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As part of a larger, federally funded study, the purpose of this preliminary, descriptive study was to describe the sexual feelings and sexual functioning of women who used large amounts of crack cocaine. A structured interview with questions pertaining to the effect of crack use on sexual feelings and sexual function was conducted with 100 African-American women who either were in treatment for crack abuse or were currently using the drug. The data did not support the commonly held notions that crack is an aphrodisiac for women and that crack makes women want sex. Furthermore, the women in this study had a higher level of sexual dysfunction than was found in a previous study of women who used alcohol. More research on the sexual experiences of women who use illicit drugs such as crack is needed if practitioners are to base their interventions on women's realities, not on stereotypes. [ABSTRACT FROM AUTHOR]

Applying research methods and techniques developed in a dominant culture to other cultures can threaten the validity and generalizability of research conducted with other cultures. Guidelines are proposed for increasing the cultural sensitivity of research, and a case example is discussed. [ABSTRACT FROM AUTHOR]

Therapeutic drug monitoring (TDM) of elexacaftor/tezacaftor/ivacaftor (ETI) remains challenging due to a lack of clarity around the parameters that govern ETI plasma concentrations, whilst the use of concomitant CYP3A inducers rifabutin and rifampicin is not recommended. We present the complexities of TDM for ETI performed in a person with cystic fibrosis and refractory Mycobacterium abscessus pulmonary disease. Utilising National Association of Testing Authorities (NATA) accredited assays and target considerations published by the Therapeutic Goods Administration (TGA), Australia, ETI plasma concentration variability was monitored over the course of an acute admission with added complexity from an antibiotic regimen including rifabutin, a moderate cytochrome P450 3A (CYP3A) inducer, and clofazimine, a mild CYP3A inhibitor. This case highlights the challenges surrounding ETI TDM in the context of acute severe illness, malnutrition, chronic infection, and drug-to-drug interactions. The marked clinical improvement seen, alongside sustained ETI plasma concentrations and suppressed sweat chloride levels on serial testing, provided reassurance of the use of ETI and rifabutin concomitantly in this case, and highlights the potential utility of TDM in helping guide clinical practice. Though a current barrier to the application of TDM includes ETI only being available as a fixed dose combination., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

A proper appreciation of cardiac development can now provide the necessary background to understand the anatomical findings in the congenitally malformed heart. We recently presented an account of human cardiac development based on reconstructions of histological datasets from human embryos aged between 3.5 and 8 weeks subsequent to conception. In this review, we summarize the changes observed relative to the findings when the heart is congenitally malformed. Beginning at the stage when it is first possible to recognize the primary heart tube, we describe the looping of its ventricular component, which occurs in the 5th week. We proceed with discussion of the formation of the atrial and ventricular chambers in the 6th week. The phases are successive, albeit partially overlapping. Separation of the circulations at the venous pole is completed at stage 17, equivalent to almost 6 weeks of development. During stages representing the 7th week of development, we concentrate on the remodeling of the outflow tract. This involves initially septation, but then separation of the developing circulations. The changes involve incorporation of the proximal outflow tract into the ventricles, with formation of the arterial roots in its middle part, and addition of a distal non-myocardial component to produce the intrapericardial arterial trunks. We pay particular attention to the changes occurring during remodeling of the interventricular foramen. We show that an understanding of this process provides the basis for understanding the functionally univentricular heart, as well as the arrangement found in double outlet right ventricle., (© 2024 The Author(s). Clinical Anatomy published by Wiley Periodicals LLC on behalf of American Association of Clinical Anatomists and British Association of Clinical Anatomists.)

