fru^NP0021/fru^ΔC (but not fru^NP0021/fru^ΔA or fru^NP0021/fru^ΔB) MARCM clones (in Scer\GAL4^fru-NP0021 neurons) fail to develop a male-specific mAL ipsilateral neurite.

Homozygous males have reduced viability.

fru^ΔC/Df(3R)fru^4-40 males lack the muscle of Lawrence.

Compared to controls, fru^ΔC/Df(3R)fru^4-40 males show no significant difference in latency to courtship of or courtship index towards females. However, the males are markedly unsuccessful at achieving copulation, with no males managing to copulate in the 1 hour observation period. The males show dramatically low levels of fertility over a one-week observation period. fru^ΔC/Df(3R)fru^4-40 males show vigorous chaining behaviour (forming male-male courtship chains).

The wing extension index of fru^ΔC/Df(3R)fru^4-40 males is significantly reduced compared to controls. The interpulse interval is significantly longer than normal, pulse frequency is slightly, but significantly increased and sine song is completely absent. The interpulse interval is significantly longer than normal and sine song is completely absent in homozygous fru^ΔC and fru^ΔC/fru^sat15 males.

Nearly all XY fru^P1.LexA/fru^ΔC animals show complete loss of midline crossing by foreleg gustatory receptor neuron (GRN) axons.

Flies homozygous for fru^ΔC exhibit 52% and 44% viability in females and males respectively. They also exhibit approximately 31% fertility. These flies also exhibit reduced courting of females while displaying higher levels of intermale courtship and chaining.

Flies transheterozygous for fru^ΔC and fru^sat15 exhibit approximately 13% fertility compared to wild-type. They also experience reduced viability, with approximately 32% the wild-type level of male and female progeny surviving. These flies also exhibit reduced courting of females while displaying higher levels of intermale courtship and chaining.

Flies transheterozygous for fru^ΔC and fru^4-40 exhibit approximately 21% fertility compared to wild-type. They do not experience reduced viability. These flies also exhibit reduced courting of females while displaying higher levels of intermale courtship and chaining.

Flies transheterozygous for fru^ΔC and fru³ exhibit approximately 33% fertility compared to wild-type. They do not experience reduced viability. These flies also exhibit reduced courting of females while displaying higher levels of intermale courtship and chaining. The Muscle of Lawrence fails to differentiate in 90% of cases, with the remaining 10% exhibiting only a vestigial muscle of Lawrence.

fru^ΔC/fru³ transheterozygotes exhibit a reduced number of male serotonergic neurons and improper patterning. The dorsal serotonergic abdominal giant neurons (dSAbg) exhibits approximately 18%, and the ventral serotonergic abdominal giant neurons (vSAbg) approximately 6% of the normal complement of serotonergic neurons. At least one or the other of these clusters is absent in a significant portion of these males; the vSAbg is undetectable in approximately 70%, whereas approximately 22% exhibit no dSAbg. In animals lacking the vSAbg, the remaining dSAbg neurons innervate the vas deferens, accessory glands, and ejaculatory duct. Similarly, in animals with no dSAbg, the same target organs are innervated by neurons of the vSAbg. In animals with only one cluster, while the innervation of the vas deferens is wild-type in pattern, the innervations are less dense. Similar observations are found for the accessory glands and ejaculatory duct. Unlike wild-type males, 90% of accessory glands are not fully innervated and a further 5% have no innervation. This phenotype is repeated with the vas deferens. These males experience a 8.5% decrease in fru[M]-labelled neurons compared to wild-type.

fru^ΔC/fru^ΔC homozygotes exhibit a reduced number of male serotonergic neurons and improper patterning. At least one or the other of the dorsal serotonergic abdominal giant neuron cluster or the ventral serotonergic abdominal giant neuron cluster is absent in a significant portion of these males. In animals lacking the vSAbg, the remaining dSAbg neurons innervate the vas deferens, accessory glands, and ejaculatory duct. Similarly, in animals with no dSAbg, the same target organs are innervated by neurons of the vSAbg. In animals with only one cluster, while the innervation of the vas deferens is wild-type in pattern, the innervations are less dense. Similar observations are found for the accessory glands and ejaculatory duct. Unlike wild-type males, 90% of accessory glands are not fully innervated and a further 5% have no innervation. This phenotype is repeated with the vas deferens. These males experience a 15% decrease in fru[M]-labelled neurons compared to wild-type.

fru^ΔC heterozygotes have a wild-type number of serotonergic neurons.

Males heterozygous for fru^ΔC and Df(3R)fru^w24 exhibit reduced fertility (approximately 9% fertility). Female flies exhibit 72% viability while males exhibit 80% viability. These flies also exhibit reduced courting of females while displaying higher levels of intermale courtship and chaining.

During a 6hr observation, fru^ΔC/fru³ males do not mate, whereas approximately 50% of fru^ΔC/fru³ males expressing fru^{MC.Scer\UAS.cSa} do. These males are slower to initiate mating, although the duration of copulation is similar to that of wild-type males. A small number of control flies (i.e. fru^{MC.Scer\UAS.cSa}/+ ; fru^ΔC/fru³) manage to mate within the same time as the 'rescued' males, probably due to 'leakage' of the transgene, although mating durations are still significantly longer than those of wild-type males.

fru^AJ96u3/fru^ΔC is an enhancer of increased cell number phenotype of brat^DG19310/brat¹¹

fru^AJ96u3/fru^ΔC is an enhancer of increased cell number phenotype of numb^Ex112/numb¹⁵

fru³/fru^ΔC has muscle cell of male abdominal 5 muscle phenotype, suppressible by Agam\fru^MC.UAS/Scer\GAL4^fru.16

fru³/fru^ΔC has serotonergic neuron phenotype, suppressible by Agam\fru^MC.UAS/Scer\GAL4^fru.16

fru^AJ96u3/fru^ΔC is an enhancer of neuroblast | increased number phenotype of brat^DG19310/brat¹¹

fru^AJ96u3/fru^ΔC is an enhancer of type II neuroblast | increased number phenotype of numb^Ex112/numb¹⁵