β Scribed by Seto, Frank
No coin nor oath required. For personal study only.
Despite the wide niention and use of genetic lethal factors, very little is known of their time and manner of action. Of the 557 or more lethals listed up to 1914 (Bridges and Brehme, '44) there were oiily 60 about which there was any information on the stage of death. The time of action of individual lethals has been studied by Sivertzev-Dobzalinsky ( '27) , Brehme ( '37, '39), and Rrody ( '40). Detailed studies on the manner of action of certain recessive lethals and chromosome deficiencies have been made by Hadorn ('37, '48, '5l), Li ( W), and Poulson ('37, '40, ,45).
The first systematic study of the time of action of a large series of lethals was by Medvedev ('38, '39a, '39b), who reported oii 48 spontaneously occurring sex-linked recessive lethals. Oster ('52) studied the time of cessation of developinent of 55 sex-linked recessive lethals obtained from ultraviolet treated Drosophila melaNogaster. Rizki ( '52) studied the time of death of 72 autosomal lethals in D. zuiZZisto*ti obtained from three sources : spontaneously occurring, x-ray induced, and extracted from a wild population.
This paper reports the results of studies beg-un in 1951 on a series of '77 second chromosoine lethals in D. melcmogaster.
π SIMILAR VOLUMES
Nitroguanidine (NG) and its degradation product nitrosoguanidine (NSG) were evaluated for their mutagenic potential by using Drosophila melanogaster sex-linked recessive lethal (SLRL) assay. Following 72 h of feeding exposure, NG and NSG at concentrations of 4-8 pg ml-' and 15-20 mg ml-I, respective
To determine whether a 50-Hz magnetic field will induce mutations, a sex-linked recessive lethal test of Drosophila rnekunoguster was performed. Adult flies were exposed at an rms flux density of 500 FT or 5 mT to the homogeneous field of a Helmholtz coil. The ambient field to which controls were ex
The roots of the herb Combretum erythrophyllum are prescribed and consumed as a medicine for sexual diseases, as an aphrodisiac, as a purgative and for treating leprosy. This plant is also a source of gums used as food adulterants. In earlier studies, the aqueous extract of this plant induced oxidat
## Abstract In the presence of tetraethylammonium or barium ions, the larval muscle fibers of __Drosophila melanogaster__ were found to produce an allβorβnone action potential operated by the calcium channels. The development of this distinctive membrane property during the maturation of muscle cel