Hilde Mangold: Original microscope slides and records of the gastrula organizer experiments.

The discovery of the amphibian gastrula organizer and its publication by Hans Spemann and Hilde Mangold in 1924 is a foundation of experimental embryology, and has shaped our understanding of embryonic induction and pattern formation in vertebrates until today. The original publication is a piece of scientific art, characterized by the meticulous hand drawings by Hilde Mangold, as well as the text that develops mechanistic concepts of modern embryology. While historic microphotographs of specimens got lost, the original microscope slides and Hilde Mangold's laboratory notebook have been secured in embryological collections until today. Here, we make the original data of the six embryonic specimens reported in 1924, as well as the laboratory notebook, available in an accessible digital format. Together, these data shed light on the scientific process that led to the discovery, and should help to make the experiments on the most important signalling center in early vertebrate development transparent for generations of embryologists to come.

Self-organization of human dorsal-ventral forebrain structures by light induced SHH.

Organizing centers secrete morphogens that specify the emergence of germ layers and the establishment of the body's axes during embryogenesis. While traditional experimental embryology tools have been instrumental in dissecting the molecular aspects of organizers in model systems, they are impractical in human in-vitro model systems to dissect the relationships between signaling and fate along embryonic coordinates. To systematically study human embryonic organizer centers, we devised a collection of optogenetic ePiggyBac vectors to express a photoactivatable Cre-loxP recombinase, that allows the systematic induction of organizer structures by shining blue-light on human embryonic stem cells (hESCs). We used a light stimulus to geometrically confine SHH expression in neuralizing hESCs. This led to the self-organization of mediolateral neural patterns. scRNA-seq analysis established that these structures represent the dorsal-ventral forebrain, at the end of the first month of development. Here, we show that morphogen light-stimulation is a scalable tool that induces self-organizing centers.

Controlled spermatozoa-oocyte interaction improves embryo quality in sheep.

The current protocols of in vitro fertilization and culture in sheep rely on paradigms established more than 25 years ago, where Metaphase II oocytes are co-incubated with capacitated spermatozoa overnight. While this approach maximizes the number of fertilized oocytes, on the other side it exposes them to high concentration of reactive oxygen species (ROS) generated by active and degenerating spermatozoa, and positively correlates with polyspermy. Here we set up to precisely define the time frame during which spermatozoa effectively penetrates and fertilizes the oocyte, in order to drastically reduce spermatozoa-oocyte interaction. To do that, in vitro matured sheep oocytes co-incubated with spermatozoa in IVF medium were sampled every 30 min (start of incubation time 0) to verify the presence of a fertilizing spermatozoon. Having defined the fertilization time frame (4 h, data from 105 oocytes), we next compared the standard IVF procedures overnight (about 16 h spermatozoa/oocyte exposure, group o/nIVF) with a short one (4 h, group shIVF). A lower polyspermic fertilization (> 2PN) was detected in shIVF (6.5%) compared to o/nIVF (17.8%), P < 0.05. The o/nIVF group resulted in a significantly lower 2-cell stage embryos, than shIVF [34.6% (81/234) vs 50.6% (122/241) respectively, P < 0.001]. Likewise, the development to blastocyst stage confirmed a better quality [29% (70/241) vs 23.5% (55/234), shIVF vs o/nIVF respectively] and an increased Total Cell Number (TCN) in shIVF embryos, compared with o/n ones. The data on ROS have confirmed that its generation is IVF time-dependent, with high levels in the o/nIVF group. Overall, the data suggest that a shorter oocyte-spermatozoa incubation results in an improved embryo production and a better embryo quality, very likely as a consequence of a shorter exposure to the free oxygen radicals and the ensuing oxidative stress imposed by overnight culture.

Artificial intelligence-the future is now.

The pros and cons of artificial intelligence in assisted reproductive technology are presented.

How embryology knowledge can help radiologists in the differential diagnosis of canal of Nuck pathologies.

