Various methods have detected miRNA-target interactions via immunoprecipitation of UV-crosslinked Argonaute ribonucleoprotein complexes, followed by intermolecular ligation of bound miRNAs to target strands, forming chimeric RNAs. To date, these methods have relied on conventional viral reverse transcriptases (RTs) to generate cDNAs for sequencing. However, crosslinked RNAs often retain adducts after purification, which can make them poor templates for viral RTs. Here, we adapted OTTR (Ordered Two-Template Relay) techniques to generate cDNAs from Ago2-bound RNAs. OTTR makes use of a modified retroelement-encoded RT, which is strongly processive even on templates with modifications or adducts. We show that this "OTTR-CLASH" method increases the frequency of generating chimeric RNAs compared to previous methods. We also developed an improved bioinformatic pipeline for analysis of these data, and we use this to catalog miRNA-target interactions not previously described in the literature.

The sweeping progress in the nuclear organization-function field over the past two decades constitutes a major advance, to be sure. This work significantly impacts molecular, cell, and developmental biology and has uncovered numerous clinical implications. Here I offer perspectives around the epistemological axis in this field of ours, viz. what we knew and when, and what we know (or think we know) now.

Having trained as a physician, Étienne-Émile Baulieu soon turned his focus to research, as early as his medical internship. He went on to make major contributions on ketosteroids and other steroids, such as estrogen, and how they act on target organs through receptors to which the hormones bind and activate physiological responses. Later, he consulted with a French pharmaceutical company, encouraging them to pursue his concept for an antigestational agent, which became the iconic RU-486 (Mifepristone). For this, he was applauded by many and criticized by others. He died at his home in a suburb of Paris on May 30, 2025, at the age of 98. To his last days, he vigorously maintained his support for women’s reproductive rights.

Having trained as a physician, Étienne-Émile Baulieu soon turned his focus to research, as early as his medical internship. He went on to make major contributions on ketosteroids and other steroids, such as estrogen, and how they act on target organs through receptors to which the hormones bind and activate physiological responses. Later, he consulted with a French pharmaceutical company, encouraging them to pursue his concept for an antigestational agent, which became the iconic RU-486 (Mifepristone). For this, he was applauded by many and criticized by others. He died at his home in a suburb of Paris on May 30, 2025, at the age of 98. To his last days, he vigorously maintained his support for women's reproductive rights.

The late David Baltimore will long be remembered as a towering figure in the modern era of virology and immunology. But less well known is that early in his career, he discovered the existence of eukaryotic RNA-binding proteins, in collaboration with Alice Huang. This work was an extension of previous experiments he had done in which poliovirus RNA added to HeLa cell cytoplasmic extracts underwent an increase in its sucrose gradient sedimentation velocity. The subsequent work revealed the existence of a soluble pool of RNA-binding proteins and had two impacts. On the one hand, it was the beginning of the eukaryotic RNA-binding protein field. On the other hand, it led some investigators to challenge the reality of isolated mRNP complexes. As we know, the latter concern was settled by the introduction of in vivo UV-mediated RNA-protein crosslinking. The mRNA-protein interaction landscape now is at a very advanced and richly enabling stage, but as always in scientific epistemology, it is appropriate to recall from whence it arose.

John Gurdon was a curiosity-based inquisitor of embryonic development, beguiled by its mysteries, and he stayed with this focus all his career. His landmark cloning of Xenopus laevis using a donor nucleus from adult somatic tissue conclusively settled a longstanding question and was foundational to cloning of a mammal and subsequent advances in nuclear reprogramming. He was awarded the 2012 Nobel Prize in Physiology or Medicine. As a person, Gurdon was confident but not arrogant, an elegant writer and speaker, a warm colleague, and a revered mentor of those fortunate to have worked with him. We may not see his like in developmental biology anytime soon, or in biology altogether.

