Journal of Developmental Biology

12 pages, 29836 KiB

Open AccessFeature PaperArticle

Cytology Techniques Can Provide Insight into Human Placental Structure Including Syncytiotrophoblast Nuclear Spatial Organisation

by Cassie Fives, André Toulouse, Louise Kenny, Therese Brosnan, Julie McCarthy and Brendan Fitzgerald

J. Dev. Biol. 2023, 11(4), 46; https://doi.org/10.3390/jdb11040046 - 15 Dec 2023

Cited by 1 | Viewed by 2740

Abstract

The aim of this study was to provide the first systematic description of human placental cytology appearances and to investigate syncytiotrophoblast nuclear organisation patterns using cytology techniques. Term placentas from normal pregnancies were sampled using fine-needle aspiration (FNA) and direct scrapes. Standard histological [...] Read more.

The aim of this study was to provide the first systematic description of human placental cytology appearances and to investigate syncytiotrophoblast nuclear organisation patterns using cytology techniques. Term placentas from normal pregnancies were sampled using fine-needle aspiration (FNA) and direct scrapes. Standard histological examination was also performed to exclude pathological changes in the placentas being studied. Both Papanicolaou-stained cytospin preparations and air-dried Giemsa slides from FNA provided high-quality material for cytological assessment with good cellularity. Among the key features of the cytology preparations were villous “microbiopsies” that allowed for the three-dimensional appreciation of villous branching patterns. Cytological appearances, including nuclear characteristics of villous cytotrophoblast and syncytiotrophoblast, were also well demonstrated. In microbiopsies and detached villous trophoblast sheets, complex patterns of syncytiotrophoblast nuclear organisation, not previously described cytologically, were observed, including irregular spacing of nuclei, syncytioplasm windows and linear nuclear arrangements. This study showed that placental cytology (a) provides technically excellent material for cytological evaluation, (b) confirms the presence of complex nuclear organisational patterns in the syncytiotrophoblast by eliminating the possibility of tangential sectioning artefact, (c) provides superior nuclear detail over standard histological sections and (d) may be an untapped research resource for the investigation of normal and pathological processes because of its ability to look at the placenta in a novel way and through its potential for both ex vivo and in vivo placental sampling. Full article

(This article belongs to the Special Issue The 10th Anniversary of JDB: Feature Papers)

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16 pages, 6321 KiB

Open AccessFeature PaperReview

Phase Separation as a Driver of Stem Cell Organization and Function during Development

by Amalia S. Parra and Christopher A. Johnston

J. Dev. Biol. 2023, 11(4), 45; https://doi.org/10.3390/jdb11040045 - 12 Dec 2023

Cited by 5 | Viewed by 3317

Abstract

A properly organized subcellular composition is essential to cell function. The canonical organizing principle within eukaryotic cells involves membrane-bound organelles; yet, such structures do not fully explain cellular complexity. Furthermore, discrete non-membrane-bound structures have been known for over a century. Liquid–liquid phase separation [...] Read more.

A properly organized subcellular composition is essential to cell function. The canonical organizing principle within eukaryotic cells involves membrane-bound organelles; yet, such structures do not fully explain cellular complexity. Furthermore, discrete non-membrane-bound structures have been known for over a century. Liquid–liquid phase separation (LLPS) has emerged as a ubiquitous mode of cellular organization without the need for formal lipid membranes, with an ever-expanding and diverse list of cellular functions that appear to be regulated by this process. In comparison to traditional organelles, LLPS can occur across wider spatial and temporal scales and involves more distinct protein and RNA complexes. In this review, we discuss the impacts of LLPS on the organization of stem cells and their function during development. Specifically, the roles of LLPS in developmental signaling pathways, chromatin organization, and gene expression will be detailed, as well as its impacts on essential processes of asymmetric cell division. We will also discuss how the dynamic and regulated nature of LLPS may afford stem cells an adaptable mode of organization throughout the developmental time to control cell fate. Finally, we will discuss how aberrant LLPS in these processes may contribute to developmental defects and disease. Full article

(This article belongs to the Special Issue The 10th Anniversary of JDB: Feature Papers)

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28 pages, 38808 KiB

Open AccessArticle

Special Nuclear Structures in the Germinal Vesicle of the Common Frog with Emphasis on the So-Called Karyosphere Capsule

by Dmitry S. Bogolyubov, Sergey V. Shabelnikov, Alexandra O. Travina, Maksim I. Sulatsky and Irina O. Bogolyubova

J. Dev. Biol. 2023, 11(4), 44; https://doi.org/10.3390/jdb11040044 - 12 Dec 2023

Cited by 2 | Viewed by 2397

Abstract

The karyosphere (karyosome) is a structure that forms in the oocyte nucleus—germinal vesicle (GV)—at the diplotene stage of meiotic prophase due to the assembly of all chromosomes in a limited portion of the GV. In some organisms, the karyosphere has an extrachromosomal external [...] Read more.

