Molecular population genetics of structural variants of esterase 6 in Drosophila melanogaster

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 788-796 ◽  
Author(s):  
J. G. Oakeshott ◽  
P. H. Cooke ◽  
R. C. Richmond ◽  
A. Bortoli ◽  
A. Y. Game ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Selection ◽  
Amino Acid ◽  
Seminal Fluid ◽  
Biochemical Properties ◽  
Nucleotide Polymorphisms ◽  
Amino Acid Polymorphism ◽  
Sequence Comparisons ◽  
Esterase 6 ◽  
Latitudinal Clines

Several lines of evidence indicate that natural selection operates between the major EST6-F and EST6-S allozymes of Drosophila melanogaster. In particular, consistent latitudinal clines and seasonal variation in their relative frequencies strongly suggest that they are not selectively equivalent in field populations. Several laboratory studies have found frequency-dependent fitness differences among the Est6-F and Est6-S genotypes. Moreover, the purified EST6-F and EST6-S allozymes differ in biochemical properties and the physiology of the enzyme, as a major component of the seminal fluid, suggests that these differences could affect reproductive aspects of fitness. However, molecular analyses reveal high levels of variation in the EST6 protein both within and between the EST6-F and EST6-S allozymes. Limited thermostability and more sensitive electrophoretic analyses reveal at least 17 variants of the two allozymes and sequence comparisons among 13 isolates of the Est6 gene reveal 16 nucleotide polymorphisms that would lead to amino acid differences. Two closely linked amino acid differences are strongly associated with the major difference between EST6-F and EST6-S; either or both of these are likely to cause the observed biochemical differences between EST6-F and EST6-S and may be the primary targets for the selection between these allozymes. The functional and adaptive significance of the other amino acid polymorphisms is unclear, although the data suggest that the EST6-8 haplotype within EST6-S has both arisen and proliferated relatively recently.Key words: Drosophila melanogaster, esterase 6, nucleotide and amino acid polymorphism, natural selection.

Latitudinal clines for nucleotide polymorphisms in the Esterase 6 gene of Drosophila melanogaster

Genetica ◽  
2006 ◽  
Vol 129 (3) ◽  
pp. 259-271 ◽  
Author(s):  
Christopher W. Coppin ◽  
Wendy A. Odgers ◽  
John G. Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
Nucleotide Polymorphisms ◽  
Esterase 6 ◽  
Latitudinal Clines

scholarly journals Extensive Amino Acid Polymorphism at the Pgm Locus Is Consistent With Adaptive Protein Evolution in Drosophila melanogaster

Genetics ◽  
2000 ◽  
Vol 156 (4) ◽  
pp. 1737-1752 ◽  
Author(s):  
Brian C Verrelli ◽  
Walter F Eanes
Keyword(s):  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Protein Evolution ◽  
Branch Point ◽  
Glycogen Metabolism ◽  
Strong Linkage Disequilibrium ◽  
Amino Acid Polymorphism ◽  
Specific Amino Acid ◽  
Functional Studies ◽  
Latitudinal Clines

Abstract PGM plays a central role in the glycolytic pathway at the branch point leading to glycogen metabolism and is highly polymorphic in allozyme studies of many species. We have characterized the nucleotide diversity across the Pgm gene in Drosophila melanogaster and D. simulans to investigate the role that protein polymorphism plays at this crucial metabolic branch point shared with several other enzymes. Although D. melanogaster and D. simulans share common allozyme mobility alleles, we find these allozymes are the result of many different amino acid changes at the nucleotide level. In addition, specific allozyme classes within species contain several amino acid changes, which may explain the absence of latitudinal clines for PGM allozyme alleles, the lack of association of PGM allozymes with the cosmopolitan In(3L)P inversion, and the failure to detect differences between PGM allozymes in functional studies. We find a significant excess of amino acid polymorphisms within D. melanogaster when compared to the complete absence of fixed replacements with D. simulans. There is also strong linkage disequilibrium across the 2354 bp of the Pgm locus, which may be explained by a specific amino acid haplotype that is high in frequency yet contains an excess of singleton polymorphisms. Like G6pd, Pgm shows strong evidence for a branch point enzyme that exhibits adaptive protein evolution.

