You can read about my research.
You can read about my work in undergraduate education.
The first student who worked with me on undergraduate research was Reid Bishop, on the left in the above photograph (with Dr. Janelle Pryor center and Reid's brother Charles on the right in this photograph taken in the deep, dark woods of J. P. Coleman State Park in the northeastern corner of Mississippi). Reid worked on size variation among ramets in the clonal fern Woodwardia areolata. I completed a study of genetic variation in the same group of ramets using an analysis of isozymes, and am just getting a paper ready for submission. I had some trouble resolving that a large group of ramets were in fact one clone. (It is easier to say something is different than it is to say they are the same using a method like isozyme analysis!).
One of our undergraduate students, Mac Alford, presented a poster of an investigation of Mussel diversity at a session in the senate office building in Washington DC on April 10, 1997. This poster session is sponsored by the Council on Undergraduate Research, and is intended to provide a means for Congress to gain an appreciation of the value of undergraduate research.
Mac presented a poster entitled "Clonal Growth in Pleopeltis polypodioides" at the 1997 Ecological Society of America meetings in Albequerque, NM.
Mac has also worked in my laboratory on methods of eliminating contamination for Random Amplified Polymorphic DNAs (RAPDs) analysis, which is a method of detecting polymorphisms in DNA among individuals. The conclusion of the study was that since RAPDs is a very sensitive method of PCR, it is essential impossible to eliminate the effects of DNA contamination in the commercially obtained Stoeffel fragment DNA polymerase that we used, however, the presence of the bands in control lanes does indicate that reaction conditions are optimal, because if conditions are sub-optimal, the bands will not appear. We also discovered that the eukaryotic template DNA will out compete the contaminating DNA from DNA polymerase, as has been suggested in previous studies. This study was part of an HHMI supported research program for undergraduate students. This research was also Mac's honors project at Mississippi College.
We have completed an investigation of gender expression in gametophytes of the fern species Ceratopteris richardii, which has been submitted for publication. One of the investigators, Anna Powers, is a high school student at Jackson Academy, and completed her work as part of the Honors Applied Research Program at Jackson Academy. Anna presented her work at the Mississippi Junior Academy of Sciences in mid January 1997, and at the first Annual HARC held at Jackson Academy in late January, 1997.
The above photograph is of the participants in the first annual Honors Applied Research Conference (HARC). The idea for this conference was developed by myself and Virginia Ingram of Jackson Academy as a result of participation in the Howard Hughes Medical Institute (HHMI) sponsored summer workshops for high school teachers held at Mississippi College. Anna Powers is seated in the middle. The student seated on the left end is Robert McGehee, who attended St. Andrew's Episcopal School, and completed an investigation of the effects of gibberellic acid on the growth of the bacterium Agrobacterium tumifaciens in my lab. Robert presented his work as HARC and the Mississippi Junior Academy of Sciences. Virginia Ingram is standing at the far right in the above photograph. HARC is sponsored by Jackson Academy and Mississippi College.
We (myself and Cora Chaffin) have completed an investigation of the effects of contamination on Ceratopteris richardii. We discovered that deliberate contamination of cultures leads to a significant effect on gender expression and gametophyte size. We observed a slight effect of presterilization of spores with a bleach solution. A paper has been published in the American Fern Journal.
I worked with 2 of the 4 Howard Hughes Medical Institute high school student/teacher research pairs in 1997. One such pair was Cora Chaffin and her student Vashaundra Hill (pictured above) from Yazoo City high school. Cora and Vashaundra worked on developing STS (sequence tagged sites) using RAPD (random amplified polymorphic DNA) fragments. We successfully isolated, cloned and sequenced RAPD products from both tomato and Ceratopteris richardii and used the DNA sequences obtained to design and successfully generate the RAPD fragments using regular PCR primers. Vashaundra presented her work at HARC and the Mississippi Junior Academy of Sciences in 1998. Cora completed a paper describing the research that was published in the Ceratopteris Journal, an on line journal. This paper is also Cora's masters thesis.
