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Only a very small fraction of long noncoding RNAs (lncRNAs) are well characterized. The evolutionary history of lncRNAs can provide insights into their functionality, but the absence of lncRNA annotations in non-model organisms has precluded comparative analyses. Here we present a large-scale evolutionary study of lncRNA repertoires and expression patterns, in 11 tetrapod species. We identify approximately 11,000 primate-specific lncRNAs and 2,500 highly conserved lncRNAs, including approximately 400 genes that are likely to have originated more than 300 million years ago. We find that lncRNAs, in particular ancient ones, are in general actively regulated and may function predominantly in embryonic development. Most lncRNAs evolve rapidly in terms of sequence and expression levels, but tissue specificities are often conserved. We compared expression patterns of homologous lncRNA and protein-coding families across tetrapods to reconstruct an evolutionarily conserved co-expression network. This network suggests potential functions for lncRNAs in fundamental processes such as spermatogenesis and synaptic transmission, but also in more specific mechanisms such as placenta development through microRNA production. Evolutionary study of long noncoding RNA (lncRNA) repertoires and expression patterns in 11 tetrapod species identifies approximately 11,000 primate-specific lncRNAs and 2,500 highly conserved lncRNAs, including approximately 400 genes that are likely to have ancient origins; many lncRNAs, particularly ancient ones, are actively regulated and may function mainly in embryonic development. Regulatory lncRNAs go back a long way Little is known about the evolutionary history of long noncoding RNAs (lncRNAs), but such insight could shed light on their functionality. To this end Henrik Kaessmann and colleagues present the first large-scale evolutionary study of lncRNA repertoires and expression patterns, in eleven tetrapod species. They identify more than 10,000 primate-specific lncRNAs and about 2,500 highly conserved lncRNAs, about 400 of which probably originated at least 300 million years ago, very early in tetrapod history. Many lncRNAs, especially the more ancient ones, are still in active use and may function largely in the regulation of embryonic development as well as other functions from spermatogenesis to synaptic transmission.

While a few researchers have started to chip away at the notion that retail density is always negative, extant studies do not empirically address the question of why some shoppers respond negatively to a specific level of density while others respond positively. We examine this issue by drawing upon field theory (Lewin 1939 ) to shed light on how shoppers vary in terms of deeper motives (McClelland 1953 ) to seek control or intimacy with others in retail mall settings, and whether these motives influence shopping orientations. Shopping orientation is then hypothesized to affect perceptions of crowding, and, in turn, subsequent affective responses to the mall shopping experience. Moreover, we examine whether individual differences (gender and age) can help retailers segment those with different shopping orientations and the motives that influence these orientations. We found that task and social shopping orientations were influenced by deeper motives for control and intimacy. The causal relationships between shopping motive, shopping orientation, and consumers’ affective responses of stress and excitement were also discovered. Finally, we address theoretical and managerial implications of our results.

Julie Baker and colleagues report epigenome and transcriptome profiles of rat and mouse trophoblast stem cells and show that endogenous retroviruses serve as a genome-wide source of species-specific enhancer elements in the placenta. The mammalian placenta is remarkably distinct between species, suggesting a history of rapid evolutionary diversification 1 . To gain insight into the molecular drivers of placental evolution, we compared biochemically predicted enhancers in mouse and rat trophoblast stem cells (TSCs) and found that species-specific enhancers are highly enriched for endogenous retroviruses (ERVs) on a genome-wide level. One of these ERV families, RLTR13D5, contributes hundreds of mouse-specific histone H3 lysine 4 monomethylation (H3K4me1)- and histone H3 lysine 27 acetylation (H3K27ac)-defined enhancers that functionally bind Cdx2, Eomes and Elf5—core factors that define the TSC regulatory network. Furthermore, we show that RLTR13D5 is capable of driving gene expression in rat placental cells. Analysis in other tissues shows that species-specific ERV enhancer activity is generally restricted to hypomethylated tissues, suggesting that tissues permissive for ERV activity gain access to an otherwise silenced source of regulatory variation. Overall, our results implicate ERV enhancer co-option as a mechanism underlying the extensive evolutionary diversification of placental development.