scholarly journals An amino acid polymorphism in the couch potato gene forms the basis for climatic adaptation in Drosophila melanogaster

2008 ◽  
Vol 105 (42) ◽  
pp. 16207-16211 ◽  
Author(s):  
P. S. Schmidt ◽  
C.-T. Zhu ◽  
J. Das ◽  
M. Batavia ◽  
L. Yang ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Amino Acid Polymorphism ◽  
Climatic Adaptation

scholarly journals Contrasting Molecular Population Genetics of Four Hexokinases in Drosophila melanogaster, D. simulans and D. yakuba

Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1191-1201 ◽  
Author(s):  
David D Duvernell ◽  
Walter F Eanes
Keyword(s):  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Metabolic Pathways ◽  
Fat Body ◽  
Amino Acid Level ◽  
Population Subdivision ◽  
Phosphate Binding ◽  
Linkage Phase ◽  
Molecular Population Genetics ◽  
Latitudinal Clines

Abstract As part of a larger study contrasting patterns of variation in regulatory and nonregulatory enzymes of the central metabolic pathways we have examined the molecular variation in four uncharacterized hexokinase genes unique to muscle, fat body, and testis in Drosophila melanogaster, D. simulans, and D. yakuba. Earlier isoenzyme studies had designated these genes as Hex-A, Hex-C, and Hex-t. There are two tightly linked testes-specific genes designated here as Hex-t1 and Hex-t2. Substantial and concordant differences across species are seen in levels of both amino acid and silent polymorphism. The flight muscle form Hex-A is the most conserved followed by the fat body hexokinase Hex-C and testis-specific hexokinases Hex-t1 and Hex-t2. While constraints acting at the amino acid level are expected, the silent polymorphisms follow this pattern as well. All genes are in regions of normal recombination, therefore hitchhiking and background selection are not likely causes of interlocus differences. In D. melanogaster latitudinal clines are seen for amino acid polymorphisms at the Hex-C and Hex-t2 loci. There is evidence for accelerated amino acid substitution in Hex-t1 that has lost residues known to be associated with glucose and glucose-6-phosphate binding. D. simulans shows substantial linkage phase structuring that suggests historical population subdivision.

scholarly journals Screening for Mutations and Polymorphisms in the Genes KCNH2 and KCNE2 Encoding the Cardiac HERG/MiRP1 Ion Channel: Implications for Acquired and Congenital Long Q-T Syndrome

2001 ◽  
Vol 47 (8) ◽  
pp. 1390-1395 ◽  
Author(s):  
Lars Allan Larsen ◽  
Paal Skytt Andersen ◽  
Jørgen Kanters ◽  
Ida Hastrup Svendsen ◽  
Joes Ramsøe Jacobsen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Ion Channel ◽  
Single Strand Conformation Polymorphism ◽  
K Channel ◽  
Delayed Rectifier ◽  
Nucleotide Polymorphisms ◽  
Amino Acid Polymorphism ◽  
Α Subunit ◽  
Delayed Rectifier Current ◽  
Gene Coding