The other pair of high school teacher/high school student researchers that I worked with in 1997 was Bill Miles and his student Keith Keeton (pictured above) from Morton High School. Bill and Keith investigated retinoic acid, sequencing the cDNA for an mRNA induced by retinoic acid in human cells. The cDNA sequenced by Bill and Keith turned out to be a brain and reproductive organ expressed protein called BRE. A comparison with known sequences revealed a match to a chimeric HIV/BRE mRNA, where a portion of the the HIV genome was inserted into the reading frame for BRE resulting in the chimeric mRNA, which required that Keith also learn about the life history of viruses like HIV, and the effect of an inopportune event such as the insertion of a piece of the virus genome into a functional gene on patients infected with such viruses.
High School teachers and students have been sequencing human cDNA clones obtained from Research Genetics, a business in Huntsville Alabama that maintains and supplies DNAs as part of the human genome project.
Marian Sampson (left in the above photograph), a high school teacher at Murrah High School in Jackson, MS and her student Kristy Wiley (Center right in the above photograph), worked with Dorothy McClendon (right in the above photograph), a high school teacher at East Lincoln High School, near Brookhaven, MS, and her student, Christy Barlow (center left in the above photograph), sequenced two human cDNAs, and deposited the sequences in Genebank (Clone #80578, accession number U67934 and clone #137308, accession number U60873). Marian, Dorothy and their students completed their work in 1996, and worked in my lab as part of the HHMI sponsored research program for high school teachers and their students.
One of my HHMI undergraduate students for 1998-1999, Wendy McLean worked with Dr. Jon Hosler (both pictured above) of the University of Mississippi Medical Center on an investigation of the biophysical properties of cyhrome c oxidase, completing and honors paper entitled "Effects of multiple gene copies on expression levels of cytochrome c oxidase in Rhodobacter sphaeroides". Wendy presented a poster of her work at the Annual Meeting of the Biophysical Society in Baltimore, MD (1999) entitled "Cytochrome c oxidase assembly complex suggested from expression studies".
My other HHMI undergraduate student for 1998-1999, Wende Joyner (right in above photograph) began working on flowering times of coexisting species Liatris in the Homochitto National Forest; however the plants did not flower in 1998, and thus Wende worked on generating STS markers in Ceratopteris richardii from RAPDs fragments, and an analysis of genetic variation among Daffodil cultivars. Wende worked with an HHMI high school teacher/high school student pair, Amanda Millsaps (student) and Cindy Coon (teacher) on the generation of STS markers in Ceratopteris richardii. Cindy Coon participated in a workshop on genetic linkage at the Mississippi Science Teachers Association meetings in Biloxi, MS in 1998. Wende and Amanda presented a paper on the making of STS markers from RAPDs fragments at the Mississippi Association of Science meetings in Tupelo, MS in 1999.
Another HHMI high school teacher/high school student pair, Joan Priddy (teacher) and Bradley Burch (student), worked on variation in daffodil cultivars during the summer of 1998. Joan participated in a workshop on genetic linkage at the Mississippi Science teachers Association meetings in Biloxi, MS in 1998 and Bradley presented a paper on variation in Daffodil cultivars at the Mississippi Junior Academy of Sciences meetings here at Mississippi College in 1999.
The photograph above is of the people who participated in the HHMI program in my laboratory in 1998. Back row, left to right are LaTonya Gillespie and Dr. Janelle Pryor. Middle row, left to right are Kenny Young, Wende Joyner, Amanda Millsaps, Cindy Moon and Joan Priddy. Front row is Bradley Burch.
My wife, Dr. Janelle Pryor, and I worked with her student, Emma Noongo on the isolation of proteins from fern gametophytes. We were able to observe differences in the level of RUBISCO (ribulose-bis-phosphate carboxylase/oxygenase), between male and female gametophytes of the fern species Ceratopteris richardii.