Congenital heart defects (CHDs), the most common congenital anomalies, are considered to have a significant genetic component. However, despite considerable efforts to identify pathogenic genes in patients with CHDs, few gene variants have been proven as causal. The complexity of the genetic architecture underlying human CHDs likely contributes to this poor genetic discovery rate. However, several other factors are likely to contribute. For example, the level of patient phenotyping required for clinical care may be insufficient for research studies focused on mechanistic discovery. Although several hundred mouse gene knockouts have been described with CHDs, these are generally not phenotyped and described in the same way as CHDs in patients, and thus are not readily comparable. Moreover, most patients with CHDs carry variants of uncertain significance of crucial cardiac genes, further complicating comparisons between humans and mouse mutants. In spite of major advances in cardiac developmental biology over the past 25 years, these advances have not been well communicated to geneticists and cardiologists. As a consequence, the latest data from developmental biology are not always used in the design and interpretation of studies aimed at discovering the genetic causes of CHDs. In this Special Article, while considering other in vitro and in vivo models, we create a coherent framework for accurately modelling and phenotyping human CHDs in mice, thereby enhancing the translation of genetic and genomic studies into the causes of CHDs in patients., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Aims: Bicuspid Aortic Valve (BAV) is the most common congenital heart defect, affecting at least 2% of the population. The embryonic origins of BAV remain poorly understood, with few assays for validating patient variants, limiting the identification of causative genes for BAV. In both human and mouse, the left and right leaflets of the arterial valves arise from the outflow tract cushions, with interstitial cells originating from neural crest cells and the overlying endocardium through endothelial-to-mesenchymal transition (EndoMT). In contrast, an EndoMT-independent mechanism of direct differentiation of cardiac progenitors from the second heart field (SHF) is responsible for the formation of the anterior and posterior leaflets. Defects in either of these developmental mechanisms can result in BAV. Although zebrafish have been suggested as a model for human variant testing, their naturally bicuspid arterial valve has not been considered suitable for understanding human arterial valve development. Here, we have set out to investigate to what extent the processes involved in arterial valve development are conserved in zebrafish and ultimately, whether functional testing of BAV variants could be carried out., Methods and Results: Using a combination of live imaging, immunohistochemistry and Cre-mediated lineage tracing, we show that the zebrafish arterial valve primordia develop directly from SHF progenitors with no contribution from EndoMT or neural crest, in keeping with the human and mouse anterior and posterior leaflets. Moreover, once formed, these primordia share common subsequent developmental events with all three aortic valve leaflets., Conclusions: Our work highlights a conserved ancestral mechanism of arterial valve leaflet formation from the SHF and identifies that development of the arterial valve is distinct from that of the atrioventricular valve in zebrafish. Crucially, this confirms the utility of zebrafish for understanding the development of specific BAV subtypes and arterial valve dysplasia, offering potential for high-throughput variant testing., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Much has been learned over the last half century regarding the molecular and genetic changes that take place during cardiac development. As yet, however, these advances have not been translated into knowledge regarding the marked changes that take place in the anatomical arrangements of the different cardiac components. As such, therefore, many aspects of cardiac development are still described on the basis of speculation rather than evidence. In this review, we show how controversial aspects of development can readily be arbitrated by the interested spectator by taking advantage of the material now gathered together in the Human Developmental Biology Resource; HDBR. We use the material to demonstrate the changes taking place during the formation of the ventricular loop, the expansion of the atrioventricular canal, the incorporation of the systemic venous sinus, the formation of the pulmonary vein, the process of atrial septation, the remodelling of the pharyngeal arches, the major changes occurring during formation of the outflow tract, the closure of the embryonic interventricular communication, and the formation of the ventricular walls. We suggest that access to the resource makes it possible for the interested observer to arbitrate, for themselves, the ongoing controversies that continue to plague the understanding of cardiac development., (© 2024 The Author(s). Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)

The separation of the outflow tract of the developing heart into the systemic and pulmonary arterial channels remains controversial and poorly understood. The definitive outflow tracts have three components. The developing outflow tract, in contrast, has usually been described in two parts. When the tract has exclusively myocardial walls, such bipartite description is justified, with an obvious dogleg bend separating proximal and distal components. With the addition of non-myocardial walls distally, it becomes possible to recognise three parts. The middle part, which initially still has myocardial walls, contains within its lumen a pair of intercalated valvar swellings. The swellings interdigitate with the distal ends of major outflow cushions, formed by the remodelling of cardiac jelly, to form the primordiums of the arterial roots. The proximal parts of the major cushions, occupying the proximal part of the outflow tract, which also has myocardial walls, themselves fuse and muscularise. The myocardial shelf thus formed remodels to become the free-standing subpulmonary infundibulum. Details of all these processes are currently lacking. In this account, we describe the anatomical changes seen during the overall remodelling. Our interpretations are based on the interrogation of serially sectioned histological and high-resolution episcopic microscopy datasets prepared from developing human and mouse embryos, with some of the datasets processed and reconstructed to reveal the specific nature of the tissues contributing to the separation of the outflow channels. Our findings confirm that the tripartite postnatal arrangement can be correlated with the changes occurring during development., (© 2023 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)

