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PubMed1993

Allelic variations clustered in the antigen binding sites of HLA-Bw62 molecules.

HLA-Bw62 is a serologically defined class I antigen specificity, but we show that it represents a family of five distinct alleles in this study. Five variants of HLA-Bw62 antigens were identified by isoelectric focusing, and sequencing studies revealed that these are a family of closely related alleles differing from one another by one to six amino acid substitutions at eight positions: 63 in the alpha 1 domain and 94, 95, 97, 99, 113, 152, and 156 in the alpha 2 domain. These substitutions are located in the two alpha-helices and two adjacent beta-strands, and the side chains of most amino acids face into the antigen binding groove. Functional assays using an in vitro generated Epstein-Barr virus (EBV)-specific Bw62-restricted cytotoxic T lymphocyte clone indicated that the minimal structural variations located in the antigen binding sites of the HLA-Bw62 variant molecules could affect the presentation of the nominal EBV antigen. This study revealed that the HLA-Bw62 antigen family consists of at least five closely related alleles, and further demonstrated that these alleles with minimal structural variations might play distinct functional roles in regard to antigen presentation.

Alleles↗
PubMed2002

Assessing habitat utilization by neotropical primates: a new approach.

This study aims to ascertain habitat utilization, in relation to forest structural variation, by a multi-species group of primates in tropical lowland rainforest in Southeast Peru during dry season. A new approach to assessing habitat utilization was used. Habitat variation was described by structural and indicator variables collected in quadrats along transects through a study area within Terra Firme and Floodplain forest. Variables were grouped into 'factors' accounting for most of the variation by means of a Principal Components Analysis (PCA). Presence or absence of the primates within the quadrats, assessed by repeat transect surveys, was taken to indicate habitat preferences. Discrimination between the habitat and forest structure in areas of primate presence as opposed to absence was carried out by means of Discriminant Function Analysis (DFA). This highlighted patterns in most utilized habitat. Vertical utilization of the forest was also assessed along with presence in bamboo and general activity on encounter. Suggestions of habitat preference and utilization are made for each of the six sympatric species studied, based on significantly discriminating habitat factors, vertical stratification on encounter and relationships with bamboo. Saguinus fuscicollis and Cebus moloch appeared as habitat generalists. Cebus apella, Saimiri sciureus, and Aotus spp., exhibited varying degrees of preference for habitat factors suggesting disturbed forest, Cebus albifrons was more generalistic but with a possible association with primary, naturally disturbed forest. C. apella was encountered in Terra Firme forest significantly more than in Floodplain. For S. sciureus, C. moloch, and C. apella, upper understory was the most utilized forest layer, for C. albifrons, middle canopy and for S. sciureus and Aotus spp., lower understory. Both positive and negative relationships with bamboo were highlighted. Significant positive relationships between Aotus spp., and bamboo suggest dense bamboo stands provide important daytime resting sites for this nocturnal species. C. moloch was also shown to utilize bamboo whereas S. fuscicollis appeared to actively avoid it. High levels of conformity with past studies in terms of habitat utilization patterns described for the species studied supports the conclusion that the methods used in this study provide an effective means of assessing primate habitat utilization within complex habitat.

Animals↗
PubMed2000

Investigations into the Genetic Variation, Population Structure, and Breeding Systems of the Fern Asplenium trichomanes subsp. quadrivalens.

The genetic structure of five populations of the tetraploid fern Asplenium trichomanes subsp. quadrivalens in northern Switzerland was analyzed. Asplenium trichomanes subsp. quadrivalens is one of the most common and most widespread ferns in Europe. In this study we have combined genetic investigations, spatial autocorrelation, and breeding experiments to investigate in detail five populations from natural rock faces. Enzyme electrophoresis revealed very low genetic variability within and among the populations. The small amount of variation was partitioned mainly among the localities, indicated by high Fst values up to 0.764. Overall means of the proportion of polymorphic loci (P=0.076), the mean number of alleles per locus (A=1.086), and the mean expected heterozygosity (H=0.018) were low compared with other ferns (e.g., Kirkpatrick et al. 1990). Very few heterozygous individuals were found. Values of the fixation index (F) were high, ranging between 0.732 and 1.000 and indicating substantial inbreeding. Spatial autocorrelation showed different patterns of substructure in populations of A. trichomanes subsp. quadrivalens with a tendency for patches in short distances (up to 1.5 m). The breeding experiments with isolated prothalli and prothalli pairs showed that a mean of 56.4% of the isolated prothalli were successful in sporophyte formation. The highest rate in one population was 83.3%. We conclude that genetic load must be low in A. trichomanes subsp. quadrivalens. Sporophyte formation was statistically more successful in the experiments with gametophyte pairs than in isolates, indicating that additional cross-fertilization occurred. The latter agreed with the occurrence of few heterozygote samples and the small number of multilocus phenotypes found in natural habitats. Asplenium trichomanes subsp. quadrivalens is shown to be a highly inbreeding taxon with the capability of single spore colonization and subsequent founding of new populations. Such features can be hypothesized to have contributed to the postglacial colonization and the widespread distribution of this taxon in Europe.

