Inversion polymorphism of the malarial mosquito Anopheles messeae. IV. The stability of the frequency distribution of the inversions by species area

Distribution of the frequencies of inversions XL1, 2R1, 3R1, 3L1, from geographically widely separated 8 populations had been studied during a long period of time. The geographical inclines of distribution of inversions XL1, 3R1 (a longitudinal) and 2R1 (a latitudinal) are stable in time. Stationarity of inversional polymorphism is not connected with superdominance of heterozygotes. It is supposed that the stable equilibrium of the frequencies of inversions is supported by variable selection.     

Inversion polymorphism of the malarial mosquito Anopheles messeae. V. The interaction of different chromosomal inversions in the spatial area

The relations between inversions of chromosome XL, 2R, 3R, 3L from 8 populations of the central part and periphery of the species area were studied. 2-, 3- and 4-factor analysis was carried out. Interaction of inversions XL1, 2R1, 3R1 in central populations (Riga, Moscow, Tomsk) was observed. The nonrandom association of definite inversional genotypes was stationary in spatial - temporary. The phylogenetic initial sequences XL0, 2R0, 3R0 display "+" interaction. The 3-factor analysis of populations of Tomsk shows: 1) interaction of inversions is more essential in males than in females; 2) the statistically significant interaction of 3-4 inversions is not always determined by the effect of 2-factor analysis; 3) the chromosome 3R has a dominance influence on the pattern of association of the multiinversional complex. These data support the hypothesis that differential selection for chromosomes with certain combinations of arrangements is mainly responsible for this phenomenon. In peripheral area populations (Syctyvkar, Irkutsk, Chita), no associations were observed (2R and 3R). When they do take place, their character is changed (Kiev - XL and 3R). This phenomenon may be explained by the influence of frequency-dependent selection.     

Inversion polymorphism in malarial mosquito Anopheles messeae natural populations from the north-eastern region of the range

A cytogenetic study of eight natural populations of Anopheles messeae from the north-eastern part of the species areal was conducted. Complete predominance of homozygotes XL11 and 3R11 in the northern populations was observed. Change in the chromosome 2 inversion frequencies from south northwards was shown. The 2R11 variant, which was not observed in the southern region, was found in the northern populations. These results indicate the maintenance of chromosome frequency of the distribution of inversions XL1 and 3R (in longitude) and 2R1 (in latitude). The inversion frequency distribution in the examined part of the areal have been preserved for a long time.     

Inversion polymorphism in malaria mosquito Anopheles messeae. Part X. Resistance of larvae with different genotypes to toxins of crystal-forming bacteria Bacillus thuringiensis subsp. israelensis (serovar H14)

Insensibility of larvae with different chromosomal inversions to the toxins of Bacillus thuringiensis subsp. israelensis (Bti) was examined. It has been shown that larvae with inversion combinations XL0(XL1)2R0-3R0-3L0 had greater variability after treatment with Bti than larvae with inversions XL1(XL2)2R1-3R1-3L1(3L0). The former inversion combinations were previously shown to dominate in the south of the species area and to be supported by K-selection. The latter inversion combinations form "northest" karyotypes and are supported by r-selection. It is obvious that genetic effects of treatments with Bti depend on the population's structure and the directions of natural selection. The decrease in the level of heterozygotes after treatment of larvae with Bti reflects destruction of the system of genetic homeostasis in the natural populations of A. messeae.     

Inversion polymorphism of the malaria mosquito Anopheles messeae. VIII. Distribution of larvae in biotopes under conditions of co-habitation with Anopheles beklemishevi

The role of chromosomal variability was studied in the process of biotopical distribution of larvae of the sibling species Anopheles messeae and A. beklemishevi. It is shown that frequency of the inversions XL1, XL2, 2R1, 3R1 of A. messeae was changed in the lakes with different larval quantity of the sibling species. Mosquito of A. beklemishevi were developed in the suboptimal biotops having low larwal quantity of A. messeae with the analogous chromosomal arrangement 2R1. The larvae with "northeast" genocomplexes of A. messeae prevailed over A. beklemishevi in the lakes with high larval quantity and this prevalence determined dominant state of A. messeae. It is noted that natural selection on the preimaginal stages of development acts in the direction of karyotypic divergence of the sibling species and promotes more effective utilisation of food resources by each species.     

The Xenopus laevis aurora-related protein kinase pEg2 associates with and phosphorylates the kinesin-related protein XlEg5.

