It seems that Titin is on the top of the list in many species. Interesting.More
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I think a good candidate is the human titin gene. The gene itself has 363 exons, depending on the isoform it has between 27.000 and 34.000 residues. This makes up a processed mRNA length of up to 100kb for the full length isoform. See either the Wikipedia article or the one linked below for more details:
If you are looking for the longest primary transcript, then the human dystrophin gene should be your favorite. It has a length of about 2.4 Megabases for the primary transcript, the processed transcript has only a length of about 14kb. It takes about 16 hours to transcribe and co-transcriptionally splice the sequence. See here for more details:
I think a good candidate is the human titin gene. The gene itself has 363 exons, depending on the isoform it has between 27.000 and 34.000 residues. This makes up a processed mRNA length of up to 100kb for the full length isoform. See either the Wikipedia article or the one linked below for more details:
If you are looking for the longest primary transcript, then the human dystrophin gene should be your favorite. It has a length of about 2.4 Megabases for the primary transcript, the processed transcript has only a length of about 14kb. It takes about 16 hours to transcribe and co-transcriptionally splice the sequence. See here for more details:
why does it transcribe 2.4 million bases and cut it down to 14,000? Seems like a waste of time and energy, not to mention the potential for mutations, which if muscular dystrophy is any clue, would be deadly.More
I don't have a reference for this, but I was told by a professor once that a long developmental gene is Drosophila takes longer to transcribe than the length of the cell cycle during initial development so that is not actually expressed until the cell cycle lengthens later in development. That's perhaps one answer (if uncommon) to the question of why some genes are so long.More
alternative splicing is a wierd thing to be sure. biology is not rational but then human science has not yet produced a living cell from first principles...More
Cases like this make me wonder why alternative splicing would be worth it. If you divide 2.4 million bases by 14000 bases you get 171.4. Seems like you could just make multiple copies of dystrophin to cover all the isoforms and still save space, and only need to transcribe the copy you want. Evolution should have gotten an engineering degree.More
Top 10 long processed transcripts in humans (with multiple isoforms), from gencode 19 annotations:
Ignoring isoforms (only longest isoforms shown)
Titin clearly is the longest transcript in humans
However this is the list of longest genes:
Top 5 in Zebrafish (Zv9.75); longest isoforms:
Top 5 in Drosophila (FlyBase r6.02); longest isoforms:
Top 5 in C.elegans (WormBase WS220); longest isoforms:
Top 5 in Arabidopsis (TAIR 10.23):
Top 5 in yeast (SGD):
Top 10 long processed transcripts in humans (with multiple isoforms), from gencode 19 annotations:
Ignoring isoforms (only longest isoforms shown)
Titin clearly is the longest transcript in humans
However this is the list of longest genes:
Top 5 in Zebrafish (Zv9.75); longest isoforms:
Top 5 in Drosophila (FlyBase r6.02); longest isoforms:
Top 5 in C.elegans (WormBase WS220); longest isoforms:
Top 5 in Arabidopsis (TAIR 10.23):
Top 5 in yeast (SGD):
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I think a good candidate is the human titin gene. The gene itself has 363 exons, depending on the isoform it has between 27.000 and 34.000 residues. This makes up a processed mRNA length of up to 100kb for the full length isoform. See either the Wikipedia article or the one linked below for more details:
If you are looking for the longest primary transcript, then the human dystrophin gene should be your favorite. It has a length of about 2.4 Megabases for the primary transcript, the processed transcript has only a length of about 14kb. It takes about 16 hours to transcribe and co-transcriptionally splice the sequence. See here for more details:
I think a good candidate is the human titin gene. The gene itself has 363 exons, depending on the isoform it has between 27.000 and 34.000 residues. This makes up a processed mRNA length of up to 100kb for the full length isoform. See either the Wikipedia article or the one linked below for more details:
If you are looking for the longest primary transcript, then the human dystrophin gene should be your favorite. It has a length of about 2.4 Megabases for the primary transcript, the processed transcript has only a length of about 14kb. It takes about 16 hours to transcribe and co-transcriptionally splice the sequence. See here for more details:
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