Journal Article↗
PubMed2003

Geographical variation, population structure and gene flow between populations of Chrysophtharta agricola (Coleoptera: Chrysomelidae), a pest of Australian eucalypt plantations.

Chrysophtharta agricola (Chapuis) is a pest of commercial eucalypt plantations in Tasmania and Victoria. Vagility of pest populations may result in difficulty predicting temporal and spatial pest outbreaks, and influence genetic resistance to chemical control. Gene flow in this pest species was estimated to assess predictability of attack, the potential efficacy of natural enemies, and the likelihood of resistance build-up. Ten geographic populations of C. agricola (six from Tasmania, one from the Australian Capital Territory, one from New South Wales and two from Victoria) were examined for genetic variation and gene flow using cellulose acetate allozyme electrophoresis. Six enzyme systems (PGI, PGD, PGM, IDH, HEX and MPI) were consistently polymorphic and scorable and were used to quantify estimated gene flow between populations. FST values and analysis of molecular variance indicated that gene flow was restricted between populations. Chrysophtharta agricola exhibited high levels of heterozygosity, probably because of high allelic diversity, and because all loci examined were polymorphic. The southern-most population was the most genetically different to other Tasmanian populations, and may also have been the most recently colonized. Limited gene flow implies that outbreaks of C. agricola should be spatially predictable and populations susceptible to control by natural enemies. Our results also imply that genetic resistance to chemical control may occur under frequent application of insecticide. However, testing population movement between plantations and native forest also needs to be conducted to assess gene flow between forest types.

Animals↗
PubMed2026

CHITRA: an interactive visualization tool for comparative genomic rearrangement analysis.

MOTIVATION: The increasing availability of chromosome-scale genome assemblies has fuelled a renewed interest in studying chromosomal evolution and rearrangements. Synteny visualization plays a critical role in understanding genome organization, structural variations, and evolutionary relationships. However, existing tools often have steep learning curves, produce static plots, or are limited in their ability to analyse multiple genomes simultaneously. There is a growing need for an intuitive and interactive visualization tool that can effectively explore syntenic relationships and chromosomal rearrangements. RESULTS: Here, we present CHITRA, a web-based interactive tool designed to visualize synteny blocks, chromosomal rearrangements, and breakpoints in both linear and circular styles. CHITRA-enables real-time exploration of genome structural variations with an intuitive graphical interface, customizable visualization options, and high-resolution export capabilities for publication-ready figures. The tool supports chromosome- and scaffold-level assemblies and allows users to filter, highlight, and interactively examine syntenic relationships. AVAILABILITY AND IMPLEMENTATION: CHITRA is freely available at https://chitra.bioinformaticsonline.com/, with comprehensive documentation at https://chitra.bioinformaticsonline.com/docs. The source code is open-source and accessible on GitHub at https://github.com/pranjalpruthi/CHITRA.

Journal Article↗
PubMed2001

Glassy cholesteric structure: thickness variation induced by electron radiation in transmission electron microscopy investigated by atomic force microscopy.

During the observation of glassy cholesteric liquid crystals in transmission electron microscopy (TEM), a new contrast is created or enhanced by electron radiation which has a direct relationship with the periodic microstructure of the specimen. In this paper, we investigate the variations of the sample thickness and mass density as possible causes of this irradiation contrast. By means of observations in atomic force microscopy (AFM) coupled to TEM, we compared the surface corrugations of non-irradiated and irradiated specimens. It is shown that the final contrast is the result of several processes. including fracture during ultramicrotomy and mass loss during irradiation. Mass loss acts as an etching, and hence results in a decrease of the sample thickness. The etching depends on the initial molecular orientation, thus evidencing the latent structure. An electron channelling mechanism is suggested to explain this behaviour.

