Research Interests

My research program encompasses various aspects of molecular genetic studies of insect pest species. Insect pest species are model systems for studying many important basic research questions in biology. In addition, my research program has the applied goal of using the tools of molecular genetics in the development of new methods of biological control for these pest species.

At the present time we are focusing on three species of "true" fruit flies which rank among the world's most destructive agricultural pests. These are the Medfly, the Oriental fruit fly and the Melon fly. These flies severely impact agricultural practices where they are present, and they pose a constant invasion threat to new habitats containing agriculturally important commodities. These species have also significantly expanded their world wide distribution within this century.

One major area of research I have ongoing is the use of genetic markers such as RAPD (randomly amplified polymorphic DNA) markers, amplified using PCR, in genome mapping and in documenting genetic relationships within and between populations of these pest species. Because these species can so rapidly expand their host range and colonize new habitats, they can be ideal systems for studies of gene flow, population bottlenecks and other evolutionary phenomena.

We are also attempting to develop transformation systems for these pest species. This involves the development of new vector delivery systems as well as new schemes for detecting transformation events when they occu

A final area of research ongoing is understanding the genetic basis of sex determination in these species. The Medfly in particular has a Y chromosome based system of sex determination. This is analogous to the mammalian system of sex determination, and it is quite different from the well characterized "balance" system known in Drosophila. We have cloned and characterized a number of regions of the Medfly Y chromosome. Our long term goal here is to characterize the region of this chromosome which is critical for sex determination. This may allow us to identify genes that are sex specific in their expression, and it may be possible to genetically manipulate the sex determining process.

Selected Publications

Douglas, L., Untalan, P. and D. Haymer. 2003. Molecular sexing in the Mediterranean fruit fly. Insect Molecular Biology and Biochemistry (in press).

Tam, E.K., Jourdan-LeSaux, C., Stauder, S., Bollt, O., Reber, B., Yamamoto, F. and Haymer, D. 2003. Polymorphisms in the Interleukin-4 Receptor A chain: Association with traits of allergy and asthma in an admixed population in Hawaii. Cellular and Molecular Biology 49: (in press).

Naeole, C.K.M. and D. Haymer. 2003. Use of oligonucleotide arrays for molecular taxonomic studies of closely related species in the oriental fruit fly (Bactrocera dorsalis) complex. Molecular Ecology Notes 3: 662-665.

Bonizzoni M., Zheng L., Haymer D.S., Gasperi G. , Gomulski L.M. and Malacrida A.R. 2001 Genetic aspects of medfly bioinfestations in California as inferred from microsatellite markers. Molecular Ecology 10: 2515-2524.

Douglas, L. and D. Haymer. 2001. Ribosomal ITS1 polymorphisms in Ceratitis capitata and Ceratitis rosa (Diptera:Tephritidae). Annals of the ESA 94:726-731.

Zhou, Q., Untalan, P. and D. Haymer. 2000. Repetitive, A-T rich DNA sequences from the Y chromosome of the Mediterranean fruit fly. Genome 43: 434-438.

He, M. and D. Haymer. 1999. Genetic relationships of populations and the origins of new infestations of the Mediterranean fruit fly. Molecular Ecology (in press).

Zhou, Q. and D. Haymer. 1998. Molecular structure of yoyo, a gypsy-like retrotransposon from the Mediterranean fruit fly, Ceratitis capitata. Genetica 101:167-178.

Thanaphum, S. and D. Haymer. 1998. A heat shock cognate gene from the Mediterranean fruit fly. Insect Molecular Biology 7:63-72.

Thanaphum, S. and D. Haymer. 1997. A member of the hsp70 gene family in the Mediterranean fruit fly. Insect Molecular Biology (In press).

He, M. and D. Haymer. 1997. Polymorphic intron sequences detected within and between populations of Bactrocera dorsalis. Annals of the ESA 90:825-831.

Haymer, D., M. He and D. McInnis. 1997. Genetic marker analysis of spatial and temporal relationships of existing populations and new infestations of the Medfly. Heredity 78:302-309.

He, M. and D. Haymer. 1995. Codon bias in the actin multigene family and effects on phylogenetic reconstruction. Journal of Molecular Evolution .

Haymer, D. 1995. Genetic analysis of laboratory and wild strains of the melon fly, Bactrocera cucurbitae, using RAPD-PCR. Annals of the ESA 88:705-710

Haymer, D., T. Tanaka and C. Teramae. 1994. DNA probes can be used to discriminate between Tephritid species at all stages of the life cycle. Journal of Economic Entomology 87:741-746.

Haymer, D. and D. McInnis. 1994. Resolution of populations of the Mediterranean fruit fly, Ceratitis capitata, at the DNA level using random primers for the polymerase chain reaction. Genome 37:244-248.

He, M. and D. Haymer. 1994. The actin multigene family in the oriental fruit fly Bactrocera dorsalis: The muscle specific actins. Insect Biochemistry and Molecular Biology 24:891-906.

Haymer, D. 1994. RAPDs and microsatellites: What are they and can they tell us anything we don't already know? Annals of the ESA 87(6):717-722.

Haymer, D. 1994. Arbitrary (RAPD) primer sequences used in insect studies. Insect Molecular Biology 3(3):191-194.