Genetic relationships among perennial and annual Cicer species growing in Turkey assessed by AFLP fingerprinting.

AFLP markers were used to assess genetic relationships among Cicer species with distribution in Turkey. Genetic distances were computed among 47 Cicer accessions representing four perennial and six annual species including chickpea, using 306 positions on AFLP gels. AFLP-based grouping of species revealed two clusters, one of which includes three perennial species, Cicer montbretii, Cicer isauricum and Cicer anatolicum, while the other cluster consists of two subclusters, one including one perennial, Cicer incisum, along with three annuals from the second crossability group ( Cicer pinnatifidum, Cicer judaicum and Cicer bijugum) and the other one comprising three annuals from the first crossability group ( Cicer echinospermum, Cicer reticulatum and Cicer arietinum). Consistent with previous relationship studies in the same accession set using allozyme and RAPD markers, in AFLP-based relationships, C. incisum was the closest perennial to nearly all annuals, and C. reticulatum was the closest wild species to C. arietinum. Cluster analysis revealed the grouping of all accessions into their distinct species-clusters except for C. reticulatum accessions, ILWC247, ILWC242 and TR54961; the former was found to be closer to the C. arietinum accessions while the latter two clustered with the C. echinospermum group. Small genetic distance values were detected among C. reticulatum accessions (0.282) and between C. reticulatum and C. arietinum (0.301) indicating a close genetic similarity between these two species. Overall, the AFLP-based genetic relationships among accessions and species were congruous with our previous study of genetic relationships using allozymes. The computed level of AFLP variation and its distribution into within and between Cicer species paralleled the previous report based on RAPD analyses. AFLP analysis also confirmed the presence of the closest wild relatives and previous projections of the origin of chickpea in southern Turkey. Results presented in this report indicate that AFLP analysis is an efficient and reliable marker technology in determination of genetic variation and relationships in the genus Cicer. Obviously, the use of AFLP fingerprinting in constructing a detailed genetic map of chickpea and cloning, and characterizing economically important traits would be promising as well.

Analysis of genetic relationships among perennial and annual Cicer species growing in Turkey using RAPD markers.

Random amplified polymorphic DNA (RAPD) fragments were used to assess genetic relationships among Cicer spp. growing in Turkey. Seven 10-mer primers selected from a 50 random oligonucleotide primer set, depending on their ability to amplify genomic DNA in all species, were used to detect RAPD variation in 43 wild and cultivated accessions representing ten species. These primers yielded 95 reproducible amplification products, 92 of which were polymorphic. Pairwise genetic distances of accessions estimated according to Nei and Li (1979) were used to produce a dendrogram using UPGMA. The dendrogram contained two main clusters, one of which comprised accessions of the four perennial species ( Cicer montbretii, Cicer isauricum, Cicer anatolicum and Cicer incisum) together with the accessions of the three annual species ( Cicer pinnatifidum, Cicer judaicum and Cicer bijugum), and the other cluster included the remaining three annual species ( Cicer echinospermum, Cicer reticulatum and Cicer arietinum). Analysis of RAPD variation showed that C. incisum is the most similar perennial species to annuals, and C. reticulatum is the closest annual species to chickpea. These results generally agree with our allozyme study which was carried out using same Cicer collection and previous studies of relationships among annual species. The results also show that RAPD markers can be used to distinguish Cicer species and to survey genetic variation and relationships among taxonomic units in this genus.

Polymorphism of M factors in populations of the housefly, Musca domestica L., in Turkey.

M factors, which determine maleness in Musca domestica, were found on the second, third, fourth and fifth linkage groups in housefly populations of Turkey. As in European populations, the male-determining factor was more frequently located on linkage group III (MIII). Some males homozygous or double heterozygous for M factors were identified. Deviations from a 1:1 sex ratio in favour of males, as well as mosaics for somatic marker mutations and sexual mosaics (gynandromorphs), were also observed. The results reveal an extensive polymorphism in the sex-determining system.

Polymorphism of precore region of hepatitis B virus DNA among patients with chronic HBV infection in Turkey.

The prevalence of mutations in the precore and core promoter regions of hepatitis B virus DNA and the association with the hepatitis B e antigen-negative phenotype vary in different geographical areas. It is rather high especially in the Far East and Mediterranean countries. The mutations occurring in the precore and the minimal essential region of the core promoter of HBV-DNA were analyzed in the sera of 81 patients (HBeAg-positive, 47 patients; HBeAg-negative, 34 patients) with chronic hepatitis B virus infection by direct sequencing of amplified polymerase chain reaction products. All patients had thymine at nucleotide 1858. Seven of 47 HBeAg-positive patients (15%) and 29 of 34 HBeAg-negative patients (85%) had precore stop codon mutations (G to A change at nucleotide 1896). No nucleotide change was found in the minimal essential region of HBV core promoter in any patient studied. In conclusion, the hepatitis B e antigen-negative phenotype in Turkish patients with chronic hepatitis B is associated with mutations in the precore but not in the minimal essential region of the core promoter. These results representing a part of the eastern Mediterranean support the studies conducted for the other populations of the region.

