For
lin-39 and
mab-5, previous work reported their partially overlapping expression in the ventral cord motor neurons (MNs). In this study, we used two fosmid reporters wgIs18[
lin39::EGFP] and wgIs27[
mab-5::EGFP] to map their expression to the single-cell resolution among the 75 motor neurons (MNs), which include 54 cholinergic MNs, 19 GABAergic MNs, and 2 serotonergic MNs with stereotypical positions. These MNs can be further classified into eight neuron classes (DA, DB, VA, VB, AS, VC, DD, and VD). By crossing the GFP reporters with mCherry strains labelling cholinergic or GABAergic neurons in the ventral cord, we identified
lin-39 expression in DA2-5, DB2-7, VA3-8, VB4-9, AS2-8, VC1-6, DD2-6, and VD3-12 and
mab-5 expression in DA4-8, DB5-7, VA6-11, VB8-11, AS5-11, VC3-6, DD2-6, and VD2-12. Both
lin-39 and
mab-5 expression were generally weaker in more anterior MNs. Interestingly, for cholinergic MNs,
mab-5 and
lin-39 expression only overlapped in a set of mid-body MNs; MNs more anterior to this region expressed only
lin-39 and MNs more posterior expressed only
mab-5. For GABAergic MNs (DD and VD), however,
lin-39and mab-5 expression overlapped entirely. Outside of the ventral nerve cord,
lin-39 was expressed in AQR and AIYL/R in the head and AVM, SDQL/R, PDEL/R, and PVDL/R neurons along the body;
mab-5 was expressed in the AVL in the head, SDQL in the mid-body region, and PQR neuron in the tail.