Journal Article↗
PubMed1983

Variations in structure and response properties of horizontal cells in the retina of the rabbit.

The response waveform of rabbit horizontal cells to diffuse white light stimulation was correlated with their anatomy by intracellular injection of horseradish peroxidase. In both axonless horizontal cells and the somatic end of axon-bearing cells the light evoked hyperpolarization may exhibit a transient at the onset of high intensity stimuli and is consistently followed by a rod aftereffect at stimulus cessation. In both types of cells the on-transient may be small and the rod aftereffect very prominent; this response pattern, however, is more frequently a property of the somatic end of axon-bearing cells. The morphology of axon-bearing cells is the same regardless of their response properties. On the other hand, axonless horizontal cells exhibit a wide variation in shape and the vast majority of them have asymmetric dendritic fields. No correlation, however, exists between cell shape and response properties. These are also independent of the location of horizontal cells in the retina or the orientation of their long axis with respect to the optic nerve head and medullary rays.

Animals↗
PubMed2025

Cell-type-specific enrichment of somatic aneuploidy in the mammalian brain.

Somatic mutations alter the genomes of a subset of an individual's brain cells, impacting gene regulation and contributing to disease processes. Mosaic single-nucleotide variants have been characterized with single-cell resolution in the brain, but we have limited information about large-scale structural variation such as whole-chromosome duplication or loss. We used a dataset of over 415,000 single-cell DNA methylation and chromatin conformation profiles from the adult mouse brain to comprehensively identify and characterize aneuploid cells. Somatic trisomy events were strongly enriched on chromosome 16, which is syntenic with human chromosome 21. We also observed a specific enrichment of chromosome gain and loss events in specific cell types, including Pons neurons and oligodendrocyte precursor cells. Chromosome 16 trisomy occurred in multiple cell types and across brain regions, suggesting that nondisjunction is a recurrent feature of somatic structural variation in the brain.

Animals↗
PubMed1998

Evolutionary changes in the structures of the cox2 and atp6 loci in the mitochondrial genome of soybean involving recombination across small interspersed sequences.

Mitochondrial DNA (mtDNA) fragments that contained cox2 or atp6 loci were cloned from three accessions of wild soybean (Glycine soja) in order to understand the evolutionary changes of mitochondrial genomes in the genus Glycine subgenus Soja. Cox2 was cloned as a single configuration, while atp6 was cloned as either one or two configurations from each accession. Structural variations were detected in the 5' upstream region of cox2 and in both the 5' upstream and 3' downstream regions of atp6. These variations appeared to be the results of recombination events. A comparison of the mtDNA fragments previously cloned from a cultivated soybean (G. max) and a wild soybean revealed various sites of recombination, as well as various combinations of the 5' and 3' regions, at the cox2 and atp6 loci. Some of the cloned fragments were found to contain a set of repeated sequences, namely 299-bp and 23-bp repeats in the 5' region of cox2 or atp6, which were interspersed in the mitochondrial genome in the subgenus Soja. Recombination events involving the 299-bp or 23-bp repeated sequences were shown to account for the generation of structural variations in the 5' regions of these loci.

Base Sequence↗
PubMed1999

Genetic variation, population structure and cryptic species within the black mudfish, Neochanna diversus, an endemic galaxiid from New Zealand.

To investigate the phylogenetic relationships and geographical structure among landlocked populations of the black mudfish, Neochanna diversus, mitochondrial DNA nucleotide sequence data were sampled from seven populations from the Waikato and Northland regions of New Zealand. The complete D-loop region was sequenced from 70 individuals, with 913 bp from the tRNA-pro end used in population and phylogenetic analysis. A tandem repeat array, which ranged in size up to 200 bp, was found in most populations at the 3' end of the D-loop that was not able to be aligned for analysis. Of the seven sites sampled, two from Northland exhibited significant sequence divergence from all other sites. There was also a clear distinction among remaining Northland sites and those from the Waikato. An additional 518 bp segment of the 16S region was sequenced from all sites and compared with the other New Zealand mudfish species, N. apoda, N. burrowsius and the Tasmanian mudfish Galaxias (Neochanna) cleaveri using Galaxias maculatus as an outgroup. Both D-loop and 16S sequence data provided strong evidence for a cryptic species of mudfish present in Northland. The significant genetic structure apparent in the black mudfish appears most probably to be attributed to geological conditions during the Pliocene, where peat wetlands became apparent in the Waikato while Northland consisted of disjunct 'islands'. Conservation and management of these populations must take into account the historical processes that have shaped these patterns of genetic diversity.

