#gastrul

[bpod-bpod]

Culture of Continuity

Models of embryo formation called blastoids created from human pluripotent stem cells grown on a 3D matrix bear characteristics of continuous early development from pre-implantation to early gastrulation – the point of multi-layered organisation

Read the published research paper here

Image from work by Rowan M. Karvas and colleagues

Department of Developmental Biology and Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Cell Stem Cell, September 2023

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[dasloddl]

developmental biology really just straight up sucks

[biology-geology-beaches-india]

TSRNOSS. Page 174.

[covid-safer-hotties]

Reference preserved in our archive (Daily updates!)

Just a 'mild' reversal of a fetus's internal organs...

Context and significance A striking increase in situs inversus cases, diagnosed by ultrasound, was observed several months following removal of zero-COVID-19 policies in China, which coincided with a surge in SARS-CoV-2 infection. The rare clinical evidence presented here reveals a previously unobserved possible fetal consequence of maternal SARS-CoV-2 infection specifically during gestational weeks 4–6. To date, visceral lateralization has never been definitively linked to a specific developmental time in humans due to the rarity of such fetal samples. This study advances our current understanding of gastrulation-stage development and possibly provides the most robust support yet linking an environmental factor to occurrence of situs inversus, opening new research directions into mechanisms of visceral lateralization in humans and consequences of SARS-CoV-2 infection in pregnancy.

Highlights • Situs inversus is associated with SARS-CoV-2 infection at gestational weeks (GWs) 4–6 • Results herein support previously undefined visceral lateralization at GWs 4–6 in humans • SARS-CoV-2 infection at GWs 4–6 is well supported as an environmental risk factor for situs inversus

Summary Background A dramatic increase in fetal situs inversus diagnoses by ultrasound in the months following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surge of December 2022 in China led us to investigate whether maternal SARS-CoV-2 exposure could be associated with elevated risk of fetal situs inversus.

Methods In this multi-institutional, hospital-based, matched case-control study, we investigated pregnant women who underwent ultrasonographic fetal biometric assessment at gestational weeks 20–24 at our hospitals. Each pregnant woman carrying a situs inversus fetus was randomly matched with four controls based on the date of confinement. Relevant information, including SARS-CoV-2 infection, and other potential risk factors were collected. Conditional logistic regression was used to test possible associations between fetal situs inversus and SARS-CoV-2 infection at different gestational weeks as well as individual risk factors.

Findings A total of 52 pregnant women diagnosed with fetal situs inversus between January 1 and October 31, 2023 and 208 matched controls with normal fetuses were enrolled. We found no association between an increased risk of fetal situs inversus with gestational SARS-CoV-2 infection or with other risk factors. However, fetal situs inversus was significantly associated with SARS-CoV-2 infection specifically in gestational weeks 4–6 (adjusted odds ratio [aOR] 6.54 [95% confidence interval 1.76–24.34]), but not with infection at other gestational ages, after adjusting for covariates.

Conclusions Increased risk of fetal situs inversus is significantly associated with maternal SARS-CoV-2 infection at gestational weeks 4–6, corresponding to the fetal developmental window for visceral lateralization in humans.

[entryn17]

embryology turning out to be a soul-sucking subject to study for cause i could not. care less about gastrulation in birds. actively painful to read about i'm gonna be honest

[fuzzyfrizzlefrack]

Do you know any cool science facts? Bonus points if the inspire awe and wonder!

As a former science educator, it is my moral duty to have and share cool science facts. ;)

Would you believe that humans are more closely related (evolutionarily speaking) to a sea urchin than to an octopus?

One of our strongest pieces of evidence for this comes from the study of embryonic development, or embryology. Some time after germ cells combine to form a single-celled zygote, the cell divides several times to form a hollow sphere of cells called a blastula. In animals with bilateral body plans (i.e., digestive tract surrounded by a separate internal body cavity, with a mouth at one end and an anus at the other), that digestive tract begins forming as the blastula undergoes gastrulation, a process by which one part of the surface of the sphere turns in on itself.

This initial opening into the digestive tract, the blastopore, is either the mouth or the anus. In protostomes ("mouth-first"), the blastopore is the the mouth! As the digestive tract develops, it will eventually form an anus at the other end of the embryo. In deuterstomes ("mouth-second"), the mouth... forms second. The blastopore is the anus.

As it turns out, many worms, slugs, and the like - including molluscs and cephalopods - are protostomes. Deuterostomes then encompass many of the creatures you might name with bilateral body plans (and related, radial body plans like starfish and sea urchins), including arthropods, birds, fish, reptiles, mammals, even tunicates! And humans.

At one point in our development, each and every one of us was nothing more than a butthole. Sometimes it seems some people never progressed past that stage!