Geographic variation analysis of the ABO and RH systems in Turkey.

In this study, we report the results of a geographical variation analysis on the gene frequencies of ABO and RH systems in 67 provinces of Turkey. The gene frequencies of A, O and RH(-), were subjected to spatial autocorrelation analysis and significant spatial autocorrelation coefficients were observed for each gene in the first distance class. The average I-correlogram for the three genes displayed a clinal pattern. The results also suggested a marked decrease in genetic similarity in relation to geographic distance.

Control of insecticide resistance in laboratory populations of house fly (Diptera: Muscidae) by introduction of susceptibility genes.

We investigated the effects of immigration of individuals carrying susceptibility alleles on the level of resistance in populations of the house fly, Musca domestica L., selected for malathion resistance. Two types of males, WHO/IN males (homozygous for susceptibility genes) and A14-WHO males (heterozygous for the second chromosome) were released into the resistant populations in 1:9, 1:1, and 9:1 ratios of immigrant/resident males. In both experiments, we observed that increasing the ratio of immigrant to resident males from 1:9 to 9:1 caused an associated increase in mortality caused by malathion applications. Release of A14-WHO males was more effective in stopping the evolution of resistance in resistant populations than was release of WHO/IN males. Fitness parameters of resistant and susceptible strains were also compared. The WHO/IN strain had low viability and fecundity. R and A14-WHO males were longer-lived compared with WHO/IN males, although they did not differ in mating success.

Genetic consequences of linkage between malathion resistance and an autosomal male-determining factor in house fly (Diptera: Muscidae).

The pattern of inheritance of genes conferring resistance to malathion and genetic consequences of linkage between an autosomal male-determining factor and resistance genes on the second chromosome were investigated in a strain of house fly, Musca domestica L., selected for malathion resistance. The second and fifth chromosomes contribute significantly to malathion resistance. The presence of a male-determining factor linked with the resistance genes on the second chromosome resulted in a strong sexual dimorphism in malathion resistance. We also observed that the male-determining factor changed its linkage relationship from the third linkage group to the second linkage group during the selection experiments.

A rare-male advantage in the housefly induced by wing clipping and some general considerations for Drosophila.

Multiple-choice crosses among five geographic strains of the housefly, Musca domestica L., were carried out in equal (10:10) and low-frequency (4:16) ratios. Initially, a low-frequency-male mating advantage was apparent, but further analyses related this minority advantage to a reduction of male mating success during marking by wing clipping. When there are fluctuating differences in the level of sexual vigor between competing male types over replicate trials of a cross, a mating advantage will accrue to the minority type. Even if males from the two competing strains are equally vigorous, such fluctuating differences will occur during sampling of flies. Harming the flies during marking will serve to enhance this effect and make significant departures toward greater mating success of rare males highly likely. This statistical bias in favor of minority males was substantiated in simulations of the KENCE-BRYANT model of mating success and compared with our results of a minority advantage in the housefly and with published results of a minority advantage in Drosophila. Our evidence, though circumstantial, that an advantage to minority males could have been induced by such an experimental bias suggests that a re-examination of existing data, as well as new experimentation, is necessary to discern whether or not a real rare-male advantage exists.

The survival of mutants at very low frequencies in tribolium populations.

Forty population cages, each with 499 adult T. castaneum of the wild-type UPF strain, received a bb female newly mated with UPF males. Half of the immigrants had a Chicago Black genetic background, the other half a UPF background. These conditions simulate, respectively, the fate of a rare, genetically differing immigrant or the fate of a mutation in populations of considerable size. Adults were censused for 11 discrete generations. The semi-dominant autosomal black gene survived in 26 out of 40 cultures by the end of the experiment, demonstrating its selective advantage at these very low frequencies. The gene increased from an initial frequency of 0.002 to 0.055 (at generation 11) in at least one replicate. Although frequency-dependent fitness has been shown for black at higher frequencies, no such dependence could be demonstrated at the low frequencies of this study. The cultures simulating mutations (immigrants with native backgrounds) had a higher average gene frequency, different distribution of gene frequencies across replicates, and a lower extinction rate of black than did the cultures with alien background immigrants. The observations only partially fitted expectation based on a branching process model. The data show a tendency for the persistence of a few heterozygotes in cultures and for a deficiency of cultures that lost the mutant or those with many heterozygotes. The increase in frequency of black cannot be attributed to increased reproductive success of heterozygotes. The advantage of heterozygotes appears due to delayed developmental period as a result of tactile stimulation and probable differential cannibalism among pupae.