In contrast to wild-type, supplementing Apis mellifera royal jelly to food does not influence body size or developmental time in Egfr^tsla/Egfr^f24 mutants. When wild-type flies are reared on medium containing royal jelly, they show increased body size (body weight and body length) and fecundity, and have extended lifespan and shortened developmental time compared with flies reared on control medium.

In stage 16 Egfr^tsla/Egfr^f24 embryos the two neurons that normally arise closest to the midline are lost, vdaB (in 79% of cases) and the class III neurons (in 76% of cases). Loss of these neurons are preceded by the loss of SOPs 1a (73%() and 1 (69%).

The lymph glands in Egfr^tsla/Df(2R)Egfr18 mutant larvae develop normally.

The cardiac function of Egfr^f24/Egfr^tsla flies is similar to that of wild-type controls at 18[o]C. The cardiac function of Egfr^f24/Egfr^tsla flies deteriorates after 24 h at 25[o]C.

Marker expression analysis shows that in Egfr^tsla/Egfr^f24 flies heat shocked for 24 hours at the beginning of pupariation, the proportion of pale-ommatidia is reduced and hybrid ommatidia are present with a yellow-type R8 and a pale-type R7. These animals have very rough eyes.

Primordial germ cells overproliferate in Egfr^tsla/Egfr^f24 larvae grown at a restrictive temperature. Fewer intermingled cells (somatic cells adjacent to primordial germ cells) are present in Egfr^tsla/Egfr^f24 gonads compared to wild-type.

At the restrictive temperature, additional cells enter the second mitotic wave in Egfr^tsla eye discs.

Complete posterior spiracles are present in Egfr^tsla embryos that have been maintained at the restrictive temperature from 5-8 hours of development despite severe segment polarity defects.

Egfr^tsla protein is wild-type at 18^oC for ligand-dependent signalling activity. However, at 30^oC its activity is very low, and is indistinguishable from no activity at all. The Egfr^tsla protein undergoes a ligand-independent conformational change at 30^oC, leading to rapid internalisation.

R8 cells form in Egfr^tsla eye mutant clones, although at later stages they are sometimes abnormally close.

Egfr^tsla mutant clones do not exhibit any changes in morphogenetic furrow progression, compared to wild-type clones. Egfr^tsla has no effect on R8/founder cell initial spacing, neither with a 24-hour shift, nor when raised continuously at the non-permissive temperature.

Egfr^tsla/Egfr^f24 animals shifted to restrictive temperatures for 24 hours during the first half of the third larval instar have leg truncations, with the size of the truncation increasing with temperature. At lower restrictive temperatures (28.7^oC) only the most distal structures (the claws) are missing but at high temperatures (33^oC) structures tarsal segments 2-5 are absent. At 33^oC development of regions more proximal to the tarsal segments is occasionally disrupted. Egfr^tsla/Egfr^f24 clones do not survive in distal regions of the leg disc at temperatures above 31^oC. Egfr^tsla/Egfr^f24 animals shifted to 33^oC for 12 hours during the first quarter of the third larval instar show truncations of the tarsus. However, a 12 hour shift during the second quarter of the third larval instar results in legs with normal distal elements (claw and tarsal segment 5) but fusions or deletions of the intermediate tarsal segments 2-4.

When Egfr^tsla/Egfr^f24 mutants are grown at the permissive temperature (18^oC) throughout larval development, and then shifted to the non-permissive temperature (29^oC) between 0 and 10 hours after puparium formation (APF) recognizable transverse rows (t-rows) of bristles are seen on the basitarsus and distal tibia are seen, but bristles within each row are jumbled in irregular groups. (bristles line up, with sockets touching in wild-type). Up shifts after 10h APF have little effect. When these mutants are grown at 18^oC throughout larval development, shifted up to 29^oCat pupariation and shifted back down between 0 and 14 hours APF, little effect is seen. Down shifts after 21h APF cause disruption of the organisation of the t-rows. When downshifts occur between 14 and 20h APF, other phenotypes emerge. In a minority of legs (13%) adjacent rows bend toward one another and join at Y or X shaped intersections.

When Egfr^tsla/Egfr^f24 animals are raised at the permissive temperature (of 18^oC) they have a wild-type pattern of bracts. Those raised at 29^oC lack all bracts. The sensitive period for tibial and basitarsal bracts are 17-28h and 13-28h AP respectively.

Egfr^tsla clones induced in the wing disc in a Minute background after the mid-second instar (and maintained at the restrictive temperature of 31^oC) can contribute to the prospective lateral notum, albeit rarely. Clones in the prospective lateral notum are abnormally round in shape. Egfr^tsla clones in the wing disc maintained at 28^oC can be recovered in the prospective lateral notum, even when induced during the first larval instar. Homozygous clones generated before the second larval instar and maintained at the permissive temperature of 25^oC can contribute to either or both of the dorsal and ventral compartments of the wing disc. However, there is an enhanced tendency for the clones to occupy the ventral compartment as the clones are maintained at more restrictive temperatures.

