hopTum heterozygous adults exhibit a range of small to large tumor frequencies.
Heterozygous adult females contain melanotic tumours. The incidence of lamellocytes as a percentage of the total hemocytes is increased compared to wild type in hemolymph preparations from third instar heterozygous larvae.
Mutant adults contain multiple, large melanotic tumours.
Mutant third instar larvae show an increase in the number of circulating hemocytes compared to controls.
The number of hemocytes is increased in hopTum mutant third instar larvae compared to wild type.
hopTum lymph glands display considerable numbers of lamellocytes when larvae are raised at 23, 25, or 27[o]C.
Lymph glands of hopTum/Y larvae at 72 hours of development show hyperplasia and extensive lamellocyte differentiation. Lamellocytes reproducibly appear in the mutant lymph glands at around 54-56 hours of development at 25[o]C. A large population of lamellocytes are seen in the mutant hemolymph at 72 hours of development, and lamellocytes are reproducibly seen in the mutant hemolymph before 56 hours of development at 25[o]C.
Heterozygous larvae show a massive overproduction of both lamellocytes and non-lamellocyte hemocytes in the hemolymph.
Mutant larvae have a large number of lamellocytes within the circulating hemolymph.
75% of mutant larvae are melanised.
Lymph glands from hopTum/Y animals are hypertrophic and produce increased numbers of hemocytes and lamellocytes.
Heterozygous third instar larvae have melanotic nodules found in the hemocoel or in association with He-positive lymph glands. The melanotic nodules are surrounded by lamellocytes.
Mutant larvae show overproliferation of plasmatocytes in the primary lymph gland lobes and hemocytes aberrantly differentiate into lamellocytes in the secondary lymph gland lobes.
Heterozygotes often have melanotic tumours.
hopTum is dominant semi-lethal at 29oC (survival of females to adulthood is 48% of wild-type).
The proportion of completely melanised tumours by larva is significantly decreased in hopTum larvae parasitised by the G431 L.boulardi strain compared to unparasitised hopTum larvae, while the proportion of partially melanised tumours is significantly increased.
hopTum embryos have nearly twice as many pole cells as wild-type embryos. At stage 3, the pole cells in hopTum mutants change shape and migrate away from the posterior pole, while pole cells in wild-type embryos remain a spherical shape and are confined to the posterior area. Pole cells in the mutants are frequently observed to prematurely transit through the gut and migrate errantly. Such pole cells survive, in contrast to wild-type embryos where errant pole cells are destroyed by apoptosis, and aggregate in ectopic locations. Pole cells from cellularization stage hopTum embryos are more active both in dispersion and translocation movements when observed in Schneider culture medium, than pole cells from wild-type embryos.
In mutants the tracheal pits are larger than in wild-type. The hindgut is also longer than seen in wild-type. The hindgut nuclei in mutants form a single layer and are further apart from each other, giving the appearance of being stretched. The peripheral nervous system of mutants differentiate and grow axons prematurely - the PNS is nearly fully differentiated at stage 12 (as compared to 15 in wild-type).
About a quarter of heterozygous mutant larvae exhibit melanotic tumours when grown at 25oC about half exhibit tumours when grown at 28oC.
Mutant larvae raised at the non-permissive temperature (29oC) have melanotic tumours.
At 28oC, hopTum larvae show a six-fold increase in the concentration of circulating blood cells compared to wild-type larvae. 48% of the plasmatocytes are differentiated into lamellocytes in hopTum larvae compared to 6% in wild-type larvae. The larvae have overgrown and melanised lymph glands.
The concentration of circulating hemocytes in hemizygous larvae is increased compared to controls. The distribution of blood cell types is altered compared to wild type; in the mutant larvae 63.2% are plasmatocytes (more than 99% in controls), 11.4% are podocytes (less than 0.1% in controls) and 25.4% are lamellocytes (0.1% in controls).
100% of hemizygous third instar larvae show multiple melanotic capsules at 18oC, 25oC and 29oC. Hemizygous adults show multiple melanotic capsules at 25oC.
At 25oC 37% of heterozygous mutant adult females have at least one abdominal tumour.
When raised at 25oC, second instar mutant larvae have abundant (10-15%) lamellocytes in circulation and in some larvae lamellocytes can be seen in lymph gland lobes. Melanotic tumours are not yet present. Lamellocyte numbers increase very rapidly in the course of the third instar stage and but the end of the instar represent close to 50% of the circulating blood cell population. Plasmatocytes frequently show abnormal oversized features. Lamellocytes are very abundant in the lymph glands before pupariation. Crystal cells are rarely round in mutant larvae.
Larvae contain free-floating melanotic masses.
Heterozygotes grown above 25oC have reduced viability and develop melanotic tumors.
At high culture temperatures, abnormalities in hemocyte proliferation and differentiation, melanization of hematopoetic and gut tissue and recessive lethality result.
Formation of melanotic tumours and hypertrophy of the lymph glands. Tissue transplantation indicates the lymph glands can autonomously generate melanotic masses associated with the mutation.
Homozygotes raised at 29oC form black melanotic masses, haematopoietic defects. Lymph gland material transplanted into a wild type host that is cultured at 29oC causes the appearance of melanotic masses in the abdominal cavity and/or in the leg joints, bloating is also observed. Elevated levels of lamellocytes are found in the haemolymph due to overproliferation and premature differentiation.
Blood cell neoplastic phenotype.
Hematopoietic neoplasms, overproliferation of hemocyte stem cells in the larval lymph gland and premature differentiation of circulating haemocytes. Lethality occurs at 29oC.
Dominant tumorous gene that is a temperature-sensitive lethal at 29oC in hemizygous males and homozygous females; about two-thirds of the hemizygous males survive at 18oC and one-quarter of these have melanotic tumors. Males raised at 26oC and heterozygous females raised at 29oC survive to adulthood, but show melanotic masses in the abdominal cavity or small black specks in the legs, wings, or thorax. Mutant larvae kept at 29oC show enlargement of the lymph glands in the late second- or early third instar larvae, but no melanotic masses. By mid third instar, the lymph glands are large and diffuse and the gastric caeca have become encapsulated and melanized. By late third instar, the larvae have melanotic masses in the body cavity, lack lymph glands and have reduced, encapsulated and melanized gastric caeca as well as encapsulated and melanized muscles and fat bodies. These mutants do not survive beyond the late third instar or the early pupal stage. When lymph glands from Tum larvae are injected into adult female hosts, transplantable neoplasms are produced. Melanization, at first associated with the leg joints and later with the head, thorax and abdomen, takes place; also abdominal bloating. The lymph glands become melanotic and the abdomen is filled with encapsulated masses before the premature death of the injected individuals. Injection of Tum tissue other than lymph glands fails to produce these effects. The melanotic neoplasms can be transplanted into a succession of hosts in which they produce the same abnormalities. The neoplastic cells resemble hemocytes; some cell lines are melanotic and others are unpigmented, but in both types, the tissue, when transplanted, grows rapidly in the hosts and kills them.