[Report] Arabidopsis NAC45/86 direct sieve element morphogenesis culminating in enucleation

Cellular remodeling to develop phloem cells orchestrates degradation of the cell’s nucleus. [Also see Perspective by Geldner] Authors: Kaori Miyashima Furuta, Shri Ram Yadav, Satu Lehesranta, Ilya Belevich, Shunsuke Miyashima, Jung-ok Heo, Anne Vatén, Ove Lindgren, Bert De Rybel, Gert Van Isterdael, Panu Somervuo, Raffael Lichtenberger, Raquel Rocha, Siripong Thitamadee, Sari Tähtiharju, Petri Auvinen, Tom Beeckman, Eija Jokitalo, Ykä Helariutta

[Report] Chromatin state dynamics during blood formation

A chromatin precipitation technique identifies changes during the differentiation of blood cells. Authors: David Lara-Astiaso, Assaf Weiner, Erika Lorenzo-Vivas, Irina Zaretsky, Diego Adhemar Jaitin, Eyal David, Hadas Keren-Shaul, Alexander Mildner, Deborah Winter, Steffen Jung, Nir Friedman, Ido Amit

[Report] Early allopolyploid evolution in the post-Neolithic Brassica napus oilseed genome

The polyploid genome of oilseed rape exhibits evolution through homologous gene conversion. Authors: Boulos Chalhoub, France Denoeud, Shengyi Liu, Isobel A. P. Parkin, Haibao Tang, Xiyin Wang, Julien Chiquet, Harry Belcram, Chaobo Tong, Birgit Samans, Margot Corréa, Corinne Da Silva, Jérémy Just, Cyril Falentin, Chu Shin Koh, Isabelle Le Clainche, Maria Bernard, Pascal Bento, Benjamin Noel, Karine Labadie, Adriana Alberti, Mathieu Charles, Dominique Arnaud, Hui Guo, Christian Daviaud, Salman Alamery, Kamel Jabbari, Meixia Zhao, Patrick P. Edger, Houda Chelaifa, David Tack, Gilles Lassalle, Imen Mestiri, Nicolas Schnel, Marie-Christine Le Paslier, Guangyi Fan, Victor Renault, Philippe E. Bayer, Agnieszka A. Golicz, Sahana Manoli, Tae-Ho Lee, Vinh Ha Dinh Thi, Smahane Chalabi, Qiong Hu, Chuchuan Fan, Reece Tollenaere, Yunhai Lu, Christophe Battail, Jinxiong Shen, Christine H. D. Sidebottom, Xinfa Wang, Aurélie Canaguier, Aurélie Chauveau, Aurélie Bérard, Gwenaëlle Deniot, Mei Guan, Zhongsong Liu, Fengming Sun, Yong Pyo Lim, Eric Lyons, Christopher D. Town, Ian Bancroft, Xiaowu Wang, Jinling Meng, Jianxin Ma, J. Chris Pires, Graham J. King, Dominique Brunel, Régine Delourme, Michel Renard, Jean-Marc Aury, Keith L. Adams, Jacqueline Batley, Rod J. Snowdon, Jorg Tost, David Edwards, Yongming Zhou, Wei Hua, Andrew G. Sharpe, Andrew H. Paterson, Chunyun Guan, Patrick Wincker

[New Products] New Products

A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.

[Editorial] Science for lasting peace

Thomas Barnett, a U.S. military geostrategist, has argued that we have leviathan armies that quickly win wars, only to lose the peace. To change that outcome, stability must be established by rebuilding the infrastructure, institutions, and economy of a war-torn nation. An outstanding example of science applied to nation rebuilding is the hyperspectral survey of Afghanistan by the U.S. Geological Survey (USGS) in 2007. This survey quantified 24 world-class mineral deposits (including iron, cobalt, gold, copper, and rare earth elements), positioning Afghanistan to become a major supplier of minerals (see the News story on p. 725), most of which are in demand for the manufacture of cell phones, computers, and renewable energy technologies. Author: Marcia McNutt

[Feature] The rising toll

Newly released data reveal that the war in Afghanistan is becoming more dangerous for civilians. Author: John Bohannon

[Feature] Civilian casualties in Afghanistan

The first release of military data on civilian casualties in Afghanistan is now publicly available. Authors: Neil Shortland, John Bohannon

[Feature] Mother of all lodes

The United States is putting scientific boots on the ground in Afghanistan to assess its mineral riches. Author: Richard Stone

[Perspective] Letting go of mucus

Defective release of mucus from airway glands is present at birth in cystic fibrosis [Also see Report by Hoegger et al.] Author: Jeffrey J. Wine

[Perspective] Self-assembled RNA nanostructures

RNA structures have been designed that self-assemble and are programmable and scalable [Also see Report by Geary et al.] Authors: Neocles B. Leontis, Eric Westhof

[Perspective] You are what you eat, but what about your DNA?

