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Checking Cancer At Its Origin..

In a first, the lab led by Leonard Zon at Boston Children’s Hospital has visualised the emergence of the primary melanoma cell in transgenic zebrafish that harbour the human oncogenic BRAFV600E mutation in melanocytes. This cancerous state is characterised in maturing fish by the formation of neural crest progenitors [NCPs], which are the predecessors of melanocytes and are only seen in the embryonic stage of healthy zebrafish.

The Zon lab placed the human mutated oncogene, BRAFV600E (a characteristic of benign human nevi/moles) under the control of a melanocyte-specific promoter and introduced it into the zebrafish. Generations of this transgenic fish were engineered such that they were also deficient in functional p53 (loss of function mutation). They used previous findings that in healthy zebrafish, a gene called crestin is expressed only in the embryonic NCPs and never throughout maturity, but is re-expressed selectively in melanomatous cells during adulthood. crestin was cloned adjacent to a reporter, enhanced green fluorescent protein [EGFP] for live imaging purposes.

The developmental phases of the fish, that were by now triple transgenic (for human BRAFV600E, p53 LOF and crestin:EGFP) were observed by live imaging; ~21 days after fertilisation, the expression of crestin:EGFP localised precisely to the (future) melanoma sites, and the very first triple-transgenic (individual) cells that went on to form larger masses of cells were also observed. To summarise, melanoma formation was observed in three stages: individual fluorescent cells, followed by these cells multiplying to form groups of <50 cells, and lastly these groups forming raised lesions. This consistently held true, with all 30 observed individual cells turning into 30 lesions. These results are illustrated in Figure 1.

Figure 1. In the top left box, a single cell is visualised as it multiplies into a group of melanoma cells (top right). The bottom images show the raised melanoma lesion as observed by the naked eye and by live imaging. The green fluorescence emitted from EGFP indicates that it is localised only to the melanoma (as is crestin expression), that is, it has not metastasised elsewhere. 

These pre-cancerous cells were also shown to be self-sustaining and tumourigenic: when fish scales containing the mutant cells were transplanted to another part of the same fish (auto-transplant) or to another fish (allo-transplant) that was also exposed to radiation, the cells proliferated in the new site, as well as penetrated the hypodermis underneath (Figure 2).

Figure 2. The fluorescence indicates a single scale being auto-transplanted elsewhere on the same fish. As the days progress, the patch expands as well, and after day 33, the cells penetrate deeper into the hypodermis and thrive independently, and excising the transplanted scale proves futile. 

Role of Transcription Factor sox10

sox10 is a master TF in NCP and its over-expression has been correlated with increased crestin expression, and accordingly, sox10 over expression in the transgenic melanocytes accelerated the melanoma onset. Following the logical train of thought that sox10 promotes melanoma progression, it was then targeted by CRISPR-Cas9 and inactivated in the transgenic cells. This resulted in a delayed onset of melanoma (180 days) compared to the controls (133 days). sox10 is also known to be expressed in most human melanoma cell lines. Moreover, the DNA element that acts as the binding site for Sox10 is also found in a hyper-acetylated [H3K27Ac], super-enhancer state. This is an epigenetic alteration and may prove a useful target in therapy (ex. HAT inhibitors).

Summary

The key finding clears up a hitherto ambiguous association between a reversion to stem/progenitor cell-like status and cancer: it indicates that the apparent devolution of a specialised cell to a primitive cellular state is not a consequence of cancer progression, but that it is an hallmark of pre-cancerous cells that may contribute to tumour progression. The rarity of melanoma formation among the mutant cells also suggests that the double mutant [BRAFV600E; p53 LOF] is not the only factor to influence the onset. Experimentally, crestin expression was a definitive prelude to formation of nevi which transformed into full-fledged raised melanomas in that spot.

