Sensory organ description

			vp1 = p1 = vc1 (vesA neuron)
		sensory organ type	ventral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	md-es lineage. Its md neuron associated by lineage is vdaD (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vp2 = p2 = vc2 (vesB neuron)
		sensory organ type	ventral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	md-es lineage. Its md neuron associated by lineage is vdaC (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vp3 = p3 = vc3 (vesC neuron)
		sensory organ type	ventral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986). Unlike other abdominal socket cells, the vp3 socket cell emits numerous short cytoplasmic extensions visible with the Su(H)-GFP transgene described in Barolo et al., 2000 (V. Orgogozo, personal observations). However, no cuticular particularity has been  documented  (Dambly-Chaudiere and Ghysen, 1986). The unique characteristic of the vp3 socket cell may be related to the specific accumulation of Runt in one of the vp3 accessory cells (socket or shaft cells, undetermined) and in no other PNS cells (V. Orgogozo, personal observations).
		development	md-es lineage. Its md neuron associated by lineage is vbd (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vp4 = p4 = vc4 (v'esA neuron)
		sensory organ type	ventral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	md-es lineage. Its md neuron associated by lineage is vdaA (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vp4a = p5 = vc5 (v'esB neuron)
		sensory organ type	ventral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla burried in a narrow slit of the cuticule among the denticles (Dambly-Chaudiere and Ghysen, 1986).
		development	md-es lineage. Its md neuron associated by lineage is v'ada (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vp5 = p6 = vc5 = v'es2 (v'es2 neurons)
		sensory organ type	bi-innervated ventral papilla (es organ) (five cells: socket cell, shaft cell, sheath cell, two neurons)
		morphology	papilla surrounded by a ruffled annulus (Dambly-Chaudiere and Ghysen, 1986). Only one of the vp5 neurons accumulates Senseless at stage 16-17 (V. Orgogozo, personal observations).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In pox-neuro mutants, vp5 and the nearby v'dap neuron are transformed into a mono-innervated es organ associated with an md neuron (Dambly-Chaudiere et al., 1992; Awasaki and Kimura, 2001).

			vch1 = vchA (vchA neuron)
		sensory organ type	ventral mono-innervated chordotonal organ composed of a single scolopidium.
		morphology	This scolopidium comprises three cells: cap cell, scolopale cell and neuron.
		development	not described. atonal is required for its formation (Jarman et al., 1993). In spitz, rhomboid, pointed or Star mutants, vch1 is absent whereas vch2 is still present (Okabe and Okano, 1997; zur Lage et al., 1997).

			vch2 = vchB (vchB neuron)
		sensory organ type	ventral mono-innervated chordotonal organ composed of a single scolopidium.
		morphology	This scolopidium comprises three cells: cap cell, scolopale cell and neuron.
		development	not described. atonal is required for its formation (Jarman et al., 1993).  In spitz, rhomboid, pointed or Star mutants, vch2 is still present  whereas vch1 is still present (Okabe and Okano, 1997; zur Lage et al., 1997).

			vpda = vdap
		sensory organ type	ventral md neuron
		morphology	presents a long single dorsal dendrite from which originate anterior-posterior-directed secondary dendrites. Its simple branching pattern places it in class I md neurons together with ddaD and ddaE (Grueber et al., 2002). It accumulates the class I md marker Abrupt (Sugimura et al., 2004; Li et al., 2004).
		development	not described. atonal is required for its formation  (Jarman et al., 1993). No BrdU accumulation has been detected in this neuron (Bodmer et al., 1989) but FLP-FRT clones containing this cell have been obtained (Grueber et al., 2002).

