Characterisation of a gene critical in eye and lens development

Visual impairment or blindness caused by vision disorders affect over 500,000 Australians, with approximately one-third caused by genetic eye disorders. Previous work identified a cataract and anterior segment abnormality patient with a de novo balanced chromosomal translocation transecting the 5’ UTR of a novel candidate disease gene. An expression vector containing the candidate gene and a GFP tag revealed its subcellular localisation to the plasma membrane domain of two epithelial cell lines. Colocalisation experiments showed colocalisation of the candidate disease gene with proteins of adherens junctions, tight junctions and cytoskeletal F-actin in Caco2 cells. Caco2 cells transfected with a mutation in the candidate disease gene caused clustering of F-actin stress fibres in the basal regions of the cell, suggesting the presence of functional actin-binding domains in this candidate disease gene. Stable knockdown cells when cultured in a 3D-cell assay produced abnormal cyst structures characterised by the presence of additional ectopic lumens, multilayering of cells and misexpression of a polarity marker. Knockdown cells generated a significantly greater number of abnormal cysts. The phenotype exhibited by knockdown cell lines is suggestive of defects affecting the actin cytoskeleton and polarity. To further investigate the role of the candidate disease gene in eye development, gene trap loss-of-function mice were generated and examined. Homozygous loss-of-function mice developed congenital cataracts and demonstrated structural lens abnormalities and abnormalities in the expression of cell adhesion and polarity proteins in the developing lens. The lens abnormalities exhibited by the mutant mice, along with the defects observed in the mutant and knockdown cell assays suggests that this novel candidate disease gene has an important role in the regulation of the actin cytoskeleton and cellular polarity in epithelial cells and lens development

Watching eyes on potential litter can reduce littering: evidence from two field experiments

Littering constitutes a major societal problem, and any simple intervention that reduces its prevalence would be widely beneficial. In previous research, we have found that displaying images of watching eyes in the environment makes people less likely to litter. Here, we investigate whether the watching eyes images can be transferred onto the potential items of litter themselves. In two field experiments on a university campus, we created an opportunity to litter by attaching leaflets that either did or did not feature an image of watching eyes to parked bicycles. In both experiments, the watching eyes leaflets were substantially less likely to be littered than control leaflets (odds ratios 0.22–0.32). We also found that people were less likely to litter when there other people in the immediate vicinity than when there were not (odds ratios 0.04–0.25) and, in one experiment but not the other, that eye leaflets only reduced littering when there no other people in the immediate vicinity. We suggest that designing cues of observation into packaging could be a simple but fruitful strategy for reducing littering

A review of the role of parasites in the ecology of reptiles and amphibians

A great diversity of parasites, from viruses and bacteria to a range of remarkable eukaryotic organisms, exploit reptile and amphibian hosts. Recent increases in the emergence of infectious disease have revealed the importance of understanding the effects of interactions between hosts and their parasites. Here we review the effects of parasite infection on a range of demographic, behavioural, genomic and physiological factors in reptile and amphibian species. Reviewing these parasite roles collectively, and prioritising areas for research, advances our ecological understanding and guides direction for conservation in a time of rapid species decline. Poorly resolved systems include Gymnophionan amphibians and Crocodilian hosts, in addition to viral and bacterial parasites. Future research should seek to understand processes enabling population recovery and examining synergistic interactions of parasites with fragmentation, climate change and other processes that threaten species persistence

Mutations in SIPA1L3 cause eye defects through disruption of cell polarity and cytoskeleton organization

Correct morphogenesis and differentiation are critical in development and maintenance of the lens, which is a classic model system for epithelial development and disease. Through germline genomic analyses in patients with lens and eye abnormalities, we discovered functional mutations in the Signal Induced Proliferation Associated 1 Like 3 (SIPA1L3) gene, which encodes a previously uncharacterized member of the Signal Induced Proliferation Associated 1 (SIPA1 or SPA1) family, with a role in Rap1 signalling. Patient 1, with a de novo balanced translocation, 46, XY, t(2;19)(q37.3; q13.1), had lens and ocular anterior segment abnormalities. Breakpoint mapping revealed transection of SIPA1L3 at 19q13.1 and reduced SIPA1L3 expression in patient lymphoblasts. SIPA1L3 downregulation in 3D cell culture revealed morphogenetic and cell polarity abnormalities. Decreased expression of Sipa1l3 in zebrafish and mouse caused severe lens and eye abnormalities. Sipa1l3(-/-) mice showed disrupted epithelial cell organization and polarity and, notably, abnormal epithelial to mesenchymal transition in the lens. Patient 2 with cataracts was heterozygous for a missense variant in SIPA1L3, c.442G>T, p.Asp148Tyr. Examination of the p.Asp148Tyr mutation in an epithelial cell line showed abnormal clustering of actin stress fibres and decreased formation of adherens junctions. Our findings show that abnormalities of SIPA1L3 in human, zebrafish and mouse contribute to lens and eye defects, and we identify a critical role for SIPA1L3 in epithelial cell morphogenesis, polarity, adhesion and cytoskeletal organization

Bi-allelic variants in WNT7B disrupt the development of multiple organs in humans

International audienceBackground Pulmonary hypoplasia, Diaphragmatic anomalies, Anophthalmia/microphthalmia and Cardiac defects delineate the PDAC syndrome. We aim to identify the cause of PDAC syndrome in patients who do not carry pathogenic variants in RARB and STRA6 , which have been previously associated with this disorder. Methods We sequenced the exome of patients with unexplained PDAC syndrome and performed functional validation of candidate variants. Results We identified bi-allelic variants in WNT7B in fetuses with PDAC syndrome from two unrelated families. In one family, the fetus was homozygous for the c.292C>T (p.(Arg98*)) variant whereas the fetuses from the other family were compound heterozygous for the variants c.225C>G (p.(Tyr75*)) and c.562G>A (p.(Gly188Ser)). Finally, a molecular autopsy by proxy in a consanguineous couple that lost two babies due to lung hypoplasia revealed that both parents carry the p.(Arg98*) variant. Using a WNT signalling canonical luciferase assay, we demonstrated that the identified variants are deleterious. In addition, we found that wnt7bb mutant zebrafish display a defect of the swimbladder, an air-filled organ that is a structural homolog of the mammalian lung, suggesting that the function of WNT7B has been conserved during evolution for the development of these structures. Conclusion Our findings indicate that defective WNT7B function underlies a form of lung hypoplasia that is associated with the PDAC syndrome, and provide evidence for involvement of the WNT–β-catenin pathway in human lung, tracheal, ocular, cardiac, and renal development

Women, violence and nonviolent resistance in east Timor

A growing literature in peace and conflict studies assesses the relationship between women and nonviolence. Numerous national liberation fronts and academic critiques assess how women participate in nonviolent resistance from Tibet and West Papua to Palestine and Eritrea. However, many liberation struggles that include female nonviolent resistance remain undocumented, and this article aims to delve into one case study in particular. The article examines the nonviolent roles adopted by women in the East Timorese liberation struggle, a national liberation movement in which the participation of female combatants was low but nonviolent participation by women in the resistance movement overall was high. However, the consequences for such women was, and remains, shaped by the overarching patriarchal structures of both the Indonesian occupiers and East Timorese society itself Female nonviolent resistance was met with highly violent responses from Indonesian troops, especially in the form of rape and sexual exploitation. Yet, this study also found that women acting under religious auspices faced less violent responses overall. Interviews with East Timorese women are used to reveal some of the sexual dynamics of nonviolent action and reprisal. This material is placed in the context of theoretical work on gender, violence and nonviolence