Which of the following is most likely to increase expression of a particular gene? Group of answer choicesa mutation in a silencerrecruitment of histone methyltransferasesrecruitment of histone deacetylasescis regulation by a lncRNA

The option most likely to increase the expression of a particular gene is "cis regulation by a lncRNA".

Here's why:

a) A mutation in a silencer: Silencers are DNA sequences that, when bound by specific proteins, can inhibit the transcription of a gene. A mutation in a silencer could potentially increase gene expression, but it could also decrease it, depending on the nature of the mutation. Therefore, this is not the most likely option.

b) Recruitment of histone methyltransferases: Histone methyltransferases are enzymes that add methyl groups to histones, the proteins around which DNA is wound. This usually leads to a more compact and less accessible chromatin structure, which generally decreases gene expression. So, this option is not likely to increase gene expression.

c) Recruitment of histone deacetylases: Histone deacetylases are enzymes that remove acetyl groups from histones. This also leads to a more compact chromatin structure, which generally decreases gene expression. So, this option is not likely to increase gene expression either.

d) Cis regulation by a lncRNA: Long non-coding RNAs (lncRNAs) can regulate gene expression in a variety of ways, including both upregulation and downregulation. Cis regulation refers to regulation of a gene by elements (in this case, the lncRNA) on the same strand of DNA. If a lncRNA is acting in cis to upregulate a gene, it could very well increase gene expression. Therefore, this is the most likely option.