Establishment of two midgut cell lines from the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)

Two cell lines were generated from larval midguts of Spodoptera frugiperda and have been 26 passaged over 50 times. The CT/BCIRL-SfMG1-0611-KZ line was established from 27 trypsinized, minced whole midgut tissues: the CT/BCIRL-SfMG-0617-KZ line from isolated 28 midgut muscle tissue (containing some residual epithelial cells). Additional midgut cultures were 29 generated from isolated epithelial cells; some passaged not more than three times, which grew 30 very slowly and survived longer than 1 year. The continuously replicating cell lines contain 31 firmly adhering cells with different morphologies, including elongated, spherical, and/or 32 rectangular. The mean diameters of these cell lines are 9.3 ± 4.0 μm (SfMG1-0611) and 9.2 ± 3.9 33 μm (SfMG-0617). Growth curves for the two lines have relatively lengthy doubling times of 73.9 34 h and 50.4 h for SfMG1-0611 and SfMG-0617, respectively. We confirmed the identity of these 35 lines using DNA amplification fingerprinting (DAF-PCR) and noted that the DNA patterns for 36 each cell line were similar to their host tissues but distinctly different from other cell lines or 37 tissues from different insect species. Amplification of genomic DNA with species-specific 38 primers yielded DNA fragments of the expected sizes and with sequences nearly identical to 39 those from the S. frugiperda genome. Both cell lines were exposed to selected Bt Cry proteins 40 with minimal impact. These lines are currently available to researchers worldwide.