[capricorn-0mnikorn]

More "holiday" music -- for biology lovers and nerds:

An a cappella version of the "Hallelujah" Chorus -- with the lyrics changed to celebrate the entire Animal Kingdom (Lyrics in the video, and this post. Eye contact. 3 minutes, 45 seconds. Proper closed captions in Galician, auto-generated captions in Spanish):

Lyrics:

Animalia! (x10)

Our cells are phospholipid membranous Animalia (x4) But have no form-restrictive containers Animalia (x4) Our high motility is what shapes us For heterotrophy as predators Chordata, annelids and ctenophores Animalia!

The opisthokonta clade Has become The kingdoms of fungi And animals And animals

In the domain of eukaryota ATP made inside mitochondria But we contain no plastids like chloroplasts With blastulae as diplo- or triploblasts

Kingdom of Mollusca Tardigrada Arthropoda Chordata:

The phylum of Larvacia Agnatha Amphibia And Mammalia:

Classis of Rodentia Cetacea Carnivora Primates:

The order of Lemuridae Tarsiidae Atelidae Hominidae:

Family of Gorilla and Pongo Chimpanzee And homo:

The genus of Homo sapiens sapiens

(But we all came from before the Cambrian)

But we all came But we all came But we all came But we all came

From a concestor in the Precambrian

Protostomes (And deuter- ostomia) With desmosomes (Gap junctions, tight junctions) And microtubules nucleated by centrosomes

Coelomates with hollow cores Gastrulate from blastopores And we chordates have tails and gill slits and notochords

Echinoderms (Platyzoa, Nematoda) And Arthropods (Porifera and Cnidaria) Animalia (x4)

ANIMALIA!

[chaosstudiesmed]

finally something that makes sense gastrulation i love you everyone say thank you gastrulation

[ask-la-squadra]

For everyone!! If you could pic another job aside from the mafia...what would you choose?

And to the mod, have a lovely day 💜

Risotto Nero - I'd probably be a teacher, science in particular

Pros - I'd be an architect, almost went to university for it before things went south

Pesci - I honestly don't know...

Maggi - A vet or someone who works at an animal shelter I think, it would be very fulfilling

LuLu - I'd love to own a small cafe or a hair salon, something unique

Melone - Well I have a PhD so probably something in the biological research field, specifically into gastrulation, it fascinates me

Ghiaccio - Olympic skater, or I'd at least try, did you think I got my stand for nothing.

Sorbet - CEO of something, whatever pays best

Gelato - Probably an accountant, stable and pays well

[ask-spidermom]

No improvement after 2 weeks. Loss of appetite. Frequent meltdowns.

There was a crayon drawing on the bottom of the table; a stick person with a big smile, then several smaller stick people with broad Xs for eyes. Harry’s stomach twisted as he stared up at them.

Woodie murmured, almost more to themself than anyone else, “... What happened here?”

“I-I can't remember. I don't remember.”

Only in quick flickers, in shoddy projector slides.

No adverse effects yet. Complaints about the size of the pills. Split dosage into smaller capsules?

Harry scooted out from under the table and let Woodie help him to his feet.

A child’s shriek pierced the space, reverberating through the hall until, for a split second, it sounded as though coming from every direction. After a tense moment, Harry cautiously straightened his shoulders and squeezed Woodie’s hand. They led him out of what was labeled on an old staff directory map as the ‘recreation chamber’— a large room with foam padded floors, a swing and a round table with crayons and paper.

“Let's go this way.” Harry said, tapping an orange arrow on the wall. There were several similar indicators in various colours, all leading off in different directions.

An informational sign in the foyer outside the recreation chamber had denoted them as relating to the following departments:

purple: PLAGUE

green: RETROSPECTIVES

red: BILE REQUISITION

blue: DETRITUS & NUTRITION

orange: HOME

Failure begets failure. Poison in the blood. Poison in the brain. Irritability, nightmares, increasingly uncooperative. Dosage adjustment needed.

The orange arrow led them down another hallway, then around a corner. On the wall opposite, a plaque stood before a large, darkened display window.

“Press to illuminate each specimen…” Woodlock read aloud.

“That- uh, I-I don't—”

With a click, one specimen jar on the far left of the window lit up. It had something small within, a pale, pink spec with a dark spot, surrounded by nondescript tissue matter. Click. The lights buzzed and flickered. Another jar, then another, both containing humanoid fetuses at varying stages of development.

Click.

The last place looked empty, at first. Harry leaned in, then let out a small cry. The light shimmered across the fine detritus of shattered glass and dry mucus.

“It's just a dream, dear.”

Harry pulled away from the window, “It's never just a dream.”

“I mean, it’s the same old things arranged in unfamiliar patterns, is all.”

