Bacteriocin production inAgrobacterium tumefaciens

Agrobacterium tumefaciens C58 forms “plaques” during layer cultivation. The “plaques” were shown not to be caused by the presence of a temperate bacteriophage or by random contamination. The “plaques” and their central microcolonies were used to repeatedly isolate cultures producing an antibiotic substance against the original strainA. tumefaciens C58, other nopaline strains, some octopine strains ofA. tumefaciens and some strains of the related genusRhizobium. The substance is thus a bacteriocin; in analogy to agrocins 84 and D286 it was named agrocin C58. The agrocin is not inactivated by trypsin. Its production by strain C58 was found only on cultivation on solid but not liquid media. The producing isolate ofA. tumefaciens C58 (strain C58i2) contains neither plasmid pTiC58 nor the plasmid analogous to pAgK84 which controls the production of agrocin 84 inA. radiobacter K84.     

Homozygous mutations in fibroblast growth factor 3 are associated with a new form of syndromic deafness characterized by inner ear agenesis, microtia, and microdontia

We identified nine individuals from three unrelated Turkish families with a unique autosomal recessive syndrome characterized by type I microtia, microdontia, and profound congenital deafness associated with a complete absence of inner ear structures (Michel aplasia). We later demonstrated three different homozygous mutations (p.S156P, p.R104X, and p.V206SfsX117) in the fibroblast growth factor 3 (FGF3) gene in affected members of these families, cosegregating with the autosomal recessive transmission as a completely penetrant phenotype. These findings demonstrate the involvement of FGF3 mutations in a human malformation syndrome for the first time and contribute to our understanding of the role this gene plays in embryonic development. Of particular interest is that the development of the inner ear is completely disturbed at a very early stage--or the otic vesicle is not induced at all--in all of the affected individuals who carried two mutant FGF3 alleles.     

Genotoxic action of fungicide Conan 5FL (hexaconazole) on mammalian cells in vivo and in vitro

The genotoxic effects of fungicide Conan 5FL (containing 50 g/L hexaconazole) in mouse bone-marrow cells and human lymphocytes have been evaluated. Three different concentrations of Conan 5FL (17.50, 35.00 and 70.00 microg/mL for human lymphocytes and 17.50, 35.00 and 70.00 mg/kg for mouse bone marrow cells) were studied. Conan 5FL induced significant increases (except 17.50 mg/kg for mouse bone marrow) in the frequency of chromosomal aberrations (CAs) in both test systems. This fungicide caused structural and numerical abnormalities in both mammalian cells. These are sister chromatid union, chromatid and chromosome breaks, fragments, dicentric and ring chromosomes, and polyploidy. Significant increase was found in induction and in minimum-maximum numbers of sister chromatid exchanges (SCEs) at all treatments compared with the negative control. Conan 5FL did not affect the replication index (RI) in human lymphocyte cultures, however, it significantly decreased the mitotic index (MI) in all treatment concentrations in both test systems. Using of Conan 5FL should be reconsidered due to its possible cytotoxic, clastogenic and mutagenic effects.     

Age-related changes in antioxidant enzyme activities and lipid peroxidation in lungs of control and sulfur dioxide exposed rats

Antioxidant defenses within the lung are pivotal in preventing damage from oxidative toxicants. There have also been several reports with conflicting results on the antioxidant system during aging. In this study, we attempted to investigate age-related alterations in both antioxidant enzyme activities and thiobarbituric acid-reactive substances (TBARS), a product of lipid peroxidation, in the whole lung of control and sulfur dioxide (SO₂) exposed rats of different age groups (3-, 12-, and 24-months-old). Swiss-Albino Male rats were exposed to 10 ppm SO₂ 1 hr/day, 7 days/week for 6 weeks. The antioxidant enzymes examined include Cu,Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). A mixed pattern of age-associated alterations in antioxidant activities was observed. SOD, GSH-Px and GST activities were increased with age, but CAT activity was decreased. Lung SOD, GSH-Px and GST activities were also increased in response to SO₂. The level of TBARS was increased with age. SO₂ exposure stimulated lipid peroxide formation in the lung as indicated by an increase in the level of TBARS. These findings suggest that both aging and SO₂ exposure may impose an oxidative stress to the body. We conclude that the increase in the activities of the antioxidant enzymes of the lung during aging, could be interpreted as a positive feedback mechanism in response to rising lipid peroxidation.     

Two new species of the genus <Emphasis Type="Italic">Quadroppia</Emphasis> (Acari: Oribatida: Quadroppiidae) from Turkey

Two new species of the genus Quadroppia Jacot, 1939, Quadroppia (Coronoquadroppia) squarrosa sp. n. and Quadroppia (Quadroppia) foveolata sp. n. are described and illustrated from Turkey. They were collected from soil and litter under pear trees (Pyrus communis) and moss on rock, respectively.     

