Real-time quantification of the tTA gene in the DR6 and DR7 transgenic strains of the screwworm fly (Cochliomyia hominivorax)

Authors: Arp, Alex; VARGAS LOWMAN, AIDAMALIA - Universidad De Panama; MARTINEZ, ANDREA - Universidad De Panama; SCOTT, MAX - North Carolina State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/3/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: The Sterile Insect Technique (SIT) has been one of the most successful pest control systems, being used in the screwworm fly (Cochliomyia hominivorax) eradication program in Panama and thus establishing a protective barrier from Central America to North America. However, the absence of a sex separation method in the pupal stage decreases the efficiency of the SIT system in this species. For this reason, new approaches in biotechnology are developed through the collaboration of national and international institutions with the objective of enhancing the benefits of the program in Panama. The new experimental systems include the creation of transgenic fly strains with insertion of single and double components that produce specific lethality of females in embryonic and pupal stages. In this study two new sex separation genes were evaluated intensity of function thoughout the development of transformed screwworm flies. All three strains tested showed the highest activity in the early stage of embryoinic development. One strain showed higher expression overall and is a likely candidate for development of a sexing strain for use in mass-rearing.

Technical Abstract: The Sterile Insect Technique (SIT) has been one of the most successful pest control systems, being used in the screwworm fly (Cochliomyia hominivorax) eradication program in Panama and thus establishing a protective barrier from Central America to North America. However, the absence of a sex separation method in the pupal stage decreases the efficiency of the SIT system in this species. For this reason, new approaches in biotechnology are developed through the collaboration of national and international institutions with the objective of enhancing the benefits of the program in Panama. The new experimental systems include the creation of transgenic fly strains with insertion of single and double components that produce specific lethality of females in embryonic and pupal stages. Two new transgenic strains, DR6 (Nullo) and DR7 (CmCG14427) were established in the laboratory with the aim of promoting specific lethality in early stages of development. To identify its effectiveness, the expression of the tetracycline-controlled transactivator gene (tTA) was quantified. In both lines (DR6 and DR7), the highest expression of tTA was evident in early stages of development. Furthermore, between the two strains, DR7 presented higher levels of tTA expression. This indicates that the CmCG14427 promoter has greater effectiveness and can be used as a test line to identify its behavior and competitiveness under laboratory conditions.