We have previously reported on the cloning of XlEg5, a Xenopus laevis kinesin-related protein from the bimC family (Le Guellec, R., Paris, J., Couturier, A., Roghi, C., and Philippe, M. (1991) Mol. Cell. Biol. 11, 3395-3408) as well as pEg2, an Aurora-related serine/threonine kinase (Roghi, C., Giet, R., Uzbekov, R., Morin, N., Chartrain, I., Le Guellec, R., Couturier, A., Dorée, M., Philippe, M., and Prigent, C. (1998) J. Cell Sci. 111, 557-572). Inhibition of either XlEg5 or pEg2 activity during mitosis in Xenopus egg extract led to monopolar spindle formation. Here, we report that in Xenopus XL2 cells, pEg2 and XlEg5 are both confined to separated centrosomes in prophase, and then to the microtubule spindle poles. We also show that pEg2 co-immunoprecipitates with XlEg5 from egg extracts and XL2 cell lysates. Both proteins can directly interact in vitro, but also through the two-hybrid system. Furthermore immunoprecipitated pEg2 were found to remain active when bound to the beads and phosphorylate XlEg5 present in the precipitate. Two-dimensional mapping of XlEg5 tryptic peptides phosphorylated in vivo first confirmed that XlEg5 was phosphorylated by p34(cdc2) and next revealed that in vitro pEg2 kinase phosphorylated XlEg5 on the same stalk domain serine residue that was phosphorylated in metabolically labeled XL2 cells. The kinesin-related XlEg5 is to our knowledge the first in vivo substrate ever reported for an Aurora-related kinase.     

The thymidylate synthase tandem repeat polymorphism is not associated with homocysteine concentrations in healthy young subjects

Thymidylate synthase (TYMS) and 5,10-methylenetetrahydrofolate reductase (MTHFR) may compete for their common cofactor 5,10-methylenetetrahyhdrofolate (5,10-meTHF). Limiting 5,10-meTHF results in elevated homocysteine, especially in individuals homozygous for the T allele of the MTHFR C677T polymorphism. The TYMS gene has a tandem repeat polymorphism (two repeats or three repeats, designated 2R or 3R, respectively), which may also affect homocysteine concentrations. The 3R allele is subject to increased translational efficiency in vitro and the 3R3R genotype is associated with both decreased serum folate and elevated plasma homocysteine (tHcy) in a population of Singapore Chinese. We assessed the relationship between TYMS genotype and key biochemical and genetic variables in a random sample of 392 healthy young Northwestern European men and women. The tHcy concentrations for 3R3R homozygotes (median 8.5 mol/l) did not differ significantly from those for 2R2R homozygotes (median 8.7 mol/l) or 2R3R heterozygotes (median 9.3 mol/l) in the population as a whole (P=0.43), or in subsets of subjects with low serum folate (P=0.60) or the MTHFR 677TT genotype (P=0.90). Furthermore, there was no trend toward elevated tHcy in 3R3R homozygotes. Similarly, the TYMS tandem repeat polymorphism was not associated with serum folate concentrations. Our findings indicate that the TYMS 3R3R genotype is not a determinant of homocysteine in this sample of healthy young Caucasian adults from Northern Ireland.     

火炬树抗螨性生物测定

本文分别测定了二斑叶螨Tetranychus urticae Koch和山楂叶螨Tetranychus viennensis Zacher对火炬树的选择性,以及限制性条件下火炬树对叶螨的生存及产卵的影响。结果表明：在火炬树叶和苹果叶之间,二斑叶螨和山楂叶螨在2 h, 6 h, 10 h, 12 h对火炬树的选择率分别为9.5%, 6.5%,5%,5%和2%,5%,1%和0,显著低于对苹果的选择率。被限制于火炬树叶上生存的山楂叶螨144 h后死亡率100%,产卵力随生存时间增加而下降,至96 h后产卵终止; 被限制于火炬树叶上生存的二斑叶螨240 h后全部死亡,整个观察期内（24～216 h）始终没有产卵。据此认为： 叶螨强烈拒食火炬树,火炬树对叶螨具有生存、产卵抑制作用,但这种抑制作用呈现种间差异。     

Inversion polymorphism in the malaria mosquito Anopheles messeae. VI. Local selection and 3-dimensional differentiation of the inversion gene complexes for fertility

A field experiment was carried on with the view of compulsory change of the frequency of chromosomal inversion (2R1) in the population of Anopheles messeae from the centre of the area. Quick return of the population to the original structure was observed. This confirmed that the local differentiation of chromosomal polymorphism is supported by natural selection. The fertility of the females was shown to be connected with the inversion polymorphism. The females with inversion complexes of genes of the "northern" type (with homozygotes 2R1) had higher fertility and lower dispersion of the fertility, in comparison with those having gene complexes which prevailed in the south part of the area.     

