1bp deletion (G2866) resulting in a frameshift (producing an altered amino acid composition for 41 residues after the mutation site and a truncation which removes the three C-terminal zinc fingers.
Somatic clones of ham1/ham1 adult olfactory receptor neurons Or67d, Or83c, Or43a, Or2a, Or88a, Or47b, Or10a, Or92a, Or85a, Or85b, Or56a, Or82a, Or98a, Or67c, Or43b, Or67a, Or67b, Or42a, Or46a, Or59c or olfactory receptor neurons from sensilla ai1, ac1, ac3 or ac4 fail to innervate their respective target glomeruli. Olfactory receptor neurons Or9a, Or69aA, Or69aB and unknown neurons innervating glomerulus VM6 project to their target glomeruli in most cases, while Or23a, Or19a, Or19b, Or65a, Or65b, Or65c, Or13a, Or42b, Gr21a, Or59b, Or22a, Or22b, Or7a, Or47a, Or49b, Or49a/85f, Or71a, Or33c/85e, Or85d, Or35a, Ir76a and Ir76b are unaffected.
In ham1/Df(2L)ED1195 adults, olfactory receptor neuron Or67c fails to project to its target glomerulus DM6, occasionally producing ectopic branches.
65% of external sensory organs have a wild-type phenotype of 1 trichogen and 1 tormogen, while 34% of external sensory organs have a 2 trichogen and 1 tormogen phenotype in homozygous second instar larvae. 7% of external sensory organs in homozygous clones in the adult notum have a 2 trichogen and 1 tormogen phenotype, 23% have a 2 trichogen and 2 tormogen phenotype and 42% have a 1 trichogen and 2 tormogen phenotype. The elaboration of the extra sensory organ lineage from the external sensory organ precursor cell in homozygous clones (analysed between 18 and 38 hours after pupal formation) is indistinguishable from wild type in the timing, orientation and number of divisions in both the external cell branch and internal cell branch. This indicates that the extra external cells seen in mutant clones are due to the conversion of IIIB cell daughters to external cell fates. The ES neuron undergoes cell death in 15% of external sensory organs in homozygous clones.
In mutant larvae, doubling of neuron v'ada is frequently observed. When single cell mutant clones are made, duplications of class I, II and III, neurons. Duplicated class I and II neurons innervate overlapping regions of the body wall. Although these dendrites do not clearly fasciculate, they intermix extensively. The major trunks of class III neurons duplicated in clones, overlap extensively and often extend along the same direction. Extensive overlap is not observed among the short terminal extensions of the class II neurons.
Supernumerary multidendritic neuron (MD) neurons are seen in each peripheral nervous system (PNS) cluster of the embryo, with a concomitant decrease in the number of external sensory (ES) neurons. For example, homozygous embryos have 12 MD neurons (wild-type number is 8) and one ES neuron (wild-type number is 5) in the abdominal dorsal cluster. The vp4a external sensory organ precursor lineage division pattern appears normal and produces 5 cells (as in wild type). however, the ES neuron and glia are lost in the differentiated organ and instead a second MD neuron is seen in the position normally occupied by the ES neuron and a third external cell (trichogen) is seen in the position normally occupied by the glia. Mutants have no defects in muscle, gut, trachea, central nervous system or cuticle formation.
ham1 has trichogen cell | somatic clone | adult stage phenotype, suppressible by Nl1N-ts1
In ham1 homozygous clones induced in a Nl1N-ts1 background at the restrictive temperature, all external sensory organs develop a 1 trichogen/multiple tormogen phenotype, compared to ham1 homozygous clones induced in a wild-type background, where external sensory organs develop a 2 trichogen/multiple tormogen phenotype.