Abstract Background: The voltage-gated, rapid-delayed rectifier current (IKr) is important for repolarization of the heart, and mutations in the genes coding for the K+-ion channel conducting this current, i.e., KCNH2 for the α-subunit HERG and KCNE2 for the β-subunit MiRP1, cause acquired and congenital long Q-T syndrome (LQTS) and other cardiac arrhythmias. Methods: We developed a robust single-strand conformation polymorphism-heteroduplex screening analysis, with identical thermocycling conditions for all PCR reactions, covering all of the coding exons in KCNH2 and KCNE2. The method was used to screen 40 unrelated LQTS patients. Results: Eleven mutations, of which six were novel, were found in KCNH2. Interestingly, six mutations were found in the region of the gene coding for the Per-Arnt-Sim (PAS) and PAS-S1 regions of the HERG protein, stressing the need to examine the entire gene when screening for mutations. No mutations were found in KCNE2, suggesting that direct involvement of MiRP1 in LQTS is rare. Furthermore, four novel single-nucleotide polymorphisms (SNPs) and one amino acid polymorphism (R1047L) were identified in KCNH2, and one novel SNP and one previously known amino acid polymorphism (T8A) were found in KCNE2. Conclusions: The potential role of rare polymorphisms in the HERG/MiRP1 K+-channel should be clarified with respect to drug interactions and susceptibility to arrhythmia and sudden death.

scholarly journals The Functional Impact ofPgmAmino Acid Polymorphism on Glycogen Content inDrosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 159 (1) ◽  
pp. 201-210 ◽  
Author(s):  
Brian C Verrelli ◽  
Walter F Eanes
Keyword(s):  
Amino Acid ◽  
Glycogen Content ◽  
Glycogen Synthesis ◽  
In Vitro Activity ◽  
Amino Acid Polymorphism ◽  
Northern Latitudes ◽  
Latitudinal Clines ◽  
The Common ◽  
Low Activity

AbstractEarlier studies of the common PGM allozymes in Drosophila melanogaster reported no in vitro activity differences. However, our study of nucleotide variation observed that PGM allozymes are a heterogeneous mixture of amino acid polymorphisms. In this study, we analyze 10 PGM protein haplotypes with respect to PGM activity, thermostability, and adult glycogen content. We find a twofold difference in activity among PGM protein haplotypes that is associated with a threefold difference in glycogen content. The latitudinal clines for several Pgm amino acid polymorphisms show that high PGM activity, and apparently higher flux to glycogen synthesis, parallel the low activity clines at G6PD for reduced pentose shunt flux in northern latitudes. This suggests that amino acid polymorphism is under selection at this branch point and may be favored for increased metabolic storage associated with stress resistance and adaptation to temperate regions.

scholarly journals Associations between restriction site polymorphism and enzyme activity variation for esterase 6 in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 1021-1031 ◽  
Author(s):  
A Y Game ◽  
J G Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
Ejaculatory Duct ◽  
Allozyme Polymorphism ◽  
Nucleotide Polymorphisms ◽  
Adult Males ◽  
Coding Region ◽  
Activity Variation ◽  
Esterase 6 ◽  
Enzyme Activity Variation ◽  
Male Activity

Abstract Thirty-five nucleotide polymorphisms were found in a 21.5-kbp region including the Est6 locus among 42 isoallelic lines extracted from a single natural population of Drosophila melanogaster. The heterozygosity per nucleotide pair was estimated to be 0.010 overall, but was lower in sequences hybridizing to transcripts than in those not hybridizing to transcripts. Eleven of 36 pairwise comparisons among the nine most common polymorphisms showed significant gametic disequilibrium. Four of these polymorphisms were also significantly associated with the major EST6-F/EST6-S allozyme polymorphism. Significant disequilibrium was generally restricted to polymorphisms less than 1-2 kbp apart. Previously reported measures of EST6 activity in virgin adult females proved not to be significantly associated with any of the six most common nucleotide polymorphisms located in the Est6 coding region or the 1.5 kbp immediately 5'. However, the 11 haplotypes for five of these polymorphisms that lie in the 1.5-kbp 5' region could explain about half of the previously reported variation among the lines for both EST6 activity and the amount of EST6 protein in virgin adult males. One particular polymorphism, for a RsaI site 530 bp 5' of the initiation codon, could explain 21% of the male activity variation among lines. This site is embedded in a large palindrome and we suggest that sequences including or close to this site may be involved in the regulation of EST6 synthesis in the ejaculatory duct of the adult male.

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