This discovery has two chronological applications: first, of the many susceptible melanocytes harbouring the mutated oncogene, we can find out which are most likely to enter the melanoma state. Peaks in the expression profile of sox2, or a couple other TFs, dlx2 and tfap2, can prove to be a telltale pre-melanoma signature and thus be used in diagnosis. Secondly, by doing so, these can be better targeted early on before they’ve disseminated and become virtually untreatable.

Kaufman CK, Mosimann C, Fan ZP, Yang S, Thomas AJ, Ablain J, et al. A zebrafish melanoma model reveals emergence of neural crest identity during melanoma initiation. Science. 2016;351[6272]:aad2197–aad2197.

So this is an amazing thing we talked about in bio the other day. It’s a method called Brainbow. It’s really hard to track neurons when they can get so long and tangly, as you can see in this light microscopy of a mouse hippocampus, so scientists can mark each neuron with a different color of fluorescence via transgenes that produce fluorescent proteins. What a brilliant solution! 

(Image caption: Lines labeling cortical subplate, mesencephalic, and diencephalic cell types (see Fig. 7 in Shima et al.))

Trapping individual cell types in the mouse brain

The complexity of the human brain depends upon the many thousands of individual types of nerve cells it contains. Even the much simpler mouse brain probably contains 10,000 or more different neuronal cell types. Brandeis scientists Yasu Shima, Sacha Nelson and colleagues report in the journal eLife on a new approach for genetically identifying and manipulating these cell types.

Cells in the brain have different functions and therefore express different genes. Important instructions for which genes to express, in which cell types, lie not only in the genes themselves, but in small pieces of DNA called enhancers found in the large spaces between genes. The Brandeis group has found a way to highjack these instructions to express other artificial genes in particular cell types in the mouse brain. Some of these artificially expressed genes (also called transgenes) simply make the cells fluorescent so they can be seen under the microscope. Other transgenes are master regulators that can be used to turn on or off any other gene of interest. This will allow scientists to activate or deactivate the cells to see how they alter behavior, or to study the function of specific genes by altering them only in some cell types without altering them everywhere in the body. In addition to developing the approach, the Brandeis group created a resource of over 150 strains of mice in which different brain cell types can be studied.

After the pSB999 (above is a similar pBR322) plasmid has been taken into the cell, the expression of ampicillin resistance is not instantaneous. The coding region ampRmust undergo transcription into mRNA which must then be translated. Translation is the biosynthesis of proteins from mRNA. The expression of ampR results in an empirical phenotype, ampicillin resistance. 

Composite picture of a zebrafish embryo.  This fish has a transgene that causes cells  that produce isotocin, the zebrafish equivalent of oxytocin, to fluoresce green.  Zebrafish embryos are transparent, so we can actually watch the oxytocinergic system as it develops.  We can also observe the effects of different treatments, such as alcohol or various drugs, on its development.

(My boss took this picture, which is why it’s good :P)

Mirrors

Summary: Dean Winchester was used as a DNA print for underground organization Manticore. When the well known hunter is also being hunted by the FBI, Manticore takes matters on their own hands. Sending his own clone, X5 4-9-2 a.k.a Alec McDowell. 

Author: deanwinchester-af

Words: 1.1k

Beta: Wifey @waywardlullabies.

Warnings: None really. 

A/N: This is fic is based on this gifset AU/Crossover SPN x Dark Angel. It was so much fun to write and exciting since it’s something new for me. I love lec and I love Dean, I don’t think there was another better way to mix this great characters together. Feedback is always very appreciated it ♥

THANKS FOR READING AND ENJOY♥


People thought Manticore extremely created their transgenics from scratch. Little did they know, the underground facility obtained their DNA basics from everyday human beings. Normally, they would get the DNA from nobody’s, people that won’t get into any trouble or live enough. These types of missions weren’t normal for the organization, and neither was sending the target’s own DNA print. Guess they were feeling poetic.

Alec has always been true to his purpose in this organization. Since a young age, Manticore trains them to become soldiers, soon enough transforming them into deathly beings.

“Have you been briefed on your target X5 4-9-4?”