Animals↗
PubMed1983

Calorimetric studies of flavin binding protein: flavin analog binding.

The effect of flavin structure variation upon the overall binding reaction of flavin to hen egg white riboflavin binding protein (WRBP) was correlated to thermodynamic parameters obtained via titration calorimetry. This effect was measured by determining a reference binding enthalpy (delta Href) for 3-carboxymethylriboflavin and subsequently comparing delta Href to the binding enthalpies determined for all other flavin analogs in this study. The reference enthalpy change was measured in detail under a variety of temperatures (14, 25, and 38 degrees C), pH's (5.5, 6.5, 7.4, 8.5), and buffer types. The reference enthalpy for the binding of N(3)-carboxymethylriboflavin to WRBP was measured as delta H = -20.9 kcal/mol at 25.0 degrees C and pH 7.4. Evaluation of the binding thermodynamic values for the reference flavin indicates that there is no H+ flux concomitant with binding. A small negative change in heat capacity (delta Cp) occurs during the binding process suggesting a contraction of the protein. Finally, the reaction appears to be independent of pH and buffer type indicating little, if any, involvement of charged residues in the binding of flavin to apoWRBP. Thermodynamic values for the binding of an additional eight flavin analogs were then measured at pH 7.4 and 25.0 degrees C. The thermodynamic binding parameters for these analogs were evaluated by comparison to those determined for the reference flavin. The results indicate that the ribityl C2' position is a major influence in the interaction between the ribityl side chain and the protein; the C9 position of the isoalloxazine ring is sterically restricted in a manner similar to positions C7 and C8; and the positions C7 and C8 appear to be unequal with regard to enthalpy release, suggesting that the C8 position is the most restricted region in the aromatic ring. These various findings indicate the unique ability of titration calorimetry to evaluate structural variation of ligands to their corresponding binding site interactions.

Animals↗
PubMed1996

Structure distribution relationship of iodine-123-iodobenzamides as tracers for the detection of melanotic melanoma.

UNLABELLED: The influence of systematic structure variations on the biodistribution of positional isomers of N-(N'-dialkylaminoethylene)-[123I]iodobenzamide (ABA) derivatives in melanoma-bearing animals was investigated. METHODS: Radioiodination of six bromo benzamide precursors was achieved by Cu(1)-assisted nonisotopic halogen exchange. Organ distribution, scintigraphic and metabolic studies were performed in nude mice bearing a human melanotic MM (SK-MEL 25). A patient suffering from melanotic melanoma underwent scintigraphy with a [123I]iodobenzamide. RESULTS: High radiochemical yields of 80%-95% and specific activities of > 5 TBq/ mumole were obtained. Animal studies revealed specific tumor uptake of all compounds with longest retention of the most lipophilic derivative p-[123I]ABA 2-2. At shorter times, however, o-[123I]ABA 2-2 exhibited the highest tumor uptake (8.9% ID/g, 1 hr p.i., 10.9% ID/g, 4 hr p.i.). Metabolization of o-[123I]ABA 2-2, mainly to o-[123I]iodohippuric acid (OIH), followed by fast renal excretion of the metabolites lead to tumor/nontumor ratios (T/NT) of > 400 for tumor/blood, and > 70 for tumor/liver at 48 h p.i. Unknown metastases could be localized in a patient using o-[123I]ABA 2-2. CONCLUSION: The effects of the structure variation of iodobenzamides on their lipophilicity, metabolism and thus pharmacokinetics lead to the suggestion of o-[123I]ABA 2-2 as a favorable melanoma imaging agent.

Animals↗
PubMed2004

Sugar-amide surfactant micelles as effective reaction fields for enantioselective hydrolysis of alpha-amino acid esters.

