4-Azolylphenyl isoxazoline insecticides acting at the GABA gated chloride channel

Isoxazoline insecticides have been shown to be potent blockers of insect GABA receptors with excellent activity on a broad pest range, including Lepidoptera and Hemiptera. Herein we report on the synthesis, biological activity and mode-of-action for a class of 4-heterocyclic aryl isoxazoline insecticides.     

Zoophytophagous pentatomids feeding on plants and implications for biological control

Zoophytophagous insects can feed on a variety of prey, plants and plant products. By studying the interactions between predatory hemipterans and plants harbouring the prey of these insects, scientists have started to establish two potential outcomes: (1) positive effects like the enhancement of their life history characteristics by acquiring plant contents; and (2) negative effects mediated by plant resistance to herbivores or prey ingesting secondary plant metabolites. Despite this research, there is a lack of information about the feeding sites of predatory hemipterans on their host plants, what they ingest from plants, and whether they cause damage to their host plants. The results presented here indicate that the xylem is one of the feeding sites of predatory hemipterans on plants. The dissection of predators that fed on plants with marked vessels and testing insects for the presence of Cry protein constitutively expressed in the cytoplasm of plant cells revealed that bugs are not able to acquire cytoplasm contents from the plant cell. In addition, we demonstrate that systemic insecticide circulating inside plants from soil applications contaminates these predators. Our results are discussed in the context of zoophytophagous feeding behaviour exhibited by predatory hemipterans and the use of systemic insecticides for the conservation of natural enemies. This interaction contradicts the concept of ecological selectivity obtained for natural enemies through the placement of systemic insecticide in the soil as a selective method of deploying chemical control and predatory hemipteran conservation within the integrated pest management framework.     

Combinatorial regulation modules on GmSBP2 promoter: a distal cis-regulatory domain confines the SBP2 promoter activity to the vascular tissue in vegetative organs

The Glycine max sucrose binding protein (GmSBP2) promoter directs phloem-specific expression of reporter genes in transgenic tobacco. Here, we identified cis-regulatory domains (CRD) that contribute with positive and negative regulation for the tissue-specific pattern of the GmSPB2 promoter. Negative regulatory elements in the distal CRD-A (-2000 to -700) sequences suppressed expression from the GmSBP2 promoter in tissues other than seed tissues and vascular tissues of vegetative organs. Deletion of this region relieved repression resulting in a constitutive promoter highly active in all tissues analyzed. Further deletions from the strong constitutive -700GmSBP2 promoter delimited several intercalating enhancer-like and repressing domains that function in a context-dependent manner. Histochemical examination revealed that the CRD-C (-445 to -367) harbors both negative and positive elements. This region abolished promoter expression in roots and in all tissues of stems except for the inner phloem. In contrast, it restores root meristem expression when fused to the -132pSBP2-GUS construct, which contains root meristem expression-repressing determinants mapped to the 44-bp CRD-G (-136 to -92). Thus, the GmSBP2 promoter is functionally organized into a proximal region with the combinatorial modular configuration of plant promoters and a distal domain, which restricts gene expression to the vascular tissues in vegetative organs.     

Remodeling of the cervix and parturition in mice lacking the progesterone receptor B isoform

Withdrawal of progestational support for pregnancy is part of the final common pathways for parturition, but the role of nuclear progesterone receptor (PGR) isoforms in this process is not known. To determine if the PGR-B isoform participates in cervical remodeling at term, cervices were obtained from mice lacking PGR-B (PGR-BKO) and from wild-type (WT) controls before or after birth. PGR-BKO mice gave birth to viable pups at the same time as WT controls during the early morning of Day 19 postbreeding. Morphological analyses indicated that by the day before birth, cervices from PGR-BKO and WT mice had increased in size, with fewer cell nuclei/area as well as diminished collagen content and structure, as evidenced by optical density of picrosirius red-stained sections, compared to cervices from nonpregnant mice. Moreover, increased numbers of resident macrophages, but not neutrophils, were found in the prepartum cervix of PGR-BKO compared to nonpregnant mice, parallel to findings in WT mice. These results suggest that PGR-B does not contribute to the growth or degradation of the extracellular matrix or proinflammatory processes associated with recruitment of macrophages in the cervix leading up to birth. Rather, other receptors may contribute to the progesterone-dependent mechanism that promotes remodeling of the cervix during pregnancy and in the proinflammatory process associated with ripening before parturition.