DROSOPHILA PSEUDOOBSCURA Chicago, Chicago, - PDF document

DROSOPHILA PSEUDOOBSCURA Chicago, Chicago, indeed widely diverging, idea is embodied balanced selective reason for population is ideal experi- we need Allelic substitutions one locus allelic substitutions must be distinguishable each other. unbiased sample respect to physiological necessarily restricted sample. previously available visible recessive allelic substi- visible morphological changes. morphological polymorphisms precisely because is not information, since polymorphic. Nor broadly, considerable special breeding experi- is impossible, except to observe differences for is cancelled differ genetically from is done lines differ homozygotes depends geneticist finds curious position allelic substitutions detected as single segregating be detected will detect to describe such wild population described is predicated, least one polypeptide produced addition will, .Since enzymes we know, electrophoretic differences will segregate as single other proteins such proteins single individuals, electrophoretic mobility almost perfectly. single individuals. Allelic substitutions distinguishable from each simple genetics electrophoretic differences is most assumptions about gene action. Moreover, mation, to possible changes detectable, is complete discussion been investigated purposes out- five geographic locations. have been Bogota Colombia chromosomal location as follows: Chromosome gels was described by previously. Buffer assay method. boric acid gel was Glucose-6-phosphate dehydrogenase-(modified One-day- old electrophoresis was continued 150 minutes. sodium glucose-6-phosphate, gel was solution contained buffer also period followed, a-glycerophosphate dehydrogenase- (modified also contained substrate. One-day-old boric acid contain- was placed acetic acid Acid Black was removed by acetic acid Strain analysis: each assay, were examined. was observed was continued was found. Analysis contained samples contained five indi- gel for addition to giving single bands (positions giving double bands (positions 1 1 proved to be heterozy- clear bands (pocket was shown two alleles procedure was repeated one same gel to displayed no combinations to electrophoretic mobility obtained present methods. been seen enzyme. However, is one ditions employed be designated Esterase-5 populations sampled, respect to Esterase-5. single site was chosen as females exhibited sites, each above mobilities additional site one Esterase-5 site heterozygote. Genetic these conclusions. example will were sacrificed was determined. 1.12. Comparable results heterozygous females assumed hemizygous males, both heterozygous Esterase-5 differences behave simple sex-linked characters. sex-linked genetic responsible for protein will designated esterase-5 allelic forms six alleles corresponding protein six allelic electrophoretic mobility differences molecule was probably present. band was indeed by creation mobility were NaCl overnight. gel for electro- was produced bands corresponding to effort was different populations. Accordingly Esterase-5 enzymes five forms 50°C completely destroyed heterozygotes between these localities same degree five alleles. Malic dehydrogenase: dehydrogenase exists was given which also contained was considerably present. However, this was not for detection malic dehydrogenase mobility 0.90,1.11, 1.20 were demon- for these corresponding change mobility. Those forms while those individuals breeding for 1:1:2 ratio were still discernable. which chromosome controls malic dehydro- breeding for males heterozygous for to females (i.e., homozygotes) with both forms (heterozygotes however, every both forms was concluded specifying malic dehydrogenase Glucose-6-phosphate dehydrogenase was detected as conditions employed. genase revealed electrophoretic conditions. these proteins seven sites Alkaline phosphatase seven sites assay conditions. samples studied, two electrophoretic populations sampled. females yielded parent. Thus it was concluded that the locus controlling the enzyme was sex- linked. This conclusion was supported by production of one or the other parental forms of the enzyme in male progeny from F1 females. The sex-linked locus two alleles detected produce. Ap-4 sensitive to Ap-6 was females to males Ap-6 activity, Ap-6 were responsible for Ap-6 Ap-7 was to behave analogous fashion electrophoretic differences was found was detected lines derived was derived made to progeny did segregated for presence could be explained heterozygous codominant alleles since this has Leucine aminopeptidase: Leucine aminopeptidase proved to assay system to eight sites were detected lines using most consistently detected by side-by-side comparison differences, though slight, greatest difference site could characterized as to more discrete areas. detectable differences between reciprocal was consistent But we feel more elaborate enzyme, which genetic test responsible for displayed electrophoretic different forms exception was different forms proteins displayed two types observed: those displayed both called pt-7, chromosomal location genetic constitution was homozygous chromosome was homozygous was consistently heterozygous homozygous condition, was homozy- was concluded pt-10 was pt-7 was progeny assayed as allele characteristic was concluded was concluded located on pt-10 was located probable heterozygote positively identified was identified proteins tested, was consequently least reliable. We, therefore, determined. Pt-13, protein, was was seen subsequent tests been obtained eight genetic presented for controlling various proteins these loci dehydrogenase on be placed known to behave genetic control. modern genetic Consequently, we would gene products changes give rise possible genic loci investigated, needs to be we use these differences to ask detectable on been studied, two constant. difference between wide sample concentration. None grossly different. for Pt-5, two groups proteins allows approximation, to use as a tive sample chromosomal location genes involved deserves both esterase-6 been located on a common electrophoretic mobility phosphate gene was also found on chromosome Since one genetic homology pointed out like these the survey detect isoallelic Using electrophoretic mobility five geographic localities. Electrophoretic shown by genetic tests loci as alleles; malic dehydrogenase, 4 alleles; aminopeptidase, 4 alleles; alleles each; two different 4 alleles. proteins showing glucose-6-phosphate dehydrogenase, a-glycerophosphate dehydrogenase, two larval alkaline Drosophila rnelanogaster. Drosophila melanogaster. Population genetics, Human Genet. SPASSKY, 1954 Genetics A comparison Press, Cambridge. load due M., 1965 Methods Genetic studies Drosophila populations. Proc. CHILDS, 1964 Glucose-6-phosphate dehydrogenase sophila: X-linked electrophoretic