Function. In nuclear polyadenylation, a poly(A) tail is added to an RNA at the end of transcription. On mRNAs, the poly(A) tail protects the mRNA molecule from enzymatic degradation in the cytoplasm and aids in transcription termination, export of the mRNA from the nucleus, and translation.

I will try and rephrase:"knowing how strict the RNAseq is what do you do to accept a large majority of situations ;do you change the sample (as you would do normally) or does RNAseq allow some changes to the original technique if so what are they and when do they apply"

Can one of those changes be the polyA(bacteria, archaea, eukaryotes), what to do and if the solution could be a polyU.

Where would you use a polyT and why?

With the increased reads generated by newer sequencers and the decreasing cost of RNAseq overall, many groups have moved away from using polyA enrichment (pull down and keep polyadenylated RNAs) during RNAseq library preparation in favor of ribodepletion (pulldown and discard ribosomal RNAs) . For some applications, such as analysis of many noncoding RNAs, this is a necessary switch. For analyzing non-ribosomal RNAs in bacteria this seems to be the standard approach.

For a review of bacterial RNAseq library preparation see: https://currentprotocols.onlinelibrary.wiley.com/doi/10.1002/cpnc.55#cpnc55-prot-0001.

Function. In nuclear polyadenylation, a poly(A) tail is added to an RNA at the end of transcription. On mRNAs, the poly(A) tail protects the mRNA molecule from enzymatic degradation in the cytoplasm and aids in transcription termination, export of the mRNA from the nucleus, and translation.