We review and salute the third edition of E.B. Wilson's “The Cell in Development and Heredity” published a century ago, noting its unique features and placing them in context. Brief commentaries from colleagues convey how they have encountered and have been influenced by The Cell. Although soon to be 100 years old, Wilson's 1925 edition is a hallmark of our profession, reminding us of a time when certain scholars were able to advance knowledge with a singularity of both mind and pen. Our purpose is to acknowledge the accomplishment by the man who brought together so many different facets of understanding cells and who many regard as the founder of cell biology in the United States. We reflect on the volume's admirable success and bring together perspectives on why it still matters.

A 14-year boy is given a microscope by his parents. It is not a toy - but a real microscope. He deploys it to rediscover the biology he had known before, but now in a magnified world. With extraordinary intellectual gifts he then, and manifestly later becomes absorbed by the idea that all this, however mysterious at first glance, might be subject to rational understanding, with painstaking study. Thus, was the genesis of one of the greatest cell biologists of the 20th century, Joseph Grafton Gall, who died 12 September 2024, at 96. He had been professionally active up until only a few years ago. There was no one like him in the modern era of cell biology and there will not be another figure like him anytime soon.

Almost without exception, scientific breakthroughs are not epistemological orphans. Historians of science have developed a body of scholarship on this, and the cases arising in our era continue to confirm the phenomenon. The work by Katalin Karikó and Drew Weissman that proved foundational for the subsequent development of mRNA vaccines for COVID-19 had its antecedent roots yet is also a striking example of both serendipity and their persistence. Their receipt of the 2023 Nobel Prize in Physiology or Medicine was greatly deserved and, as Alfred Nobel likely envisioned the broad impact to be for all the prizes, affirms to the public at large that there is such a thing as the scientific method, and that there are such things as facts. The importance of society recognizing this has always been critically important, perhaps never more so than now.

The second FASEB conference on Nuclear Bodies: Hubs of Genome Activity was held June 2-7, 2024, at Niagara Falls, NY. The central theme was how these protein and RNA-protein complexes that are situated in the nucleus outside the genome support and regulate gene expression. Topics included their relevance to disease, especially cancer, their molecular dynamics, and their phase separation transition properties. The meeting included numerous trainees as speakers and session chairs, hosted a memorable Keynote talk on diversity, and a vibrant career development session.