The Canal of Nuck (CN) is an anatomical structure which is often forgotten. It is the female equivalent of the male processus vaginalis and corresponds to a protrusion of parietal peritoneum that extends from the inguinal canal to labia majora. Radiologists rarely encounter patients with pathology of CN, especially in adult population. It is well known that CN diseases can occur in paediatric patient (especially younger than 5 years of age) and they are associated to high morbidity (for example ovarian hernia with high risk of incarceration and torsion). The aim of our work is to review embryology, anatomy and pathologies of the CN thanks to a multi modal approach-ultrasound (US), Computed Tomography (CT) and Magnetic Resonance imaging (MRI)-to make radiologists more aware of such conditions and guarantee a prompt and correct diagnosis not only in paediatric patients but also in the adult population.

Craniofacial Development: Neural Crest in Molecular Embryology.

Craniofacial development, one of the most complex sequences of developmental events in embryology, features a uniquely transient, pluripotent stem cell-like population known as the neural crest (NC). Neural crest cells (NCCs) originate from the dorsal aspect of the neural tube and migrate along pre-determined routes into the developing branchial arches and frontonasal plate. The exceptional rates of proliferation and migration of NCCs enable their diverse contribution to a wide variety of craniofacial structures. Subsequent differentiation of these cells gives rise to cartilage, bones, and a number of mesenchymally-derived tissues. Deficiencies in any stage of differentiation can result in facial clefts and abnormalities associated with craniofacial syndromes. A small number of conserved signaling pathways are involved in controlling NC differentiation and craniofacial development. They are used in a reiterated fashion to help define precise temporospatial cell and tissue formation. Although many aspects of their cellular and molecular control have yet to be described, it is clear that together they form intricately integrated signaling networks required for spatial orientation and developmental stability and plasticity, which are hallmarks of craniofacial development. Mutations that affect the functions of these signaling pathways are often directly or indirectly identified in congenital syndromes. Clinical applications of NC-derived mesenchymal stem/progenitor cells, persistent into adulthood, hold great promise for tissue repair and regeneration. Realization of NCC potential for regenerative therapies motivates understanding of the intricacies of cell communication and differentiation that underlie the complexities of NC-derived tissues.

Rethinking embryology in vitro: A synergy between engineering, data science and theory.

Pluripotent stem cells, in the recent years, have been demonstrated to mimic different aspects of metazoan embryonic development in vitro. This has led to the establishment of synthetic embryology: a field that makes use of in vitro stem cell models to investigate developmental processes that would be otherwise inaccessible in vivo. Currently, a plethora of engineering-inspired techniques, including microfluidic devices and bioreactors, exist to generate and culture organoids at high throughput. Similarly, data analysis and deep learning-based techniques, that were established in in vivo models, are now being used to extract quantitative information from synthetic systems. Finally, theory and data-driven in silico modeling are starting to provide a system-level understanding of organoids and make predictions to be tested with further experiments. Here, we discuss our vision of how engineering, data science and theoretical modeling will synergize to offer an unprecedented view of embryonic development. For every one of these three scientific domains, we discuss examples from in vivo and in vitro systems that we think will pave the way to future developments of synthetic embryology.

Artificial intelligence in human in vitro fertilization and embryology.

Embryo evaluation and selection embody the aggregate manifestation of the entire in vitro fertilization (IVF) process. It aims to choose the "best" embryos from the larger cohort of fertilized oocytes, the majority of which will be determined to be not viable either as a result of abnormal development or due to chromosomal imbalances. Indeed, it is generally acknowledged that even after embryo selection based on morphology, time-lapse microscopic photography, or embryo biopsy with preimplantation genetic testing, implantation rates in the human are difficult to predict. Our pursuit of enhancing embryo evaluation and selection, as well as increasing live birth rates, will require the adoption of novel technologies. Recently, several artificial intelligence (AI)-based methods have emerged as objective, standardized, and efficient tools for evaluating human embryos. Moreover, AI-based methods can be implemented for other clinical aspects of IVF, such as assessing patient reproductive potential and individualizing gonadotropin stimulation protocols. As AI has the capability to analyze "big" data, the ultimate goal will be to apply AI tools to the analysis of all embryological, clinical, and genetic data in an effort to provide patient-tailored treatments. In this chapter, we present an overview of existing AI technologies in reproductive medicine and envision their potential future applications in the field.

A Transgenic System for Rapid Magnetic Enrichment of Rare Embryonic Cells.

