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 [edit]. Generation of RNA from DNA is known as transcription. In other word transcription is the process of creating a complementary RNA copy of a sequence of DNA. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand.romoter â a nucleotide sequence that enables a gene to be transcribed. The promoter is recognized by RNA polymerase, which then initiates transcription. In RNA synthesis, promoters indicate which genes should be used for messenger RNA creation â and, by extension, control which proteins the cell manufactures.