Splicing patterns of the Arabidopsis organellar rhomboid At1g74140 change during development from young to mature leaf tissues.

<p><strong>Background to the study:</strong> Four distinct rhomboid genes appear to function in <em>Arabidopsis</em> plastids, two &ldquo;active&rdquo; types from the secretases and presenilin-like associated rhomboid-like (PARL) categories (At1g25290 and At5g25752) and two &ldquo;inactive&rdquo; rhomboid forms (At1g74130 and At1g74140).&nbsp; The number of working rhomboids is further increased by alternative splicing, two reported for At1g25290 and three for At1g74130.&nbsp; Since At1g25290 and At1g74130 exist as alternative splice variants, it would be necessary to assess the splicing patterns of the other two plastid rhomboid genes, At5g25752 and At1g74140, before studying the <em>Arabidopsis</em> plastid rhomboid system as a whole. &nbsp;</p> <p><strong>Method used:</strong> This study thus specifically focused on an analysis of the At1g74140 transcript population using various RT-PCR strategies. The supplementary table provides the details of the various RT-PCR primers used in this study.</p> <p><strong>Results of the study and their relationship to the supplementary figures deposited here:</strong> The exon mapping results indicate splicing patterns different from the close relative At1g74130, despite similarity between the exonic sequences.&nbsp; The splicing patterns indicate a high level of sequence &ldquo;discontinuity&rdquo; in the At1g74140 transcript population with a significant portion of the discontinuity being generated by two regions of the gene. The three supplementary figures of RT-PCR results deposited here provide further evidence that the alternatively spliced short transcript products from the discontinuous splicing patterns fluctuate during development.</p> <p><strong>Conclusion of the main study and its relationship to the supplementary results deposited here:</strong> The overall discontinuous splicing pattern of At1g74140 may be reflective of its mode of involvement in activities like controlling gene expression.&nbsp; The developmental evidence in these deposited supplementary RT-PCR results indicate that some of the alternatively spliced short transcript products fluctuate between mature and young tissues, suggesting that the short transcripts bear functional significance.</p>