May 1, 2012

Recruitment of ribosomal release factor for light-and stress-dependent regulation of petB transcript stability in Arabidopsis chloroplasts.

It is known that land plants have four functional peptide chain release factors. Two of which are PrfA and two are PrfB. A homolog of PfrB, PfrB1 is required for termination of translation. Another homolog, PrfB3 is localized to chloroplast stroma in petB RNA complex in vascularized plants. PrfB3 is also required for photoauxotrophic growth and has been recruited in vascular plants for light-and stress-dependent regulation of stability of 3 prime processed petB transcripts that adjust cytochrome b6 levels. It is believed that PrfB3 arose from Pfrb1

Stoppel, R., J. Meurer, P. Westhoff, K. Meierhoff, S. Felder, S. Torabi, S. Schwenkert, and L. Lezhneva. “Supplemental Content.” National Center for Biotechnology Information. U.S. National Library of Medicine, 19 July 2011. Web. 01 May 2012. <http://www.ncbi.nlm.nih.gov/pubmed/21771930>.

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Tagged petB
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March 31, 2012

petB intron from 4-19 through 4-27

Courtney V. and Chandler G. used PCR to amplify the petB intron of the DNA extracted from nine orchid species. Nine samples and a negative control, water,was used to for gel electrophoresis (See figure 1). All my PCR products ran slower than the 1000 bp fragment of the Molecular Mass Ruler. Therefore, these products are larger than 1000 bp. The location of the petB intron was determined by looking at a genome sequence of chloroplast of Phalaenopsis aphrodite that Dr. Jarrell provided us with. The petB region is on the left hand side of the sequence and is included with the genes that code of photosystems 1, 2 and the B6/f complex.

The results of our gel electrophoresis are listed in the table below (See table 1). We did not run a gel marker in lane one as instructed. Our group shared a gel with another group so we only ran one marker, which was on the top of the gel. Our results were on the bottom of the gel which excluded the marker. The cause of the light background is unknown. Pippetting errors may have been the cause of some samples having a negative success. Making the gel, as well as loading and running the gel was done exactly as instructed.

Figure 1: Gel electrophoresis for DNA samples 4-19 to 4-27

++ high success + success Table 1 – no success

Lane	DNA code	Species or Marker	Success
1	Blank	Blank	n/a
2	4-19	Trichoglottis bipunctata	+
3	4-20	Malleola constricta	–
4	4-21	Phalaenopsis lobbii	+
5	4-22	Armordorum siamense	–
6	4-23	Grosourdya appendiculata	++
7	4-24	Smitinandia micrantha	++
8	4-25	Acampe papillosa	++
9	4-26	Schoenorchis fragrans	–
10	4-27	Drymoanthus minutus	++
11	-DNA control	Water	n/a

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Tagged Pet B
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March 1, 2012

Phalaenopsis equestris

http://www.aos.org/images/img_content/Education/Phal_equestris-me.jpg

http://www.phalaenopsis.net/phpBB/viewtopic.php?f=4&t=4582

Phalaenopsis equestris, Kard Lud-wig Blume 1825, was introduced into cultivation in 1833. It is an orchid species that is in the tribe Vandeae and subtribe Aeridinae. Native to the Philippines and Southern Taiwan, it grows from sea-level to 300 meters near the streams in hot and warm valleys. P. equestris can flower anytime but the most common flowering months are between September and April. These plants are monopodial so one main stem produces all the leaves and flowers. Flowers are usually purple and have five petals that are between 1.5-3 cm in length. Also, P. equestris is commonly used for breeding. It is used as one of the parents to breed miniature species with many flowering branches. These are commonly house plants.