Title: Genetics of a Sex-linked Recessive Red Eye Color Mutant of the Tarnished Plant Bug, Lygus lineolaris Author
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2013
Publication Date: June 21, 2013
Repository URL: http://www.scirp.org/journal/ojas/
Citation: Allen, M.L. 2013. Genetics of a sex-linked recessive red eye color mutant of the tarnished plant bug, Lygus lineolaris. Journal of Insect Science. 3(2A):1-9. Interpretive Summary: The tarnished plant bug (TPB) is a serious pest in several important crops including cotton, alfalfa, and strawberries. Scientists are studying many tools, including genomics, to fight this pest. Lab colonies of TBP help scientists perform genetic studies on this insect. Mutant lab strains of TPB are rare, and are valuable for genetic research. A laboratory colony of the (TPB) was kept for many years without adding new specimens from the wild. Scientists found some individuals in this colony with defects including red eyes, deformed antennae, and deformed legs. These specimens were isolated and back crossed to create strains that retained the deformities. The only successful strain established was a red eyed strain named Cardinal. Red eyes were initially found, and later more commonly found in male insects, suggesting that the red eye defect could be sex linked. To test the hypothesis that the trait was based on a recessive sex linked gene, classical genetic crosses were performed. The hypothesis was confirmed. The trait is similar to other red eyed phenotypes previously described in TPB, but the Cardinal strain is clearly based on a different gene mutation because it is sex linked. The results of crossing experiments also suggested that inbreeding in TPB results in substantial loss of reproductive health to laboratory insects. These results will help scientists understand reproduction and pigmentation in TPB, and develop better control methods to use against this pest.
Technical Abstract: An inbred colony of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Miridae: Hemiptera), was observed to contain specimens with abnormal traits including red eyes, deformed antennae, and deformed legs. These specimens were isolated and back crossed to create stable phenotypic strains. The only successful strain established was a red eyed strain named Cardinal. The trait was more prevalent and stable in males, suggesting that it could be sex linked. To test the hypothesis that the trait was based on a recessive sex linked allele, classical genetic crosses were performed. The hypothesis was confirmed, and the eye colors phenotype was measured and characterized using color analysis software. The trait is similar to other red eyed phenotypes described in this species, but is clearly based on a different mutation since it is sex linked rather than autosomal. The results of crossing experiments also suggest that inbreeding in this species results in substantial fitness cost to laboratory insects.