Category: Embryology
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Connection (and difference) between buccal membrane and buccopharyngeal membrane
A Tale of Two Tissues Prepare yourself for a thrilling journey into the world of microscopic membranes! Today, we’re diving deep into the oral cavity to explore the buccal membrane and its embryonic cousin, the buccopharyngeal (aka oropharyngeal) membrane. It’s a story of similarities, differences, and developmental drama! Act I: The Buccal BombshellOur first star,…
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embryonic intrigue that’ll make your buccopharyngeal membrane quiver with excitement!
Picture, if you will, the humble beginnings of life, where a thin membrane known as the buccopharyngeal membrane (or oropharyngeal membrane for those who like their words extra fancy) plays the role of the ultimate gatekeeper between the primitive mouth and pharynx. It’s like nature’s very own “You shall not pass!” moment, but with fewer…
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Sex-determining region Y protein (SRY), or testis-determining factor (TDF)
Sex-determining region Y protein (SRY), or testis-determining factor (TDF), is a DNA-binding protein (also known as gene-regulatory protein/transcription factor) encoded by the SRY gene that is responsible for the initiation of male sex determination in therian mammals (placental mammals and marsupials). SRY is an intronless sex-determining gene on the Y chromosome. Mutations in this gene lead to a range of disorders of sex development with varying effects on an individual’s phenotype and genotype. SRY is a member of the SOX (SRY-like box)…
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DAX1
DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1) is a nuclear receptor protein that in humans is encoded by the NR0B1 gene (nuclear receptor subfamily 0, group B, member 1). The NR0B1 gene is located on the short (p) arm of the X chromosome between bands Xp21.3 and Xp21.2, from base pair 30,082,120 to base pair 30,087,136. Function This gene encodes a protein…
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Steroidogenic factor 1 (SF-1) protein and a few related things
The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling the activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the NR5A1 gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles…
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Structure of DNA repair protein XRCC4 aka X-ray repair cross-complementing protein 4
XRCC4 protein is a TETRAMER that resembles the shape of a DUMBBELL containing two globular ends separated by a long, thin stalk. The tetramer is composed of two dimers, and each dimer is made up of two similar subunits. The first subunit (L) contains amino acid residues 1 – 203 and has a longer stalk than the second…
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Vitelline duct connects the yolk sac to the small intestine. This duct obliterates when the embryo is about 6 weeks old. Complete failure of the duct to obliterate results in a fistula from the ileum to the umbilicus (vitelline fistula).
In the human embryo, the vitelline duct, also known as the vitellointestinal duct, the yolk stalk, the omphaloenteric duct, or the omphalomesenteric duct, is a long narrow tube that joins the yolk sac to the midgut lumen of the developing fetus. It appears at the end of the fourth week, when the yolk sac (also known as the umbilical vesicle) presents the appearance of a small pear-shaped vesicle. Function Obliteration Generally, the duct…
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A Mad Scientist’s Dream – Rumpless Chickens (and more)
Today, we delve into the bizarre phenomenon of rumpless chickens—a feathered marvel characterized by caudal dysplasia, or as some like to call it, the ultimate chicken makeover! These quirky birds are missing their pygostyle, that charming little appendage known as the “parson’s nose,” a mutation that defies nature itself. This peculiar trait is inherited through…
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Prenatal exposure to paracetamol/acetaminophen and precursor aniline impairs masculinisation of male brain and behaviour
Paracetamol/acetaminophen (N-Acetyl-p-Aminophenol; APAP) is the preferred analgesic for pain relief and fever during pregnancy. It has therefore caused concern that several studies have reported that prenatal exposure to APAP results in developmental alterations in both the reproductive tract and the brain. Genitals and nervous system of male mammals are actively masculinised during foetal development and…
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Agrin is a large chimeric proteoglycan, a heparan sulfate and chondroitin proteoglycan, whose best-characterised role is in the development of the neuromuscular junction during embryogenesis
Agrin was originally found in the electric organ of Tarpedo california and in the basal lamina at the neuromuscular junction as a protein that directs the aggregation of acetylcholine receptors (AChR) and acetylcholinesterase (AChE) at synaptic sites. Tetronarce californica also known as the Pacific electric ray is a species of electric ray in the family Torpedinidae, endemic to the coastal waters of the northeastern Pacific Ocean from Baja California to British Columbia. It generally inhabits sandy flats, rocky reefs, and kelp forests from the surface…
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Cleavage (embryology)
In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula. Cleavage ends with the formation of the blastula, or of the blastocyst in…
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Vitellin is essential in the fertilization process, and embryonic development in egg-laying organisms
Vitellin is a protein found in the egg yolk. It is a phosphoprotein. Vitellin is a generic name for major of many yolk proteins. Vitellin has been known since the 1900s. The periodic acid-Schiff method and Sudan black B dye was used to help determine that Vitellin is a glycolipoprotein because it stained positive when tested. This protein was…
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Opioid growth factor receptor
Opioid growth factor receptor, also known as OGFr or the ζ-opioid receptor, is a protein which in humans is encoded by the OGFR gene. The protein encoded by this gene is a receptor for opioid growth factor (OGF), also known as [Met(5)]-enkephalin. The endogenous ligand is thus a known opioid peptide, and OGFr was originally discovered and named as a new opioid receptor zeta (ζ). However it was…
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Pulmonary neuroendocrine cells
Neuroendocrine cells are cells that receive neuronal input (through neurotransmitters released by nerve cells or neurosecretory cells) and, as a consequence of this input, release messenger molecules (hormones) into the blood. In this way they bring about an integration between the nervous system and the endocrine system, a process known as neuroendocrine integration. An example of a neuroendocrine cell is a cell…
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CBP and p300 are critical for normal embryonic development
Mouse models CBP and p300 are critical for normal embryonic development, as mice completely lacking either CBP or p300 protein, die at an early embryonic stage. In addition, mice which lack one functional copy (allele) of both the CBP and p300 genes (i.e. are heterozygous for both CBP and p300) and thus have half of the normal amount…
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Cadherin-1
Cadherin-1 or Epithelial cadherin(E-cadherin), (not to be confused with the APC/C activator protein CDH1) is a protein that in humans is encoded by the CDH1gene.[5] Mutations are correlated with gastric, breast, colorectal, thyroid, and ovarian cancers. CDH1 has also been designated as CD324 (cluster of differentiation 324). It is a tumor suppressor gene.[6][7] History The discovery of cadherin cell-cell adhesion proteins is attributed to Masatoshi Takeichi, whose experience…
