Complementary Volume Electron Microscopy-based approaches reveal ultrastructural changes in germline intercellular bridges of D. melanogaster

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Фев. 23, 2025

ABSTRACT Intercellular bridges are essential to connect developing germline cells. The Drosophila melanogaster egg chamber is a powerful model system study intercellular bridges, or ring canals (RCs). RCs the oocyte supporting nurse cells, and defects in their stability growth lead infertility. Despite importance, it has been technically difficult use electron microscopy-based approaches monitor changes RC structure during oogenesis. Here, we describe application of complementary set volume EM-based visualize ultrastructural RCs. combination array tomography (AT) focused ion beam (FIB) scanning microscopy (SEM) allowed us gain insight into previously unappreciated aspects structure. We were able quantify differences size thickness within between germ cell clusters at different developmental stages. Within cluster, correlates with lineage; largest formed first division, smallest fourth mitotic division. observed formation membrane interdigitations vicinity much earlier than reported, reconstruction from mid-stage EC provided 3D orientation these extensive cell-cell contacts. Our imaging also revealed novel that appeared line interior lumen. Although focus was on RCs, our dataset contains valuable details additional types structures, including fusome, stem cells niche, migrating border This framework could be applied other tissues samples face similar technical challenges, where small interest located large sample volume.

Язык: Английский

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Genome dilution by cell growth drives starvation-like proteome remodeling in mammalian and yeast cells

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Окт. 19, 2023

SUMMARY Cell size is tightly controlled in healthy tissues and single-celled organisms, but it remains unclear how influences cell physiology. Increasing was recently shown to remodel the proteomes of cultured human cells, demonstrating that large small cells same type can be biochemically different. Here, we corroborate these results mouse hepatocytes extend our analysis using yeast. We find size-dependent proteome changes are highly conserved mostly independent metabolic state. As eukaryotic grow larger, dilution genome elicits a starvation-like phenotype, suggesting growth limited by manner analogous limiting nutrient. also this phenomenon explains many proteomic ascribed yeast aging. Overall, data suggest concentration universal determinant content growing cells.

Язык: Английский

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Epigenetic programming in the ovarian reserve

BioEssays, Год журнала: 2023, Номер 45(10)

Опубликована: Июль 7, 2023

Abstract The ovarian reserve defines female reproductive lifespan, which in humans spans decades. consists of oocytes residing primordial follicles arrested meiotic prophase I and is maintained independent DNA replication cell proliferation, thereby lacking stem cell‐based maintenance. Largely unknown how cellular states the are established for Our recent study revealed that a distinct chromatin state during formation mice, uncovering novel window epigenetic programming germline development. We showed an regulator, Polycomb Repressive Complex 1 (PRC1), establishes repressive perinatal mouse essential I‐arrested to form reserve. Here we discuss biological roles mechanisms underlying formation, highlighting current knowledge gaps emerging research areas biology.

Язык: Английский

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The Ancient Origin and Function of Germline Cysts

Results and problems in cell differentiation, Год журнала: 2023, Номер unknown, С. 3 - 21

Опубликована: Ноя. 23, 2023

Язык: Английский

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Epigenetic aging of mammalian gametes

Molecular Reproduction and Development, Год журнала: 2023, Номер 90(12), С. 785 - 803

Опубликована: Ноя. 24, 2023

Abstract The process of aging refers to physiological changes that occur an organism as time progresses and involves DNA, proteins, metabolism, cells, organs. Like the rest cells in body, gametes age, it is well established there a decline reproductive capabilities females males with aging. One major pathways known be involved epigenetic changes. epigenome multitude chemical modifications performed on DNA chromatin affect ability transcribed. In this review, we explore effects female male focus throughout Quality oocytes occurs at relatively early age. Epigenetic constitute important part oocyte methylation reduced along expression methyltransferases (DNMTs). Histone deacetylases (HDAC) also reduced, loss heterochromatin marks As consequence loss, retrotransposon elevated, aged suffer from damage. sperm, affects sperm number, motility fecundity, may process. 5 methyl‐cytosine (5mC) elevated men, but Long interspersed nuclear elements (LINE) reduced. Di trimethylation histone 3 lysine 9 (H3K9me2/3) men 27 (H3K27me3) elevated. protamine makeup changed, misbalanced ratio between proteins P1 P2. study recently gaining interest. current status field suggests many aspects gamete are still open for investigation. clinical applications these investigations have far‐reaching consequences fertility sociological human behavior.

Язык: Английский

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Single-nucleus atlas of the Artemia female reproductive system suggests germline repression of the Z chromosome

PLoS Genetics, Год журнала: 2024, Номер 20(8), С. e1011376 - e1011376

Опубликована: Авг. 30, 2024

Our understanding of the molecular pathways that regulate oogenesis and define cellular identity in Arthropod female reproductive system extent their conservation is currently very limited. This due to focus on model systems, including Drosophila Daphnia, which do not reflect observed diversity morphologies, modes, sex chromosome systems. We use single-nucleus RNA ATAC sequencing produce a comprehensive single nucleus atlas adult Artemia franciscana system. map our data Fly Cell Atlas dataset melanogaster ovary, shedding light conserved regulatory programs between two distantly related species. identify major cell types known be present germ cells, follicle ovarian muscle cells. Additionally, we cells explore gene regulation expression Z during meiosis, highlighting its unique dynamics allowing us presence meiotic silencing this group.