The textbook assigned when I took a cytology course as an undergraduate was what it purported to be, cytology per se.1 The term “cell biology” was on the wing, but my student view was “cytology”—it was listed in the directory of courses as such, and I signed up. I did not know it at the time but have recently looked up that this textbook had not had a warm reception.2 In the second semester, cytochemistry, we were assigned Histochemistry, by a grand master of this art.3 It was a jumbo tome and was well reviewed.4 (The latter I have, of course, looked up now, never having had any reason to do so then.) I used many of the recipes for staining cells, keen to see what they did. Another student decades earlier, Emil Fischer, had been equally fascinated by such dyes and how they stained cells. He reasoned presciently that if different cells and tissues take these stains to varying degrees, then their chemical composition must not all be the same. Such a simple idea in retrospect but what a penetrating insight. It was not until I was in graduate school that I first heard anything about “iconic” textbooks. The first was Albert Lehninger's biochemistry text,5 which seemed to have everyone in rapture. In my biochemistry course, we were assigned a different book.6 I do not recall looking at it much, but I do remember being turned on by a very engaging professor. One of his mantras was “You will not be able to answer the exam questions from anything in the text, or in your notes from the classes. But if you have been paying attention, you will answer them all.” I thought his dismissal of the textbook was overdone (wondering if perhaps he was frustrated for not having written one), but I do wonder how many times a student gets more from a gifted teacher than from a textbook. Ideally, both should combine for something more than the sum of the parts. Lehninger's book was certainly transformative, as was, for molecular biology, James Watson's Molecular Biology of the Gene.7, 8 From that book, arising from a course he taught, there came a sequala: The first textbook of pure cell biology.9 Watson corralled a group of authors, and a publisher was found, the prescient and intrepid Gavin Borden. When the book was published, in 1983, there had never been anything quite like it. Inter alia, it had powerful illustrations, thanks to coauthor Keith Roberts. These were engaging at a time when this mode of pedagogy was just arriving. In his textbook,7 Watson used declarative sentences as chapter section headings. This is something his Harvard colleagues Ursula Goodenough and Paul Levine had done earlier in their genetics textbook,10 the best at the time in my opinion. The authors of Molecular Biology of the Cell (MBC)9 emulated this, to good effect. The book became to known as “Alberts” among students and faculty, the iconic text on its subject. I reviewed the second edition and applauded this teaching of cell biology as a molecular science.11 In 1986, another important cell biology textbook came out, Molecular Cell Biology (MCB), authored by James Darnell, Harvey Lodish, and David Baltimore.12 I reviewed it, too, and pointed out differences in emphasis and balance.13 For example, I thought it was somewhat stronger on immunology, perhaps given the expertise of one of its authors (Baltimore). Some years later, in 2002, Thomas Pollard and William Earnshaw published the economically titled textbook Cell Biology (CB).14 (There are at least two other textbooks with this title, but unlike the content of a book, titles cannot be copyrighted—hence, an author could publish a book titled Gone with the Wind or even The Holy Bible.) Much as MBC, first edition, et seq. had included principles of physical chemistry as applied to cell biology and an engaging style, Pollard and Earnshaw did this in what I thought was a new and pedagogically effective way. As a reviewer noted, the book's biochemical and molecular focus was manifest to an extent that the index did not include cell types.15 As a backdrop, well before this textbook appeared, the first author gave a lecture one summer in the physiology course at the Marine Biological Laboratory (Woods Hole, MA, USA), having served a few years earlier as this course's director. At one point, he asked the students if anyone knew the typical concentration of a protein in the cytoplasm, of any cell. Dead silence, with each of us faculty in the course thinking: “I hope he doesn't ask us—we don't know either!” A second feature of CB was that hardcore biochemistry was featured in every setting where it mattered. This is not to say that the other two texts skirted biochemistry, but just that it was a more consistent feature of CB, perhaps reflecting Pollard's training as a biochemist16 and Earnshaw's as a structural biologist.17 CB subsequently came out in two more editions, in 2008 and 2017, and now we have the fourth. The third addition included a collaborating author, Jennifer Lippincott-Schwartz, invited due to her command of an entire revolution in the dynamics of the cytoplasm, as well as “Illustrations by” Graham T. Johnson, not intended as an understatement by any means. Lippincott-Schwartz and Johnson are full coauthors of the fourth edition, and we shall return to them shortly. Before taking up an assessment of the fourth edition, it is worth looking at the history of the three texts. The current numerical record for editions is held by MCB, now in its ninth (2022). MBC is in its seventh edition (2022). After its launch in 2002, CB's subsequent editions were in 2008 and 2017, and now 2023. The periodicity of editions of the three textbooks have been 6.5 years for MBC, 4.5 years for MCB, and 7.0 years for CB. I am no haruspex, and thus draw no inferences, but note the data. These timelines may reflect the respective authors' perceptions of intervening progress and new developments, as well as the publishers' perceptions of marketing opportunities. The portrayal of the lives of cells in a textbook is a vexing subject. Leaving aside ones written with a medical student/physiology slant, situated in a different pedagogical sphere, Alberts et al. got it right when a cartoon in the preface of the second edition showed a safe-cracking amoeba sliding around the surface, moving entirely at random, until coming upon the lock. This was the gifted Keith Roberts at his best and was one of the most powerful pictures in the book (one I still vividly remember all these years). But diffusion-limited reactions are only one part of how cells work. The first edition of CB by Pollard et al. laid down physical chemistry and biochemistry as a gauntlet, and this emphasis has been carried forward in all its editions, including this latest one. The fourth edition of CB maintains the overall format of the third edition. In the chapters in which I have expertise, the most recent advances have been incorporated well. As just two examples, the chapters on the functional organization of the nucleus (of which, for full disclosure, I was a reviewer) and how cytoplasmic organelles can no longer be considered to be acting alone, are richly and accurately updated. Overall, I found this new edition to be very well composed both as inheriting the very powerful style of the first three editions, but being very au courant. A very creative subchapter from the third edition, “Research Strategies,” has been retained but in a completely revised form. This alone is worth the (fair) price of the book. One consideration of the book's success is how well this new edition has deployed images. As mentioned above, the previous editions were not devoid of this feature, but it is now the single most powerful teaching tool, both as renderings of cell images in stills and as videos. With the addition of Lippincott-Schwartz and Johnson in the third edition and now as full coauthors in the fourth, CB now has a tremendous edge over the current editions of MBC and MCB. These two coauthors are world leaders in discovering and imaging new frontiers in cell biology, and this will be a huge factor in my predicted high impact of this book. It also is to be noted that the connectivity of these two authors to two of the world's leading centers of cell biology, the Janelia Research Campus of the Howard Hughes Medical Institute (Lippincott-Schwartz) and The Allen Institute for Cell Biology (Johnson) provided an enabling nexus. Some of the figures in CB 4E are among the most engaging and pedagogically powerful of any I have even seen. A final point has to do with teacher and student friendliness. The previous and most recent editions of all three textbooks had accompanying CDs, problem sets, etc. CB 4E has several of these ancillary modes, and I think they look very good. Postpublication and marketing-driven surveys by Elsevier will track this important point. Meanwhile, the authors of CB 4E will doubtless receive feedback from faculty across the world. My instinct is that it will be very positive. Finally, an e-book version of CB 4E is already in revision, including findings published only in the past few months. Richard S. Westfall titled his famous biography of Isaac Newton Never at Rest,18 and it applies to this quartet of authors. We should always bear in mind, and salute, the teachers who can make the most of texts, such as this one, deploying them in collaboration with their own insights in each lecture or hallway encounters with students, endeavoring to make budding scientists the best that they can be. Pollard et al. have once again produced a wonderful textbook to catalyze these collision-dependent interactions, in the classroom or beyond.