The enantioselective hydrolysis of p-nitrophenyl esters of alpha-amino acids (Phe, Leu, Ala) was accomplished in micelles formed with the surfactants bearing one or two sugar-amide headgroups. The effect of structural variations in such sugar-amide surfactants on the rates and enantioselectivity (kD/kL) for hydrolysis of p-nitrophenyl esters of D- and L-phenylalanine hydrogen bromides (D- and L-PheONp) was studied. Both the hydrolysis rate of D-PheONp and the enantioselectivity increased with an increase in the alkyl chain length as well as an increase in the number of the alkyl chains in the maltobionamide-type surfactants. Enantioselectivity also increased with an increase in the sugar chain length from bisgluconamide to bismaltobionamide (by one glucose unit per each sugar chain) in the double-sugar-chain surfactants, but enantioselectivity was no longer influenced by a further increase to bismaltotrionamide. The stereochemistry of the linkage between the sugar units in the sugar chain remarkably affected the enantioselectivity: the maltobionamide-type surfactant, in which the two sugar units are connected by an alpha-1,4-glucosidic linkage, showed high enantioselectivity (kD/kL = 5.5), whereas the surfactant bearing cellobionamide headgroups (beta-1,4-glucosidic linkage) showed no enantioselectivity. Similar trends were observed when p-nitrophenyl esters of D- and L-leucine hydrogen bromides were used as substrates. On the other hand, the rates and enantioselectivity for hydrolysis of p-nitrophenyl esters of D- and L-alanine hydrogen bromides were not so largely affected by the structural variations in the sugar-amide surfactants. Additionally, the effects of the surfactant concentration and the reaction temperature on the rates and enantioselectivity for the hydrolysis of D- and L-PheONp were examined.

Amides↗
PubMed1996

Molecular recognition by cholesterol esterase of active site ligands: structure-reactivity effects for inhibition by aryl carbamates and subsequent carbamylenzyme turnover.

Interactions of mammalian pancreatic cholesterol esterases from pig and rat with a family of aryl carbamates CnH2n+1NHCOOAr [n = 4-9; Ar = phenyl, p-X-phenyl (X = acetamido, bromo, fluoro, nitro, trifluoromethyl), 2-naphthyl, 2-tetrahydronaphthyl, estronyl] have been investigated, with an aim of delineating the ligand structural features which lead to effective molecular recognition by the active site of the enzyme. These carbamates inhibit the catalytic activity of CEase by rapid carbamylation of the active site, a process that shows saturation kinetics. Subsequent slow decarbamylation usually leads to full restoration of activity, and therefore aryl carbamates are transient inhibitors, or pseudo-substrates, of CEase. Structural variation of carbamate inhibitors allowed molecular recognition in the fatty acid binding and steroid binding loci of the extended active site to be probed, and the electronic nature of the carbamylation transition state to be characterized. Optimal inhibitory activity is observed when the length of the carbamyl function is n = 6 and n = 7 for porcine and rat cholesterol esterases, respectively, equivalent to eight- and nine-carbon fatty acyl chains. In contrast, inhibitory activity increases progressively as the partial molecular volume of the aromatic fragment increases. Hammett plots for p-substituted phenyl-N-hexyl carbamates indicate that the rate-determining step for carbamate inhibition is phenolate anion expulsion. Effects of the bile salt activator taurocholate on the kinetically resolved phases of the pseudo-substrate turnover of aryl carbamates were also studied. Taurocholate increases the affinity of the carbamate for the active site of cholesterol esterase in the reversible, noncovalent complex that precedes carbamylation and increases the rate constants of the serial carbamylation and decarbamylation steps. Structural variation of the N-alkyl chain and of the aryl fused-ring system provides an accounting of bile salt modulation of the fatty acid and steroid binding sites, respectively. In that pseudo-substrate turnover of aryl carbamates proceeds by a three-step mechanism that is analogous to that for rapid turnover of lipid ester substrates, these investigations illuminate details of ligand recognition by the extended active site of cholesterol esterase that are prominent determinants of the substrate specificity and catalytic power of the enzyme.

Animals↗
PubMedDate not supplied

Geographic variations in structure and composition of gallstones and their correlation with brittleness.