			vdaD= vmd1 (one of the vmd5 neurons)
		sensory organ type	ventral md neuron
		morphology	Its dendritic arborization harbors long primary and secondary  branches. Its dendrites have spiked protusions (1-20um long) along most of their length. It thus belongs to class III md neurons together with v'dap, ldaB, ddaA and ddaF (Grueber et al., 2002). Like them, it accumulates higher amounts of Cut than other md neurons (Grueber et al., 2003).
		development	md-es lineage. Its es organ associated by lineage is vp1 (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vdaC = vmd2 (one of the vmd5 neurons)
		sensory organ type	ventral md neuron
		morphology	Its dendrites are simply branched but they are typically more symmetrically bifurcating than the class I neurons. It thus belongs to class II md neurons together with vdaA, ldaA and ddaB (Grueber et al., 2002).
		development	md-es lineage. Its es organ associated by lineage is vp2 (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vbd = vmd3 (one of the vmd5 neurons)
		sensory organ type	ventral bipolar md neuron
		morphology	It emits only two long dendritic branches along the antero-posterior axis (Bodmer and Jan, 1987). Its projection within the ventral nerve cord differs from other md neurons (Merritt and Whitington, 1995).
		development	md-es lineage. Its es organ associated by lineage is vp3 (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vdaA = vmd4 (one of the vmd5 neurons)
		sensory organ type	ventral md neuron
		morphology	Its dendrites are simply branched but they are typically more symmetrically bifurcating than the class I neurons. It thus belongs to class II md neurons together with vdaC, ldaA and ddaB (Grueber et al., 2002).
		development	md-es lineage. Its es organ associated by lineage is vp4 (Orgogozo et al., 2001). achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			vdaB = vmd1a (one of the vmd5 neurons)
		sensory organ type	ventral md neuron
		morphology	It presents a highly complex dendritic arborization and thus belongs to class IV md neurons together with v'ada and ddaC (Grueber et al., 2002). These three md neurons specifically accumulate the following markers: Pickpocket (Adams et al., 1998), Collier (Orgogozo et al., 2004) and B6-2-25 (V. Orgogozo, personal observations).
		development	md-solo lineage (Orgogozo et al., 2002). Its primary precursor cell is located in the anterior part of the abdominal segment as the primary precursor cell of the vp4 organ and v'ada neuron. In hamlet mutant, the vdaB neuron is not duplicated whereas the other ventral md neurons (originating from md-es lineages) are duplicated (W. Grueber et al., 2003b, W. Grueber, personal observations). This suggests that in hamlet mutants, the md neurons originating from an md-solo lineage are lost whereas the ones originating from an md-es lineage are duplicated. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			v'ada = vmd4a = vdaa
		sensory organ type	ventral md neuron
		morphology	It presents a highly complex dendritic arborization and thus belongs to class IV md neurons together with vdaB and ddaC (Grueber et al., 2002). These three md neurons specifically accumulate the following markers: Pickpocket (Adams et al., 1998), Collier (Orgogozo et al., 2003) and B6-2-25 (V. Orgogozo, personal observations).
		development	md-es lineage. Its es organ associated by lineage is vp4a (Orgogozo et al., 2001). Its primary precursor cell is located in the anterior part of the abdominal segment, as the vdaB's primary precursor cell. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In hamlet mutant MARCM clones, the v'ada neuron is duplicated (W. Grueber et al., 2003b) (see vdaB).

			v'dap =v'pda
		sensory organ type	ventral md neuron
		morphology	Its dendritic arborization harbors long primary and secondary  branches. Its dendrites have spiked protusions (1-20um long) along almost their length. It thus belongs to class III md neurons together with vdaD, ldaB, ddaA and ddaF (Grueber et al., 2002). Like them, it accumulates higher amounts of Cut than other md neurons (Grueber et al., 2003).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). Since it is always found adjacent to both vp5 neurons, it may be associated by lineage to vp5.

			vtd1 (one of the v'td2 neurons)
		sensory organ type	ventral tracheal md neuron
		morphology	Its dendrites are associated to the trachea (Bodmer and Jan, 1987). As opposed to other abdominal sensory neurons, vtd1 and vtd2 axons do not project within the segment where they originate but project more anteriorly up to segment T3 where they cross the midline (Merritt and Whitington, 1995).
		development	not described. atonal is required for its formation (Jarman et al., 1993). In spitz1 mutant, when both vch1 and vch2 neurons are absent (13/29 hemisegments), vtd1 and vt2 are always absent, and when one vch1/2 is still present (16/29), a single vtd neuron is sometimes present (5/16) (V. Orgogozo, personal observations). This correlation suggests that the vch cells, as well as Spitz/EGF signalling, are necessary for vtd formation. BrdU accumulation has been observed in vtd1 and vt2 (Bodmer et al., 1989).

			vtd2 (one of the v'td2 neurons)
		sensory organ type	ventral tracheal md neuron
		morphology	Its dendrites are associated to the trachea (Bodmer and Jan, 1987). As opposed to other abdominal sensory neurons, vtd1 and vtd2 axons do not project within the segment where they originate but project more anteriorly up to segment T3 where they cross the midline (Merritt and Whitington, 1995). It is the only abdominal sensory cell to accumulate Senseless at stage 15-17 (V. Orgogozo, personal observations).
		development	atonal is required for its formation (Jarman et al., 1993). In spitz1 mutant, when both vch1 and vch2 neurons are absent (13/29 hemisegments), vtd1 and vt2 are always absent, and when one vch1/2 is still present (16/29), a single vtd neuron is sometimes present (5/16) (V. Orgogozo, personal observations). This correlation suggests that the vch cells, as well as Spitz/EGF signalling, are necessary for vtd formation. BrdU accumulation has been observed in vtd1 and vt2 (Bodmer et al., 1989).

