First expirience in the CRAG

The Center for Research in Agricultural Genomics (CRAG) has been very kind with me,and has decided to help me in my research work. Montse Martín, a renouned scientist, leader in the investigation group plant virus, they recieved me with the open hands and hostesd me inside the investigation group, so I could document myself with first hand information so I can develop my Batxillerat final work. She will be my orientator in this agrifood work.

Image 1.1. Logo CRAG

CRAG is an independent investigation center associated with the Consell Superior d'Investigacions Científiques (CSIC), Institut d'Investigació i Tecnología agroalimentaria (IRTA), Universitat Autònoma de Barcelona (UAB), and the Universitat de Barcelona (UB).

Image 1.2. CRAG building situated on the UAB

What is a gene?

A gene is a lineal sequence of nucleotides of DNA or RNA, located in cell nucleus, essential to carry out a manifestation of an inheritable characteristic of an alive individual. In terms of structure, a gen is a fragment of a large molecule of DNA that storage information to fabricate a determined protein. This protein is the one who determine the corresponding character, as the eyes color, skin color, presence of seeds, resistance to a disease,...

Image 2.1. Image of a chromatide and the material contained on it, showing in an augmentated way, a gene (yellow)

Image 2.2. An image that shows
in yellow and red two different 
locus.

Usually, genes develop its function through transcription and translation. In some cases, although, can happen that a gene can make its function doesn't necessarily requiring this genetic processes. 

Each gene occupies a certain position in the chromosome called locus. And if you take into account the whole chromosomes of an individual we talk about the genome, as it is the set of genes of species.

To understand it easily, maybe is better to think of the DNA or RNA that form an individual (genome) as an ecnyclopedia, in which the nucleotides are the letters, the genes are the amount of chapters that compose the volumes created by the agrupation of letters in a determined way, and the chromosomes are the different volumes that form the encyclopedia.

Image 2.3. Gene sequence showing the nucleotides and each aminoacid formed

What is the genetic engineering?

Image 3.1. Picture showing
how we can play with the
DNA.

Is an amount of techniques that allow you modify the characteristics of an alive organism through directed and controlled modification of its genome, adding, eliminating or modifiying some of its genes, that it is not other than a modification in the DNA of the organism all time oversight by humans who carry it out. 

Image 3.2. Picture showing how we can play
with the DNA.

Thus, among other applications, genetic engineering allows you to eliminate an undesirable characteristic as producing a toxine, annulling the corresponding gene. 

Also it allows you to introduce a new characteristic as an insect resistance, copying the corresponding gene resistant to this individual from a resistant specie and introducing it in the genome of the susceptible specie. 

As it exist an universality of the genetic code, genetic engineering can use the "information" in all organisms.

What is a transgenic?

Image 4.1. gold rice 

transgenic plant.

Is an individual whose genome has been modified through genetic engineering, to introduce new genes or to modify the function of an own gene. Due to this modification the transgenic plant shows a new characteristic. Once carried out the insertion or modification of the gene, this expresses, and transmites itself to the offspring as one more gene of the individual. In concrete, in transgenic plants this genetic modification is performed in a coontrolled way that only affects a reduced number of well known genes. As a result of this fact, the transgenic variety don't differ much from none transgenic ones.

Image 4.2. Photo taken by me of a crop of transgenic plants resistant to a virus which has been tested by putting the virus in the atmosphere, hence, showing wich plants has acquired the gene (red) and which not, and are dying (yellow).

Who is the guilty of this vegetable crime?

There is no other culpable than Cucumovirus, which can be identified if looking to it  you are able to diferenciate a non-enveloped, spherical virion of about 29 nanometers in diameter, which has a T=3 icosahedral symmetry composed of 180 coat proteins: 12 pentamers and 20 hexamers.

Image 2.1. Picture about the real 
morfology of CMV

How this murderer is formed of?

It is not an easy question, and there must have being other researchs before answering this issue. His structure is formed of a segmented tripartite linear RNA composed of RNA1, RNA2 and RNA3. Each genomic segment is 3' tRNA-like structure and a 5' cap.

Image 2.2. Position of dierent RNA that compose the 
segmented tripartite linear virus RNA

This Cucumovirus expresses himself by using the RNA as a messager RNAs. Then, RNA1 and RNA2 encode proteins 1a and 2a, involved in the genome replication and internal transcription of sgRNA4 from the negative copy of RNA3. HRNA3 is translated into a movement protein, while sgRNA4 it translates to a capsid one. Apart from this, ORF2b, present at RNA2, encodes a viral supressor of RNA silencing.

How does it commit the crimes?

When the expression is done, virus expresses the protein 1st and 2nd to produce replication proteins, as I have mentioned before, on the viral factory and after it transcribes/replicates providing new ssRNA genomic (new viruses).

Everithing continues translating RNA4 that produces the capsid that envolves the ssRNA genome, and assemblying this virus particles.

Image 2.3. Picture of diferent viral factories for viruses

Finally, it is the turn of the viral movement protein, that triggers the information of tubular structures that mediate viron cell-to-cell transfer via a tubule-guided mechanism.