Язык: Английский

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A High-Throughput Method for Quantifying Drosophila Fecundity

Toxics, Год журнала: 2024, Номер 12(9), С. 658 - 658

Опубликована: Сен. 9, 2024

The fruit fly, Drosophila melanogaster, is an experimentally tractable model system that has recently emerged as a powerful “new approach methodology” (NAM) for chemical safety testing. As oogenesis well conserved at the molecular and cellular level, measurements of fecundity can be useful identifying chemicals affect reproductive health across species. However, standard assays have been difficult to perform in high-throughput manner because experimental factors such physiological state flies environmental cues must carefully controlled achieve consistent results. In addition, exposing large number different conditions (such additives diet) manually counting eggs laid determine impact on time-consuming. We overcome these challenges by combining new multiwell fly culture strategy with novel 3D-printed transfer device rapidly accurately from one plate another, RoboCam, low-cost, custom-built robotic camera capture images wells automatically, image segmentation pipeline automatically identify quantify eggs. show this method compatible robust egg laying throughout assay period demonstrate automated quantifying very accurate (r2 = 0.98 correlation between counts ground truth). we used efficiently detect effects induced dietary exposure chemicals. Taken together, substantially increases efficiency reproducibility egg-laying require multiple media conditions.

Язык: Английский

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The bHLH-PAS transcriptional complex Sim:Tgo plays active roles in late oogenesis to promote follicle maturation and ovulation

Development, Год журнала: 2023, Номер 150(12)

Опубликована: Май 23, 2023

Across species, ovulation is a process induced by myriad of signaling cascades that ultimately leads to the release encapsulated oocytes from follicles. Follicles first need mature and gain ovulatory competency before ovulation; however, pathways regulating follicle maturation are incompletely understood in Drosophila other species. Our previous work has shown bHLH-PAS transcription factor Single-minded (Sim) plays important roles downstream nuclear receptor Ftz-f1 Drosophila. Here, we demonstrate Tango (Tgo), another protein, acts as co-factor Sim promote cell differentiation stages 10 12. In addition, discover re-upregulation stage-14 cells also essential upregulating octopamine mushroom body (OAMB), matrix metalloproteinase 2 (Mmp2) NADPH oxidase (NOX), either independently or conjunction with zinc-finger protein Hindsight (Hnt). All these factors crucial for successful ovulation. Together, our indicates transcriptional complex Sim:Tgo multiple late-stage

Язык: Английский

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Delayed abscission in animal cells – from development to defects

Journal of Cell Science, Год журнала: 2023, Номер 136(13)

Опубликована: Июнь 30, 2023

ABSTRACT Cell division involves separating the genetic material and cytoplasm of a mother cell into two daughter cells. The last step division, abscission, consists cutting cytoplasmic bridge, microtubule-rich membranous tube connecting cells, which contains midbody, dense proteinaceous structure. Canonically, abscission occurs 1–3 h after anaphase. However, in certain cases, can be severely delayed or incomplete. Abscission delays caused by mitotic defects that activate ‘NoCut’ checkpoint tumor as well when cells exert abnormally strong pulling forces on bridge. Delayed also occur during normal organism development. Here, we compare mechanisms triggering incomplete healthy disease scenarios. We propose NoCut is not bona fide cycle checkpoint, but general mechanism control dynamics multiple contexts.

Язык: Английский

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Professional phagocytes are recruited for the clearance of obsolete nonprofessional phagocytes in the Drosophila ovary

Frontiers in Immunology, Год журнала: 2024, Номер 15

Опубликована: Июнь 27, 2024

Cell death is an important process in the body, as it occurs throughout every tissue during development, disease, and regeneration. Phagocytes are responsible for clearing away dying cells typically characterized either professional or nonprofessional phagocytes. Professional phagocytes, such macrophages, found nearly part of body while epithelial cells, type. However, there organs that considered “immune-privileged” they have little to no immune surveillance rely on phagocytes engulf cells. These surrounded by barriers protect from viruses, bacteria, perhaps even The Drosophila ovary immune-privileged, however presence hemocytes, macrophages , around suggests may a potential function. Here we analyze hemocyte localization functions response starvation-induced cell ovary. Hemocytes were accumulate oviduct vicinity mature eggs follicle debris. Genetic ablation hemocytes revealed affects oogenesis phagocytose ovarian debris their absence fecundity decreases. Unpaired3, IL-6 like cytokine, was be required recruitment clear obsolete findings demonstrate role ovary, providing more thorough understanding phagocyte communication clearance previously thought immune-privileged organ.

Язык: Английский

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