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91.
Damir Valić Irena Vardić Smrzlić Damir Kapetanović Zlatica Teskeredžić Bruna Pleše Emin Teskeredžić 《Biologia》2013,68(3):539-545
In order to determine an unknown fish population from the Vrana Lake, mitochondrial cytochrome b gene and non-coding nuclear region Cyfun P were investigated. Stabile population of Bulldog rudd, Scardinius dergle Heckel & Kner, the endemic Croatian freshwater fish in the Krka River, was genetically characterized with the same markers in order to compare it with the material from the Vrana Lake. Genetic markers were sequenced and aligned with the similar ones obtained from the GenBank in order to determine taxonomic and phylogenetic position of these two species. A significant discrepancy between nuclear genetic markers of our specimens and the sequence from the GenBank was found. Phylogenetic analysis suggested that the specimens from the Vrana Lake belong to the species S. hesperidicus. Morphometric characteristics, the maximum length and body mass showed new maximum values for both S. dergle and S. hesperidicus. 相似文献
92.
Małgorzata Proćków Magda Drvotová Lucie Juřičková Elżbieta Kuźnik-Kowalska 《Biologia》2013,68(1):131-141
For the first time the life cycle of the common land snail Trochulus hispidus was completely described in Central Europe (Poland). This is a semelparous species predominantly with an annual life cycle and the reproductive period lasting from April till October. The first young snails hatch in spring, grow rapidly in summer and reach ca. 4 whorls until winter. In spring of the next year they mature and reproduce. After that they die. There is hardly any growth from late autumn till early spring. The average proportional growth rate is ca. 0.3 whorl/month in the wild. The fastest growth is present in the youngest snails and then gradually decreases over the course of their age. Laboratory and field observations allowed for establishing the following life cycle parameters: eggs calcified, almost spherical, ca. 1.5 mm, laid in spring and summer in batches of between 1 and 47. Time to hatching is 6–24 days, hatching is asynchronous; newly-hatched snails have approximately 1.5 whorls. Analysis of food preferences revealed, that T. hispidus tends to restrict its diet during the life. Generally the youngest snails equally consumed leaves of all four tree species offered (Fraxinus excelsior, Acer pseudoplatanus, Tilia cordata and A. platanoides) whereas adults preferred F. excelsior over A. pseudoplatanus and A. platanoides. 相似文献
93.
Primož Treven Kristyna Turkova Aljoša Trmčić Tanja Obermajer Irena Rogelj Bojana Bogovič Matijašić 《Folia microbiologica》2013,58(6):623-630
Lactobacillus gasseri K7 is a probiotic strain that produces bacteriocins gassericin K7 A and K7 B. In order to develop a real-time quantitative PCR assay for the detection of L. gasseri K7, 18 reference strains of the Lactobacillus acidophilus group and 45 faecal samples of adults who have never consumed strain K7 were tested with PCR using 14 pairs of primers specific for gassericin K7 A and K7 B gene determinants. Incomplete gassericin K7 A or K7 B gene clusters were found to be dispersed in different lactobacilli strains as well as in faecal microbiota. One pair of primers was found to be specific for the total gene cluster of gassericin K7A and one for gassericin K7B. The real-time PCR analysis of faecal samples spiked with K7 strain revealed that primers specific for the gene cluster of the gassericin K7 A were more suitable for quantitative determination than those for gassericin K7 B, due to the lower detection level. Targeting of the gassericin K7 A or K7 B gene cluster with specific primers could be used for detection and quantification of L. gasseri K7 in human faecal samples without prior cultivation. The results of this study also present new insights into the prevalence of bacteriocin-encoding genes in gastrointestinal tract. 相似文献
94.
Jadwiga Handzlik Ewa Szymańska Sandrine Alibert Jacqueline Chevalier Ewa Otrębska Elżbieta Pękala Jean-Marie Pagès Katarzyna Kieć-Kononowicz 《Bioorganic & medicinal chemistry》2013,21(1):135-145
A series of amine-alkyl derivatives of 5-arylidenehydantoin 3–21 was evaluated for their ability to improve antibiotic effectiveness in two strains of Gram-negative Enterobacter aerogenes: the reference strain (ATCC-13048) and the chloramphenicol-resistant derivative over-producing the AcrAB-TolC efflux pump (CM-64). Three antibiotics, chloramphenicol, nalidixic acid and sparfloxacin were used as markers of efflux pump activity. New compounds (5–16) were obtained within 3–4 step synthesis using Knoevenagel condensation, Mitsunobu reaction and microwave aided N-alkylation. Molecular modeling based structure–activity relationship (SAR) studies were performed. The most active compounds: (Z)-5-(4-(diethylamino)benzylidene)-3-(2-hydroxy-3-(4-(2-hydroxyethyl)piperazin-1-yl)propyl)imidazolidine-2,4-dione (14) and (Z)-5-(2,4-dimethoxybenzylidene)-3-(2-hydroxy-3-(isopropylamino)propyl)imidazolidine-2,4-dione (15) induced fourfold decrease of minimal inhibition concentration (MIC) of all tested antibiotics in the strain CM-64 overexpressing the AcrAB-TolC pump. 相似文献
95.