The nucleolus is a multifunctional nuclear body. To tease out the roles of nucleolar structure without resorting to the use of multi-action drugs, we knocked down the RNA polymerase I subunit RPA194 in HeLa cells by siRNA. Loss of RPA194 resulted in nucleolar-structural segregation and effects on both nucleolus-proximal and distal-nuclear components. The perinucleolar compartment was disrupted, centromere clustering around nucleoli was significantly reduced, and the intranuclear locations of specific genomic loci were altered. Moreover, Cajal bodies, distal from nucleoli, underwent morphological and some compositional changes. In comparison, when the preribosomal RNA-processing factor, UTP4, was knocked down, neither nucleolar segregation nor the intranuclear effects were observed, demonstrating that the changes of nucleolar proximal and distal nuclear domains in RPA194 knockdown cells unlikely arise from a cessation of ribosome synthesis, rather from the consequence of nucleolar-structure alteration. These findings point to a commutative system that links nucleolar structure to the maintenance and spatial organization of certain nuclear domains and genomic loci.

The staggering biodiversity of angiosperms has been difficult to reconcile with the gradual Darwinian process thought to create it. Changes in climate through the Earth’s history could have instigated this diversification, but perceived ...Although climate change has been implicated as a major catalyst of diversification, its effects are thought to be inconsistent and much less pervasive than localized climate or the accumulation of species with time. Focused analyses of highly speciose ...

