Split-GFP lamin as a tool for studying C. elegans LMN-1 dynamics in vivo

Abstract

We engineered a fluorescent fusion protein of C. elegans lamin, by fusing the eleventh beta strand of GFP to the N-terminus of LMN-1 at the endogenous lmn-1 locus. When co-expressed with GFP1-10, GFP11::LMN-1 was observed at the nuclear periphery of a wide variety of somatic cells. Homozygous gfp11::lmn-1 animals had normal numbers of viable embryos. However, the gfp11::lmn-1 animals had a mild swimming defect. While not completely functional, the GFP11::LMN-1 strain is more healthy than other published fluorescent LMN-1 lines, making it a valuable reagent for studying lamins.

Figure 1. GFP11:: LMN-1 localization and function

(A) GFP fluorescence is shown in three different focal planes of an L4 larvae. A lateral view is shown with ventral down and anterior to the left. The scale bar is 20 mm. GFP localizes to the periphery of most somatic cells, including cells from the ventral hypodermis (arrows in A), body wall muscles (arrows in A’), and intestine (arrows in A”). GFP can also be seen in many other cells, including the developing vulva (above the line in A”). (B) The brood size and, (C) the percent of embryonic lethality in wild type and GFP11::LMN-1 (split-GFP lamin) animals. Each data point represents the brood from a single adult. The means are shown with error bars of 95% CI. Significance was calculated using student’s t-test. (D) The swimming rate, measured in body bends per second, of wild type, lmn-1 (Y59C) and split-GFP lamin in L4 larvae. Means and error bars of 95% CI are shown. n=40. Significance was calculated using a one-way ANOVA and corrected for multiple comparisons by Tukey HSD. **p≤0.01; n.s.= not significant.