Homozygous embryos have a significantly reduced number of pericardial cells and lymph gland blood progenitors compared to wild type, as well as a small decrease in the number of cardioblasts.

Mutant stage 14 embryos have the same number of posterior midline glia per segment as wild-type controls.

Homozygous intestinal stem cell clones grow similarly to wild-type clones and do not show defects in intestinal stem cell maintenance.

Df(1)sc-B57 mutants are homozygous lethal. Df(1)sc-B57/+ mutants show loss of the posterior supra-alar, posterior notopleural, anterior notopleural and anterior postalar bristles to varying degrees.

Combining Df(2L)GR4 (which removes the ASC: Achaete-scute Complex) and ato¹ causes the loss of most cells in the embryonic peripheral nervous system (PNS) - only the two dorsal located md neurons remain.

The bristle phenotype seen female D.simulans/D.melanogaster hybrids is significantly exacerbated by the Df(1)260-1 deletion, which removes the achaete-scute complex. Bristle loss is greater at 25^oC than at 18^oC. In female D.simulans/D.melanogaster hybrids heterozygous for pnr^VX6 and Df(1)sc-B57, the posterior and anterior scutellar bristles and the posterior and anterior dorsocentral bristles are lost at a high frequency compared to female D.simulans/D.melanogaster hybrid with pnr^VX6 or Df(1)sc-B57 alone.

Malpighian tubule tip cells are absent in homozygous embryos.

Embryos lack most brain neuroblasts.

SNSPs are reduced or absent. Typically a single, large SNS pouch, which may be branched, invaginates from the stomodeal epithelium.

Loss of neuron mutant.

In embryos lacking the AS-C, large basophilic midgut cells are absent and the number of adult midgut precursors is strongly reduced. No cell death accompanies the losses suggesting that the cells that would have developed as large basophilic midgut cells and adult midgut precursors develop as principal midgut epithelial cells instead. The resulting midgut epithelium is structurally normal. Double mutants with Delta^9P have normal midgut epithelium, but the large basophilic midgut cells are missing and the number of adult midgut precursor cells are reduced.

Df(1)sc-B57 mutants express normal levels of dpn in their reduced number of neuroblasts. Females doubly heterozygous for Df(1)sc-B57 and a heat shock dpn contruct, and heat shocked during pupation, have many missing bristles.

Homozygous embryos have a smaller, more disorganised ventral nerve cord than normal, with noticeable thinning in areas along the nerve cord.

20--25% of neuroblasts are absent in homozygous Df(1)sc-B57 embryos due to commitment of fewer cells. Neuroblasts in the medial and lateral rows are preferentially affected. Neuroblasts that succeed in segregating are smaller than wild type. The median neuroblast and midline precursor cell MP2 are missing. The death of cells that have segregated from the neuroectoderm and their progeny contribute to the neural hypoplasia.