Discovery of lineage-specific somatic copy number variation (CNV) in mammals has led to debate over whether CNVs are mutations that propagate disease or whether they are a normal, and even essential, aspect of cell biology. We show that 1,000 N polyploid trophoblast giant cells (TGCs) of the mouse placenta contain 47 regions, totaling 138 Megabases, where genomic copies are underrepresented (UR). UR domains originate from a subset of late-replicating heterochromatic regions containing gene deserts and genes involved in cell adhesion and neurogenesis. While lineage-specific CNVs have been identified in mammalian cells, classically in the immune system where V(D)J recombination occurs, we demonstrate that CNVs form during gestation in the placenta by an underreplication mechanism, not by recombination nor deletion. Our results reveal that large scale CNVs are a normal feature of the mammalian placental genome, which are regulated systematically during embryogenesis and are propagated by a mechanism of underreplication.

Fostering attachment between consumers and organizations is developing into a cornerstone of relationship marketing strategy. However, little is known about how an organization can develop strong emotional ties with consumers. Our research addresses one aspect of this gap by showing that in atmosphere dominant service firms, sense of place leads to place attachment, which in turn plays a critical role in driving desirable customer behaviors. In Study 1 we demonstrate that sense of place influences the strength of consumers’ attachment to a service location, which ultimately has positive effects on consumers’ behaviors. In Study 2, we identify characteristics that influence the sense of place dimensions and extend the model to better account for the dynamics of social relationships that develop within a service firm. This research provides an initial investigation into how organizations can better manage the service place and provides a rich framework for future research on managing attachment with service consumers.

Uterine injury from procedures such as Cesarean sections (C-sections) often have severe consequences on subsequent pregnancy outcomes, leading to disorders such as placenta previa, placenta accreta, and infertility. With rates of C-section at ∼30% of deliveries in the USA and projected to continue to climb, a deeper understanding of the mechanisms by which these pregnancy disorders arise and opportunities for intervention are needed. Here we describe a rodent model of uterine injury on subsequent in utero outcomes. We observed three distinct phenotypes: increased rates of resorption and death, embryo spacing defects, and placenta accreta-like features of reduced decidua and expansion of invasive trophoblasts. We show that the appearance of embryo spacing defects depends entirely on the phase of estrous cycle at the time of injury. Using RNA-seq, we identified perturbations in the expression of components of the COX/prostaglandin pathway after recovery from injury, a pathway that has previously been demonstrated to play an important role in embryo spacing. Therefore, we demonstrate that uterine damage in this mouse model causes morphological and molecular changes that ultimately lead to placental and embryonic developmental defects. Summary Sentence In a novel mouse model of uterine injury, damaged uteri lead to embryo misspacing, placental defects, and embryo demise, with parallels to human disorders such as placenta previa, placenta accreta, and infertility.

Placentation evolved many times independently in vertebrates. Although the core functions of all placentas are similar, we know less about how this similarity extends to the molecular level. Here, we study Poeciliopsis, a unique genus of live-bearing fish that have independently evolved complex placental structures at least three times. The maternal follicle is a key component of these structures. It envelops yolk-rich eggs and is morphologically simple in lecithotrophic species but has elaborate villous structures in matrotrophic species. Through sequencing, the follicle transcriptome of a matrotrophic, Poeciliopsis retropinna, and lecithotrophic, P. turrubarensis, species we found genes known to be critical for placenta function expressed in both species despite their difference in complexity. Additionally, when we compare the transcriptome of different river populations of P. retropinna, known to vary in maternal provisioning, we find differential expression of secretory genes expressed specifically in the top layer of villi cells in the maternal follicle. This provides some of the first evidence that the placental structures of Poeciliopsis function using a secretory mechanism rather than direct contact with maternal circulation. Finally, when we look at the expression of placenta proteins at the maternal–fetal interface of a larger sampling of Poeciliopsis species, we find expression of key maternal and fetal placenta proteins in their cognate tissue types of all species, but follicle expression of prolactin is restricted to only matrotrophic species. Taken together, we suggest that all Poeciliopsis follicles are poised for placenta function but require expression of key genes to form secretory villi.

