Check out our New Publishers' Select for Free Articles

Biochemical Genetics (v.37, #1-2)

SDS-PAGE Pattern Polymorphism of X-Chromosomal Glue Proteins in Natural Populations of Two Drosophila nasuta Subgroup Species by S. R. Ramesh; N. Shivanna (pp. 1-21).

For the first time, the glue protein patternpolymorphism in natural populations of D. n.nasuta and D. s. neonasuta has beenanalyzed by SDS-PAGE. The study involving 200 and 185isofemale lines comprising 2028 and 1900 individuals of D. n.nasuta and D. s. neonasuta, respectively,revealed the occurrence of eight variant glue proteinphenotypes in D. n. nasuta and seven in D.s. neonasuta. The number and frequency of variant phenotypes in differentpopulations of both species were found to vary. Analysisof glue protein patterns in the F₁ progeny ofcrosses involving parents with variant glue proteinphenotypes revealed that the polymorphic fractions areproduced by co-dominant genes located on the Xchromosome. More than 87% of the naturally inseminatedadult females were found to produce polymorphic progeny. The heterozygous female larvae were found toexceed the homozygotes in the isofemale line progeny ofmost of the populations.

Keywords: DROSOPHILA; SDS-PAGE; GLUE PROTEINS; X-CHROMOSOMAL GENES; POLYMORPHISM

Analysis of Background-Dependent Genetic Interactions Without Inbred Strains by Ilija Kovac; Dragoslav Marinkovic (pp. 23-40).

Experimental analysis of background dependenteffects of genetic interactions can be designed usingstrains generated by introgression of small geneticregions containing identical genotypes at loci in question into different inbred strains. We usea novel multilocus paradigm, denoted conditionalintergenic functional association (CIFA), to simulatethis procedure, with the trade-off of power forconvenience that is affordable when sufficiently strongeffects are present. We analyze nine enzyme loci atthree chromosomes in groups of D. melanogasterwith different developmental rates that showed similarallelic frequencies at individual loci. Resultsobtained suggest the presence of adaptive interactionbetween particular alleles at two loci when geneticvariation at seven background loci is eliminated.Biochemical considerations show that, in the resultingdevelopmental context, strong interaction between thesegenes may emerge from shifted control of the pentosephosphate pathway, with cascading effects on theglycolysis, TCA cycle, and biosynthetic pathways: one genemay assume control of the irreversible rate-limitingstep in the pentose phosphate pathway, whereas the othergene may assume control of the NADP⁺ levelthat regulates the same rate-limiting step as anelectron acceptor. The newly developing functionalgenomics research and the absence of inbreeding makeCIFA directly applicable to complex human traits inlarge samples.

Keywords: MULTILOCUS; ASSOCIATION; DEVELOPMENT; ALLOZYME; GENOMICS

Divergence of the Regulation of alpha-Amylase Activity in Drosophila melanogaster, Drosophila funebris, and Drosophila saltans by Yozo Eguchi; Yoshinori Matsuo (pp. 41-52).

The regulation of amylase activity in threeDrosophila species, D. melanogaster,D. funebris and D. saltans, wasanalyzed by measuring the specific activity levels infour dietary environments, cornmeal, glucose, 5% starch, and 10% starch, at threedevelopmental stages, i.e., the third-instar larval,pupal, and 2-day-old adult stages. The developmentalprofiles of amylase activity for the threeDrosophila species showed that the level of activity washigh at the larval and adult stages but substantiallylow at the pupal stage, suggesting thatDrosophila does not utilize starch at the pupalstage. Divergence in the regulation of amylase was observed amongthe three Drosophila species on the followingpoints. (1) The order of amylase specific activity wasD. melanogaster > D. funebris >D. saltans. (2) The response pattern to the dietary environment varied amongthe species and changed during development. (3) Thetiming of the switch in the response pattern to thedietary environment during development was before pupation in D. funebris and D.saltans but after pupation in D.melanogaster. The significance of the divergence inthe regulation of amylase activity for adaptation to astarch environment in Drosophila is discussed.

Keywords: ALPHA-AMYLASE; DROSOPHILA MELANOGASTER; D. FUNEBRIS; D. SALTANS; DIETARY ENVIRONMENT; DEVELOPMENTAL STAGE

Adaptation to a Starch Environment and Regulation of alpha-Amylase in Drosophila by Junichi Fujimoto; Chie Kanou; Yozo Eguchi; Yoshinori Matsuo (pp. 53-62).

The adaptation to glucose and starch foods insix species, D. melanogaster, D.virilis, D. saltans, D. funebris,D. levanonensis and D. americana, wasstudied by measuring productivity. D.melanogaster and D. virilis adapted more to thestarch environment than to the glucose environment,while D. saltans adapted more to the glucoseenvironment than to the starch environment. D.funebris, D. levanonensis, and D. americana did not distinctlyadapt to either environment. In addition, the regulationof amylase in the six species was investigated bymeasuring the levels of amylase activity with glucoseand starch food environments. The levels of amylaseactivity in D. levanonensis and D.saltans were substantially low, indicating thatthese species cannot utilize starch as a carbon source.The starch-adapted species, D. melanogaster and D.virilis, showed higher levels of amylase activitywith the starch environment and higher inducibility.These results suggest that changing the regulation ofamylase is important for the adaptation to a starch environment inDrosophila.

Keywords: ALPHA-AMYLASE; DROSOPHILA MELANOGASTER ; D. VIRILIS ; D. SALTANS ; D. FUNEBRIS ; LEVANONENSIS ; D. AMERICANA ; GLUCOSE; STARCH

Frequencies in the Japanese Population of HFE Gene Mutations by Tetsuro Sohda; Junichi Yanai; Hidenobu Soejima; Kazuo Tamura (pp. 63-68).

We studied the frequencies of C282Y and H63Dmutations in the HFE gene, thought to be responsible forhereditary hemochromatosis (HH), in 504 chromosomesobtained from 252 unrelated Japanese. Allele-specific PCR and PCRrestriction fragment lengthpolymorphism methods revealed that the C282Y mutationwas not found and the H63D mutation was low in frequency(at only 0.99%) compared with data from European people. Since most HH is thought to be associated withthe HFE gene mutation, the low incidence of thesemutations is a likely reason for the rarity of thisdisease in the Japanese population.

Keywords: ALLELE-SPECIFIC PCR; PCR-RESTRICTION FRAGMENT LENGTH POLYMORPHISM

Sections

Personal tools

Biochemical Genetics (v.37, #1-2)

Sections

Personal tools

Local resources

Biochemical Genetics (v.37, #1-2)