My term as The FASEB Journal's Editor-in-Chief (January 2016–January 2023) was a great privilege, among which was writing monthly editorials on a wide range of topics, including women's health.1-3 When Patricia Morris, a leader in both female reproductive biology and related healthcare policies, accepted my invitation to join the editorial board, I proposed that she consider leading a series on women's sexual and reproductive health. She was keen, but we had to wait because she soon was elected President of FASEB and thus stepped down from the Journal's editorial board for that year. But then we rekindled our shared idea and she went forward with her typical wisdom and energy, with only a modest degree of input from me on potential subjects and authors. The series now comes to fruition with the publication of the first article,4 together with Dr. Morris' eloquent introduction.5 I am most grateful for her leadership in creating this series and I believe it is one of the most important things the Journal has ever done. In the contraceptive axis of this field, we think of Gregory Pincus, M. C. Chang and Carl Djerassi—all three geniuses in my opinion. Pincus and Chang discovered the Pill,6 and Djerassi invented a pharmaceutical process for an orally active progestin that eclipsed the G. D. Searle compound Pincus and Chang discovered.7 But all along, there were also key nonphysician/nonscientists who rallied the cause. In remembering and saluting such volunteers, I hold at the pinnacle Mary Woodward Lasker. Although the foundation she and her husband created had rules about their coveted awards, the trustees were allowed to make other awards at their discretion. Coordinating with Planned Parenthood, they launched a Special Award in World Population; Chang and Pincus were the 1954 and 1960 recipients, respectively. (Of historical note, Mary Lasker had a long association with Planned Parenthood; her husband Albert, a public relations master, was credited with coming up with the organization's name, with the view that it would be more acceptable than the “birth control”-bearing name Margaret Sanger had proposed). Some volunteers bring money and an elite circle of supporters, and I suspect Mary Lasker would have supported women's causes whatever her wealth. But there were others too, less well-known. Marion Fennelly Levy (1925–2023), known to all as Penny, started out in public relations at the department store chain Lord & Taylor but then became a champion of women's rights and health. Her many leadership roles in women's reproductive health included serving as Director of Women's Programs and Family Planning at Save the Children, as Chair of the Board of Planned Parenthood of New York City, and as a member of the board of the Alan Guttmacher Institute. Levy died on May 18, 2003. Another heroic volunteer in this theater who has recently passed away is Peg Diem Yorkin (Peggy was her given name, which she hated and never used). Following years of fundraising for charitable organizations in Hollywood, for example, SHARE Inc., which focused on support for disabled children, in 1987 she cofounded the Feminist Majority, whose initial mission was to get more women elected to Congress, an effort which many historians agree succeeded. Three years later, she teamed with Feminist Majority cofounder Eleanor Smeal and others to travel to Paris and lobby the company Roussel Uclaf, which held the patent on mifepristone (a.k.a. RU-486), to seek U.S. Food and Drug Administration (FDA) approval. (A parallel lobbying effort had been made by Etienne Baulieu, based on his preclinical and clinical studies, as well as by Dr. Sheldon Segal of the Rockefeller Foundation's Population Council.) The company agreed to support FDA approval, which was granted in 2000. Levy and Yorkin, like many other advocates, women and men alike, had the dream of women—all women—being able to have full access to sexual and reproductive healthcare. At 98 and 96, respectively, they lived to see this dream come to reality in some respects, and yet they also lived to see the U.S. Supreme Court decision in Dobbs. Only a few weeks after their deaths, the FDA approved, on July 3, a blood test to detect preeclampsia risk and then, on July 17, an evolved version of the Pill for over-the-counter sale, putting control of a contraceptive state into the option of so many women who had not had it before or at least not without prescription impediments. The latter FDA decision descends from decades of research and safety studies. Everything the pioneers of the first Pill knew led them to deploy two hormones, correct strategy at the time. Science marches on, and improvements come, as this new series in the Journal will attest. And yet, the United States still ranks shockingly low on many indices of how women, worldwide, are at risk from inadequate healthcare on all fronts, including their sexual and reproductive health. We must always bear in mind the global dimensions of this problem. This series updates much progress on several fronts, welcome indeed. But there is so much more to be done.

Many of us use the term “mechanism” when we shouldn’t. Here I offer some thoughts, especially as guidance for young scientists.