The mechanisms linking systems-level programs of gene expression to discrete cell biological processes in vivo remain poorly understood. In this study, we have defined such a program for multi-ciliated epithelial cells (MCCs), a cell type critical for proper development and homeostasis of the airway, brain and reproductive tracts. Starting from genomic analysis of the cilia-associated transcription factor Rfx2, we used bioinformatics and in vivo cell biological approaches to gain insights into the molecular basis of cilia assembly and function. Moreover, we discovered a previously un-recognized role for an Rfx factor in cell movement, finding that Rfx2 cell-autonomously controls apical surface expansion in nascent MCCs. Thus, Rfx2 coordinates multiple, distinct gene expression programs in MCCs, regulating genes that control cell movement, ciliogenesis, and cilia function. As such, the work serves as a paradigm for understanding genomic control of cell biological processes that span from early cell morphogenetic events to terminally differentiated cellular functions. Cells that have hundreds of tiny hair-like structures called cilia on their surface have important roles in our airways and also in the brain and reproductive system. By beating in a coordinated manner, the cilia cause fluid to flow in a particular direction. The development of these multiciliated cells is a complex process in which genes are expressed as proteins, with this gene expression being regulated by other proteins called transcription factors. In invertebrates the development of the cilia is controlled by transcription factors from the RFX family, which also appear to be important for development of cilia in vertebrates. However, the details of this process—in particular, the identities of the genes that are involved and how their functions are related—are not well understood in vertebrates. Chung et al. have sought to remedy this by analyzing the network of genes whose expression is controlled by the transcription factor Rfx2 in vertebrates. The results showed that the genes controlled by Rfx2 were involved in all aspects of cilia, including several genes that are known to be mutated in diseases caused by abnormal cilia. Chung et al. also identified genes that were not previously thought to be relevant to cilia. As multiciliated cells are developing, but before they can generate cilia, they must first migrate from the bottom of the epithelium, the layer of tissue in which they function, to the top of this layer. Chung et al. found that Rfx2 was also involved in this process. The approach taken by Chung et al.—which involved a combination of RNA sequence analysis, examination of Rfx2 binding sites on chromosomes, computational predictions of protein interactions and in vivo cellular imaging—could be used to perform similar systems-level analyses of other developmental and biological processes.

The mechanisms ensuring the long-term self-renewal of human embryonic stem cells are still only partly understood, limiting their use in cellular therapies. Here we found that increased activity of the RB cell cycle inhibitor in human embryonic stem cells induces cell cycle arrest, differentiation and cell death. Conversely, inactivation of the entire RB family (RB, p107 and p130) in human embryonic stem cells triggers G2/M arrest and cell death through functional activation of the p53 pathway and the cell cycle inhibitor p21. Differences in E2F target gene activation upon loss of RB family function between human embryonic stem cells, mouse embryonic stem cells and human fibroblasts underscore key differences in the cell cycle regulatory networks of human embryonic stem cells. Finally, loss of RB family function promotes genomic instability in both human and mouse embryonic stem cells, uncoupling cell cycle defects from chromosomal instability. These experiments indicate that a homeostatic level of RB activity is essential for the self-renewal and the survival of human embryonic stem cells. While human embryonic stem cells (ESC) hold great therapeutic promise, many aspects of their basic biology remain poorly understood. Conklin et al. show that too much or too little activation of RB family proteins is detrimental to human ESC populations and identify unique cell cycle regulatory networks in these cells.

New studies show that the instructional effectiveness of preservice candidates and their cooperating teachers are positively related. However, we neither know if these relationships are causal nor, assuming they are, if it is possible to significantly increase the instructional effectiveness of the cooperating teacher pool. In this study, we randomly assign districts to receive recommendation lists (generated using administrative data) for the recruitment of more promising cooperating teachers. Districts receiving lists recruited significantly more effective/experienced cooperating teachers, while candidates placed in these districts felt significantly better prepared to teach. As a result, this study offers an innovative, low-cost strategy for recruiting effective/experienced cooperating teachers and presents the first causal estimates that more effective/experienced cooperating teachers improve candidates’ preparedness to teach.