Biomaterial Database

Comparison between rDNA magnification and bb lethal mutation frequencies in Drosophila melanogaster. 1980

C Malva, and A La Volpe, and G Gargiulo

Unequal mitotic sister strand crossing over has been evoked to explain the occurrence of phenotypically bb+ males in the progeny of phenotypically bobbed males during magnification. If this is the case, complementary bbl loci should be obtained together with the bb+. To test this hypothesis we compared the frequency of bb lethal mutations in the sperms of bb males with the percentages of phenotypically bb+ males obtained during magnification of these bb males. We then compared these values with those occurring in phenotypically bb+ control males. We found that, while the number of bb+ males obtained during magnification, though variable, is high, the bb lethal mutation occurs at a very low frequency in all the genetic conditions, whatever the phenotype of the parental male.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005787	Gene Frequency	The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.	Allele Frequency,Genetic Equilibrium,Equilibrium, Genetic,Allele Frequencies,Frequencies, Allele,Frequencies, Gene,Frequency, Allele,Frequency, Gene,Gene Frequencies
D005804	Genes, Lethal	Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.	Alleles, Lethal,Allele, Lethal,Gene, Lethal,Lethal Allele,Lethal Alleles,Lethal Gene,Lethal Genes
D005838	Genotype	The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.	Genogroup,Genogroups,Genotypes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S