Collecting large numbers of rare cells for high-throughput molecular analysis remains a technical challenge, primarily due to limitations in existing technologies. In developmental biology this has impeded single-cell analysis of primordial organs, which derive from few cells. In this study, we share novel transgenic lines for rapid cell enrichment from zebrafish embryos using human surface antigens for immunological binding and magnetic sorting. As proof of principle, we tagged, enriched, and performed single-cell RNA sequencing on nascent hematopoietic stem/progenitor cells and endothelial cells from early embryos. Our method is a quick, efficient, and cost-effective approach to a previously intractable problem.

Anatomía segmentaria del recto. Nuevo enfoque / Anatomy segmentation of the rectal. New approach

RESUMEN Se actualizó la clasificación anatómica del tumor de recto, con la revisión de varios tratados sobre anatomía. El estudio de la morfología interna del recto reconoce la formación de anchos pliegues. La formación de anchos pliegues de mucosas transversales, denominadas válvulas: una válvula inferior a 7 cm del ano, otra a 2 cm. Más arriba con una forma de media luna y la tercera a 11 cm del ano. Como estas válvulas son pliegues mucosos sin localización precisa no pueden ser consideradas como puntos anatómicos para segmentación del recto. De esta manera, la segmentación rectal como el límite entre recto superior e inferior se sitúa en la reflexión peritoneal; en el diagnóstico de tumores rectales la definición de su situación anatómica es importante para la conducta terapéutica, ya que el recto inferior tiene su origen embriológico en el proctodeo (ectoblástica) y puede ser más sensible a las radiaciones y los tumores del recto superior son tumores que se originan de tejido de formación entoblástica, las radiaciones producen lesiones del peritoneo y de otros órganos de la cavidad pelviana. La segmentación rectal es importante para el estadio locorregional del tumor y para la definición de un esquema de tratamiento adecuado. En primer lugar, establece el concepto anatómico de localización de un tumor de recto inferior, se diagnóstica con un tacto rectal, si es tocable es del recto inferior. En segundo lugar, define cuáles son los estudios complementarios para saber el estadio de la enfermedad y establece los parámetros anatómicos necesarios para la indicación del tratamiento neoadyuvante (AU).

SUMMARY To present a recent an anatomic classification of rectal tumor localization. Review of many anatomy treaties. The rectal internal morphology studies recognize the formation of thick folds of transversal mucosa thick folds named valves: a low valve to 7 cm from anus. Another is to 2 cm upper with a half moon form, a third one to 11 cm from anus. As this valves are mucosal folds without a clear localization they can't be consider as anatomical points to the rectum segment. Therefore, the rectal segmentation as the limit between up and low rectum, is located in the peritoneal reflection. In the rectal tumors diagnosis definition of it's anatomic situation is important for the therapeutic behavior, because the low rectum has its embryologic origin in the Proctodeum (ectoblastic). It can be more sensitive to the radiation the up rectum tumors are originated from the formation entoblast tissue (endoblast) the radiations cause peritoneal injuries and other pelvic cavity organs. The rectal segmentation is important for the locate-regional tumor stadium and for the appropriate treatment definition. In first place, establish the anatomic concept of the low rectal tumor localization. In second place defines which are the complementary for the new adjuvant indication (AU).

Assessing Clinical Embryology Research: A Global Bibliometric Analysis.

Background and Objectives: The evaluative strength of available bibliometric tools in the field of clinical embryology has never been examined in the literature. The aim is to bring insight regarding the identity of clinical embryology research, introducing concerns when solely relying on the methodology of bibliometric analysis. Methods: An all-inclusive analysis of the most bibliometrically highlighted scientific contributions regarding the cornerstones of clinical embryology was performed employing the Scopus, Web of Science (WoS) and PubMed databases, between 1978-2018. An analysis of the number of publications, respective citations and h-index, g-index, along with m-quotient is presented. The top 30 contributing authors for each distinctive area of research are listed. An attempt at visualizing the yearly published articles, clusters, and collaborations of authors, along with the geographic origin of publications, is also presented. Results: Combining all searches and keywords yielded 54,522 results. In the Scopus database, employing the keyword "In Vitro Fertilization" yielded 41,292 results. The publications of the top five authors in each research field were analytically presented and compared to the total number of publications for each respective field. The research field of Preimplantation Genetic Diagnosis/Screening/Testing was allocated the highest percentage of publications produced by the top five authors. Regarding journal bibliometrics, based on the year 2017 metrics, there are only 29 journals according to WoS that refer to "Reproductive Biology", ranking it 187th among 235 disciplines. The USA produced the highest number of publications (12,537). Conclusion: Results indicate an explosion of interest published in the literature regarding the field of clinical embryology. Further analysis on collaborations and the trends involved should be of added value as productivity between countries varies significantly. This may guide researchers, in vitro fertilization professionals, and prospective authors during literature search, while proving useful regarding manuscript design and concurring on keywords and abstract content.

