Mortality in Three African Tephritid Fruit Fly Puparia and Adults Caused by the Entomopathogenic Fungi, Metarhizium anisopliae and Beauveria bassiana

The pathogenicity of 13 isolates of Metarhizium anisopliae and two isolates of Beauveria bassiana to Ceratitis capitata and Ceratitis var. rosa fasciventris exposed as late third instar larvae in sand was evaluated in the laboratory. All isolates caused a significant reduction in adult emergence and a corresponding large mortality on puparia of both species. All isolates also induced large deferred mortality in emerging adults following treatment as late third instar larvae. On C. capitata , seven isolates ( M. anisopliae ICIPE 18, 20, 32, 60 and 69 and B. bassiana ICIPE 44 and 82) caused significantly higher mortality on puparia than other isolates. With the exception of ICIPE 32, the other four isolates of M. anisopliae above were the most pathogenic against C. r. fasciventris . Dose-response study carried out with these isolates of M. anisopliae on the two species of flies above plus another species, Ceratitis cosyra showed that the dose-mortality regression lines of ICIPE 18 and 20 were steeper with lower LC 50 values when compared with ICIPE 60 and 69 on the three species. When these two isolates were evaluated with regard to their pathogenicity to different pupal age, adult emergence was found to increase with increasing pupal age with a corresponding decrease in mortality in puparia and emerging adults in the three species of fruit flies. M. anisopliae ICIPE 18 and 20 were equally pathogenic to all pupal ages tested in C. capitata and C. cosyra but ICIPE 18 was more pathogenic to older puparia of C. r. fasciventris than ICIPE 20. Our results suggest that soil inoculation with M. anisopliae under mango trees might form an important component of integrated pest management strategies in areas where these three species of fruit fly coexist.     

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A new class of long-acting hormonal steroid preparation: synthesis of dimeric androgens coupled at C3-C3 and C-17-C3 and of an androgen-progestogen combination

3β-Hydroxy-4-androsten-17-one was prepared from 4-androsten-3, 17-dione according to the method of Klimstra and Colton (1) and dimerized by means of esterification with succinic acid. The reduction with lithium-tri-t-butoxyaluminium hydride gave a testosterone derivative coupled between C₃-C₃ which showed after a single Injection of 10 mg a protracted but relatively weak androgenic effect in castrated male rats. The direct esterification of testosterone hemisuccinate with 4-androsten-3β,17β-diol gave the testosterone derivative coupled between C₁₇-C₃ which showed a more even and more protracted time response curve than testosterone enanthate. The testosterone-ethynodiol succinate also coupled between C₁₇-C₃, showed an androgenic depot-effect similar to that of the dimeric C₁₇-C₃ testosterone derivative.     

Effects of chemical modification of lysine residues in trypsin

Chemical modifications are a simple method to identify and modify functional determinants of enzymes. In the case of serine proteases, it is possible to induce characteristics which are advantageous for peptide synthesis. In this work, we investigated the influence of guanylation and succinylation of lysine residues on the S′-subsite specificity, the catalytic behavior and stability of trypsin. We have found, that succinylation leads to an about 10-fold better acceptance of basic residues in P1′, whereas guanylation shows no remarkable effects. Furthermore, guanylation enhances, succinylation reduces the general enzyme–substrate interactions in P2′. The structural fundamentals of these specificity changes are discussed. The catalytic behavior of trypsin was not influenced by guanylation and succinylation but an enhancement of the stability against autolytic processes by introducing additional negative charges into the protein was observed.     

Female mice carrying a defective Alox15 gene are protected from experimental colitis via sustained maintenance of the intestinal epithelial barrier function

Lipoxygenases (ALOXs) are involved in the regulation of cellular redox homeostasis. They also have been implicated in the biosynthesis of pro- and anti-inflammatory lipid mediators and play a role in the pathogenesis of inflammatory diseases, which constitute a major health challenge owing to increasing incidence and prevalence in all industrialized countries around the world. To explore the pathophysiological role of Alox15 (leukocyte-type 12-LOX) in mouse experimental colitis we tested the impact of systemic inactivation of the Alox15 gene on the extent of dextrane sulfate sodium (DSS) colitis. We found that in wildtype mice expression of the Alox15 gene was augmented during DSS-colitis while expression of other Alox genes (Alox5, Alox15b) was hardly altered. Systemic Alox15 (leukocyte-type 12-LOX) deficiency induced less severe colitis symptoms and suppressed in vivo formation of 12-hydroxyeicosatetraenoic acid (12-HETE), the major Alox15 (leukocyte-type 12-LOX) product in mice. These alterations were paralleled by reduced expression of pro-inflammatory gene products, by sustained expression of the zonula occludens protein 1 (ZO-1) and by a less impaired intestinal epithelial barrier function. These results are consistent with in vitro incubations of colon epithelial cells, in which addition of 12S-HETE compromised enantioselectively transepithelial electric resistance. Consistent with these data transgenic overexpression of human ALOX15 intensified the inflammatory symptoms. In summary, our results indicate that systemic Alox15 (leukocyte-type 12-LOX) deficiency protects mice from DSS-colitis. Since exogenous 12-HETE compromises the expression of the tight junction protein ZO-1 the protective effect has been related to a less pronounced impairment of the intestinal epithelial barrier function.     

The occurrence of multiperforate perforation plates in maize root metaxylem

A characteristic feature for both the early and late metaxylem of maize roots fs the occurrence of porous perforation plates. Occasionally but very rarely scalariform perforation, plates are also formed with the less specialized early metaxylem. Of a larger number of representatives analysed the line 4 Y is exceptional, various types of multiperforate plates occurring there more often, even with the late metaxylem. The taxonomical or ecological value of this character is not known.     

Die Bedeutung der Hormone für die Temperaturanpassung im normalen Temperaturbereich

Experiments dealing with an influence of endocrine glands in oxygen consumption of poikilothermic vertebrates are briefly reviewed. In spite of the negative findings of other investigators, some results suggest an endocrine control of the ability of cold-blooded vertebrates to adapt their respiration to changing environmental temperature. However, if hormones play a role in stimulating oxidative metabolism, it would be expected that the metabolic rate of isolated tissues would reflect the capacity adaptation of intact animals. Experimental results do not confirm this expectation in all cases; furthermore, there is only little evidence that thyroid hormones increase thein vitro respiration. On the other hand, tissue respiration is stimulated by adding small quantities of blood taken from cold-adapted animals. Some aspects concerning hormone induced shifts in metabolic pathways are discussed.