Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

(C and D) TOP-1a is specifically associated with chromosomes in the germline.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

(A and B) TOP-1b is expressed in the nuclei of the most germ cells and strongly DTC (see inset).

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

Fig. 3. Subcellular localization of TOP-1 isoforms in C. elegans germlines. (A and B) TOP-1b is expressed in the nuclei of the most germ cells and strongly DTC (see inset). (C and D) TOP-1a is specifically associated with chromosomes in the germline. (E) GFP expression in distal tip cell (DTC) during the L3-L4 stage. (F-I) In oocytes, TOP-1b is distributed in nucleoplasm and strongly expressed in the nucleoli (arrows in F), but TOP-1a is predominantly associated with chromosomes. Dashed circles indicate oocyte nuclei. Chromosomes were stained by DAPI. DIC, differential interference contrast microscopy.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

In oocytes, TOP-1b is distributed in nucleoplasm and strongly expressed in the nucleoli (arrows in F). Dashed circles indicate oocyte nuclei. Chromosomes were stained by DAPI. DIC, differential interference contrast microscopy.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

(E-G) GFP expression driven by the top-1 promoter. Ptop-1::gfp expression is shown in (E) inner labial neurons and socket cells (ILso, IL1/2, respectively), ring interneurons (URX, RIC, RIG/RIF and AIM) and amphid interneuron (AIY) in the head of a hermaphrodite; (F) ventral cord motor neurons (VC4, VC5), hermaphrodite specific motor neurons (HSN), lateral neuron (PVD) adjacent to the excretory canal and mechanosensory neuron (PVM) in the body of a hermaphrodite; (G) sensory neurons of the copulatory spicule (SPD and SPV) and specific sensory/motor neurons (SPC) in the tail of a male.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

Fig. 1. Subcellular localization and function of top-1 isoforms in C. elegans embryos. (A) TOP-1 isoforms and location of peptides used to generate TOP-1a and TOP-1b antibodies (See Section 2). The subcellular localization of TOP-1b (B-D) and TOP-1a (E-G) in embryos. Dashed line in B indicates the boundary of gut cells. Centrosomes (green) and dividing chromosomes (Blue) were merged in inset of E. (H-M) top-1RNAi phenotypes in embryos. (H) Schematics of two top-1 mRNA isoforms. The region targeted with top-1dsRNA is indicated by thick bar below. RNAi experiments were started in the L4 larval stage and phenotypes were analyzed in the F1 progeny. (I) Embryonic lethality of top-1RNAi.CI, confidence interval in number of germ cells from average. n, number of embryos counted for embryonic lethal phenotype. (J-M) Chromosomal segregation defects. Chromosomes were stained with DAPI and observed by fluorescence microscopy. (J) Wild-type embryo. (K-M) top-1 (RNAi) embryos show chromosomal defects such as chromosomal fragmentation (arrowheads in K), chromosomal bridge (arrowhead in L) and endoreplication (M).

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

(E) GFP expression in distal tip cell (DTC) during the L3-L4 stage.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

Expression of TOP-1a isoform in C. elegans head. TOP-1a is detected in neuronal cells and excretory duct (arrow).

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

Fig. 2. Neuronal expression of TOP-1a. (A) Expression of TOP-1 isoforms in C. elegans head. TOP-1b is localized at the most cells, but TOP-1a is detected in neuronal cells and excretory duct (arrow). (E-G) GFP expression driven by the top-1 promoter. Ptop-1::gfp expression is shown in (E) inner labial neurons and socket cells (ILso, IL1/2, respectively), ring interneurons (URX, RIC, RIG/RIF and AIM) and amphid interneuron (AIY) in the head of a hermaphrodite; (F) ventral cord motor neurons (VC4, VC5), hermaphrodite specific motor neurons (HSN), lateral neuron (PVD) adjacent to the excretory canal and mechanosensory neuron (PVM) in the body of a hermaphrodite; (G) sensory neurons of the copulatory spicule (SPD and SPV) and specific sensory/motor neurons (SPC) in the tail of a male.

Picture from Cha DS et al. (2012) Gene Expr Patterns "Differential subcellular localization of DNA topoisomerase-1 isoforms and ...."

The subcellular localization of TOP-1b (B-D) and TOP-1a (E-G) in embryos. Dashed line in B indicates the boundary of gut cells. Centrosomes (green) and dividing chromosomes (Blue) were merged in inset of E.