Here, we report that chromosomal amplification is common in non-laboratory yeast strains, which are inherently tolerant of aneuploidy and display an active mode of gene-dosage compensation at the transcript level, for specific classes of amplified genes.
In zebrafish, maternally supplied transcripts or compensation by another translocon protein, ERj1, might account for the absence of the early, general defects observed in the sec63 st67 mutants.
For both compensation mechanisms, increased transcription rates had a minimal effect on the abundance of bulk transcripts (F and L ).
In mammalian dosage compensation, the large Xist transcript along with its antisense counterpart, Tsix, are crucial in modulating the epigenetic state of X-linked loci (reviewed in [ 4]).
The dilutive component, ρ.δv/δx assesses potential compensation of the dilution of transcript abundance during expansive growth through net transcript synthesis (that is, if ρ.δv/δx = 0, then net transcript synthesis just compensates for the expansion-driven dilution).
The compensation that we observed in transcript levels of dilps 3 and 5 upon reduction in dilp2 transcript may not be sufficient to bring overall dilp transcript levels in the mNSCs back to normal, because dilp2 is much more highly expressed than the other two [14], [18].
A similar effect has been noted before in other studies using translation-blocking MOs, and may reflect transcript stabilisation or compensation mechanisms [ 26].
An interesting question for future study is whether MES-4 and DRM act like established X dosage compensation mechanisms to balance X transcript levels between the sexes.
Thus, we propose that the higher ribosome density participates in dosage compensation by both stabilizing the X-chromosome transcripts and translating more encoded proteins.
A mode of dosage compensation that functions at the level of transcript abundance may provide an additional level of regulation to control protein stoichiometry.