Developmental studies have shown that the evolutionarily conserved Wnt Planar Cell Polarity (PCP) pathway is essential for the development of a diverse range of tissues and organs including the brain, spinal cord, heart and sensory organs, as well as establishment of the left-right body axis. Germline mutations in the highly conserved PCP gene VANGL2 in humans have only been associated with central nervous system malformations, and functional testing to understand variant impact has not been performed. Here we report three new families with missense variants in VANGL2 associated with heterotaxy and congenital heart disease p.(Arg169His), non-syndromic hearing loss p.(Glu465Ala) and congenital heart disease with brain defects p.(Arg135Trp). To test the in vivo impact of these and previously described variants, we have established clinically-relevant assays using mRNA rescue of the vangl2 mutant zebrafish. We show that all variants disrupt Vangl2 function, although to different extents and depending on the developmental process. We also begin to identify that different VANGL2 missense variants may be haploinsufficient and discuss evidence in support of pathogenicity. Together, this study demonstrates that zebrafish present a suitable pipeline to investigate variants of unknown significance and suggests new avenues for investigation of the different developmental contexts of VANGL2 function that are clinically meaningful., (© The Author(s) 2023. Published by Oxford University Press.)

eNOS (NOS3) is the enzyme that generates nitric oxide, a signalling molecule and regulator of vascular tone. Loss of eNOS function is associated with increased susceptibility to atherosclerosis, hypertension, thrombosis and stroke. Aortopathy and cardiac hypertrophy have also been found in eNOS null mice, but their aetiology is unclear. We evaluated eNOS nulls before and around birth for cardiac defects, revealing severe abnormalities in the ventricular myocardium and pharyngeal arch arteries. Moreover, in the aortic arch, there were fewer baroreceptors, which sense changes in blood pressure. Adult eNOS null survivors showed evidence of cardiac hypertrophy, aortopathy and cartilaginous metaplasia in the periductal region of the aortic arch. Notch1 and neuregulin were dysregulated in the forming pharyngeal arch arteries and ventricles, suggesting that these pathways may be relevant to the defects observed. Dysregulation of eNOS leads to embryonic and perinatal death, suggesting mutations in eNOS are candidates for causing congenital heart defects in humans. Surviving eNOS mutants have a deficiency of baroreceptors that likely contributes to high blood pressure and may have relevance to human patients who suffer from hypertension associated with aortic arch abnormalities., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Abnormalities of the arterial valves, including bicuspid aortic valve (BAV) are amongst the most common congenital defects and are a significant cause of morbidity as well as predisposition to disease in later life. Despite this, and compounded by their small size and relative inaccessibility, there is still much to understand about how the arterial valves form and remodel during embryogenesis, both at the morphological and genetic level. Here we set out to address this in human embryos, using Spatial Transcriptomics (ST). We show that ST can be used to investigate the transcriptome of the developing arterial valves, circumventing the problems of accurately dissecting out these tiny structures from the developing embryo. We show that the transcriptome of CS16 and CS19 arterial valves overlap considerably, despite being several days apart in terms of human gestation, and that expression data confirm that the great majority of the most differentially expressed genes are valve-specific. Moreover, we show that the transcriptome of the human arterial valves overlaps with that of mouse atrioventricular valves from a range of gestations, validating our dataset but also highlighting novel genes, including four that are not found in the mouse genome and have not previously been linked to valve development. Importantly, our data suggests that valve transcriptomes are under-represented when using commonly used databases to filter for genes important in cardiac development; this means that causative variants in valve-related genes may be excluded during filtering for genomic data analyses for, for example, BAV. Finally, we highlight "novel" pathways that likely play important roles in arterial valve development, showing that mouse knockouts of RBP1 have arterial valve defects. Thus, this study has confirmed the utility of ST for studies of the developing heart valves and broadens our knowledge of the genes and signalling pathways important in human valve development., Competing Interests: The authors have declared that no competing interests exist.
, (Copyright: © 2023 Queen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The extraembryonic yolk sac (YS) ensures delivery of nutritional support and oxygen to the developing embryo but remains ill-defined in humans. We therefore assembled a comprehensive multiomic reference of the human YS from 3 to 8 postconception weeks by integrating single-cell protein and gene expression data. Beyond its recognized role as a site of hematopoiesis, we highlight roles in metabolism, coagulation, vascular development, and hematopoietic regulation. We reconstructed the emergence and decline of YS hematopoietic stem and progenitor cells from hemogenic endothelium and revealed a YS-specific accelerated route to macrophage production that seeds developing organs. The multiorgan functions of the YS are superseded as intraembryonic organs develop, effecting a multifaceted relay of vital functions as pregnancy proceeds.

