Precisely controlled gene regulatory networks are required during embryonic development to give rise to various structures, including those of the cardiovascular system. Long non-coding RNA (lncRNA) ...loci are known to be important regulators of these genetic programs. We have identified a novel and essential lncRNA locus Handsdown (Hdn), active in early heart cells, and show by genetic inactivation that it is essential for murine development. Hdn displays haploinsufficiency for cardiac development as Hdn-heterozygous adult mice exhibit hyperplasia in the right ventricular wall. Transcriptional activity of the Hdn locus, independent of its RNA, suppresses its neighboring gene Hand2. We reveal a switch in a topologically associated domain in differentiation of the cardiac lineage, allowing the Hdn locus to directly interact with regulatory elements of the Hand2 locus.
Display omitted
•The essential lncRNA Handsdown is haploinsufficient for embryonic development•The Handsdown RNA transcript is dispensable for cardiac gene regulation•The TAD association of Handsdown shifts during cardiac differentiation•Transcription of Handsdown regulates the cis-located Hand2 gene
Ritter et al. characterize an essential lncRNA locus, Handsdown, which regulates development by controlling cardiac gene programs during early vertebrate embryo formation. The Handsdown locus physically interacts with the Hand2 gene during cardiac differentiation and genetic ablation of Handsdown leads to elevated Hand2 levels.
Abstract
After myocardial infarction in the adult heart the remaining, non-infarcted tissue adapts to compensate the loss of functional tissue. This adaptation requires changes in gene expression ...networks, which are mostly controlled by transcription regulating proteins. Long non-coding transcripts (lncRNAs) are taking part in fine-tuning such gene programs. We describe and characterize the cardiomyocyte specific lncRNA
Sweetheart RNA
(
Swhtr
), an approximately 10 kb long transcript divergently expressed from the cardiac core transcription factor coding gene
Nkx2-5
. We show that
Swhtr
is dispensable for normal heart development and function but becomes essential for the tissue adaptation process after myocardial infarction in murine males. Re-expressing
Swhtr
from an exogenous locus rescues the
Swhtr null
phenotype. Genes that depend on
Swhtr
after cardiac stress are significantly occupied and therefore most likely regulated by NKX2-5. The
Swhtr
transcript interacts with NKX2-5 and disperses upon hypoxic stress in cardiomyocytes, indicating an auxiliary role of
Swhtr
for NKX2-5 function in tissue adaptation after myocardial injury.
We have recently identified endothelial cell-secreted developmental endothelial locus-1 (Del-1) as an endogenous inhibitor of β2-integrin-dependent leukocyte infiltration. Del-1 was previously also ...implicated in angiogenesis. Here, we addressed the role of endogenously produced Del-1 in ischaemia-related angiogenesis. Intriguingly, Del-1-deficient mice displayed increased neovascularisation in two independent ischaemic models (retinopathy of prematurity and hind-limb ischaemia), as compared to Del-1-proficient mice. On the contrary, angiogenic sprouting in vitro or ex vivo (aortic ring assay) and physiological developmental retina angiogenesis were not affected by Del-1 deficiency. Mechanistically, the enhanced ischaemic neovascularisation in Del-1-deficiency was linked to higher infiltration of the ischaemic tissue by CD45+ haematopoietic and immune cells. Moreover, Del-1-deficiency promoted β2-integrin-dependent adhesion of haematopoietic cells to endothelial cells in vitro, and the homing of hematopoietic progenitor cells and of immune cell populations to ischaemic muscles in vivo. Consistently, the increased hind limb ischaemia-related angiogenesis in Del-1 deficiency was completely reversed in mice lacking both Del-1 and the β2-integrin LFA-1. Additionally, enhanced retinopathy-associated neovascularisation in Del-1-deficient mice was reversed by LFA-1 blockade. Our data reveal a hitherto unrecognised function of endogenous Del-1 as a local inhibitor of ischaemia-induced angiogenesis by restraining LFA-1-dependent homing of pro-angiogenic haematopoietic cells to ischaemic tissues. Our findings are relevant for the optimisation of therapeutic approaches in the context of ischaemic diseases.
Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies ...are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T p.Arg853∗) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage.
Neun Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden.
Neun Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden.
Among tool-using animals 1–4, none are known to adaptively change the hydrodynamic properties of a free jet of water—a task considered difficult in human technology 5–7. Hunting archerfish can strike ...their targets with precisely aimed water jets (e.g., 8, 9), but they are also presently thought to be unable to actively control the hydrodynamics of their jets 8–13. By using specifically trained fish, we were able to monitor several aspects of jet production and propagation as the fish fired at targets over a much wider range of distances than previously explored 10, 13. We show that jets that have to travel farther also live longer. Furthermore, the time needed until water assembles at the jet tip is not fixed. Rather, it is adjusted so that maximum focusing occurs just before impact. Surprisingly, the fish achieve this by modulating the dynamics of changes in the cross-section of their mouth opening, a mechanism that seems to not have been applied yet in human-built nozzles. The timing adjustments archerfish make in order to powerfully hit targets over an extended range strikingly parallel the situation in the “uniquely human” ability of powerful throwing 14–18. Based on the key role throwing played in human encephalization and cognitive evolution 14–20, skillfully “throwing” water should similarly have led to the correlated rapid evolution of cognitive skills in this animal.
