Fragment of the gene encoding chymotrypsin and trypsin inhibitor protein of potato tubers

Product of polymerase chain reaction designated as PKPIJ-B was isolated after amplification from genomic DNA of potato (Solarium tuberosum L., Zhukov Jubilee cultivar) using the designed primers. Nucleotide sequence of PKPIJ-B was determined and amino acid sequence of protein was restored. Analysis of this sequence has allowed us to suggest that isolated gene fragment encodes chymotrypsin and trypsin inhibitor protein (PKCI-23 potato Kunitz-type chymotrypsin inhibitor) of potato tubers.     

In vitro propagation of the medicinal plant Plumbago zeylanica L. Through nodal explants

Summary A protocol for rapid in vitro propagation using nodal explants obtained from 2-yr-old, field-grown medicinal plants of Plumbago zeylanica L. belonging to the family Plumbaginaceae is described. High frequency bud break and fast development of shoots were induced on Murashige and Skoog's basal medium supplemented with 27.2 μM adenine sulfate +2.46 μM indole-3-butyric acid (IBA). Induction of rooting was achieved by transferring the shoots to the same basal medium containing 4.92 μM IBA. Using our protocol from one twig of P. zeylanica (eight responsive nodes per explant shoot) within a period of 5 mo., eight plantlets could be raised. After a hardening period of 4 wk, there was a 90% transplantation success in the field compared to the 60–65% survival of plantlets recorded in the experiments of previous workers. The plantlets derived through in vitro propagation mimic the growth and morphological characteristics of the donor plants.     

A chemically-defined medium for production of compactin by Penicillium citrinum

A mutant strain of Penicillium citrinum grown in a chemically-defined production medium, yielded 145 mg compactin l^–1. The medium also facilitated spectrophotometric analysis of compactin. Addition of KH₂PO₄in the production medium did not increase the compactin production, while addition of a surfactant, Tween 80, increased compactin to 175 mg l^–1. Inoculation with 10⁷ spores ml^–1 and initial pH of 6.5–7 were the most suitable for compactin production.     

Geometric morphometric analysis of the effect of temperature on wing size and shape in Aedes albopictus

Wing geometry helps to identify mosquito species, even cryptic ones. On the other hand, temperature has a well‐known effect on insect metric properties. Can such effects blur the taxonomic signal embedded in the wing? Two strains of Aedes albopictus (laboratory and field strain) were examined under three different rearing temperatures (26, 30 and 33 °C) using landmark‐ and outline‐based morphometric approaches. The wings of each experimental line were compared with Aedes aegypti. Both approaches indicated similar associations between wing size and temperature. For the laboratory strain, the wing size significantly decreased as the temperature increased. For the field strain, the largest wings were observed at the intermediate temperature. The two morphometric approaches describing shape showed different sensibilities to temperature. For both strains and sexes, the landmark‐based approach disclosed significant wing shape changes with temperature changes. The outline‐based approach showed lesser effects, detecting significant changes only in laboratory females and in field males. Despite the size and shape changes induced by temperature, the two strains of Ae. albopictus were always distinguished from Ae. aegypti. The present study confirms the lability of size. However, it also suggests that, despite environmentally‐induced variation, the architecture of the wing still provides a strong taxonomic signal.     

Analysis of the fine specificity and cross-reactivity of monoclonal anti-lipid A antibodies

We have investigated the fine specificity of anti-lipid A antibodies to identify conserved lipid A antigens. Because lipid A derived from many different Gram-negative bacteria has similar biologic activities, the conserved regions may be of particular importance for the immunostimulatory and toxic properties of lipid A. We found that five of nine antibodies bound to a wide variety of Gram-negative bacteria. All these widely cross-reactive antibodies bound to the same antigenic site within lipid A. Polymyxin B, an inhibitor of lipid A activity, bound to this site as well. The widely cross-reactive antibodies bound to native and base-hydrolyzed lipid A equally well, and also bound to the monosaccharide precursor lipid X. The less cross-reactive antibodies recognized base-hydrolyzed lipid A poorly, and did not recognize lipid X at all. Other investigators have shown that lipid X has some of the activities of lipid A in vitro and can inhibit the lethal toxicity of LPS in vivo. On the basis of this study, we suggest that lipid X contains a conserved lipid A epitope as well.