extracts of O. sanctum and R. nasutus against the larvae of C. tritaeniorhynchus (LC50 = 38.15, 72.40, 109.12 and 39.32 ppm; LC90 = 184.67, 268.93, 646.62 and 176.39 ppm), peel hexane extract of C. sinensis, leaf methanol extracts of O. canum and R. nasutus and leaf ethyl acetate extract of O. sanctum against the nymph of A. gossypii (LC50 = 162.89, 80.99, 73.27 and 130.19 ppm; LC90 = 595.40, 293.33, 338.74 and 450.90 ppm), respectively. These results suggest that the peel methanol extracts of C. sinensis and O. canum, ethyl acetate leaf extract of O. sanctum and leaf chloroform and ethyl acetate extract of R. nasutus have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus, C. tritaeniorhynchus and A. gossypii.  相似文献   

15.
Between 1995 and 2006, we surveyed the presence of Fasciola hepatica in Iberian ibex (Capra pyrenaica) from Andalucía (southern Spain) by both necropsy (n = 2,096) and coprological approaches (n = 380). Most of the samples came from the Sierra Nevada mountain range (n = 1,884 and 267, respectively), and all positive cases involved animals from this location. The prevalence reached 0.53% by necropsy and 1.87% by faecal examination. Taking into account both diagnostic methodologies and the total number of animals affected (n = 14), we obtained a yearly prevalence of 0.7 ± 0.3%. The infection with F. hepatica was found not to be related to host sex, climatology or to co-infection with Sarcoptes scabiei (the most important parasite affecting Iberian ibex, with a prevalence of 49.27 ± 7.90% in the examined animals). The prevalence of fasciolosis decreased significantly during the period under study and this would be explained by an increase of ibex resistance to this fluke as a result of a reduction of the parasite abundance in the area and/or a reduction of the host infection rate. There was no statistical difference between the two diagnostic methods for the examination of fasciolosis during the period in which both methods were used. Therefore, examination of faecal samples as a non-invasive procedure may provide a useful approach for monitoring fasciolosis in wild ungulate populations. The results of the present study provided foundation for the effective control of F. hepatica infection in Iberian ibex.  相似文献   

16.
The microRNA encoding genes miR-34a and miR-34b/c represent direct p53 target genes and possess tumor suppressive properties as they mediate apoptosis, cell cycle arrest, and senescence. We previously reported that the miR-34a gene is subject to epigenetic inactivation by CpG methylation of its promoter region in primary prostate cancer and melanomas, and in 110 different cancer cell lines of diverse origin. Here we analyzed the methylation status of miR-34a and miR-34b/c in additional primary tumors of divergent sites. We found methylation of miR-34a or miR-34b/c in formalin-fixed, paraffin-embedded (FFPE) tumor samples from 178 patients with the following frequencies: colorectal cancer (74% miR-34a, 99% miR-34b/c; n = 114), pancreatic cancer (64%, 100%; n = 11), mammary cancer (60%, 90%; n = 10), ovarian cancer (62%, 69%; n = 13), urothelial cancer (71%, 57%; n = 7), and renal cell cancer (58%, 100%; n = 12). Furthermore, soft tissue sarcomas showed methylation of miR-34 gene promoters in FFPE samples (64%, 45%; n = 11), in explanted, cultured cells (53%, 40%; n = 40), and in frozen tissue samples (75%, 75%, n = 8). In the colorectal cancer samples a statistically significant correlation of miR-34a methylation and the absence of p53 mutation was detected. With the exception of sarcoma cell lines, the inactivation of miR-34a and miR-34b/c was concomitant in most cases. These results show that miR-34 inactivation is a common event in tumor formation, and suggest that CpG methylation of miR-34a and miR-34-b/c may have diagnostic value. The mutual exclusiveness of miR-34a methylation and p53 mutation indicates that miR-34a inactivation may substitute for loss of p53 function in cancer.  相似文献   

