The two origins of hemocytes in Drosophila.

As in many other organisms, the blood of Drosophila consists of several types of hemocytes, which originate from the mesoderm. By lineage analyses of transplanted cells, we specified two separate anlagen that give rise to different populations of hemocytes: embryonic hemocytes and lymph gland hemocytes. The anlage of the embryonic hemocytes is restricted to a region within the head mesoderm between 70 and 80% egg length.

FlyMove--a new way to look at development of Drosophila.

Development of any organism requires a complex interplay of genes to orchestrate the many movements needed to build up an embryo. Previously, work on Drosophila melanogaster has provided important insights that are often applicable in other systems. But developmental processes, which take place in space and time, are difficult to convey in textbooks.

Mapping and identification of essential gene functions on the X chromosome of Drosophila.

The Drosophila melanogaster genome consists of four chromosomes that contain 165 Mb of DNA, 120 Mb of which are euchromatic. The two Drosophila Genome Projects, in collaboration with Celera Genomics Systems, have sequenced the genome, complementing the previously established physical and genetic maps. In addition, the Berkeley Drosophila Genome Project has undertaken large-scale functional analysis based on mutagenesis by transposable P element insertions into autosomes.

The formation of syncytia within the visceral musculature of the Drosophila midgut is dependent on duf, sns and mbc.

The visceral musculature of the Drosophila midgut consists of an inner layer of circular and an outer layer of longitudinal muscles. Here, we show that the circular muscles are organised as binucleate syncytia that persist through metamorphosis. At stage 11, prior to the onset of the fusion processes, we detected two classes of myoblasts within the visceral trunk mesoderm.

Clonal analysis of the blastoderm anlage of the Malpighian tubules in Drosophila melanogaster.

Genetically marked maroon-like (mal) clones were induced by mitotic recombination with X-rays at the blastoderm stage in mal/mal heterozygotes and were analysed in differentiated Malpighian tubules (MT). Marked cells were not confined to single anterior (MA) or posterior (MP) tubules, but were distributed among the four tubules. About 70% of the clones with two or more cells were fragmented, i.

Cell lineage restrictions in the genital disc ofDrosophila revealed byMinute gynandromorphs.

The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes.

[Developmental studies on gynandromorphs ofDrosophila melanogaster : IV. Comparison of morphogenetic fate maps of larval and imaginal structures].

Gynandromorphs with female XX-and male XO-areas result from the loss of an unstable ring-X-chromosome in the early cleavage mitoses of ring/rod-X-chromosome heterozygotes. The phenotypes of the recessive alleles on the rod-X-chromosome are expressed in the XO-areas.377 larval gynandromorphs of the genotypeR(1)2, In(1)w /y w snIz mal were examined and scored for the phenotypes of 13 paired and 10 unpaired structures (Table 2, Fig.

[Developmental studies on gynandromorphs ofDrosophila melanogaster : II. The morphogenetic fate map].

The distribution of XX- and XO-areas within the cuticle and in the internal organs was examined in 355 adult gynandromorphs of the genotypeR(1)2,In(1)w /y w sn lz mal, whereby XO-areas could be recognized by the phenotypes of the recessive alleles on the rod-X-chromosome.The percentage of gynandromorphs in which selected pairs of structures show different genotypes is taken as a measurement (in sturt-units) for the distance between the presumptive areas of these structures in early developmental stages. The calculated distances between cuticular structures (Table 2) agree well with those reported by Hotta and Benzer (1972).

[Developmental studies on gynandromorphs ofDrosophila melanogaster : I. The internal organs of the imago].

In ring/rod-X-chromosome heterozygotes the ring-X-chromosome is frequently lost in the early cleavage mitoses. The resulting gynandromorphs are mosaics with female XX- and male XO-areas. The phenotypes of the recessive alleles on the rod-X-chromosome are expressed in the XO-areas.

[Autonomous determination for pigment formation inwhite position-effect ofDrosophila melanogaster].

Inwhite position-effect ofDrosophila melanogaster, determination for the potential of pigment formation of eye cells takes place at the end of the first larval instar. Eye discs, prior to or after this developmental stage, were transplanted together with some larval tissue into the abdomens of adult females. After a cultivation period of 5 to 7 days, the implants were transplanted back into larvae.