Developmental Biology and Transgenic Avian Embryology: Body Alterity Bioart Wet Lab.

Public experimental embryology opens a relationship between an embryo and an amateur transgenic designer. Artists produce real-world effects by forcing hereditary aesthetics on developing bodies. This lab was meant to aid in public understanding of the relationship between transgenics and aesthetics. How do we to take an active and hands-on tactical stance on the role of hereditary designer and how does this help in public analysis of the bioethics of genetic engineering. Through naming and funeral rites, we assign the embryos an uncertain amount of clout or cultural worth. This lab is an example of how to understand the relationship between institutional oversight in pre-animal experimentation, embryonic dignity, and the problem of humane sacrifice. The intention is to make a hands-on wet bioart lab meant to aid in public comprehension of the range of politics and responsibilities involved in play at the level of heredity. The Developmental Biology and Transgenic Avian Embryology Bioart Wet Lab was held in Gorlaeus Laboratories, LIC, University of Leiden, Leiden, Netherlands, 2007.

Consistency and objectivity of automated embryo assessments using deep neural networks.

OBJECTIVE: To evaluate the consistency and objectivity of deep neural networks in embryo scoring and making disposition decisions for biopsy and cryopreservation in comparison to grading by highly trained embryologists. DESIGN: Prospective double-blind study using retrospective data. SETTING: U.S.-based large academic fertility center. PATIENTS: Not applicable. INTERVENTION(S): Embryo images (748 recorded at 70 hours postinsemination [hpi]) and 742 at 113 hpi) were used to evaluate embryologists and neural networks in embryo grading. The performance of 10 embryologists and a neural network were also evaluated in disposition decision making using 56 embryos. MAIN OUTCOME MEASURES: Coefficients of variation (%CV) and measures of consistencies were compared. RESULTS: Embryologists exhibited a high degree of variability (%CV averages: 82.84% for 70 hpi and 44.98% for 113 hpi) in grading embryo. When selecting blastocysts for biopsy or cryopreservation, embryologists had an average consistency of 52.14% and 57.68%, respectively. The neural network outperformed the embryologists in selecting blastocysts for biopsy and cryopreservation with a consistency of 83.92%. Cronbach's α analysis revealed an α coefficient of 0.60 for the embryologists and 1.00 for the network. CONCLUSIONS: The results of our study show a high degree of interembryologist and intraembryologist variability in scoring embryos, likely due to the subjective nature of traditional morphology grading. This may ultimately lead to less precise disposition decisions and discarding of viable embryos. The application of a deep neural network, as shown in our study, can introduce improved reliability and high consistency during the process of embryo selection and disposition, potentially improving outcomes in an embryology laboratory.

Microfluidic System for Rapid Isolation of Sperm From Microdissection TESE Specimens.

OBJECTIVES: To demonstrate a novel prototype microfluidic system for rapid isolation of sperm from real and simulated microdissection testicular sperm extraction samples. METHODS: The novel microfluidic system was tested using minced testicular biopsies from patients with nonobstructive azoospermia. The samples were split into 2 portions, conventional processing vs microfluidic. The embryologists were blinded to the processing protocol and searched the specimens for sperm after processing. We recorded the number of sperm found and the time to sperm identification and compared the sperm retrieval rates. RESULTS: When compared to conventional methods, samples processed through the microfluidic system were cleaner (decreased somatic cells/debris), with the average number of sperm identified per minute improving from 1.52 sperm per minute for the control and 13.5 sperm per minute with the device yielding an 8.88 fold improvement in the sperm found per minute for the device as compared to the control. Preliminary viability and morphology tests show a minimal impact on sperm processed through the microfluidic system. CONCLUSION: The presented microfluidic system can facilitate rapid and efficient isolation of sperm from microdissection testicular sperm extraction samples. A prospective clinical trial to verify these results is needed to confirm this preliminary data.