|Matteri, Robert - Bob|
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: By using a reverse transcription competitive polymerase chain reaction (RT-cPCR) technique, the quantity of cyclin B1 was measured in in vitro derived embryos over the porcine maternal to zygotic transcript transition. In vitro derived 4-cell embryos were randomly assigned to the 5, 10, 18, 25, or 33 h post-4-cell cleavage (P4CC) control groups or the RNA Polymerase inhibitor, alpha-amanitin (alpha), groups. The alpha groups consisted of culture in control media for 5, 10, 18, or 25 h P4CC, followed by culture in inhibitor (0.2 ug/ml) until 33 h P4CC. Following isolation of poly-A RNA from individual embryos, RT-cPCR co-amplified an embryonic derived 503 bp cyclin B1 cDNA along with an introduced 435 bp truncated competitor. By comparing the ratio of full length cDNA:competitor to a cPCR derived standard curve, cyclin B1 transcript values were calculated (n=8 embryos/group). The means (attomoles/embryo) for the 5, 10, 18, 25, and 33 h time points in the control groups were 20.18**a, 11.83**ab, 9.91**b, 9.40**b, and 7.52**b, respectively (p<0.03; means not bearing a superscript in common differ significantly). The means for the 5, 10, 18, and 25 h time points in the alpha groups at 33 h were 7.67, 9.92, 8.58, and 9.47, respectively, and did not differ from the 33 h control (7.52). The control embryos exhibit a drop in cyclin B1 transcript levels from 5 to 18 h P4CC with latter time points maintaining this level. The alpha treated embryos display a low cyclin B1 transcript level irrespective of the time point. These findings suggest that no detectable embryonic cyclin B1 transcripts were produced. Rather, an apparent decline in cyclin B1 message was observed which is consistent with maternal degradation of oocyte derived transcripts.