96.
Dragan M. Popović 《Amino acids》2013,45(5):1073-1087
The function of cytochrome c oxidase as a biomolecular nanomachine that transforms energy of redox reaction into protonmotive force across a biological membrane has been subject of intense research, debate, and controversy. The structure of the enzyme has been solved for several organisms; however details of its molecular mechanism of proton pumping still remain elusive. Particularly, the identity of the proton pumping site, the key element of the mechanism, is still open to dispute. The pumping mechanism has been for a long time one of the key unsolved issues of bioenergetics and biochemistry, but with the accelerating progress in this field many important details and principles have emerged. Current advances in cytochrome oxidase research are reviewed here, along with a brief discussion of the most complete proton pumping mechanism proposed to date, and a molecular basis for control of its efficiency. 相似文献
97.
Abstract Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin (Diptera: Drosophilidae) populations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead (Pb). To determine whether flies from different natural populations exposed to the Pb‐contaminated media in the laboratory show population specific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations (F2, F5, and F8) for fecundity, developmental time, and egg‐to‐adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution. 相似文献
98.
Djordje Malenčić Jelena Cvejić Vesna Tepavčević Mira Bursać Biljana Kiprovski Miloš Rajković 《Central European Journal of Biology》2013,8(9):921-929
Soybean [Glycine max (L.) Merr.] cultivars (Meli, Alisa, Sava and 1511/99) were grown up to V1 phase (first trifoliate and one node above unifoliate) and then inoculated with Sclerotinia sclerotiorum (Lib.) de Bary under controlled conditions. Changes in L-phenylalanine ammonia-lyase (PAL) activity and isoflavone phytoalexins were recorded 12, 24, 48 and 72 h after the inoculation. Results showed an increase in PAL activity in all four examined soybean cultivars 48 h after the inoculation, being the highest in Alisa (2-fold higher). Different contents of total daidzein, genistein, glycitein and coumestrol were detected in all samples. Alisa and Sava increased their total isoflavone content (33.9% and 6.2% higher than control, respectively) as well as 1511/99, although 48 h after the inoculation its content decreased significantly. Meli exhibited the highest rate of coumestrol biosynthesis (72 h after the inoculation) and PAL activity (48 h after the inoculation). All investigated cultivars are invariably susceptible to this pathogen. Recorded changes could point to possible differences in mechanisms of tolerance among them. 相似文献
99.
The most prominent colors observed in insects are black or brown, whose production is attributed to the melanin pathway. At present, though, the contribution of this pathway to overall body pigmentation throughout ontogenesis is still lacking. To address this question we examined the roles of 2 key melanin genes (TH and DDC), in embryonic and postembryonic development of the American cockroach, Periplaneta americana. Our results show that the melanin pathway does not contribute to the light brown coloration observed in the first nymphs. However, the dark brown coloration in mid nymphs and adults is produced solely from the melanin pathway. In addition, the DDC RNAi results reveal that it is dopamine melanin, not DOPA melanin, acts as the main contributor in this process. Overall, present study provides a new insight into insect pigmentation suggesting that genetic mechanisms of coloration can change during ontogenesis. Future studies of additional basal insect lineages will be required to assess in more details the generality of this phenomenon. 相似文献
100.
Chemical Composition of Ballota macedonica Vandas and Ballota nigra L. ssp. foetida (Vis.) Hayek Essential Oils – The Chemotaxonomic Approach 下载免费PDF全文
Aleksandra S. Đorđević Olga P. Jovanović Bojan K. Zlatković Gordana S. Stojanović 《化学与生物多样性》2016,13(6):782-788
The essential oils isolated from fresh aerial parts of Ballota macedonica (two populations) and Ballota nigra ssp. foetida were analyzed by GC and GC/MS. Eighty five components were identified in total; 60 components in B. macedonica oil (population from the Former Yugoslav Republic of Macedonia), 34 components in B. macedonica oil (population from the Republic of Serbia), and 33 components in the oil of B. nigra ssp. foetida accounting for 93.9%, 98.4%, and 95.8% of the total oils, respectively. The most abundant components in B. macedonica oils were carotol (13.7 – 52.1%), germacrene D (8.6 – 24.6%), and (E)‐caryophyllene (6.5 – 16.5%), while B. nigra ssp. foetida oil was dominated by (E)‐phytol (56.9%), germacrene D (10.0%), and (E)‐caryophyllene (4.7%). Multivariate statistical analyses (agglomerative hierarchical cluster analysis and principal component analysis) were used to compare and discuss relationships among Ballota species examined so far based on their volatile profiles. The chemical compositions of B. macedonica essential oils are reported for the first time. 相似文献