They continued down the hall. The orange arrow, smudges of something wet and viscous dragging itself along. Harry pushed away memories of his mother sobbing, despondent with a kind of grief too heavy for his little arms to hold when he scrambled onto the couch to comfort her.

“I found out about it by accident. Uh, just poking around in old project folders. Stuff about producing genetically identical embryos with various minor tweaks in the nucleic code,” Harry laughed dryly, “And then I was like, hold on, I know that genome. That's me!”

“You recognize your genome sequence?”

“It’s usually apparent by the second page.”

Specimen No.1

21 days. Perished during later stages of gastrulation.

Specimen No.4

4 weeks. Death due to complications regarding chromosomal abnormalities.

Specimen No.13

32 weeks. Complications with cardiac development.

Specimen No. 15

1 day.

The blue arrow was visible on a wall down the side corridor. The wall had a dark smeared handprint along the bottom that trailed beyond view.

“I try not to think about it. I don't like bringing up stuff mom has done, ‘cause she gets upset.” Harry picked at a loose thread at the hem of his sleeve.

“It was her hand that carved in you a wound that never healed.”

“... I try not to think about it.”

At the end, there was a large room with pretty wood flooring and floral wallpaper. Inside, an overturned dinner table and two chairs.

It felt, somehow, as if there were something missing in the space. Harry closed his eyes, trying to remember what it could've been. A girl, maybe. She had long, frizzy strawberry blonde hair tied into a french braid. She wore a stained yellow-orange jumpsuit.

The absence, her absence. The empty space folded into the figure of the girl, crouched on her hands and knees by the table. She was crunching something between her teeth, pulling a string of sinew from her lips. She jerked upright, eyes wide.

Harry met her gaze. He knew her face, even smeared with blood. It looked a lot like his.

She took a breath and screamed.

[caesarsaladinn]

regardless of the researcher’s overall weirdness it does take a certain baseline insanity to spend a six-decade career watching the same 72 hours of embryo development happen over and over and over and over and over again. six decades of gastrulation. you could wind up in a time loop and might not even notice

[bpod-bpod]

Feeling the Squeeze

A critical process in early development, gastrulation defines the transition from a single layer of cells, known as the epiblast, to a more complex structure formed of three germ layers – the endoderm, mesoderm and ectoderm – which later give rise to different structures in the body. A key process in gastrulation is the epithelial-to-mesenchymal transition (EMT), in which epiblast cells undergo major changes in shape and gene expression to detach from their neighbours and move away. By labelling cell membranes with fluorescent proteins and using time-lapse microscopy, researchers were able to film cells undergoing the EMT (pictured in green) in developing mouse embryos, revealing how cells extract themselves by incrementally contracting their outer, or apical, surfaces (in red). EMTs are also a feature of cell movements later in life, from wound healing to cancer cell migration in metastasis, so studying these transitions could inspire new ways to prevent cancers from spreading.

Written by Emmanuelle Briolat

Image from work by Alexandre Francou, Kathryn V Anderson and Anna-Katerina Hadjantonakis

Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA

Image copyright held by the original authors

Research published in eLife, May 2023

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[science-selected-yura15cbx]

Mechanical induction in metazoan development and evolution: from earliest multi-cellular organisms to modern animal embryos | Nature Communications

A gentle marine hydrodynamic flow, simulating gentle waves on the seashore, was found to be able to induce active gastrulation in a Myo-II-dependent process in the cnidarian sea anemone H. vectensis... the organism would have been stabilized by natural selection due to its advantageous ability to capture and digest more prey by sensing the flow. Later, such mechanical signals could arise spontaneously and homogeneously around the embryo as active mechanical fluctuations.

Обнаружено, что пологий морской гидродинамический поток, имитирующий мягкие волны на берегу моря, способен вызывать активную гаструляцию в процессе, зависящем от Myo-II, у книдарной актинии Н. вектенсис... организм был бы стабилизирован за счет естественного отбора из-за его выгодной способности захватывать и переваривать больше добычи, ощущая поток. Позже такие механические сигналы могли возникать спонтанно и гомогенно вокруг эмбриона в виде активных механических флуктуаций.

