As a consequence of gene order in the mitochondrial genome, the tRNA-punctuated mode of transcript processing can result in mature transcripts that encode more than one PCG [5], where bicistronic transcripts are predicted for mitochondrial PCG sequences (cds) that overlap within the genomic sequence, which includes atp8/atp6 and nd4/nd4L within insect mitochondria.
Adenosine-to-inosine (A-to-I) RNA editing, the most prevalent mode of transcript modification in higher eukaryotes, is catalysed by the adenosine deaminases acting on RNA (ADARs).
While interruption of coverage was sometimes seen near the 3' end of certain tRNAs, it is clear that the "tRNA punctuation" mode of transcript processing described in mitochondria of animals and to some extent yeast and red algae, relying on precise excision of the tRNAs from the primary transcript [ 20– 22], is not predominant in the mitochondrion of L. incisa.
Reporter analysis did show alternative exons were utilised for unc-62, but in combination with other modes of alternative transcript generation and, uniquely, the alternative internal exons were mutually exclusive rather than optional.
In the absence of any known classical activation route available for these genes, facilitated re-initiation could be a very important mode of enhancing transcript yield in vivo.
One of the important modes of post-transcriptional regulation is miRNA-mediated repression of mRNA transcripts.
A final possibility is that lack of L29 creates an altered ribosomal exit tunnel that somehow occludes the nascent polypeptide, thereby resulting in elongation arrest, which in turn induces either A-site cleavage or other modes of cleavage of the transcript [ 24].
These data illustrate both shared and unique regulatory patterns of transcript expression for the two modes of reproduction.
One centrally important mode of post-transcriptional regulation is the repression of mRNA transcripts by miRNAs.
One important mode of post-transcriptional regulation is the repression of mRNA transcripts by miRNAs.