“Yes, sir. Dean Winchester, 31 from Lawrence, Kansas. He was used as a DNA print for Manticore.”

“Good. You leave tomorrow at first light, don’t make us regret sending you back out there.”

“You will not be disappointed of me, sir.”

Alec’s superior nodded his head once before leaving him alone inside the cell. Manticore wasn’t a the typical place someone would call home. The facilities were something in between a military base and jail. And they were more close to a maxim jail. No one walked out of Manticore unless they were assigned on missions, and even so, they were always place killing ships just below their brains to make sure their transgenics came back.

Keep reading

Semana 5 – CRISPR: el segundo aire de la revolución genética

/ Esta semana les traemos como tema principal algo que promete ser una nueva revolución de las tecnologías biológicas: la edición genética con CRISPR. ¿Qué es CRISPR? Siglas complicadas, pero pegajosas, que nombran a la biotecnología que permite modificar el ADN de prácticamente cualquier organismo a bajísimo costo y muy fácilmente. Pero, ¿hay que empezar a tener miedo de los peores escenarios de ciencia ficción? ¿Cómo es que surgió esta tecnología? ¿Por qué está en el centro de una encarnizada pelea por la patente? Y, sobre todo, ¿estamos listos para ella? Invitamos a Sofía Flores, miembro del equipo Cienciacional, a que nos ayudara a despejar estas dudas.  

Además, comentamos con Emiliano Rodríguez, también miembro de HC, la noticia de que muchos gobiernos del mundo han estado reportando menos contaminantes atmosféricos de los que en realidad emiten, y México es uno de los que ofreció cifras más discordantes.

¡Acompáñennos a hablar de ciencia!

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Menú

00:13 – Introducción

3:36 – CRISPR y la nueva revolución de la edición genética, con Sofía Flores

46:00 – Gobiernos que reportan menos de lo que contaminan, con Emiliano Rodríguez

Créditos musicales completos en nuestra página de Soundcloud.

Este podcast es producido independientemente desde un lugar no determinado de la Ciudad de México.

Promethean Thieves by YesBothWays on AO3

They were careful. Delphine treated Cosima, ran tests on her computer at night, and deleted the data as best she could. As soon as she was strong enough, Cosima helped on Delphine’s current project developing transgenic skin grafts that could slowly introduce new genetic material into the entirety of the recipient’s skin cells. Cosima knew failed attempts would be horrifying – grievous burns and wounds healed only to turn into a cancer that consumed healthy tissues. But successes were promising. It was easy enough to play their parts as two scientists enamored of the same potential. Other than that, they tried to appear relatively estranged, even though they were clinging to one another silently everyday.

(Read fic on AO3)

Years ago i had a Dom who broke up with me over the internet.  He wanted to dress as a Mistress to tie me up and spank me.  i accepted it was a part of Him, but said i couldn’t do that, though i was happy for Him to do it with someone else.  So He did.  Played with a transgenered sub we knew and dumped me.

i accept everyone having a right to do what is right for them.  i just can’t be in a relationship with someone who wants to cross dress in front of me.  Maybe i’m old fashioned, but i need my Men to be Men.

anonymous asked:

Why do you say that one of the reasons of you not going to the U.S. is because the food is unhealthy? The country, like any other, has both healthy and unhealthy food.

…hi dear anonymous…:D…yeah i agree …in that point…but the problem to me is that in America is more unhealthy….than healthy….coz most of them r transgenic food….even if u want to cook ur own food and eat “healthy” u can’t coz -  at least to me-  it’s difficult find the ingredients…:D…. all those brands who said “organic” r  just marketing….the difference with other countries it’s that u can find  organic food…..don’t get me wrong…i don’t say it that other countries don’t have transgenics …..but my point is that in some of them u still have real organic food…:D….and u can eat healthy if u want…….that’s my opinion…;D…..but i rly don’t want to get a disscusion for this…so hope now it’s clear…:D..HUGE THANKS 4 asking and have a wonderful day and life!!!!..;D!!!