Department of Entomology

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J. Spencer Johnston

Title:

  • Professor of Genetics/Entomology
  • Member of Genetics Faculty
  • Member of Graduate Faculty

Education:

  • University of Washington, Seattle, Washington, Zoology, B.S., 1967
  • University of Arizona, Tucson, Arizona, Genetics, Ph.D., 1972 (Advisor: W. B. Heed)
  • University of Texas, Austin, Texas, Drosophila genetics, 1972-1975, NIH Fellow

Appointments

  • Sept. ‘97 – Present: Professor, Dept. Entomol., Texas A&M University, College Station, TX
  • 1989 – Present: Dtr. Flow Cytometry, Center for Biosystematics and Biodiversity, TAMU
  • Sept. ‘86 – Aug. ’97: Assoc. Prof., Dept. Entomology, Texas A&M University, Col. Sta., TX
  • Jan. ‘80 - Aug. ’86: Assoc. Prof., Dept. Plant Science, Texas A&M University, Col. Sta., TX
  • Sept. ‘75 - Dec. ’79: Asst. Prof., Dept. Biology, Baylor University, Waco, TX
    June ‘67 – July ’68: Systems Analyst, Boeing Company, Seattle, WA

Teaching Activities
 My teaching involves undergraduate courses in introductory genetics (GENE 301), population and ecological genetics (GENE 412 and 412H) and genetics seminar (GENE 481). The GENE 301 course covers the fundamentals of genetics. Power point slides used in the GENE 301 course are available for students in the course. The GENE 412 course is entirely new as of Fall 2003. GENE 412 was reorganized to reflect not only the impact of DNA sequence data on population studies, but also to take advantage of a new text which presents population genetics through examples. GENE 481 involves student attendance at the regularly scheduled seminars of the TAMU faculty of genetics plus graded written summaries of selected seminars.

Research Interests:
Genomics: Our honey bee genomic efforts use BACFISH to anchor linkage groups onto each chromosome arm. Our long term goal is to fully integrate the physical, genetic, and cyto-molecular map of the honey bee and make this information available in a highly flexible relational database format that will serve the needs of the honey bee research community, honey bee breeders, research scientists and interested individuals in the community at large. We are also developing a white paper for Caencholax fenyesi (Strepsitpera:Myrmecolacidae), an insect parasitic in the red imported fireant, and the smallest known insect genome.

Population level studies:  We have been assessing the genetic impact of the arrival of the Africanized form of the honey bee, Apis mellifera scutellata. We have extensive collections of feral bees from colonies in South Texas and bait hive bees in Mexico spanning the period 1990 to 2003, which is three years prior, the time during, and the successive years after the invasion of the Africanized bee. We score mtDNA mitotypes and 15 nuclear microsatellite loci. The data shows that the African and European mitochondrial lineages coexist, while the nuclear genome is a mixture of the genomes of both lineages. Mexican populations and European colonies in Texas that survived the Africanization process are being studied further.

Genome size estimation: Our laboratory uses flow cytometry to provide genome size estimates for a variety of insects, plants and other animals. We measure genome size to correct questionable values produced by other methods, and provide new values for researches who need to know genome size to develop gene libraries. We uniquely determine genome size in groups of closely related organisms in an effort to better understand the process of genome size evolution.

Grants Received (Last 5 years)

  • Development of an integrated cyto-molecular map for the honeybee. USDA-NRI Competitive Grant. $52,000 (2003-2004), (J. S. Johnston).
  • A BAC library for genomic sequencing of the honeybee. The American Beekeeping Federation, the College of Agriculture and Life Sciences and the Office of University Research, Texas A&M University, College Station, TX., $40,000 (2001), (J. S. Johnston).
  • Population structure of the red imported fire ant, Solenopsis invicta Buren. The Texas Fireant Initiative. $150,000, (2000-2002), (J. S. Johnston).
  • Ploidy and genetic sterility in the red imported fire ant, Solenopsis invicta Buren. The Texas Fireant Initiative. $150,000, (1997-1999), (J. S. Johnston).

Publications

Gillespie, J., C. McKenna, J. S. Johnston, J. Kathirithamby, A. Cognato. 2005. Assessing the odd secondary structural properties of nuclear small subunit ribosomal RNA sequences (18S) of the twisted-wing parasites (Insecta: Strepsiptera) Jn. Insect Mol. Biol. 14:625-643.

Johnston, J. S., L. D. Ross, D. P. Hughes, L. Beani and J. Kathirithamby. 2004. Tiny genomes and Endoreduplication in Strepsiptera. Insect Molecular Biology 13:581-5. B (Suppl.) 271, S5-S8.

Bennett, M. D., I. J. Leitch, H. J. Price, J. S. Johnston. 2003. Comparisons with Caenorhabditis (~100 Mb) and Drosophila (~175 Mb) using flow cytometry show genome size in Arabidopsis to be ~157 Mb and thus ~25 % larger than the Arabidopsis initiative estimate of ~125 Mb. Ann. Botany 91:547-557.

Kathirithamby, J., L. D. Ross, and J. Spencer Johnston. 2003. Masquerading as self? Endoparasitic Strepsiptera (Insecta) enclose themselves in host-derived epidermal bag. PNAS 100:7655-7659

Bennett, M. D., I. J. Leitch, H. J. Price, J. S. Johnston. (2003). Comparisons with Caenorhabditis (~100 Mb) and Drosophila (~175 Mb) using flow cytometry show genome size in Arabidopsis to be ~157 Mb and thus ~25 % larger than the Arabidopsis initiative estimate of ~125 Mb. Ann. Botany 91:547-557.

Honors and Awards

  • 1992 Outstanding Undergraduate Genetics Professor
  • 1996 Outstanding Undergraduate Genetics Professor
  • 1998 C-value (plant Genome size) Workshop, Jodrell Labs, RBGKew, UK
  • 1999 Visiting Fellow, Department of Zoology, Oxford University
  • 2000 Comparative Insect Genomics Workshop, Washington, D.C.
  • 2001 The honey bee genome white paper workshop, BHGSC, Houston
  • 2002 NCBI Honey bee genomics workshop, Bethesda, MA
  • 2003 Honey bee genomics workshop, Int. Cong. Genet., Melbourne, Australia
  • 2003 C-value (plant Genome size) Workshop, Jodrell Labs, RBGKew, UK
  • 2003 Visiting Fellow, St. Hugh’s College, Oxford University
  • 2004 Invited speaker International Congress of Entomology, Brisbane, Aus.
  • 2005 Bennett, Price & Johnston (2003) featured in ESI website October 2005 'Emerging Research Front' and cited in Nature Genetics.
  • 2006 Bennett, Price & Johnston (2003) identified by Thompson ISIR as most cited in the area of 'Recent Genome Size Variation'
  • 2006 Named "Author of the Year" by Jn. Insect Mol. Biol. for Johnston et al. (2004).
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