Not exact matches
The first page
of Larsen's Human Embryology states that, `... [W] e begin our description
of the developing human
with the formation and differentiation
of the male and female sex cells or gametes [sperm and egg], which will unite at fertilisation to initiate the
embryonic development of a new individual».
This complex society may be said to begin
with conception, or
with a late stage
of embryonic development, or
with early childhood, depending upon the purpose which determines what one takes as its defining characteristic.
I have decided to break this topic down into 3 parts: How to Incubate Chicken Eggs
with Kids, Stages
of Embryonic Development and Activities to do while Incubating, and finally The Hatch and Going Home.
Perhaps the most astonishing stage
of pregnancy is that
of the
embryonic development as your unborn child goes from being the size
of a sesame seed and looking like a tadpole to being the size
of a kidney bean
with some neck definition and tiny webbed fingers and toes.
The latest findings show that genetic defects in the body's ability to manufacture carnitine might be associated
with an increased risk
of autism because carnitine deficiency interferes
with the normal processes by which neural stem cells promote and organize
embryonic and fetal brain
development.
To investigate whether maternally supplied gdf3 mRNA also plays a role in left - right patterning, the researchers used a series
of experimental tricks to supply embryos
with enough Gdf3 protein to form the mesoderm and endoderm and survive until the later stages
of embryonic development.
Others have tracked the first few hours
of the
embryonic development of sea urchins and other organisms
with the goal
of seeing how various transcription factors alter gene expression over time.
Belyaev suggested that sometime during
embryonic development the production
of dopa was delayed, creating docile foxes
with patches
of white fur and skin.
In 2014, UCSF's Nathan Young and Ralph Marcucio, working
with Schneider, carried out extensive skull measurements on a variety
of embryonic vertebrates and determined the point during
development at which the bird face begins to diverge from those
of other vertebrates.
«The new experimental techniques we used, combined
with collaborative efforts
of biologists and computer scientists, are allowing us to gain new insight into the exquisite accuracy
of embryonic development.»
Because
development often reprises stages
of evolution, the growth
of embryonic ears in tandem
with the jaw is no accident: the sound - transmitting middle ear bones that are a distinguishing feature
of mammals evolved from what used to be gill arches in fish and jawbones in reptiles.
They tried hundreds
of different recipes; eventually they discovered that if they mixed liver precursor cells (derived from iPS cells)
with two other types
of standard human cell lines known to be important for
embryonic liver
development, then the cells would spontaneously form a 4 to 5 - millimeter 3D structure called a liver bud.
This molecule pours out
of embryonic cranial cells after infection
with Zika virus, and could harm brain
development.
These are essential for supporting
embryonic and fetal
development, and many pregnancies fail because
of problems
with these tissues.
Veronica Palma, from University
of Chile, led the study
with Rehen and highlights the combined approaches allowed the creation
of an environment that mimics the one during
embryonic brain
development.
The next step, he says, is to investigate how
embryonic mouse brains
with induced folds develop as they mature past the fetal stages
of development and to look across species to see if the gene has similar effects in other mammals.
Now,
with more ways to monitor gene activity during
development — and fully sequenced genomes
of various snakes and other reptiles for comparison — Cohn and graduate student Francisca Leal have tracked the genetic activity in
embryonic pythons to see why their legs start, but never finish, developing.
Because bat experts think that the ancestor
of all bats was a small mammal
with short forelimbs like that
of the mouse, the researchers next compared bat and mouse
embryonic development.
The researchers hope that these assays will be used by many laboratories that are studying the events associated
with early
embryonic development and the effect
of repeat length and methylation status on gene expression and differentiation.
Embryonic development in mammals begins
with the division
of the fertilized egg, which is then followed by several further rounds
of division to form the blastocyst, a sphere
of cells made up
of two layers
of cells surrounding a fluid - filled cavity.
However, malformation
of skeletal bones during embryogenesis also occurs in FOP patients and illustrates that the underlying genetic mutation occurs in a gene
with functional importance in regulating chondro - osseous differentiation during
embryonic skeletal
development as well as in adult musculoskeletal tissues.
Although we agree that greater investments are needed in the clinical
development of these therapies, we disagree
with the authors» suggestion that, relative to
embryonic stem cells, adult stem cells provide a superior vehicle for cell - based therapies because they lack tumorigenic activity, can be prepared by methods approved by the Food and Drug Administration (FDA), and have been free
of ethical controversy.