			lh2 = b = shC = h1 (lesA neuron)
		sensory organ type	lateral mono-innervated hair (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	hair pointing towards the dorsal region (Dambly-Chaudiere and Ghysen, 1986)
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ldaA neuron.

			lp2 = p7 = lc1 (lesB neuron)
		sensory organ type	lateral mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ltd neuron.

			lh1 = H = shC = h2 (lesC neuron)
		sensory organ type	lateral mono-innervated hair (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	hair pointing towards the dorsal region (Dambly-Chaudiere and Ghysen, 1986)
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ldaB neuron.

			lch5 (lch5 neurons)
		sensory organ type	lateral chordotonal organ composed of five scolopidia arrayed along the anterior-posterior axis.
		morphology	The two anterior scolopidia comprise five cells (from posterior-dorsal to anterior-ventral: attachment cell, cap cell, scolopale cell, neuron and ligament cell) whereas the three posterior scolopidia are deprived of an attachment cell and thus comprise four cells. The ligament cells are also anchored to the cuticle through other specialized attachment cells (not represented in the diagram) (Inbal et al., 2004). Note that there are two types of attachment cells: the lineage-related ligament-attachment cells and the non-lineage-related cap-attachment cells. All the cells of this sensory organ are the only abdominal chordotonal cells to accumulate Engrailed (Brewster et al., 2001).
		development	Each scolopidium originates from a single primary precursor cell (pI) (reviewed in Gould et al., 2001).  Three atonal-positive pI cells appear first in the lateral region. They produce the three anterior scolopidia through a yet undescribed lineage (see Lai and Orgogozo, 2004 for a probable cell lineage). The most ventral pI cell also recruits two other ch pI cells via EGF/Spitz signalling. These two pI cells will form the two posterior scolopidia through a yet undescribed lineage (this lineage is probably the one that has been first proposed in Brewster et al., 1995, see Lai and Orgogozo, 2004 for details). In spitz, rhomboid, pointed or Star mutants, at least the two posterior scolopidia are absent (Rutledge et al., 1992; Okabe and Okano, 1997; zur Lage et al., 1997). In atonal mutants, a single sclopidium is still formed at this position (Jarman et al., 1993). The most dorsal ch pI cell also induces the formation of six neighboring oenocytes via EGF/Spitz signalling. The difference in the fate induced by Spitz (oenocytes versus ch pI cell) is determined by the Spalt expression domain (Elstob et al., 2001; Rusten et al., 2001). During stages 12 -13, chordotonal cells migrate ventrally and the whole chordotonal organ rotates while the attachment cells do not change their position. Once the lch5 organ acquires the right orientation, the ligament cells stretch ventrally (Inbal et al., 2003), and when they reach their final position in the lateral region, ligament cells recruit attachment cells from the ectoderm through EGF/Spitz signalling and induce their specialization (Inbal et al., 2004).

			lch1 = lch1x = v'ch1 (v'ch1 neuron)
		sensory organ type	lateral chordotonal organ composed of a single scolopidium.
		morphology	This scolopidium comprises three cells: cap cell, scolopale cell and neuron.
		development	not described. atonal is required for its formation (Jarman et al., 1993). spitz is not required for its formation (Okabe and Okano, 1997; zur Lage et al., 1997).

			ldaA = lda
		sensory organ type	lateral md neuron
		morphology	Its dendrites are simply branched but they are typically more symmetrically bifurcating than the class I neurons. It thus belongs to class II md neurons together with vdaC, vdaA and ddaB (Grueber et al., 2002).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby lh2 organ.

			ldaB
		sensory organ type	lateral md neuron
		morphology	Its dendritic arborization harbors long primary and secondary  branches. Its dendrites have spiked protusions (1-20um long) along almost their length. It thus belongs to class III md neurons together with vdaD, v'dap, ddaA and ddaF (Grueber et al., 2002). Like them, it accumulates higher amounts of Cut than other md neurons (Grueber et al., 2003).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby lh1 organ.

			ltd = istd
		sensory organ type	lateral tracheal md neuron
		morphology	Its dendrites are associated with the trachea (Bodmer and Jan, 1987).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby lp2 organ.

