A chalazion is caused by the oil in the gland becoming too thick to flow out of the gland or the opening of the gland being obstructed. Without anywhere to go, the oil builds up inside the gland and forms a lump in the eyelid.ach of the oil glands, called meibomian glands, produces oil that flows out of the gland into the tears. The oil exits from each gland through a tiny circular opening just behind the eyelashes of the upper and lower lids of both eyes.
Transcription activator-like effector nucleases (TALENs) are artificial restriction enzymes generated by fusing a TAL effector DNA-binding domain to a DNA cleavage domain.Restriction enzymes are enzymes that cut DNA strands at a specific sequence.rom Wikipedia, the free encyclopedia. Transcription activator-like effector nucleases (TALENs) are artificial restriction enzymes generated by fusing a TAL effector DNA-binding domain to a DNA cleavage domain. Restriction enzymes are enzymes that cut DNA strands at a specific sequence.
Transcription is carried out by an enzyme called RNA polymerase and a number of accessory proteins called transcription factors.Transcription factors can bind to specific DNA sequences called enhancer and promoter sequences in order to recruit RNA polymerase to an appropriate transcription site.Together, the transcription factors and RNA polymerase form a complex called the transcription initiation complex.he newly formed mRNA copies of the gene then serve as blueprints for protein synthesis during the process of translation. Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA).