A genome-wide transcriptome profiling reveals the early molecular events during callus initiation in Arabidopsis multiple organs

AbstractInduction of a pluripotent cell mass termed callus is the first step in an in vitro plant regeneration system, which is required for subsequent regeneration of new organs or whole plants. However, the early molecular mechanism underlying callus initiation is largely elusive. Here, we analyzed the dynamic transcriptome profiling of callus initiation in Arabidopsis aerial and root explants and identified 1342 differentially expressed genes in both explants after incubation on callus-inducing medium. Detailed categorization revealed that the differentially expressed genes were mainly related to hormone homeostasis and signaling, transcriptional and post transcriptional regulations, protein phosphorelay cascades and DNA- or chromatin-modification. Further characterization showed that overexpression of two transcription factors, HB52 or CRF3, resulted in the callus formation in transgenic plants without exogenous auxin. Therefore, our comprehensive analyses provide some insight into the early molecular regulations during callus initiation and are useful for further identification of the regulators governing callus formation

Adolescent and non-consensual anal sexual debut among Chinese men who have sex with men: a cross-sectional study.

BACKGROUND: Adolescent sexual debut and non-consensual sex have been linked to higher sexual risk and STI infection in adulthood among men who have sex with men (MSM) in high-income countries. This study aimed to examine adolescent and non-consensual anal sexual debut among Chinese MSM and to evaluate factors associated with adolescent sexual debut and non-consensual anal sex. METHODS: A cross-sectional study was conducted recently among Chinese men assigned male sex at birth, ≥18 years old, and who had ever engaged in anal sex with a man. Participants answered questions regarding socio-demographics, condomless sex, age at anal sexual debut with a man, and whether the first anal sex was consensual. Factors associated with an adolescent sexual debut (< 18 years old) and non-consensual sex at sexual debut were evaluated. We defined adolescent sexual debut as having anal sex with another man at 17 years old or younger, and the participants were asked whether their first male-to-male anal sex was non-consensual. RESULTS: Overall, 2031 eligible men completed the survey. The mean age of sexual debut was 20.7 (SD = 4.3) years old. 17.6% (358/2031) of men reported adolescent sexual debut, and 5.0% (101/2031) reported a non-consensual sexual debut. The adolescent sexual debut was associated with having more male sexual partners (adjusted OR 1.10, 95% CI 1.06-1.15) and condomless anal sex in the last three months (AOR = 1.71, 95% CI 1.34-2.18). MSM whose sexual debut was non-consensual were more likely to have condomless anal sex (AOR = 1.76, 95% CI 1.17-2.66), and to have reported an adolescent sexual debut (AOR = 2.72, 95% CI 1.75-4.21). CONCLUSIONS: Many Chinese MSM reported adolescent sexual debut and non-consensual sex, both of which are associated with sexual risk behaviors and drive STI transmission. These findings highlight the need for designing tailored interventions for MSM who experienced adolescent sexual debut and non-consensual sex at debut

Crowdsourcing HIV Test Promotion Videos: A Noninferiority Randomized Controlled Trial in China.

BACKGROUND: Crowdsourcing, the process of shifting individual tasks to a large group, may enhance human immunodeficiency virus (HIV) testing interventions. We conducted a noninferiority, randomized controlled trial to compare first-time HIV testing rates among men who have sex with men (MSM) and transgender individuals who received a crowdsourced or a health marketing HIV test promotion video. METHODS: Seven hundred twenty-one MSM and transgender participants (≥16 years old, never before tested for HIV) were recruited through 3 Chinese MSM Web portals and randomly assigned to 1 of 2 videos. The crowdsourced video was developed using an open contest and formal transparent judging while the evidence-based health marketing video was designed by experts. Study objectives were to measure HIV test uptake within 3 weeks of watching either HIV test promotion video and cost per new HIV test and diagnosis. RESULTS: Overall, 624 of 721 (87%) participants from 31 provinces in 217 Chinese cities completed the study. HIV test uptake was similar between the crowdsourced arm (37% [114/307]) and the health marketing arm (35% [111/317]). The estimated difference between the interventions was 2.1% (95% confidence interval, -5.4% to 9.7%). Among those tested, 31% (69/225) reported a new HIV diagnosis. The crowdsourced intervention cost substantially less than the health marketing intervention per first-time HIV test (US$131 vs US$238 per person) and per new HIV diagnosis (US$415 vs US$799 per person). CONCLUSIONS: Our nationwide study demonstrates that crowdsourcing may be an effective tool for improving HIV testing messaging campaigns and could increase community engagement in health campaigns. CLINICAL TRIALS REGISTRATION: NCT02248558

Genome-Wide Identification of Arabidopsis LBD29 Target Genes Reveals the Molecular Events behind Auxin-Induced Cell Reprogramming during Callus Formation

Auxin-induced callus formation represents an important cell reprogramming process during in vitro regeneration of plants, in which the pericycle or pericycle-like cells within plant organs are reprogrammed into the pluripotent cell mass termed callus that is generally required for subsequent regeneration of root or shoot. However, the molecular events behind cell reprogramming during auxin-induced callus formation are largely elusive. We previously identified that auxin-induced LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factors act as the master regulators to trigger auxin-induced callus formation. Here, by ChIP-seq (chromatin immunoprecipitation-based sequencing) and RNA sequencing approaches, we identified the potential LBD29 target genes at the genome-wide level and outlined the molecular events of LBD-triggered cell reprogramming during callus formation. We showed that LBD29 preferentially bound to the G-box (CACGTG) and TGGGC[C/T] motifs and potentially targeted > 350 genes, among which the genes related to methylation, reactive oxygen species (ROS) metabolism, cell wall hydrolysis and lipid metabolism were rapidly activated, while most of the light-responsive genes were suppressed by LBD29. Further examination of a few representative genes validated that they were targeted by LBD29 and participated in the regulation of cell reprogramming during callus formation. Our data not only outline a framework of the early molecular events behind auxin-induced cell reprogramming of callus formation, but also provide a valuable resource for identification of genes that regulate cell fate switch during in vitro regeneration of plants