Cholesterol gallstones obtained from different geographic regions have been reported to show significant differences in their minor chemical constituents. We undertook the present study with two objectives: (i) to investigate the possible physiochemical and radiological differences between cholesterol gallstones obtained from Indian and German patients; and (ii) to compare the brittleness of the two stone groups. Forty Indian and 36 German gallstones (matched in size and shape) were subjected to assessment of physical characteristics, in vitro computed tomography (CT) and chemical analysis. German stones more often had a stone density distribution index of > or = 50 Hounsfield units (HU) (26 vs 14; P < 0.01), peripheral calcification (18 vs 9; P < 0.02), maximum CT density > or = 90 HU (17 vs 9; P < 0.05) and significant calcium carbonate (9 vs 5; P < 0.05), compared to Indian stones. The in vitro lithotripsy performed with the Siemens Lithostar Plus machine at a constant energy level showed the German stones to be more brittle (easy to fragment), more often requiring < 1000 shocks for fragmentation (25/36; 69%) compared to Indian stones (18/40; 45%, P < 0.05). Gallstones from different geographic regions may show significant variations in their physicochemical characteristics that may explain the differences in their brittleness to lithotripsy.

Calcinosis↗
PubMed1995

Fibrous architecture of the dorsal aponeurosis of the thumb.

BACKGROUND: The extensor apparatus of the thumb displays obvious structural variations in its proximo-distal expanse. Its associated tissue comes in close relation to the dorsal aponeurosis that have varying topographical relationships to the extensor apparatus of the thumb. This region is especially important as the location of pathological and repair processes. METHODS: In this anatomical study using a modified embedding technique a histological description of the fibrous architecture of the dorsal aponeurosis and the peritendinous connective tissue body of the thumb is presented. RESULTS: The dorsal connective tissue of the thumb forms different layers of collagen lamellae as a peritendinous system around the tendons of the long and short extensor tendons of the thumb. This peritendinous laminar system as the main part of the dorsal aponeurosis is connected with both the capsular and the retinacular ligaments of the thumb. CONCLUSIONS: It will be shown that the structural variations of the dorsal aponeurosis and peritendinous connective tissue are an expression of different topographical zones of stress along the lines of a balanced musculofibrous stabilization of the interphalangeal joint of the thumb. The expansions in the peritendinous intercellular space act as defined gliding spaces or clefts of the extensor apparatus.

Aged↗
PubMed2002

Characterization of mitochondrial ribosomal RNA genes in gadiformes: sequence variations, secondary structural features, and phylogenetic implications.

Secondary structure features of mitochondrial ribosomal RNAs (mt-rRNAs) of bony fishes were investigated by a DNA sequence alignment approach. The small subunit (SSU) and large subunit (LSU) mt-rRNA genes were found to contain several additional variable regions compared to their mammalian counterparts. Fish mt-LSU rRNA genes were found to be longer than the mammalians due to increased length of some of the variable regions. The 5' and 3' ends of Atlantic cod mt-rRNAs were precisely mapped. The 3' ends of mt-SSU rRNAs were found to be homogenous and mono-adenylated, whereas that of the mt-LSU rRNAs were heterogenous and oligo-adenylated. The 5' ends of mt-SSU rRNAs appeared to be heterogenous, corresponding to the presumed first and second positions of the gene. Sequences of the central domain and the D-domain of the mt-SSU and mt-LSU rRNA genes, respectively, were determined and characterized for 11 gadiform species (representing the families Gadidae, Lotidae, Ranicipitidae, Merlucciidae, Phycidae, and Macrouridae) and one Lophiidae species. Detailed secondary structure models of the RNA regions are presented for the Atlantic cod (Gadus morhua) and Roundnose grenadier (Coryphaeonides rupestris). Saturation plots revealed that DNA nucleotide positions corresponding to unpaired RNA regions become saturated with transitions at sequence divergence levels about 0.15. Phylogenetic analyses revealed some aspects of gadiform relationships. Gadidae was identified as the most derived of the gadiform families. Lotidae was found to be the family closest related to Gadidae, and Ranicipitidae was also recognized as a derived gadiform taxon.

Animals↗
PubMed1997

Genetic variation at structural loci in the Glossina morsitans species group.

Gene diversity was investigated in four taxa of tsetse flies (Diptera: Glossinidae) including Glossina morsitans, G.m. centralis, G. Swynnertoni, and G. pallidipes. Histochemical tests were performed for 35-46 isozymes. Polymorphic loci were 20% in G. morsitans, 32% in G.m. centralis, 17.6% in G. swynnertoni, and 26% in G. pallidipes. Mean heterozygosities among all loci were 6.6% in G. morsitans morsitans, 6.0% in G.m. centralis, 7.1% in G. swynnertoni, and 6.8% pallidipes. Allozyme gene diversities were considerably less than those reported for many Diptera. The low gene diversities are probably related to small effective population sizes.

Animals↗