17.
One species of Babesia was identified on the blood smear of 20 different naturally infected sheep in the Northwest of Iran. It was polymorphic, including double pyriform with acute or obtuse angle, single pyriform, and ring form. The size of typical paired pyriforms with acute angle was 2.7 × 0.4 μm (n = 10) and with obtuse angle was 3.5 × 0.6 μm (n = 10). Although the morphological and biometrical parameters resembled the Babesia motasi, the results of seminested polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism using primers specific for small subunit of 18S rRNA confirmed this species as Babesia ovis. Furthermore, the sequence analysis of hypervariable region of small subunit of 18S rRNA revealed the corresponding sequences for B. ovis as well. Experimental infection of healthy lambs with the morphological larger B. ovis showed a milder clinical signs compared to the small one.  相似文献   

18.
Our study describes the emm type distributions of invasive and non-invasive group A streptococci (GAS) and group G streptococci (GGS) strains in one of the biggest Health Districts in Finland. A total of 571 GAS or GGS were recovered from patients with invasive or non-invasive infections during a 1-year period in 2008–2009 in Pirkanmaa Health District in Finland. We describe here the emm type distributions of GAS and GGS collected from throat (n = 246), pus (n = 217), deep tissue (n = 56) and blood (n = 52). The most common emm types among GAS were emm77, emm1, emm28, emm89 and emm12. Among GGS, the most common emm types were stG480, stG643, stG6, stC6979 and stG485. Some emm types were found to associate with certain infection focus. In GAS, emm77 associated with pus isolates, whereas emm1 and emm12 were more frequent among throat isolates. In GGS, stG480 was more commonly found from throat isolates.  相似文献   

19.
Glutathione S-transferase activity has been shown to be associated with the microsomal fraction of Taenia solium. Electron microscopy and subcellular enzyme markers indicate the purity of the microsomal fraction that contains the glutathione S-transferase activity. T. solium microsomes were solubilized under conditions used to solubilize integral microsomal proteins. This procedure proved necessary to obtain enzymatic activity. To characterize this parasite enzyme activity, several substrates and inhibitors were used. The optimum activity for microsomal glutathione S-transferase was found to be pH 6.6, with a specific enzyme activity of 0.9, 0.1, 0.067, 0.03, and 0.05 μmol min−1 mg−1 with the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene, 4-hydroxynonenal, 2,4-hexadienal, and trans-2-nonenal, respectively. No activity of glutathione peroxidase was observed. T. solium microsomes had an app K m (GSH) = 0.161 μM, app K m (CDNB) = 14.5 μM, and app V max of 0.15 and 27.9 μmol min−1 mg−1 for GSH and CDNB, respectively. T. solium microsomes were inhibited by several glutathione S-transferase enzyme inhibitors, and it was possible to establish a simple inhibition system as well as corresponding K i ’s for each inhibitor. These results indicate that the T. solium microsomal glutathione S-transferase is different from the parasite cytoplasmic enzymes that catalyze similar reactions.  相似文献   

20.
The genus Cephalanthera is an excellent plant group for karyotype evolution studies because it exhibits a dysploid series and bimodal karyotypes. With the aim of understanding their chromosomal and phylogenetic relationships, rRNA genes and the Arabidopsis-type telomeric sequence were mapped by fluorescence in-situ hybridization (FISH), and the rDNA intergenic spacer (ITS) was sequenced for the first time in three European species: C. longifolia (2n = 4x = 32), C. damasonium (2n = 4x = 36) and C. rubra (2n = 4x = 44). One 45S and three 5S rDNA sites are observed in C. longifolia, one 45S and two 5S sites in C. damasonium, and two 45S and one 5S site in C. rubra. Telomeric signals were observed at every chromosome end in all three species and C. damasonium also displays interstitial signals on three chromosome pairs. In agreement with chromosome data, molecular analyses support C. longifolia and C. damasonium as closely related taxa, while C. rubra stands apart. Possible pathways of karyotype evolution are discussed in reference to a previous hypothesis. The results indicate that complex chromosomal rearrangements, possibly involving Robertsonian fusions and fissions, loss of telomeric repeats, gain or loss of rDNA sites and other heterochromatic sequences and inversions, may have contributed to generating the present-day karyotypes. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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