			lbd = isbp = ldb
		sensory organ type	lateral bipolar md neuron
		morphology	It emits two long dendritic branches along muscle 8 (along the dorsal-ventral axis) (Williams and Shepherd, 1998). This neuron may produce neuropeptides because it expresses two genes related to neuroendocrine secretion: PHM (peptidylglycine-alpha-hydroxylating mono-oxygenase) and dimmed (as well as the c929 PlacZ-element inserted near the dimmed gene) (Hewes et al., 2003).
		development	not described. This neuron does not accumulate Cut at any stage. However, achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987; Jarman et al., 1993). No BrdU accumulation has been detected in this neuron (Bodmer et al., 1989), suggesting that it is formed directly from a primary precursor cell without cell division, or that its precursor cells are too deep to incorporate BrdU.

			dbd = dbp
		sensory organ type	dorsal bipolar md neuron
		morphology	It emits two long dendritic branches along muscle 3 (along the anterior-posterior axis) (Williams and Shepherd, 1998). Its dendrites seem to join each other between segments (Bodmer and Jan, 1989). A glial cell is always found next to this neuron (Fredieu and Mahowald, 1989). A lacZ transgene under the control of derailed 5' region is expressed in only one PNS cell, the dbd-associated glial cell (Bonkowsky and Thomas, 1999).
		development	The proneural gene amos is required for its formation (Huang et al., 2000). The dorsoventral locations of the dbd and dmd1 neurons appear reversed relative to their amos-positive proneural clusters, suggesting that one or both neurons undergo migration during development (Holohan et al., 2006). The dbd neuron and its associated glial cell derive from the single cell division of a primary precursor cell (Umesono et al., 2002). This cell division requires numb, Notch and gcm (Brewster and Bodmer, 1995; Jones et al., 1995; Umesono et al., 2002). Notch receptor is activated in the glial cell. The dbd  axonal projection undergoes a drastic reorganization late in embryogenesis (Schrader and Merritt, 2000; Zlatic et al.,, 2003).

			dp1 = p8 = dc1 (desC neuron)
		sensory organ type	dorsal mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ddaF neuron.

			dp2 = p9 = dc2 (desD neuron)
		sensory organ type	dorsal mono-innervated papilla (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron)
		morphology	papilla (Dambly-Chaudiere and Ghysen, 1986)
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ddaD neuron.

			dh1 = h3 (desA or desB neuron)
		sensory organ type	dorsal mono-innervated hair (es organ) (four cells: socket cell, shaft cell, sheath cell, neuron). Note however that this organ (identified as the anterior organ in the dh1-dh2 organ pair) is reported to be tri-innervated in Campos-Ortega and Hartenstein, 1997.
		morphology	small hair pointing towards the dorsal region (Dambly-Chaudiere and Ghysen, 1986). Its hair is very close to the long hair of the dh2 organ. The group of both hairs has been named shF.
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). It may be associated by lineage to the nearby ddaA neuron.

			dh2 = h4 (desA = des2 neurons)
		sensory organ type	dorsal bi-innervated hair (es organ) (five cells: socket cell, shaft cell, sheath cell, two neurons). Note however that this organ is reported to be mono-innervated in Campos-Ortega and Hartenstein, 1997. Also, Dambly-Chaudiere and Ghysen first reported that this sensory organ was mono-innervated (Ghysen et al., 1986), before indicating it was bi-innervated in their next paper (Dambly-Chaudiere and Ghysen, 1987).
		morphology	long hair (Dambly-Chaudiere and Ghysen, 1986). Its hair is very close to the small hair of the dh1 organ. The group of both hairs has been named shF.
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In pox-neuro mutants, dh1 is transformed into a mono-innervated es organ located in the lateral region  (Awasaki and Kimura, 2001).

			ddaD
		sensory organ type	dorsal md neuron
		morphology	presents a long single dendrite from which originate anterior-directed secondary dendrites (Sweeney et al., 2002, Grueber et al., 2002). Its simple branching pattern places it in class I md neurons together with vpda and ddaE (Grueber et al., 2002). It accumulates the class I md marker Abrupt (Sugimura et al., 2004; Li et al., 2004).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In hamlet mutant, the ddaD neuron is duplicated (Moore et al., 2002). This suggests that it originates from an md-es lineage (see vdaB). Its es organ associated by lineage may be the nearby dp2 organ.

			ddaF
		sensory organ type	dorsal md neuron
		morphology	Its dendritic arborization harbours long primary and secondary  branches. Its dendrites have spiked protusions (1-20um long) along almost their length (Sweeney et al., 2002, Grueber et al., 2002). It thus belongs to class III md neurons together with vdaD,  v'dap, ldaB and ddaA (Grueber et al., 2002). Like them, it accumulates higher amounts of Cut than other md neurons (Grueber et al., 2003).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). Several indirect pieces of evidence suggest that it originates from an md-es lineage. First, in hamlet mutant, the ddaF neuron is duplicated (W. Grueber, personal observations, see vdaB). Second, two-cell clones generated by mosaic analysis with a repressible cell marker (MARCM) often contained an es neuron and the ddaF neuron (Sweeney et al. 2002). Third, in miR-9a mutants, the ectopic ddaF neuron is associated with an ectopic Cut-positive es organ (Li et al., 2006).  Its es organ associated by lineage may be the nearby dp1 organ.