Hypoplastic left heart syndrome (HLHS) is a collective term applied to severe congenital cardiac malformations, characterised by a combination of abnormalities mainly affecting the left ventricle, associated valves, and ascending aorta. Although in clinical practice HLHS is usually sub-categorised based on the patency of the mitral and aortic (left-sided) valves, it is also possible to comprehensively categorise HLHS into defined sub-groups based on the left ventricular morphology. Here, we discuss the published human-based studies of the ventricular myocardium in HLHS, evaluating whether the available evidence is in keeping with this ventricular morphology concept. Specifically, we highlight results from histological studies, indicating that the appearance of cardiomyocytes can be different based on the sub-group of HLHS. In addition, we discuss the histological appearances of endocardial fibroelastosis (EFE), which is a common feature of one specific sub-group of HLHS. Lastly, we suggest investigations that should ideally be undertaken using HLHS myocardial tissues at early stages of HLHS development to identify biological pathways and aid the understanding of HLHS aetiology.

The establishment of the left-right axis is crucial for the placement, morphogenesis and function of internal organs. Left-right specification is proposed to be dependent on cilia-driven fluid flow in the embryonic node. Planar cell polarity (PCP) signalling is crucial for patterning of nodal cilia, yet downstream effectors driving this process remain elusive. We have examined the role of the JNK gene family, a proposed downstream component of PCP signalling, in the development and function of the zebrafish node. We show jnk1 and jnk2 specify length of nodal cilia, generate flow in the node and restrict southpaw to the left lateral plate mesoderm. Moreover, loss of asymmetric southpaw expression does not result in disturbances to asymmetric organ placement, supporting a model in which nodal flow may be dispensable for organ laterality. Later, jnk3 is required to restrict pitx2c expression to the left side and permit correct endodermal organ placement. This work uncovers multiple roles for the JNK gene family acting at different points during left-right axis establishment. It highlights extensive redundancy and indicates JNK activity is distinct from the PCP signalling pathway., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

Abnormalities in the arterial valves are some of the commonest congenital malformations, with bicuspid aortic valve (BAV) occurring in as many as 2% of the population. Despite this, most of what we understand about the development of the arterial (semilunar; aortic and pulmonary) valves is extrapolated from investigations of the atrioventricular valves in animal models, with surprisingly little specifically known about how the arterial valves develop in mouse, and even less in human. In this review, we summarise what is known about the development of the human arterial valve leaflets, comparing this to the mouse where appropriate., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Henderson, Eley, Turner and Chaudhry.)

