Egg chambers arrest early in development in homozygous females and rarely develop to stage 14. These eggs are not laid.
External morphology and sexual behavior normal (Burnet, Connolly, Kearney, and Cook, 1973). Males fertile; females sterile. After rearing on glucose diet mutant females are less receptive to copulation attempts and more vigorously courted than wild-type virgins (Cook and Connolly, 1976). Germaria of ovaries of homozygous females larger than normal; cysts contain 3 times the normal number of cells; metaphase figures found throughout germarium. Just over half the oogonia undergo complete cleavage with the loss of ring canal connections to other cells; remaining cells in small clusters with tenuous connections (Johnson and King, 1972). Vitellaria subdivided into a series of sausage-shaped cell aggregates, each surrounded with an ill-defined follicular epithelium and filled with hundreds to thousands of mitotically active oogonia-like cells (King, Burnett and Staley, 1957). These cells occasionally differentiate into cells resembling nurse cells, which may have polytene chromosomes and rarely into oocytes. Rbp9 ovaries transplanted into wild-type hosts in late larval stages and reciprocal transplants develop autonomously (Clancy and Beadle, 1937; Klug, Bodenstein and King, 1968). The cells of the corpus-allatum corpus-cardiacum complex of homozygous Rbp9 females appear to be prevented from releasing their hormone products and undergo degenerative changes; these effects reversible by vitellogenic activity of wild-type ovary implanted into the abdomen of the Rbp9 female (King, Aggarwal and Bodenstein, 1966; Aggarwal and King, 1971). Abdominal fat cells of Rbp9 females 1.5 times size of those in wild type. They resemble male fat cells in having more fat and less glycogen than those of normal females; return to normal size and composition following implantation of wild-type ovary (Butterworth and Bodenstein, 1968). Rbp9 ovaries show reduced levels of thymidylate synthetase (Carpenter, 1973). RK3.
Rbp9B has female sterile | recessive phenotype, suppressible by cup4/cup[+]
Rbp9B has female sterile | recessive phenotype, suppressible by cup13
Rbp9B has female sterile | recessive phenotype, non-suppressible by cup04506
Rbp9B, cup4/cup[+] has female semi-fertile phenotype
Rbp9B, cup13 has female semi-fertile phenotype
Rbp9B/Rbp9B cup4/+ females are weakly fertile, with an average of one viable embryo per female. Most of the mature egg chambers produced in these flies are not laid; although they resemble wild-type and are covered with an apparently normal chorion, they contain abnormal DNA masses within the oocyte. Rbp9B homozygous females are also weakly rescued to fertility by cup13, but not by cup04506.
Bridges, 25 March 1929.
The degree of underreplication of intercalary heterochromatin is lower in polytene pseudonurse cell chromosomes than in polytene salivary gland chromosomes. In chromosome 3R a large mass of granular heterochromatin is observed proximal to region 81F, the pattern of additional heterochromatin is highly reproducible. Other heterochromatic blocks are present on the X and second chromosome and unattached, all blocks are well banded.