The karyosphere (karyosome) is a structure that forms in the oocyte nucleus—germinal vesicle (GV)—at the diplotene stage of meiotic prophase due to the assembly of all chromosomes in a limited portion of the GV. In some organisms, the karyosphere has an extrachromosomal external capsule, the marker protein of which is nuclear F-actin. Despite many years of theories about the formation of the karyosphere capsule (KC) in the GV of the common frog Rana temporaria, we present data that cast doubt on its existence, at least in this species. Specific extrachromosomal strands, which had been considered the main elements of the frog’s KC, do not form a continuous layer around the karyosphere and, according to immunogold labeling, do not contain structural proteins, such as actin and lamin B. At the same time, F-actin is indeed noticeably concentrated around the karyosphere, creating the illusion of a capsule at the light microscopy/fluorescence level. The barrier-to-autointegration factor (BAF) and one of its functional partners—LEMD2, an inner nuclear membrane protein—are not localized in the strands, suggesting that the strands are not functional counterparts of the nuclear envelope. The presence of characteristic strands in the GV of R. temporaria late oocytes may reflect an excess of SMC1 involved in the structural maintenance of diplotene oocyte chromosomes at the karyosphere stage, since SMC1 has been shown to be the most abundant protein in the strands. Other characteristic microstructures—the so-called annuli, very similar in ultrastructure to the nuclear pore complexes—do not contain nucleoporins Nup35 and Nup93, and, therefore, they cannot be considered autonomous pore complexes, as previously thought. Taken together, our data indicate that traditional ideas about the existence of the R. temporaria KC as a special structural compartment of the GV are to be revisited. Full article

(This article belongs to the Special Issue The 10th Anniversary of JDB: Feature Papers)

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11 pages, 1410 KiB

Open AccessReview

Epidermal Barrier Development via Corneoptosis: A Unique Form of Cell Death in Stratum Granulosum Cells

by Takeshi Matsui

J. Dev. Biol. 2023, 11(4), 43; https://doi.org/10.3390/jdb11040043 - 30 Nov 2023

Cited by 11 | Viewed by 3732

Abstract

Epidermal development is responsible for the formation of the outermost layer of the skin, the epidermis. The establishment of the epidermal barrier is a critical aspect of mammalian development. Proper formation of the epidermis, which is composed of stratified squamous epithelial cells, is [...] Read more.

Epidermal development is responsible for the formation of the outermost layer of the skin, the epidermis. The establishment of the epidermal barrier is a critical aspect of mammalian development. Proper formation of the epidermis, which is composed of stratified squamous epithelial cells, is essential for the survival of terrestrial vertebrates because it acts as a crucial protective barrier against external threats such as pathogens, toxins, and physical trauma. In mammals, epidermal development begins from the embryonic surface ectoderm, which gives rise to the basal layer of the epidermis. This layer undergoes a series of complex processes that lead to the formation of subsequent layers, including the stratum intermedium, stratum spinosum, stratum granulosum, and stratum corneum. The stratum corneum, which is the topmost layer of the epidermis, is formed by corneoptosis, a specialized form of cell death. This process involves the transformation of epidermal keratinocytes in the granular layer into flattened dead cells, which constitute the protective barrier. In this review, we focus on the intricate mechanisms that drive the development and establishment of the mammalian epidermis to gain insight into the complex processes that govern this vital biological system. Full article

(This article belongs to the Special Issue Development of the Skin in Vertebrates)

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12 pages, 1714 KiB

Open AccessFeature PaperReview

SARS-CoV-2 Infection in Late Pregnancy and Childbirth from the Perspective of Perinatal Pathology

by Larisa Debelenko

J. Dev. Biol. 2023, 11(4), 42; https://doi.org/10.3390/jdb11040042 - 16 Nov 2023

Cited by 1 | Viewed by 2553

Abstract

This review focuses on SARS-CoV-2 infection in placental and fetal tissues. Viremia is rare in infected pregnant women, and the virus is seldom amplified from placental tissues. Definite and probable placental infection requires the demonstration of viral RNA or proteins using in situ [...] Read more.

This review focuses on SARS-CoV-2 infection in placental and fetal tissues. Viremia is rare in infected pregnant women, and the virus is seldom amplified from placental tissues. Definite and probable placental infection requires the demonstration of viral RNA or proteins using in situ hybridization (ISH) and immunohistochemistry (IHC). Small subsets (1.0–7.9%, median 2.8%) of placentas of SARS-CoV-2-positive women showed definite infection accompanied by a characteristic histopathology named SARS-CoV-2 placentitis (SP). The conventionally accepted histopathological criteria for SP include the triad of intervillositis, perivillous fibrin deposition, and trophoblast necrosis. SP was shown to be independent of the clinical severity of the infection, but associated with stillbirth in cases where destructive lesions affecting more than 75% of the placental tissue resulted in placental insufficiency and severe fetal hypoxic–ischemic injury. An association between maternal thrombophilia and SP was shown in a subset of cases, suggesting a synergy of the infection and deficient coagulation cascade as one of the mechanisms of the pathologic accumulation of fibrin in affected placentas. The virus was amplified from fetal tissues in approximately 40% of SP cases, but definite fetal involvement demonstrated using ISH or IHC is exceptionally rare. The placental pathology in SARS-CoV-2-positive women also includes chronic lesions associated with placental malperfusion in the absence of definite or probable placental infection. The direct viral causation of the vascular malperfusion of the placenta in COVID-19 is debatable, and common predispositions (hypertension, diabetes, and obesity) may play a role. Full article