Metabolic engineering of Escherichia coli for biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from glucose

The Escherichia coli XL1-blue strain was metabolically engineered to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] through 2-ketobutyrate, which is generated via citramalate pathway, as a precursor for propionyl-CoA. Two different metabolic pathways were examined for the synthesis of propionyl-CoA from 2-ketobutyrate. The first pathway is composed of the Dickeya dadantii 3937 2-ketobutyrate oxidase or the E. coli pyruvate oxidase mutant (PoxB L253F V380A) for the conversion of 2-ketobutyrate into propionate and the Ralstonia eutropha propionyl-CoA synthetase (PrpE) or the E. coli acetyl-CoA:acetoacetyl-CoA transferase for further conversion of propionate into propionyl-CoA. The second pathway employs pyruvate formate lyase encoded by the E. coli tdcE gene or the Clostridium difficile pflB gene for the direct conversion of 2-ketobutyrate into propionyl-CoA. As the direct conversion of 2-ketobutyrate into propionyl-CoA could not support the efficient production of P(3HB-co-3HV) from glucose, the first metabolic pathway was further examined. When the recombinant E. coli XL1-blue strain equipped with citramalate pathway expressing the E. coli poxB L253F V380A gene and R. eutropha prpE gene together with the R. eutropha PHA biosynthesis genes was cultured in a chemically defined medium containing 20 g/L of glucose as a sole carbon source, P(3HB-co-2.3 mol% 3HV) was produced up to the polymer content of 61.7 wt.%. Moreover, the 3HV monomer fraction in P(3HB-co-3HV) could be increased up to 5.5 mol% by additional deletion of the prpC and scpC genes, which are responsible for the metabolism of propionyl-CoA in host strains.     

ASPECTS OF THE BIOLOGY OF THE GIANT FORM OF STHENOTEUTHIS OUALANIENSIS CEPHALOPODA: OMMASTREPHIDAE) FROM THE ARABIAN SEA

An investigation was carried out on the recently discovered‘giant’ extra large (XL) form of the squid Sthenoteuthisoualaniensis from the Arabian Sea. The sample consisted of 2males, which have not been previously described, and 13 females.Diet composition, parasite loading, sucker ring dentition, biolumi-nescenceand sexual dimorphism were examined and compared to known parametersof the medium (M) form. Reproductive strategy, potential fecundity,egg size distribution in the ovary and oviducts were examinedin mature XL females. Evidence of multiple spawning in the giantform was also investigated. Overall body shape, bioluminescentstructures and coloration of the giant form were similar tothe M form, though the XL form had a smaller fin angle thanthe M form. The mature female XL form has a dorsal mantle lengthabout twice that of a mature female M form. Adult females ofthe XL form have a dorsal mantle length about twice that ofadult males of the same form. Differences between males andfemales were found in arm sucker ring dentition and parasiteload, suggesting a difference in diet. This could be linkedto size differences between the sexes. A strong correlationbetween ovary mass and mantle length was found (r² = 0.64).Poor correlation was found between mantle length and oviductmass (r² = 0.128) and potential fecundity (r² = 0.07). Potentialfecundity ranged between 2–5 million eggs and the holdingcapacity of the oviducts was approximately 300, 000 eggs. Thiscombined with the presence of spermatangia and the presenceof food in the stomach suggest that the XL form is a multiplespawner. S. oualaniensis appears to have a plastic phenotypeand has adapted to the Arabian Sea conditions by evolving thecapacity to grow to a giant size. (Received 6 November 1996; accepted 15 February 1997)     

Aseptic rearing of Epiphyas postvittana (Lepidoptera: Tortricidae) on a meridic diet

The light brown apple moth, Epiphyas postvittana (Walker), was reared aseptically from newly hatched larvae to adults for three generations on a meridic diet. Growth and development on this diet were comparable with that on oligidic diets and on host‐plants. At 25 ± 1°C, 50–60% R.H., and 12‐h photophase, the average larval period was approx. 28 days, pre‐pupal and pupal 11–12 days, and pre‐oviposition approx. 2 days; the incuva‐tion period of eggs was approx. 7 days. The average developmental period from egg to adult was thus about 49 days; 89 % of larvae reached the adult stage. The average fecundity was 598 eggs per female, and the sex ratio was nearly 1:1. There were no differences in the rate of development or in fecundity of insects reared on media with and without a mould inhibitor.     

