In spite of stringent signal-to-noise ratio criteria, our strand-specific cDNA microarrays detected a number of antisense transcripts that exceeds by far the number of previously annotated antisense genes in humans.
Considering that upregulation of the CD4 coreceptor is known to promote the selection of low-avidity TCR expressing thymocytes and CD4-coreceptor lineage committed thymocytes have stringent signaling requirements, our data help to explain the selective maturation defect observed in Th cell hypo-responsiveness.
This specific hypo-responsiveness makes sense considering that CD4 coreceptor upregulation in transgenic mouse thymus rescued T cells with weakly interacting TCR provoked a skewing of the T-cell populations, and CD4 coreceptor lineage-committed thymocytes have stringent signaling requirements for differentiation.
As shown previously for 1018, these D-amino acid peptides targeted the intracellular stringent response signal (p ppGpp.
To ensure a more stringent separation of signal from noise across the population of records, we instituted a set of criteria to select the profiles with robust oscillation for at least three days.
The initial list of genes was filtered using the following more stringent criteria: microarray signal intensity ≥ 25 at 8 wk of age, expression ratio > 2-fold in the arrays in which the gene exhibited a p-value < 0.0001, and in the case of adult sex-biased transcriptional regulators, expression ratio > 2 (or < 0.5) for the male 8 wk vs. female 8 wk comparison.
After stringent washes, fluorescent signals were scanned with the ScanArray Express Scanner (PerkinElmer, Waltham, MA, USA) and analysed using GenePix Pro version 5.0 (Molecular Devices, Sunnyvale, CA, USA).
Independent cross hybridization of pDp1, pDp2, pDp3 and pDp4 with genomic DNA from different species (mentioned in methods section) under high stringent conditions showed signals only in bovids (Additional File 4).
We applied a stringent filter criterion including signals with signal-to-noise (SNR) ratios above 10.
After extensive washing and stringent processing, the SOD signal above background was detected in none of the control SOD treated samples.