Egfr^tsla cells in the eye disc arrest in G2 at the restrictive temperature even when adjacent to preclusters of differentiating photoreceptor cells. The only cells not to enter the second mitotic wave are differentiating R8 cells. At the restrictive temperature, undifferentiated cells around the ommatidia in the developing eye disc adopt a typical apoptotic morphology. As the morphogenetic furrow progresses, apoptotic cells disappear from posterior regions, and new regions of the disc are brought into the region where cells die. Cell death is also seen in other tissues, including the eye disc anterior to the morphogenetic furrow.

Egfr^tsla/Egfr^f24 flies at 18^oC frequently lack the anterior supraalar bristle, posterior supraalar bristle and posterior postalar bristle, and the anterior postalar bristle and anterior dorsocentral bristle are frequently duplicated. When late LIII larvae are shifted to 30^oC for 15 hours, all notum macrochaetae show reduced liklihood to develop except the scutellar bristles.

Egfr^f24/Egfr^tsla embryos raised at 18^oC until approximately stage 12, and then shifted to 29^oC for the remainder of development exhibit reduced numbers and increased apoptosis of longitudinal (interface) glial cells.

Egfr^f24/Egfr^tsla animals kept at the restrictive temperature between 168-180 hours after egg deposition (AED) develop an adult eye that lacks ommatidia. Imaginal discs from these animals examined at either 192 or 204 hours AED lack both the ommatidia and the morphogenetic furrow. Egfr^f24/Egfr^tsla animals kept at the restrictive temperature between 192-204 hours AED develop an eye with severe structural defects along the posterior-lateral margins (ommatidia at the intersection of the equator and posterior margin appear not to be affected). The morphogenetic furrow has clearly initiated at the posterior margin in imaginal discs from these animals examined at 204 hours AED, but its continued re-initiation along the lateral margins is inhibited.

If Egfr^tsla/Egfr^f24 flies are raised at 17^oC, transferred to 25^oC for 24 hours at second instar larval stages, and then returned to 17^oC leads to a mirror image duplication of the wing.

When Egfr^tsla/Egfr^f24 mutant males are raised at the permissive temperature (18^oC), and then shifted to the restrictive temperature (29^oC), a spermatogenesis phenotype is seen. Although all stages of spermatogenesis are initially present, by one week of at non-permissive temperature, testes are filled with massive numbers of early germ cells with small nuclei. The early germ cells appear to proliferate at the expense of differentiation, as spermatocytes and spermatids are absent or markedly reduced in numbers. Many early germ cells displayed expression marker, subcellular structures and cell division behaviour characteristic of stem cells and gonialblasts. Mutants have many more cells with ball shaped or dumbbell-shaped spectrosomes, both near the tip and displaced down the testis. In Egfr^tsla/Egfr^f24 mutant males, early cyst cells often form improper associations with early germ cells. In general accumulation of early germ cells is not associated with a corresponding increase in the total number of cyst progenitor or early cyst cells.

When Egfr^tsla/Egfr^f24 flies are grown at the restrictive temperature for Egfr^tsla during the second instar, the notum is lost, the wings are present but have pattern abnormalities and fail to inflate.

The notum is significantly reduced in size in Egfr^tsla/Egfr^t1 wing discs raised at the non-permissive temperature.

Temperature sensitive mutation; at 18^oC the cuticle of Egfr^tsla/Egfr^f24 embryos is indistinguishable from wild-type, and at 28^oC the cuticle of Egfr^tsla/Egfr^f24 embryos is indistinguishable from that of Egfr^f24/Egfr^f24 homozygotes. Suppresses the dominant Egfr^E1 phenotype towards wild-type in transheterozygotes at 28^oC but does not suppress the dominant Egfr^E1 phenotype at 18^oC. Egfr^tsla/Egfr^f24 animals raised at the non-permissive temperature for 24 hours in late larval life and then returned to 18^oC have eye defects, including a physical scar running across the eye in a dorsal to ventral direction. Egfr^tsla/Egfr^f24 larvae raised at 18^oC and then placed at 28^oC for 24 hours show few effects on ommatidial cluster formation in and close to the morphogenetic furrow of the eye disc, but the clusters five or six columns posterior to the furrow are dysmorphic. Egfr^tsla/Egfr^f24 larvae raised at 18^oC and then shifted to 28^oC at a slightly earlier time, when the morphogenetic furrow is not yet initiated, show an inhibition of neural differentiation at the posterior margin but not at the dorsal or ventral margins of the eye disc.

Egfr^tsla, N^l1N-ts1 has abnormal mitotic cell cycle | heat sensitive phenotype

Egfr^tsla, lz^ts1 has increased cell death phenotype