Cloning,screening and characterization of enantioselective ester hydrolases from <Emphasis Type="Italic">Escherichia coli</Emphasis> K-12

Thirty-one ester hydrolases were cloned from Escherichia coli K-12 and an efficient screening strategy was applied to screen and characterize them, emphasizing on their enantioselectivity. We are the first to investigate the enantioselectivity of these enzymes, although their activity had been reported by other researchers. The enzyme XL3 from gene b0349, XL10 from gene b0494, XL15 from gene b3412, XL27 from gene b2154 and XL31 from gene b3825 exhibited high activity towards p-nitrophenyl esters with short chain. The enzyme XL15 from gene b3412 was demonstrated for the first time to show high enantioselectivity to (R)-1-phenylethyl acetate both in hydrolysis and esterification with enantioselectivity value (E) > 100 at the conversion of 31.2 and 36.8%, respectively.     

Asthma and COPD in cystic fibrosis intron-8 5T carriers. A population-based study

Background

Carriers of cystic fibrosis intron-8 5T alleles with high exon-9 skipping could have increased annual lung function decline and increased risk for asthma or chronic obstructive pulmonary disease (COPD).

Methods

We genotyped 9131 individuals from the adult Danish population for cystic fibrosis 5T, 7T, 9T, and F508del alleles, and examined associations between 11 different genotype combinations, and annual FEV₁ decline and risk of asthma or COPD.

Results

5T heterozygotes vs. 7T homozygous controls had no increase in annual FEV₁ decline, self-reported asthma, spirometry-defined COPD, or incidence of hospitalization from asthma or COPD. In 5T/7T heterozygotes vs. 7T homozygous controls we had 90% power to detect an increase in FEV₁ decline of 8 ml, an odds ratio for self-reported asthma and spirometry-defined COPD of 1.9 and 1.7, and a hazard ratio for asthma and COPD hospitalization of 1.8 and 1.6, respectively. Both 5T homozygotes identified in the study showed evidence of asthma, while none of four 5T/F508del compound heterozygotes had severe pulmonary disease. 7T/9T individuals had annual decline in FEV₁ of 19 ml compared with 21 ml in 7T homozygous controls (t-test:P = 0.03). 6.7% of 7T homozygotes without an F508del allele in the cystic fibrosis transmembrane conductance regulator gene reported asthma vs. 11% of 7T/9T individuals with an F508del allele (χ²:P = 0.01) and 40% of 7T homozygotes with an F508del allele (P = 0.04). 7T homozygotes with vs. without an F508del allele also had higher incidence of asthma hospitalization (log-rank:P = 0.003); unadjusted and adjusted equivalent hazard ratios for asthma hospitalization were 11 (95%CI:1.5–78) and 6.3 (0.84–47) in 7T homozygotes with vs. without an F508del allele.

Conclusion

Polythymidine 5T heterozygosity is not associated with pulmonary dysfunction or disease in the adult Caucasian population. Furthermore, our results support that F508del heterozygosity is associated with increased asthma risk independently of the 5T allele.     

Genetic analysis of female mating recognition between Drosophila ananassae and Drosophila pallidosa: application of interspecific mosaic genome lines

Drosophila ananassae and Drosophila pallidosa are closely related species that can produce viable and fertile hybrids of both sexes, although strong sexual isolation exists between the two species. Females are thought to discriminate conspecific from heterospecific males based on their courtship songs. The genetic basis of female discrimination behavior was analyzed using isogenic females from interspecific mosaic genome lines that carry homozygous recombinant chromosomes. Multiple regression analysis indicated a highly significant effect of the left arm of chromosome 2 (2L) on the willingness of females to mate with D. ananassae males. Not only 2L but also the left arm of chromosome X (XL) and the right arm of chromosome 3 (3R) had significant effects on the females' willingness to mate with D. pallidosa males. All regions with strong effects on mate choice have chromosome arrangements characterized by species-specific inversions. Heterospecific combinations of 2L and 3R have previously been suggested to cause postzygotic reproductive isolation. Thus, genes involved in premating as well as postmating isolation are located in or near chromosomal inversions. This conclusion is consistent with the recently proposed hypothesis that "speciation genes" accumulate at a higher rate in non-recombining genome regions when species divergence occurs in the presence of gene flow.     