Exercise may ameliorate the eventual heart failure inherent in human aging. In this study, we use zebrafish to understand how aging and exercise affect cardiomyocyte turnover and myocardial remodelling. We show that cardiomyocyte proliferation remains constant throughout life but that onset of fibrosis is associated with a late increase in apoptosis. These findings correlate with decreases in voluntary swimming activity, critical swimming speed (Ucrit), and increases in biomarkers of cardiac insufficiency. The ability to respond to severe physiological stress is also impaired with age. Although young adult fish respond with robust cardiomyocyte proliferation in response to enforced swimming, this is dramatically impaired in older fish and served by a smaller proliferation-competent cardiomyocyte population. Finally, we show that these aging responses can be improved through increased activity throughout adulthood. However, despite improvement in Ucrit and the proliferative response to stress, the size of the proliferating cardiomyocyte population remained unchanged. The zebrafish heart models human aging and reveals the important trade-off between preserving cardiovascular fitness through exercise at the expense of accelerated fibrotic change., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Although in many ways the arterial and atrioventricular valves are similar, both being derived for the most part from endocardial cushions, we now know that the arterial valves and their surrounding structures are uniquely dependent on progenitors from both the second heart field (SHF) and neural crest cells (NCC). Here, we will review aspects of arterial valve development, highlighting how our appreciation of NCC and the discovery of the SHF have altered our developmental models. We will highlight areas of research that have been particularly instructive for understanding how the leaflets form and remodel, as well as those with limited or conflicting results. With this background, we will explore how this developmental knowledge can help us to understand human valve malformations, particularly those of the bicuspid aortic valve (BAV). Controversies and the current state of valve genomics will be indicated.

During axonal ensheathment, noncompact myelin channels formed at lateral edges of the myelinating process become arranged into tight paranodal spirals that resemble loops when cut in cross section. These adhere to the axon, concentrating voltage-dependent sodium channels at nodes of Ranvier and patterning the surrounding axon into distinct molecular domains. The signals responsible for forming and maintaining the complex structure of paranodal myelin are poorly understood. Here, we test the hypothesis that the planar cell polarity determinant Vangl2 organizes paranodal myelin. We show that Vangl2 is concentrated at paranodes and that, following conditional knockout of Vangl2 in oligodendrocytes, the paranodal spiral loosens, accompanied by disruption to the microtubule cytoskeleton and mislocalization of autotypic adhesion molecules between loops within the spiral. Adhesion of the spiral to the axon is unaffected. This results in disruptions to axonal patterning at nodes of Ranvier, paranodal axon diameter and conduction velocity. When taken together with our previous work showing that loss of the apico-basal polarity protein Scribble has the opposite phenotype-loss of axonal adhesion but no effect on loop-loop autotypic adhesion-our results identify a novel mechanism by which polarity proteins control the shape of nodes of Ranvier and regulate conduction in the CNS., (© 2020 The Authors. Glia published by Wiley Periodicals, Inc.)

DNA from archived organs is presumed unsuitable for genomic studies because of excessive formalin-fixation. As next generation sequencing (NGS) requires short DNA fragments, and Uracil-N-glycosylase (UNG) can be used to overcome deamination, there has been renewed interest in the possibility of genomic studies using these collections. We describe a novel method of DNA extraction capable of providing PCR amplicons of at least 400 bp length from such excessively formalin-fixed human tissues. When compared with a leading commercial formalin-fixed DNA extraction kit, our method produced greater yields of DNA and reduced sequence variations. Analysis of PCR products using bacterial sub-cloning and Sanger sequencing from UNG-treated DNA unexpectedly revealed increased sequence variations, compared with untreated samples. Finally, whole exome NGS was performed on a myocardial sample fixed in formalin for 2 years and compared with lymphocyte-derived DNA (as a gold standard) from the same patient. Despite the reduction in the number and quality of reads in the formalin-fixed DNA, we were able to show that bioinformatic processing by joint calling and variant quality score recalibration (VQSR) increased the sensitivity four-fold to 56% and doubled specificity to 68% when compared with a standard hard-filtering approach. Thus, high-quality DNA can be extracted from excessively formalin-fixed tissues and bioinformatic processing can optimise sensitivity and specificity of results. Sequencing of several sub-cloned amplicons is an important methodological step in assessing DNA quality., (© 2020 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Socity.)