[draft-9264]

Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo.[1][2] Human embryosreach the blastocyst stage 4–5 days post fertilization, at which time they consist of 50–150 cells. Isolating the inner cell mass (embryoblast) using immunosurgeryresults in destruction of the blastocyst, a process which raises ethical issues, including whether or not embryos at the pre-implantation stage have the same moral considerations as embryos in the post-implantation stage of development.[3][4]

Researchers are currently focusing heavily on the therapeutic potential of embryonic stem cells, with clinical use being the goal for many laboratories.[2] Potential uses include the treatment of diabetes and heart disease.[2] The cells are being studied to be used as clinical therapies, models of genetic disorders, and cellular/DNA repair. However, adverse effects in the research and clinical processes such as tumors and unwanted immune responses have also been reported.[5]

Properties

IPS Cell The transcriptome of embryonic stem cells

Embryonic stem cells (ESCs), derived from the blastocyst stage of early mammalian embryos, are distinguished by their ability to differentiate into any embryonic cell type and by their ability to self-renew. It is these traits that makes them valuable in the scientific and medical fields. ESCs have a normal karyotype, maintain high telomerase activity, and exhibit remarkable long-term proliferative potential.[6]

Pluripotent

Embryonic stem cells of the inner cell mass are pluripotent, meaning they are able to differentiate to generate primitive ectoderm, which ultimately differentiates during gastrulation into all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm. These germ layers generate each of the more than 220 cell types in the adult human body. When provided with the appropriate signals, ESCs initially form precursor cells that in subsequently differentiate into the desired cell types. Pluripotency distinguishes embryonic stem cells from adult stem cells, which are multipotent and can only produce a limited number of cell types.

Self renewal and repair of structure

Under defined conditions, embryonic stem cells are capable of self-renewing indefinitely in an undifferentiated state. Self-renewal conditions must prevent the cells from clumping and maintain an environment that supports an unspecialized state.[7] Typically this is done in the lab with media containing serum and leukemia inhibitory factor or serum-free media supplements with two inhibitory drugs ("2i"), the MEK inhibitor PD03259010 and GSK-3 inhibitor CHIR99021.[8]

Growth

ESCs divide very frequently due to a shortened G1 phase in their cell cycle. Rapid cell divisionallows the cells to quickly grow in number, but not size, which is important for early embryo development. In ESCs, cyclin A and cyclin E proteins involved in the G1/S transition are always expressed at high levels.[9] Cyclin-dependent kinases such as CDK2 that promote cell cycle progression are overactive, in part due to downregulation of their inhibitors.[10] Retinoblastoma proteins that inhibit the transcription factor E2F until the cell is ready to enter S phase are hyperphosphorylated and inactivated in ESCs, leading to continual expression of proliferation genes.[9] These changes result in accelerated cycles of cell division. Although high expression levels of pro-proliferative proteins and a shortened G1 phase have been linked to maintenance of pluripotency,[11][12] ESCs grown in serum-free 2i conditions do express hypo-phosphorylated active Retinoblastoma proteins and have an elongated G1 phase.[13] Despite this difference in the cell cycle when compared to ESCs grown in media containing serum these cells have similar pluripotent characteristics.[14] Pluripotency factors Oct4 and Nanog play a role in transcriptionally regulating the embryonic stem cell cycle.[15][16]

Uses

Due to their plasticity and potentially unlimited capacity for self-renewal, embryonic stem cell therapies have been proposed for regenerative medicine and tissue replacement after injury or disease. Pluripotent stem cells have shown promise in treating a number of varying conditions, including but not limited to: spinal cord injuries, age related macular degeneration, diabetes, neurodegenerative disorders (such as Parkinson's disease), AIDS, etc.[17] In addition to their potential in regenerative medicine, embryonic stem cells provide a possible alternative source of tissue/organs which serves as a possible solution to the donor shortage dilemma. There are some ethical controversies surrounding this though (see Ethical debate section below). Aside from these uses, ESCs can also be used for research on early human development, certain genetic disease, and in vitro toxicologytesting.[6]

DRAFT

[elfpylon]

studying embryo gastrulation while listening to eva entry plug sound

[leedsomics]

Three-dimension transcriptomics maps of whole mouse embryo during organogenesis

Understanding mammalian development heavily relies on classical animal models like the house mouse (Mus musculus). Advanced spatial transcriptomics has enabled biologists to break new ground in studies of molecular dynamics and cellular patterning during embryonic development with spatiotemporal resolution. To construct a comprehensive developmental trajectory, current three-dimensional (3D) spatial transcriptomic profiling leverages mouse embryos from gastrulation (E5.5) to organogenesis (E13.5) in continuity. However, a crucial phase for early organogenesis between E9.5 and E11.5 was deficient. To unveil the mystery of this stage, we present the 3D transcriptomics of mouse embryos at E9.5 and E11.5, with a widely applicable reconstruction workflow that bypasses sophisticated bioinformatic calculations. As our 3D atlas is generated at single-cell resolution, we demonstrate how organogenetic processes can be interpreted at different levels of granularity, from local cellular interactions to whole embryonic regionalization. We release the open-access database MOSTA3D (Mouse Organogenesis Spatiotemporal Transcriptomic Atlas in Three-dimensional) and hope a broader community will contribute to extending this framework from conception to senility in the near future. http://dlvr.it/TC7NxX