domk08108/domk08108 mutants exhibit pupal lethality, and a majority of third instar larvae have necrotic lymph glands.
At two days after clone induction, the percentage of testes carrying domk08108 mutant germline stem cell (GSC) clones is indistinguishable from controls, however this decreases over time and by day 8 no testes that contain domk08108 mutant GSCs. Similarly, the proportion of testes with domk08108 mutant cyst stem cells (CySCs) progressively drops to 0 by day 15.
domk08108 mutants exhibit melanized lymph glands and a lack of hemocytes.
domk08108 homozygous female germ-line stem cells are lost from their stem cell niche at the same rate as wild-type female germ-line stem cells. However, 91% of dom3 homozygous clone follicle stem cells are lost from their niche within 17 days, compared to only 37.5% of cells in wild-type control clones. This is not accompanied by any increase in in apoptosis of these cells.
Lethality acts in the early pupal stages. Lymph glands are black, no hemocytes and reduced neuroblast region in the larval brain. Mititic defects are not evident in the neuroblasts. Females with germline clones do not lay eggs.
Homozygous third instar larvae have a striking absence of circulating hemocytes; only 0 to 10 oversized cells are seen per larva, in contrast to the wild-type number of 1000-3000 circulating hemocytes. In addition, the number of sessile plasmatocytes is significantly reduced compared to wild-type.
Homozygous larvae contain large numbers of microorganisms which can be seen on the epithelium lining the integument and on muscles.
The melanisation in response to pricking with a needle is reduced in intensity compared to wild-type larvae.
Melanisation plaques appear on the surface of homozygous larvae after natural infection by spores of B.bassiana, as are seen in wild-type larvae.
There is not a significant difference in the survival rate between larvae pricked with a sterile needle or a needle coated with Gram-positive or Gram-negative bacteria, however, infection with fungal spores induces over 60% lethality in 48 hours in homozygous larvae.
Lethality occurs during third instar larval or pupal stages. Mutants exhibit visible disc abnormalities: very small or no discs. Clones cannot be induced in wild type discs. In tergites, clones with normal size and but lower than expected frequency are recovered. Clones cannot be recovered in the wing disc.
Homozygous larvae are totally devoid of circulating hemocytes. In favourable conditions these larvae have a prolonged third instar, up to 10 days at 20oC. They show melanized lymph glands. During third instar the blackening invades the whole lobe, extending to the posterior lobes. Melanized lymph glands eventually detach from the dorsal vessel. Ultrastructural analysis reveals that the prohemocytes in the hematopoetic organ are larger than wild type. Lymph glands are filled with necrotic, melanized cells and cells packed with heterogeneous inclusions indicative of strong resorptive processes. Mutant glands are devoid of differentiating prohemocytes. The embryonic hemocytes are unaffected, but by first instar hemocytes are reduced in number. Mutants are also devoid of imaginal discs, imaginal rings and histoblasts in the gut. The size of the brain is significantly reduced. The domain of brain neuroblasts in the optic lobes is reduced. Residual imaginal disc cells exist in small clusters.