Congenital cardiovascular malformation is a common birth defect incorporating abnormalities of the outflow tract and aortic arch arteries, and mice deficient in the transcription factor AP-2α ( Tcfap2a ) present with complex defects affecting these structures. AP-2α is expressed in the pharyngeal surface ectoderm and neural crest at mid-embryogenesis in the mouse, but the precise tissue compartment in which AP-2α is required for cardiovascular development has not been identified. In this study we describe the fully penetrant AP-2α deficient cardiovascular phenotype on a C57Bl/6J genetic background and show that this is associated with increased apoptosis in the pharyngeal ectoderm. Neural crest cell migration into the pharyngeal arches was not affected. Cre-expressing transgenic mice were used in conjunction with an AP-2α conditional allele to examine the effect of deleting AP-2α from the pharyngeal surface ectoderm and the neural crest, either individually or in combination, as well as the second heart field. This, surprisingly, was unable to fully recapitulate the global AP-2α deficient cardiovascular phenotype. The outflow tract and arch artery phenotype was, however, recapitulated through early embryonic Cre-mediated recombination. These findings indicate that AP-2α has a complex influence on cardiovascular development either being required very early in embryogenesis and/or having a redundant function in many tissue layers.

The organization of spatial information, including pattern completion and pattern separation processes, relies on the hippocampal circuits, yet the molecular and cellular mechanisms underlying these two processes are elusive. Here, we find that loss of Vangl2, a core PCP gene, results in opposite effects on pattern completion and pattern separation processes. Mechanistically, we show that Vangl2 loss maintains young postmitotic granule cells in an immature state, providing increased cellular input for pattern separation. The genetic ablation of Vangl2 disrupts granule cell morpho-functional maturation and further prevents CaMKII and GluA1 phosphorylation, disrupting the stabilization of AMPA receptors. As a functional consequence, LTP at lateral perforant path-GC synapses is impaired, leading to defects in pattern completion behavior. In conclusion, we show that Vangl2 exerts a bimodal regulation on young and mature GCs, and its disruption leads to an imbalance in hippocampus-dependent pattern completion and separation processes., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

The correct formation of the aortic arch arteries depends on a coordinated and regulated gene expression profile within the tissues of the pharyngeal arches. Perturbation of the gene regulatory networks in these tissues results in congenital heart defects affecting the arch arteries and the outflow tract of the heart. Aberrant development of these structures leads to interruption of the aortic arch and double outlet right ventricle, abnormalities that are a leading cause of morbidity in 22q11 Deletion Syndrome (DS) patients. We have recently shown that Pax9 functionally interacts with the 22q11DS gene Tbx1 in the pharyngeal endoderm for 4th pharyngeal arch artery morphogenesis, with double heterozygous mice dying at birth with interrupted aortic arch. Mice lacking Pax9 die perinatally with complex cardiovascular defects and in this study we sought to validate further potential genetic interacting partners of Pax9 , focussing on Gbx2 which is down-regulated in the pharyngeal endoderm of Pax9 -null embryos. Here, we describe the Gbx2- null cardiovascular phenotype and demonstrate a genetic interaction between Gbx2 and Pax9 in the pharyngeal endoderm during cardiovascular development., Competing Interests: The authors declare no conflict of interest.

The planar cell polarity pathway is required for heart development and whilst the functions of most pathway members are known, the roles of the jnk genes in cardiac morphogenesis remain unknown as mouse mutants exhibit functional redundancy, with early embryonic lethality of compound mutants. In this study zebrafish were used to overcome early embryonic lethality in mouse models and establish the requirement for Jnk in heart development. Whole mount in-situ hybridisation and RT-PCR demonstrated that evolutionarily conserved alternative spliced jnk1a and jnk1b transcripts were expressed in the early developing heart. Maternal zygotic null mutant zebrafish lines for jnk1a and jnk1b, generated using CRISPR-Cas9, revealed a requirement for jnk1a in formation of the proximal, first heart field (FHF)-derived portion of the cardiac ventricular chamber. Rescue of the jnk1a mutant cardiac phenotype was only possible by injection of the jnk1a EX7 Lg alternatively spliced transcript. Analysis of mutants indicated that there was a reduction in the size of the hand2 expression field in jnk1a mutants which led to a specific reduction in FHF ventricular cardiomyocytes within the anterior lateral plate mesoderm. Moreover, the jnk1a mutant ventricular defect could be rescued by injection of hand2 mRNA. This study reveals a novel and critical requirement for Jnk1 in heart development and highlights the importance of alternative splicing in vertebrate cardiac morphogenesis. Genetic pathways functioning through jnk1 may be important in human heart malformations with left ventricular hypoplasia., Competing Interests: The authors have declared that no competing interests exist.