Parental nutrition influences the health of subsequent generations through epigenetic changes in germ cells [Also see Research Article by Radford et al.] Authors: Martha Susiarjo, Marisa S. Bartolomei

[Perspective] Replace contamination, not the pipes

Rethinking water treatment additives can have synergistic benefits for urban water management systems [Also see Report by Pikaar et al.] Authors: Wolfgang Rauch, Manfred Kleidorfer

[Perspective] One step closer to O2

A crucial step in photosynthesis is becoming clearer [Also see Report by Cox et al.] Authors: R. David Britt, Paul H. Oyala

[Editorial] Maternal mental illness

In the United States, more than half a million women experience postpartum depression every year; among teens and low-income mothers, the rate is one in four. For many depressed mothers, symptoms begin during pregnancy and may also include disabling anxiety. In addition, maternal mental illness adversely affects infant brain development and subsequent social and emotional health as a result of inadequate prenatal care, poor birth outcomes, and impaired parenting practices. The broad implications of these disorders have led several states to require perinatal depression screening and/or education. Also, a provision of the U.S. Affordable Care Act calls for further research on screening and treatment. These policies are a good start, but laws already on the books must be adequately funded and evaluated. In addition, there are immediate policy actions that can be taken to improve the well-being of mothers and families. Authors: Katy B. Kozhimannil, Helen Kim

[Special Issue Review] Parenting from before conception

At fertilization, the gametes endow the embryo with a genomic blueprint, the integrity of which is affected by the age and environmental exposures of both parents. Recent studies reveal that parental history and experiences also exert effects through epigenomic information not contained in the DNA sequence, including variations in sperm and oocyte cytosine methylation and chromatin patterning, noncoding RNAs, and mitochondria. Transgenerational epigenetic effects interact with conditions at conception to program the developmental trajectory of the embryo and fetus, ultimately affecting the lifetime health of the child. These insights compel us to revise generally held notions to accommodate the prospect that biological parenting commences well before birth, even prior to conception. Authors: Michelle Lane, Rebecca L. Robker, Sarah A. Robertson

[Special Issue Review] Preterm labor: One syndrome, many causes

Preterm birth is associated with 5 to 18% of pregnancies and is a leading cause of infant morbidity and mortality. Spontaneous preterm labor, a syndrome caused by multiple pathologic processes, leads to 70% of preterm births. The prevention and the treatment of preterm labor have been long-standing challenges. We summarize the current understanding of the mechanisms of disease implicated in this condition and review advances relevant to intra-amniotic infection, decidual senescence, and breakdown of maternal-fetal tolerance. The success of progestogen treatment to prevent preterm birth in a subset of patients at risk is a cause for optimism. Solving the mystery of preterm labor, which compromises the health of future generations, is a formidable scientific challenge worthy of investment. Authors: Roberto Romero, Sudhansu K. Dey, Susan J. Fisher

[Special Issue Review] Neural control of maternal and paternal behaviors

Parental care, including feeding and protection of young, is essential for the survival as well as mental and physical well-being of the offspring. A large variety of parental behaviors has been described across species and sexes, raising fascinating questions about how animals identify the young and how brain circuits drive and modulate parental displays in males and females. Recent studies have begun to uncover a striking antagonistic interplay between brain systems underlying parental care and infant-directed aggression in both males and females, as well as a large range of intrinsic and environmentally driven neural modulation and plasticity. Improved understanding of the neural control of parental interactions in animals should provide novel insights into the complex issue of human parental care in both health and disease. Authors: Catherine Dulac, Lauren A. O’Connell, Zheng Wu

[Special Issue Review] The biology of mammalian parenting and its effect on offspring social development

Parents know the transformative nature of having and caring for a child. Among many mammals, giving birth leads from an aversion to infant stimuli to irresistible attraction. Here, we review the biological mechanisms governing this shift in parental motivation in mammals. Estrogen and progesterone prepare the uterus for embryo implantation and placental development. Prolactin stimulates milk production, whereas oxytocin initiates labor and triggers milk ejection during nursing. These same molecules, interacting with dopamine, also activate specific neural pathways to motivate parents to nurture, bond with, and protect their offspring. Parenting in turn shapes the neural development of the infant social brain. Recent work suggests that many of the principles governing parental behavior and its effect on infant development are conserved from rodent to humans. Authors: James K. Rilling, Larry J. Young

[Special Issue Review] The evolution of flexible parenting

Parenting behaviors, such as the provisioning of food by parents to offspring, are known to be highly responsive to changes in environment. However, we currently know little about how such flexibility affects the ways in which parenting is adapted and evolves in response to environmental variation. This is because few studies quantify how individuals vary in their response to changing environments, especially social environments created by other individuals with which parents interact. Social environmental factors differ from nonsocial factors, such as food availability, because parents and offspring both contribute and respond to the social environment they experience. This interdependence leads to the coevolution of flexible behaviors involved in parenting, which could, paradoxically, constrain the ability of individuals to rapidly adapt to changes in their nonsocial environment. Authors: Nick J. Royle, Andrew F. Russell, Alastair J. Wilson

This Week in Science

Large-scale robotic self-assembly | Nerve cells displaying extra large spaces | Can you spot a speck of space dust? | A potential target in a deadly brain cancer | Strangleweed shares too much information | A breathtaking tale of sticky mucus | A Swiss Army knife for treating sepsis | The future of RNA origami writ large | Sourcing corrosive sewer sulfides | The nutritional sins of the mother… | Clues to a mystery with RAVE results | Setting the stage for release of oxygen | Factor in oocyte assists reprogramming | Epigenetics direct transdifferentiation | Toward an “artificial cell” on a chip

Editors' Choice

Stitching mRNA back together again | A sweet decline for the aging fly brain | The cost of economic growth | Steering an optical signal without wires | Coatings keep gunk off nanoparticles | How infection rate determines virus spread | Looking beneath the drying surface | Mercury levels in surface ocean tripled

[Research Article] In utero undernourishment perturbs the adult sperm methylome and intergenerational metabolism

Prenatal assaults change DNA methylation and chromatin structure in sperm and affect offspring. [Also see Perspective by Susiarjo and Bartolomei] Authors: Elizabeth J. Radford, Mitsuteru Ito, Hui Shi, Jennifer A. Corish, Kazuki Yamazawa, Elvira Isganaitis, Stefanie Seisenberger, Timothy A. Hore, Wolf Reik, Serap Erkek, Antoine H. F. M. Peters, Mary-Elizabeth Patti, Anne C. Ferguson-Smith