/+ adults do not have any obvious wing phenotypes.
transheterozygotes show a significant reduction in the number of synaptic boutons at the third instar larval neuromuscular junction, as compared to controls.
/+ third instar larvae have similar numbers of boutons to wild type.
mutant nuclei are small and tightly packed, unlike wild-type copper cell nuclei, which are polyploid and regularly spaced.
Eight days after induction of intestinal stem cell (ISC) clones, the number of cells in Mad12
mutant clones is significantly higher than in wild-type clones. After injury by feeding bleomycin, mutant clones have more cells than both wild-type clones and mutant clones before injury.
Wild-type clones contain one stem cell, whereas approximately one-third of Mad12
mutant clones show a gradual increase in ISC number over time.
mutant clones contain more stem cells than wild-type clones, indicating that mutant ISCs divide more often than wild-type ones.
Heterozygotes climb sightly, but significantly, better than wild-type controls in a negative geotaxis assay.
Very few Mad12
mutant wing disc clones are recovered.
mutant third instar larvae show increased uptake and transport of ingested fluorescently labeled fatty acids from the midgut lumen to the fat body compared to wild-type controls.
Clones of Mad12
-mutant cells cause premature differentiation of the adult midgut precursor cells into large, polyploid, enterocyte-like cells compared with wild-type cells.
Somatic clones of Mad12
homozygous cells in the developing retina at 42 hours APF have abnormal arrangements of inter-ommatidial cells including aberrant bristle-bristle contacts and abberant arrangements of secondary and tertiary pigment cells.
Homozygous cells in the morphogenetic furrow (in clones that encompass the morphogenetic furrow) can stil achieve proper apicobasal contraction.
mutant germline stem cells (GSCs) show maintenance and cell division defects when clones are generated during adult stages. However no defects are seen when Mad12
clones are generated during the larval and pupal stages.
Mosaic female germaria containing germline stem cells in contact only with homozygous somatic cap cells do not show any defects in germline stem cell renewal.
G1 arrest is delayed in Mad12
eye disc cells; some mutant cells don't arrest at all in larger Mad12
Homozygous clones in the wing disc extrude from the wing epithelium.
When neutral marked clones are induced in the ovary, the proportion of germaria carrying marked somatic stem cells 3 weeks after clone induction is around 70% of that seen one week after clone induction. For Mad12
homozygous clones, the equivalent figure is under 25%, resulting in significantly fewer clones in the follicle cells.
transheterozygotes exhibit abnormal L4/L5 wing veins, with no L2 or crossveins and a large margin notch.
Clones of male Mad12
homozygous germline stem cells are still present in less than 1% of testes one week after clone induction and none are present two weeks after clone induction. This is in contrast to wild-type control clones, which are present in 82% of testes one week after clone induction and 64% two weeks after clone induction.
The evoked excitatory junctional potential (EJP) (measured at muscle 6 of segment A3) shows a decrease in amplitude in Mad1
animals compared to wild type. Quantal content is reduced compared to wild type.
The average number of crystal cells per embryo is significantly reduced in homozygous stage 13-14 embryos compared to wild type.
Ovarioles carrying Mad12
GSC clones are not recovered, but ovarioles with mutant Mad12
germ cells in egg chambers are recovered, indicating that Mad12
GSCs can not be maintained before adulthood.
Homozygous clones induced before 72 hours after egg laying (AEL) show elimination of entire tarsal segments, whereas if clones are induced after 84 hours AEL, only dorsal leg pattern features are affected.
In somatic clones induced late in the third larval instar L3 bifurcates or terminates at the clone boundary. L2 was seen to loop round a small clone. In 50 clones, all were seen to disrupt vein formation in a cell autonomous manner.
When somatic clones are created in the glial cells of the developing eye, they contain fewer cells than equivalent wild-type clones. the total number glial cells remains the same as wild-type cells appear to compensate for the loss of mutant ones.
Encapsulation defects of 16-cell cysts are seen in ovaries containing homozygous follicle cell clones.
Clones induced in the pleura showed a sternite or tergite identity rarely - 6 cases out of several hundred clones. Other clones retain a pleural identity or display a weak phenotype such as mild sclerotinization. Clones at or near the dorsal midline show loss of tergal pigmentation. A partial loss of pigmentation is often observed in clones lateral to the anterior inflection of the pigment band.
20% of the dorsal branch fusion events are disrupted. The fusion cell extends a sprout but does not contact the appropriate fusion partner.
Gastric caecae frequently fail to elongate. Dorsal trunk and visceral branches of the developing trachea are essentially normal. Branching defects occur, ganglionic branches fail to fuse. Dorsal trunk is normal.
Embryos lacking maternal and zygotic Mad
embryos derived from females with homozygous Mad12
germ line clones) show loss of dorsal tissue and expansion of the lateral denticle bands into dorsal regions. The phenotype is partially paternally rescuable.
flies have imaginal disc defects. All the progeny of MadEz
females mated to wild-type males die as embryos. One-half of the embryos (presumptive genotype Mad12
/+ have a weakly ventralised phenotype, and the other half (presumptive genotype MadEz
/+) have a variably expressive dorsal-open phenotype.
Females with homozygous germ line clones lay very few eggs, all of which are unfertilised and smaller than normal. The ovaries of these females may contain no discernible ovarioles or may contain many degenerating egg chambers, the most mature of which are at stage 10.
Clonal analysis in the germarium reveals that mutant stem cells are lost more rapidly than wild type, though there is no effect on the formation of 16 cell cysts or their subsequent development. Stem cell half life is 0.25 weeks (wild type being 4.6 weeks). Stem cell division rate relative to control is 0.21. Cysts contain the normal 16 cells, including and oocyte.
Clonal analysis revealed that Mad
function is autonomously required in the eye imaginal disc cells for proliferation and/or survival.
Larval heterozygotes with Df(2L)JS17
exhibit reduced fat body, midgut defects and greatly reduced gastric caecae and dissected pupae exhibit absent or severely reduced imaginal discs.