The number of patients diagnosed with chronic bile duct disease is increasing and in most cases these diseases result in chronic ductular scarring, necessitating liver transplantation. The formation of ductular scaring affects liver function; however, scar-generating portal fibroblasts also provide important instructive signals to promote the proliferation and differentiation of biliary epithelial cells. Therefore, understanding whether we can reduce scar formation while maintaining a pro-regenerative microenvironment will be essential in developing treatments for biliary disease. Here, we describe how regenerating biliary epithelial cells express Wnt-Planar Cell Polarity signalling components following bile duct injury and promote the formation of ductular scars by upregulating pro-fibrogenic cytokines and positively regulating collagen-deposition. Inhibiting the production of Wnt-ligands reduces the amount of scar formed around the bile duct, without reducing the development of the pro-regenerative microenvironment required for ductular regeneration, demonstrating that scarring and regeneration can be uncoupled in adult biliary disease and regeneration.

Dynamic mechanical interactions between adhesion complexes and the cytoskeleton are essential for axon outgrowth and guidance. Whether planar cell polarity (PCP) proteins, which regulate cytoskeleton dynamics and appear necessary for some axon guidance, also mediate interactions with membrane adhesion is still unclear. Here we show that Vangl2 controls growth cone velocity by regulating the internal retrograde actin flow in an N-cadherin-dependent fashion. Single molecule tracking experiments show that the loss of Vangl2 decreased fast-diffusing N-cadherin membrane molecules and increased confined N-cadherin trajectories. Using optically manipulated N-cadherin-coated microspheres, we correlated this behavior to a stronger mechanical coupling of N-cadherin with the actin cytoskeleton. Lastly, we show that the spatial distribution of Vangl2 within the growth cone is selectively affected by an N-cadherin-coated substrate. Altogether, our data show that Vangl2 acts as a negative regulator of axonal outgrowth by regulating the strength of the molecular clutch between N-cadherin and the actin cytoskeleton., Competing Interests: SD, MM, YH, MG, NA, DH, VS, NS, OT, MM No competing interests declared, (© 2020, Dos-Santos Carvalho et al.)

Motile cilia provide propulsion, and immotile ones are enriched with receptors. Both are required to establish left-right identity in the developing embryo and are also implicated in a wide range of human diseases. Abnormalities in cilial function underlie heterotaxy congenital heart disease (CHD) occurring in individuals with laterality disturbance. Mitochondrial function and cellular energetics, through mTOR and autophagy, are now linked with cilial function, revealing new mechanisms and candidate genes for syndromic human disease. In the current issue of the JCI, Burkhalter et al. ask the question: Can mitochondrial disturbances produce ciliopathy and does this explain some cases of heterotaxy?

The VANGL family of planar cell polarity proteins is implicated in breast cancer however its function in mammary gland biology is unknown. Here, we utilized a panel of Vang1 and Vangl2 mouse alleles to examine the requirement of VANGL family members in the murine mammary gland. We show that Vang1CKO Δ/Δ glands display normal branching while Vangl2 flox/flox and Vangl2 Lp/Lp tissue exhibit several phenotypes. In MMTV-Cre;Vangl2 flox/flox glands, cell turnover is reduced and lumens are narrowed. A Vangl2 missense mutation in the Vangl2 Lp/Lp tissue leads to mammary anlage sprouting defects and deficient outgrowth with transplantation of anlage or secondary tissue fragments. In successful Vangl2 Lp/Lp outgrowths, three morphological phenotypes are observed: distended ducts, supernumerary end buds, and ectopic acini. Layer specific defects are observed with loss of Vangl2 selectively in either basal or luminal layers of mammary cysts. Loss in the basal compartment inhibits cyst formation, but has the opposite effect in the luminal compartment. Candidate gene analysis on MMTV-Cre;Vangl2 flox/flox and Vangl2 Lp/Lp tissue reveals a significant reduction in Bmi1 expression, with overexpression of Bmi1 rescuing defects in Vangl2 knockdown cysts. Our results demonstrate that VANGL2 is necessary for normal mammary gland development and indicate differential functional requirements in basal versus luminal mammary compartments.