We have begun analyzing Daffodil DNA samples in an effort to characterize relationships among cultivars. To date, we have completed a project involving a comparison of 3 cultivars. The results of this study were ambiguous, and we decided that a more detailed analysis of variation within cultivars was needed to develop a better understanding of relationships among cultivars.
The gel above is a silver stained gel of random amplified polymorphic DNA fragments from 3 cultivars. Each cultivar is represented by three samples of that cultivar from arouind the world. DNA fragments are separated on 43cm wide X 0.45cm thick 5% polyacrylamide gels, DNAs are detected unsing silver staining. Each sample of a cultivar is loaded twice, in tandem, to make gels easier to read. The samples in the middle of the gel are of insufficient quality for analysis. The two outer samples, however, indicate complete uniformity for the three samples of the cultivar loaded on the right, and variation among the three samples of the cultivar loaded on the right (the middle sample is different from the other two).
To analyze the gels using the computer software available, it was necessary to trace the gels onto an acetate sheet, as shown below:
The Rikki cultivar is genetically uniform, as one would expect, while the cultivar Claire is not. The significance of the devation among samples in Claire is difficult to assess from one case, and obviously more work is needed to understand the degree of variation within Daffodil cultivars and asses the meaning of that variation. We have analyzed these cultivaars wityh another primer, and the results were similar, the Rikki samples were uniform, but Claire sample 14 varied from the other two Claire samples.
To date we have completed the sequencing of 6 cDNA clones, which have been deposited in Genebank.
Genebank accession numbers for completed cDNAs:
Human cDNA clone 137308, U60873.
Human cDNA clone 80578, U67934
Human cDNA clone 208781, U92029.
Human cDNA clone 208779, AF002221.
Human cDNA clone 610437, AF015767.
Homo sapiens unknown precursor RNA AF256175
Mus musculus (mouse) cDNA clone 709914, AF144133
Mus musculus imidazoline receptor I-1-like protein mRNA, partial cds. AY032852
Zea mays mitochondrial gene fragment AF502960
We have also sequenced some other DNAs, one of which has been deposited in genebank.
Lycopersicon esculentum (Tomato) 7S signal recognition particle RNA gene, AF015484.
I have developed a method of using silver sequencing, where silver stain is used to detect products of cycle sequencing reactions, for use in undergraduate laboratories. The silver stained gel is photographed with Kodak LPD4 film, and the resulting slide image of the gel is projected onto a wall, as in the above photograph, where former Mississippi College undergraduate Terri Darby and Dr. Janelle Pryor are shown reading the gel.
I have developed the molecular biology course into a seminar/research course. The seminar includes presentations by students covering basic molecular biology as well as presentations by local researchers and myself. The seminar portion also involves the discussion of technical and theoretical problems in molecular biology. The research portion of the course involves DNA sequencing.
Students in the molecular biology class of 1997, Amy Donhardt, Wendy Mayer, Chuck Engle, Dalephine Cain, and Lester Tarbutton sequenced the human cDNA clone 20871, and deposited the sequence in Genebank, accession number U92029.
The molecular biology class of 1998, left to right in the above photograph; Leff Robbins, Wendy McLean and Jeffery Carter, along with Dalephine Cain, who was working on an independent research project, sequenced a cDNA as part of ongoing research into depression being conducted by Dr. John Piletz of the University of Mississippi Medical Center in Jackson, MS.
I have added a DNA fingerprinting exercise to the genetics laboratory. In this exercise, students determine their phenotype at the D1S80 microsatellite locus. To obtain better quality in the intensity and sharpness of banding, we used 0.4mm polyacrylamide gel and silver staining to detect PCR fragments.
This is an image of a silver stained polyacrylamide gel with the D1S80 genotypes of several Mississippi College genetics students.
Last updated 6 December 2002.