Genetic linkage in screwworms Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) assessed by AFLP and investigation of their mtDNA by PCR-RFLP

New world screwworms (NWS) (Cochliomyia hominivorax (Coquerel)), although eliminated from North America by use of the sterile insect technique (SIT), remain among the most traumatic myiasis causing and economically important pests of livestock throughout Neotropical regions. In this work, PCR-RFLP was used to developed markers for previously unamplified regions of screwworm mtDNA. Using PRIMER3® program, 5 newly designed primer pairs successfully amplified these regions of mtDNA covering about 35% of the genome. After screening 9 restriction enzymes, PCR-RFLP patterns were obtained by digestion of 2 of these PCR products with 2 restriction endonucleases. With these primers available the complete mtDNA genome can be further studied; they may be useful in the identification of the screwworm from other species that infest the wounds and in other areas of genetic research. Furthermore, AFLP was used to develop a genetic linkage map for NWS based on backcross and F2 populations. Four linkage groups of AFLP markers were constructed from crosses of the yellow eye mutant strain to a wild-type strain. In the future, this will be the good approach for developing a dense genetic linkage map that will be valuable when working to develop a genetic sexing strain of NWS. The information obtained from these two studies will enhance collateral research into developing an understanding of genetic changes in colonies used for mass rearing in application of SIT for NWS, documenting genetic variation in extant populations, and developing transgenic methods useful in studying screwworm genetics and ultimately for developing a genetic sexing strain of NWS