•Archerfish shape the hydrodynamics of their jets to adjust them to target distance•Shaping involves adjustments in the dynamics of mouth opening and closing•As in human throwing, an extended striking range requires timing control
Archerfish shoot down target prey with precisely aimed water jets. Gerullis and Schuster show that by using their mouths as active nozzles that continuously change width, archerfish are able to actively shape the hydrodynamics of their jets so that they can powerfully strike prey over an extended range.
Archerfish are renowned for dislodging aerial prey using well-aimed shots of water. Recently it has been shown that these fish can shape their aerial jets by adjusting the dynamics of their mouth ...opening and closing. This allows the fish to adjust their jet to target distance so that they can forcefully hit prey over considerable distances. Here, we suggest that archerfish use the same technique to also actively control jets under water. Fired from close range, the underwater jets are powerful enough to lift up buried food particles, which the fish then can pick up. We trained fish so that we could monitor their mouth opening and closing maneuvers during underwater shooting and compare them with those employed in aerial shooting. Our analysis suggests that the fish use the same dynamic mechanism to produce aerial and underwater jets and that they employ the same basic technique to adjust their jets in both conditions. When food is buried in substrate that consists of large particles, the fish use a brief pulse, but they use a longer one when the substrate is more fine-grained. These findings extend the notion that archerfish can flexibly shape their jets to be appropriate in different contexts and suggest that archerfish shooting might have been shaped both by constraints in aerial and underwater shooting.
Focus group discussions (FGDs) and individual interviews (IIs) with community members are common methods used in evaluations of all kinds of projects, including those in international development. As ...resources are often limited, evaluators must carefully choose methods that yield the best information for their particular program. A concern with FGDs and IIs is how well they elicit information on potentially sensitive topics; very little is known about differences in disclosure by methodology in the domain of justice. Using FGDs (n = 16) and IIs (n = 46) from a USAID project in Haiti, we systematically coded responses based on a shared elicitation guide around access to and engagement with the formal and informal justice systems and performed thematic and statistical comparisons across the two methods. We introduce the continuous thought as the novel standard unit for statistical comparison. Participants in IIs were statistically more likely to provide themes relevant to genderbased violence. Importantly, sensitive themes extracted in IIs (e.g., related to sexual violence, economic dimensions, and restorative justice) did not emerge in FGDs. Given these results and other limitations to the FGD, prioritizing interviews over focus group modalities may be appropriate to guide targeted, effective programming on justice or other socially sensitive topics.
•We use the unit of continuous thought as a novel way to generate a comparable unit of analysis between interviews and FGDs.•Interviews elicited a greater range of of sensitive information thematically in three of five domains compared to FGDs.•Interviews generated a greater number of themes statistically in one of five domains.•Choosing interviews over FGDs may be appropriate for evaluations of justice programs where content is considered sensitive.
Understanding cultural norms is essential to achieving results in development interventions and preventing interventions from causing unintended negative consequences. However, capturing norms within ...everyday contexts in ways that can be monitored and evaluated can be expensive and time consuming and is not always feasible. We tested a novel method, the cultural consensus analysis (CCA), in the context of monitoring and evaluating a United States Agency for International Development (USAID) justice project in the West Bank, Palestine. We conducted 392 survey interviews with men and women, using 60 true or false questions in the knowledge domains of women's empowerment and gender-based violence (GBV), and tested three gender propositions using CCA. We found no singular cultural understanding of women's empowerment and GBV across West Bank Palestinians (proposition 1). Distinctive cultural models for women and other subgroups (e.g., those living in villages, women who identified as discriminated against within Palestinian society) exist, although there were no shared cultural models among men of any subgroup (proposition 2). Program assumptions regarding structural barriers to women's empowerment conformed to the women's cultural models (proposition 3). To our knowledge, this is the first application of CCA as an approach for describing gender norms in international development programming. CCA was able to distinguish subtle cultural patterns, including between population subgroups, and to identify how those are associated with specific risks, such as GBV. We conclude that CCA is a potentially useful approach for development practice, to ground-truth program assumptions and, potentially, to track program impacts.
•Cultural consensus analysis (CCA) is a useful tool to measure norms of women's empowerment in Palestine.•CCA can be applied to test gender assumptions built into development programs.•CCA identified deep-set norms but may be less effective at capturing norms in transition.
PDF