Cytogenetic effects of nine <Emphasis Type="Italic">Helichrysum</Emphasis> taxa in human lymphocytes culture

Helichrysum Mill. (Asteraceae) species have been used in folk medicine for thousands of years in the world. The in vitro cytogenetic effects in human lymphocytes of nine Helichrysum taxa used in Turkey folk medicine were investigated. Blood samples were obtained from healthy donors, non-smoking volunteers, which were incubated and exposed to increasing concentrations of methanol extracts of Helichrysum taxa (0.01, 0.05, 0.1, 0.5 and 1 mg/mL). The inhibitory effects of H. stoechas (L.) Moench subsp. barrelieri (Ten.) Nyman, H. armenium DC. subsp. armenium, H. armenium DC. subsp. araxinum (Kirp.) Takht., H. plicatum DC. subsp. plicatum, H. compactum Boiss. and H. artvinense P.H.Davis & Kupicha on the mitotic index and replication index indicate that these taxa can have genotoxic and mutagenic effects. They should therefore not be used freely in alternative medicine although their antiproliferative activity may suggest anticarcinogenic properties. Increase effects of H. stoechas subsp. barrelieri, H. armenium subsp. armenium, H. armenium subsp. araxinum, H. chasmolycicum P.H.Davis, H. plicatum subsp. plicatum, H. compactum and H. artvinense on the micronucleus rates showed that these taxa can have genotoxic and carcinogenic effects.     

Mutagenic effects of short term action of N-methyl-N’-nitro-N-nitrosoguanidine onChlamydomonas geitleri

A possible method of finding the best concentration of a chemical mutagen or a shortterm action is demonstrated by the results obtained withChlamydomonas geitleri. Mostly two cases occur. We must either use the shortest time of the mutagen action with a sufficiently high effect or utilize the whole limited time for this action using a suitable concentration with a similar effect. It is possible to choose such a structure of the doae of the chemical mutagen which in the mutation spectrum ensures either the optimal frequencies of all components or of only some of them chosen beforehand.     

Taxonomic review and phylogenetic inference elucidate the evolutionary history of Mesozoic Procercopidae,with new data from the Cretaceous Jehol Biota of NE China (Hemiptera,Cicadomorpha)

The Mesozoic family Procercopidae is widely treated as the ancient group of Cercopoidea and a transitional unit to recent lineages, but its evolution and diversity are vague due to fragmentary fossil record and confusing taxonomic history. Herein, an extensive taxonomic review of Procercopidae is presented and some new fossils are reported from the Lower Cretaceous Yixian Formation of NE China. As a result, Chengdecercopis Hong, 1983 is transferred from Procercopidae to Sinoalidae; Procercopis longipennis Becker-Migdisova, 1962 and P shawanensis Zhang, Wang and Zhang, 2003 are transferred to Procercopina Martynov, 1937, resulting in Procercopina longipennis (Becker-Migdisova, 1962), comb. n. and P shawanensis (Zhang, Wang and Zhang, 2003), comb. n.; Luanpingia senjituensis Hong, 1984 is transferred to Stellularis Chen, Yao and Ren, 2015, leading to Stellulari senjituensis (Hong, 1984), comb. n.; Anthoscytina macula Hu, Yao and Ren, 2014 is transferred to Sinocercopis Hong, 1982, and Sunoscytinopteris (Scytinopteridae) and Cathaycixius (Cixiidae) are treated as junior homonym names of Sinocercopis, leading to Sinocercopis macula (Hu, Yao and Ren, 2014), comb. n., S lushangfenensis (Hong, 1984), comb. n., S pustulosis (Ren, 1995), comb. n., and S trinervis (Ren, 1995), comb. n. Additionally, two new species are erected: Stellularis bineuris Chen and Wang, sp. n. and S minutus Chen and Wang, sp. n. Our cladistic analysis based on wing (tegmen and hind wing) characteristics recovers the high-level relationships within Cercopoidea: Sinoalidae + (Procercopidae + (Cercopionidae + modern cercopoids)). Within the family Procercopidae, the cladistic analysis reveals that the Middle to Late Jurassic Titanocercopis and Jurocercopis and the Cretaceous Cretocercopis occupy the basal position, and a gradual change in wing venation can be recognized from the Early Jurassic Procercopis and Procercopina to the Jurassic Anthoscytina, and then to the Cretaceous Stellularis and Sinocercopis. The two Cretaceous genera, sharing wing traits with extant cercopoids, likely represent transitional forms between Procercopidae and recent Cercopoidea; however, they are very similar to their Jurassic relatives in body structures, suggesting it is applicable to attribute them to Procercopidae. Furthermore, our analysis suggests that the extinction of Procercopidae and the origin and early diversification of modern Cercopoidea approximately coincided with the rise and explosive radiation of angiosperms in the late Early Cretaceous and onwards.