(This article belongs to the Special Issue The 10th Anniversary of JDB: Feature Papers)

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10 pages, 1543 KiB

Open AccessObituary

Andy Golden: Mentorship through the Years

by Anna K. Allen, Xiaofei Bai, Edward S. Davis, Amy Fabritius, Aimee Jaramillo-Lambert, Peter A. Kropp, Christopher T. Richie, Jill M. Schumacher, Sanjay Shrestha, Kathryn Stein and Ann K. Corsi

J. Dev. Biol. 2023, 11(4), 41; https://doi.org/10.3390/jdb11040041 - 3 Nov 2023

Viewed by 2594

Abstract

The C [...] Full article

(This article belongs to the Special Issue Caenorhabditis elegans – a Model for Understanding Development and Disease)

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15 pages, 7476 KiB

Open AccessArticle

Use of Farnesyl Transferase Inhibitors in an Ageing Model in Drosophila

by Annely Brandt, Roman Petrovsky, Maria Kriebel and Jörg Großhans

J. Dev. Biol. 2023, 11(4), 40; https://doi.org/10.3390/jdb11040040 - 29 Oct 2023

Cited by 1 | Viewed by 2312

Abstract

The presence of farnesylated proteins at the inner nuclear membrane (INM), such as the Lamins or Kugelkern in Drosophila, leads to specific changes in the nuclear morphology and accelerated ageing on the organismal level reminiscent of the Hutchinson–Gilford progeria syndrome (HGPS). Farnesyl [...] Read more.

The presence of farnesylated proteins at the inner nuclear membrane (INM), such as the Lamins or Kugelkern in Drosophila, leads to specific changes in the nuclear morphology and accelerated ageing on the organismal level reminiscent of the Hutchinson–Gilford progeria syndrome (HGPS). Farnesyl transferase inhibitors (FTIs) can suppress the phenotypes of the nuclear morphology in cultured fibroblasts from HGPS patients and cultured cells overexpressing farnesylated INM proteins. Similarly, FTIs have been reported to suppress the shortened lifespan in model organisms. Here, we report an experimental system combining cell culture and Drosophila flies for testing the activity of substances on the HGPS-like nuclear morphology and lifespan, with FTIs as an experimental example. Consistent with previous reports, we show that FTIs were able to ameliorate the nuclear phenotypes induced by the farnesylated nuclear proteins Progerin, Kugelkern, or truncated Lamin B in cultured cells. The subsequent validation in Drosophila lifespan assays demonstrated the applicability of the experimental system: treating adult Drosophila with the FTI ABT-100 reversed the nuclear phenotypes and extended the lifespan of experimentally induced short-lived flies. Since kugelkern-expressing flies have a significantly shorter average lifespan, half the time is needed for testing substances in the lifespan assay. Full article

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12 pages, 2696 KiB

Open AccessArticle

The New Nematicide Cyclobutrifluram Targets the Mitochondrial Succinate Dehydrogenase Complex in Caenorhabditis elegans

by Fariba Heydari, David Rodriguez-Crespo and Chantal Wicky

J. Dev. Biol. 2023, 11(4), 39; https://doi.org/10.3390/jdb11040039 - 19 Oct 2023

Cited by 9 | Viewed by 3533

Abstract

Today, agriculture around the world is challenged by parasitic nematode infections. Plant-parasitic nematodes (PPNs) can cause significant damage and crop loss and are a threat to food security. For a long time, the management of PPN infection has relied on nematicides that impact [...] Read more.

Today, agriculture around the world is challenged by parasitic nematode infections. Plant-parasitic nematodes (PPNs) can cause significant damage and crop loss and are a threat to food security. For a long time, the management of PPN infection has relied on nematicides that impact not only parasitic nematodes but also other organisms. More recently, new nematicides have been developed that appear to specifically target PPN. Cyclobutrifluram belongs to this new category of nematicides. Using the nematode Caenorhabditis elegans as a model organism, we show here that cyclobutrifluram strongly impacts the survival and fertility rates of the worm by decreasing the number of germ cells. Furthermore, using a genetic approach, we demonstrate that cyclobutrifluram functions by inhibiting the mitochondrial succinate dehydrogenase (SDH) complex. Transcriptomic analysis revealed a strong response to cyclobutrifluram exposure. Among the deregulated genes, we found genes coding for detoxifying proteins, such as cytochrome P450s and UDP-glucuronosyl transferases (UGTs). Overall, our study contributes to the understanding of the molecular mode of action of cyclobutrifluram, to the finding of new approaches against nematicide resistance, and to the discovery of novel nematicides. Furthermore, this study confirms that C. elegans is a suitable model organism to study the mode of action of nematicides. Full article

(This article belongs to the Special Issue Caenorhabditis elegans – a Model for Understanding Development and Disease)

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J. Dev. Biol., Volume 11, Issue 4 (December 2023) – 8 articles

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