			ddaE
		sensory organ type	dorsal md neuron
		morphology	presents a long single dendrite from which originate posterior directed secondary dendrites (Sweeney et al., 2002, Grueber et al., 2002). Its simple branching pattern places it in class I md neurons together with vpda and ddaD (Grueber et al., 2002). It accumulates the class I md marker Abrupt (Sugimura et al., 2004; Li et al., 2004).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). Two indirect pieces of evidence suggest that it originates from an md-es lineage. First, two-cell clones generated by mosaic analysis with a repressible cell marker (MARCM) often contained an es neuron and the ddaE neuron (Sweeney et al. 2002). Third, in miR-9a mutants, the ectopic ddaE neuron is associated with an ectopic Cut-positive es organ (Li et al., 2006). However, in hamlet mutant, the ddaE neuron is not duplicated (W. Grueber, personal communication, see vdaB).

			ddaC
		sensory organ type	dorsal md neuron
		morphology	It presents a highly complex dendritic arborization (Sweeney et al., 2002, Grueber et al., 2002) and thus belongs to class IV md neurons together with v'ada and vdaB  (Grueber et al., 2002). These three md neurons specifically accumulate the following markers: Pickpocket (Adams et al., 1998), Collier (Orgogozo et al., 2004) and B6-2-25 (V. Orgogozo, personal observations).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In hamlet mutant MARCM clones, the ddaC neuron is not duplicated (W. Grueber et al., 2003b), suggesting that it comes from an md-solo lineage (see vdaB).

			dda1 = dmd1
		sensory organ type	dorsal md neuron
		morphology	Its dendritic arborization projects relatively deep below the cuticle to trachea or muscles.
		development	The proneural gene amos is required for its formation (Huang et al., 2000; Brewster et al., 2001). The dorsoventral locations of the dbd and dmd1 neurons appear reversed relative to their amos-positive proneural clusters, suggesting that one or both neurons undergo migration during development (Holohan et al., 2006). The dda1/dmd1 neuron derives from the single cell division of a primary precursor cell (Umesono et al., 2002). Nubbin accumulates in this primary precursor cell as well as its progeny cells (Umesono et al., 2002). The fate of the dmd1 sibling cell is unknown.

			ddaB
		sensory organ type	dorsal md neuron
		morphology	Its dendrites are simply branched (Sweeney et al., 2002, Grueber et al., 2002) but they are typically more symmetrically bifurcating than the class I neurons. It thus belongs to class II md neurons together with vdaC,  vdaA and ldaA (Grueber et al., 2002).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987).

			ddaA
		sensory organ type	dorsal md neuron
		morphology	Its dendritic arborization harbors long primary and secondary  branches. Its dendrites have spiked protrusions (1-20um long) along almost their length (Sweeney et al., 2002, Grueber et al., 2002). It thus belongs to class III md neurons together with vdaD, v'dap, ldaB and ddaF (Grueber et al., 2002). Like them, it accumulates higher amounts of Cut than other md neurons (Grueber et al., 2003).
		development	not described. achaete-scute is required for its formation (Dambly-Chaudiere and Ghysen, 1987). In hamlet mutant, the ddaA neuron is duplicated (W. Grueber, personal observations). This suggests that it originates from an md-es lineage (see vdaB). Its es organ associated by lineage may be the nearby dh1 organ.

References

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Awasaki, T. and Kimura, K., 2001. Multiple function of poxn gene in larval PNS development and in adult appendage formation of Drosophila. Dev. Genes Evol. 211, pp. 20-29. Medline

Barolo, S., Walker, R., Polyanovsky, A., Freschi, G., Keil, T. and Posakony, J. W., 2000. A Notch-independent activity of Suppressor of Hairless is required for normal mechanoreceptor physiology. Cell 103, pp. 957-969. Medline

Bodmer, R. and Jan, Y.N., 1987. Morphological differentiation of the embryonic peripheral neurons in Drosophila. Roux's Arch. Dev. Biol. 196, pp. 69-77.

Bodmer, R., Carretto, R. and Jan, Y.N., 1989. Neurogenesis of the peripheral nervous system in Drosophila embryos: DNA replication patterns and cell lineages. Neuron 3, pp. 21-32. Medline

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