Genetics of Glossina palpalis palpalis: designation of linkage groups and the mapping of eight biochemical and visible marker genes.

The loci for three enzymes (hexokinase, phosphoglucomutase, and testicular esterase) and two eye-color mutants (brick and tan) are mapped on the X chromosome of Glossina palpalis palpalis. The loci occur in the order brick Hex (tan/Pgm) Est-t, with a recombination frequency of approximately 78% between the outer two loci. The locus for octanol dehydrogenase is located in linkage group II and the loci for malate dehydrogenase and phosphoglucose isomerase are separated by a recombination frequency of about 42.5% in linkage group III. Intrachromosomal recombination occurs at a much lower frequency in males than in females. The distribution of five biochemical marker genes in the linkage groups of G. p. palpalis is markedly different from that found in other higher flies.

Genetic variation in a Tanzanian population of Glossina swynnertoni (Diptera: Glossinidae).

Adult Glossina swynnertoni Austen that emerged from puparia collected during 1989 and 1991 near Makuyuni, Tanzania, were examined by polyacrylamide gel electrophoresis. Fourteen of 17 enzymes were monomorphic. Midgut alkaline phosphatase (ALKPH), phosphoglucomutase (PGM), and glucose-6-phosphate isomerase (PGI) from the head and thorax were polymorphic. Banding patterns indicated that the locus for PGM was on the X chromosome and loci for ALKPH and PGI were autosomal. For the 17 loci studied, the mean heterozygosity per locus was 6.1 +/- 3.7% in the 1989 sample and 5.7 +/- 3.7% in the 1991 sample. The effective number of alleles per locus was 1.11 and 1.10 in these samples. This level of genetic variation was low compared with other populations of tsetse flies and indicated that the sample may have been drawn from a small inbred population or one that recently had gone through a genetic bottleneck.

Genetic variation in Glossina brevipalpis, G.longipennis and G.pallidipes, and the phenetic relationships of Glossina species.

Glossina brevipalpis Newstead, G.longipennis Corti, and G.pallidipes Austen maintained at ILRAD, Nairobi, Kenya, were examined for genetic variation of fourteen enzyme loci, using polyacrylamide gel electrophoresis. G.brevipalpis had six polymorphic loci, an average of 1.46 effective alleles per locus and a mean heterozygosity per locus of 20.0 +/- 7.1%. The figures for the same parameters in G.longipennis were 3, 1.16 and 8.2 +/- 4.9%, and for G.pallidipes the figures were 7, 1.40 and 22.3 +/- 6.3%. Seven rare alleles were lost from the G.brevipalpis colony during a 1-year period, but no statistically significant changes were observed in the genetics of the colony during this period. Using allele frequency data for ten of the enzymes studied, and frequencies for these enzymes in other taxa, a phenogram was constructed that indicated that the subgenus Austenina (i.e. the fusca group) is the oldest of the three subgenera within the genus Glossina, and that the subgenus Glossina s.str. (i.e. the morsitans group) may be paraphyletic.

Genetic variation in two field populations and a laboratory colony of Glossina pallidipes (Diptera: Glossinidae).

Glossina pallidipes Austen from Lambwe and Nguruman in Kenya and a laboratory colony, originating from flies collected at Lambwe, were compared for 12 enzyme-gene systems using polyacrylamide gel electrophoresis. In the Nguruman, Lambwe, and colony flies, mean heterozygosities were 9.1, 15.3, and 16.5%, and polymorphism was observed in 3, 4, and 5 loci, respectively. Significant differences in number of gene products were observed between Nguruman and Lambwe flies at three loci, between Nguruman and colony flies at four loci, and between Lambwe and colony flies at two loci. Evidence is presented indicating that the locus for phosphoglucomutase is on the X chromosome, whereas loci for octanol dehydrogenase, malate dehydrogenase, phosphoglucose isomerase, and a thoracic esterase (Esterase-1) are autosomal.

Tryptophan metabolism in tsetse flies and the consequences of its derangement.

Literature comparing salmon and wild type Glossina morsitans morsitans and that comparing tan and wild type Glossina palpalis palpalis is reviewed. New information is presented on behaviour and biochemistry of salmon and wild type G. m. morsitans. The eye color mutants result from two lesions in the tryptophan to xanthommatin pathway: lack of tryptophan oxygenase in G. m morsitans and failure to produce or retain xanthommatin in eyes (but not in testes) of G. p. palpalis. The salmon allele in G. m. morsitans is pleiotropic and profoundly affects many aspects of fly biology including longevity, reproductive capacity, vision, vectorial capacity and duration of flight, but not circadian rhythms. The tan allele in G. p. palpalis has little effect upon the biology of flies under laboratory conditions, except that tan flies appear less active than normal. Adult tsetse flies metabolize tryptophan to kynurenine which is excreted; fluctuations in activities of the enzymes producing kynurenine suggest this pathway is under metabolic control.

Tryptophan metabolism in tsetse flies and the consequences of its derangement

Literature comparing salmon and wild type Glossina morsitans morsitans and that comparing tan and wild type Glossina palpalis palpalis is reviewed. New information is presented on behaviour and biochemistry of salmon and wild type G. m. morsitans. The eye color mutants result from two lesions in the tryptophan to xanthommatin pathway: lack of tryptophan oxygenase in G. m morsitans and failure to produce or retain xanthommatin in eyes (but not in testes) of G. p. palpalis. The salmon allele in G. m. morsitans is pleiotropic and profoundly affects many aspects of fly biology including longevity, reproductive capacity, vision, vectorial capacity and duration of flight, but not circadian rhythms. The tan allele in G. p. palpalis has little effect upon the biology of flies under laboratory conditions, except that tan flies appear less active than normal. Adult tsetse flies metabolize tryptophan to kynurenine which is excreted; fluctuations in activities of the enzymes producing kynurenine suggest this pathway is under metabolic control.