Crossover suppressors in Tribolium castaneum

Abstract

The red flour beetle, Tribolium castaneum, has been used to investigate population and quantitative genetics for decades. By using this pest of stored grain, it is possible to conduct fine structure genetic analyses in a representative of an extremely successful, diverse, and economically important animal group, the beetles. We are interested in further improving this facility by developing chromosome balancers for Tribolium. Therefore, we investigated the possibility of inducing and selecting chromosomes that suppress recombination in the Tribolium genome. Translocations were identified in several screens involving four different linkage groups. An inversion was identified in one screen that suppressed recombination over 30 cM of the genome. This dominantly marked chromosome rearrangement was associated with normal fertility, fecundity, and developmental rate, and became the basis for a series of crossover suppressors developed for the longest Tribolium chromosome. The ability of these crossover suppressors to serve as balancer chromosomes was demonstrated in screens for new mutations and linked molecular markers. During the course of these experiments, the resolution of the Tribolium genomic map was improved.