CARS microscopy also confirmed the gradual increase
of the size
of lipid containing structures during oogenesis (Figs. 5A and 5B), the sudden re-localization
of these structures to the periphery
of the dividing nucleus in the first
embryonic division (Fig. 5E), and the propagation
of this phenotype, although
with gradually diminishing appearance, throughout
embryonic development (Figs. 5F and 5H).
In the new research, Pollen and co-first author Tomasz Nowakowski, PhD, also a postdoctoral researcher in the Kriegstein lab, partnered
with Fluidigm Corp. to develop a microfluidic approach to map out the transcriptional profile — the set
of genes that are actively producing RNA —
of cells collected from the VZ and SVZ during
embryonic development.
The grand architecture
of the human cortex,
with its hundreds
of distinct cell types, begins as a uniform layer
of neural stem cells and builds itself from the inside out during several months
of embryonic development.
Correspondingly, endothelial - specific deletion
of Tie2 using Ve - cad - Cre driver mice, pursued in validating the Tie2fl / fl mice used in this study, essentially phenocopied the global Tie2 KO phenotype
with embryonic lethality around E10.5 (Supplementary Fig. 13), confirming the key role
of endothelial Tie2 during
embryonic development.
Eight HARs showed differences in their enhancer activity when the human mutations were present.4 These differences modify how genes were expressed in the developing limb (HAR2, 2xHAR114), eye (HAR25), and central nervous system (2xHAR142, 2xHAR238, 2xHAR164, 2xHAR170, ANC516 / HARE5).4, 10 Because relatively few time points have been examined, it is likely that an even higher percentage
of the tested HARs are active enhancers at some point during
embryonic development or in adult tissues, possibly
with human - chimp differences.
In view
of the different timing
of meiotic initiation in female and male mammals, we determined the developmental expression profile
of mouse Boule during both male and female
embryonic gonadal
development (
embryonic day 10.5, E12.5, E16.5 and E17.5) in comparison
with adult gonads.
The challenge takes on even more urgency
with recent
developments, including a federal administration now more open to exploring the potential
of stem cells, the recent FDA approval
of a human trial involving
embryonic stem cells, as well as the reported case
of a young boy who developed a brain tumor four years after receiving a stem - cell treatment for a rare genetic disorder.
It is based on the definitive books
of mouse
embryonic development by Theiler (1989) and Kaufman (1992) yet extends these studies by creating a series
of three dimensional computer models
of mouse embryos at successive stages
of development with defined anatomical domains linked by a stage - by - stage ontology
of anatomical names.
These findings on gene expression in single
embryonic stem cells are in concert
with recent studies
of early mammalian
development, which reveal molecular heterogeneity and a stochasticity
of gene expression in blastomeres.
We show that DONSON is expressed in progenitor cells
of embryonic human brain and other proliferating tissues, is co-expressed
with components
of the DNA replication machinery, and that Donson is essential for early
embryonic development in mice as well, suggesting an essential conserved role for DONSON in the cell cycle.
For example, clusters containing genes that are upregulated during the course
of ES cell differentiation (Table 3) include in order
of time
of expression: cluster 30 that represents genes which take part in the formation
of the three
embryonic germ layers during gastrulation, i.e., Goosecoid, Cerberus like 1 homolog, Wnt3, Mesp1, Mixl1, mEomes and Even - skipped 1; cluster 15 containing molecular regulators
of early mesoderm
development including Bmp2, Bmp5, Msx1, Msx2, Cripto, Tbx20, Hey2, Smad6, Vegfr2 (Kdr), Foxf1 and Hand1; cluster 20, which comprises regulatory and structural genes linked to hemopoiesis such as Gata1, Nfe2, Klf1, Tie1, hemoglobins (Hba - x, Hbb - b1) and Glycophorin A; cluster 12, which is rich in genes involved in cardiac
development, e.g., Mef2c, Myl4, cardiac Troponin T2, Tropomodulin 1, myosin binding protein C, Bves, Angiopoietin 1 and Angiopoietin 2; and, cluster 4, which consists mostly
of genes associated
with neuronal
development and differentiation, for example, Neurog1, Neurog2, Olig2, Nkx6.1, Neurod4, Pou3f2, Pou3f4, Cacna2d3, Cacng4, Kcnq2 and EphA5.
This current is a natural adjunct
of embryonic development, present in all wild - type hair cells but declining after birth
with emergence
of the normal - polarity current.
In the process new visual languages, commodities and life forms are being generated reflecting back to us our often violent entanglement
with the world: patterns
of embryonic development in mutated lab - test worms, live - streamed flows
of CO2 gas across the planet, or a group
of near - extinct animals passing by a tree and noticing the tracking camera.