Structural organization of organs in multicellular organisms occurs through intricate patterning mechanisms that often involve complex interactions between transcription factors in regulatory networks. For example, INDEHISCENT (IND), a basic helix-loop-helix (bHLH) transcription factor, specifies formation of the narrow stripes of valve margin tissue, where Arabidopsis thaliana fruits open on maturity. Another bHLH transcription factor, SPATULA (SPT), is required for reproductive tissue development from carpel margins in the Arabidopsis gynoecium before fertilization. Previous studies have therefore assigned the function of SPT to early gynoecium stages and IND to later fruit stages of reproductive development. Here we report that these two transcription factors interact genetically and via protein-protein contact to mediate both gynoecium development and fruit opening. We show that IND directly and positively regulates the expression of SPT, and that spt mutants have partial defects in valve margin formation. Careful analysis of ind mutant gynoecia revealed slight defects in apical tissue formation, and combining mutations in IND and SPT dramatically enhanced both single-mutant phenotypes. Our data show that SPT and IND at least partially mediate their joint functions in gynoecium and fruit development by controlling auxin distribution and suggest that this occurs through cooperative binding to regulatory sequences in downstream target genes.

The most promising interventions for schools appear to be gatekeeper training and screening programs. However, more research is needed.

A total of 1,225 men and women attending a commercial event in the state of Victoria, Australia were surveyed as to whether they had ever paid for sex. Of 612 men surveyed, 143 (23.4%) had paid for sex at least once. Men who had ever paid for sex were compared with male nonclients on 13 demographic and sexual history measures; only four significantly differentiated clients from nonclients. Clients were significantly older, less likely to have been educated beyond high school, less likely to report having a regular partner in the past 6 months, and more likely to report that their most recent sexual encounter was with a casual partner. Clients of sex workers reported the major reason for paying for sex was to satisfy their sexual needs (43.8%), followed by the belief that paying for sex was less trouble (36.4%), and that it would be entertaining (35.5%). A factor analysis of reasons for visiting sex workers identified three factors labelled Ease, Engagement, and Arousal. Together, these factors accounted for 55% of the variance associated with the factor solution of motivations for paying for sex. In a setting where commercial sex is legally available from brothels, it would appear that clients are unremarkable in their social characteristics and are motivated mainly by the ease of the commercial sex encounter, the need for engagement with another, and because they feel in need of sexual "relief."

SummaryGametophytic self-incompatibility (GSI) systems involving the expression of stylar ribonucleases have been described and extensively studied in many plant families including the Solanaceae, Rosaceae and Scrophulariaceae. Pollen recognition and rejection is governed in the style by specific ribonucleases called SRNases, but in many self-incompatibility (SI) systems, modifier loci that can modulate the SI response have been described at the genetic level. Here, we present at the molecular level, the isolation and characterization of two Solanum chacoense homologues of the Nicotiana HT modifier that had been previously shown to be necessary for the SI reaction to occur in N. alata (McClure et al., 1999). HT homologues from other solanaceous species have also been isolated and a phylogenetic analysis reveals that the HT genes fall into two groups. In S. chacoense, these small proteins named ScHT-A and ScHT-B are expressed in the style and are developmentally regulated during anthesis identically to the S-RNases as well as following compatible and incompatible pollination. To elucidate the precise role of each HT isoform, antisense ScHT-A and RNAi ScHT-B lines were generated. Conversion from SI to self-compatibility (SC) was only observed in RNAi ScHT-B lines with reduced levels of ScHT-B mRNA. These results confirm the role of the HT modifier in solanaceous SI and indicate that only the HT-B isoform is directly involved in SI.

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