Chromosomal polymorphism in the populations of malaria mosquito <Emphasis Type="Italic">Anopheles messeae</Emphasis> (Diptera,Culicidae) in the Volga region

We studied the species composition and chromosomal variability of malaria mosquitoes in the Volga Basin (Upper, Middle, and Lower Volga regions). We investigated larvae karyotypes of sibling species of the Anopheles maculipennis group. We calculated the frequencies of chromosomal inversions in the local populations of the dominant species An. messeae. We discovered that karyotypic structure of An. messeae populations depends on landscape-climatic zones. Populations of the Upper, Middle and Lower Volga differ in frequency of chromosome inversions XL, 2R, 3R, and 3L.     

Reproductive and growth strategies of the red roach, Rutilus arcasii (Steindachner, 1866), in two contrasting tributaries of the River Duero, Spain

The life-histories of red roach were assessed in the R. Moros and the R. Ucero, two contrasting tributaries of the R. Duero. Growth occurred from April to October and Ucero red roach were larger than those in the Moros from their second year onwards. Condition increased with gonad development and abruptly decreased after spawning in both populations. The condition of Ucero fish recovered during the summer, but that of the Moros fish remained low. The same year classes (1980 and 1982) dominated both populations. River Moros red roach spawned in a 4-week period between the end of April and early June, while the spawning season of Ucero red roach lasted until August. The length to fecundity relationship was similar for both populations, and fecundity and ovum size increased with fish length. The life-history traits of these red roach populations are discussed in relation to current life-history theories.     

Effect of induced chromosomal rearrangements on the fertility and viability of Anopheles atroparvus

Partial sterility in 3 strains of malarial mosquito Anopheles atroparvus with heterozygous chromosomal rearrangements In2(R;L) 1+In2L1; In3(R;L) 1+D3R1; T(2R;3R)1 was studied. Fertility of these lines was decreased 2.5 to 5 times, as compared with the control. No homozygotes for rearrangements were detected. Causes for partial sterility of insects with heterozygous insertions, translocations and the significance of constructing homozygous strains are discussed.     

Enhanced hydrogen production by Rhodopseudomonas palustris CQK 01 with ultra-sonication pretreatment in batch culture

In the present study, the photo-hydrogen production performances by Rhodopseudomonas palustris CQK 01 growing from the inoculated cells with ultra-sonication pretreatment (R. palustris CQK 01-USP) were experimentally investigated in batch culture and compared with that without pretreatment (R. palustris CQK 01-NP). It was found that the ultra-sonication pretreatment modified membrane morphology and broke up part of the cells, resulting in improvement of membrane permeability and bacterial activities and hence, helping the improvement of hydrogen production. The hydrogen production rate, hydrogen yield and energy conversion efficiency with R. palustris CQK 01-USP were increased to be nearly 2 times higher than that with R. palustris CQK 01-NP. The parametric study showed that under the conditions of initial glucose concentration 50 mmol/l, inoculum size 12%, illumination wavelength 590 nm, the photobioreactor with R. palustris CQK 01-USP obtained the optimal hydrogen production rate 0.54 mmol/l/h, hydrogen yield 1.2 mol-H₂/mol-glucose and energy conversion efficiency 9.03%.     

Pyrrolo[1,4]benzodiazepine antibiotics. Biosynthesis of the antitumor antibiotic 11-demethyltomaymycin and its biologically inactive metabolite oxotomaymycin by Streptomyces achromogenes.

11-Demethyltomaymycin, an antitumor antibiotic produced by Streptomyces achromogenes, and its biologically inactive metabolite oxotomaymycin are biosynthesized from L-tyrosine, DL-tryptophan, and L-methionine. The anthranilate part of 11-demethyltomaymycin is derived from tryptophan probably via the kynurenine pathway. The predominant loss of tritium from DL-[5-3H]tryptophan, during its conversion to 11-demethyltomaymycin and oxotomaymycin is interpreted to mean by NIH shift rules, that the main pathway to the 5-methoxy-4-hydroxy anthranilate moiety is through hydroxylation at C-8 prior to hydroxylation at C-7. The methoxy carbon is derived from the S-methyl group of methionine by transfer of an intact methyl group. The ethylideneproline moiety of 11-demethyltomaymycin is biosynthesized from tyrosine, without a 1-carbon unit from methionine. The results of biosynthetic feeding experiments with L-[1-14C, 3- or 5-3H]tyrosine are consistent with a "meta" or extradiol cleavage of 6,7-dihydroxycyclodopa as has also been demonstrated previously for anthramycin and lincomycin A. An experiment in which L-[1-14C, Ala-2,3-3H]tyrosine was fed showed that both the beta hydrogens of this amino acids are retained in 11-demethyltomaymycin. It has been demonstrated in cultures and washed cell preparations that 11-demethyltomaymycin is enzymatically converted to oxotomaymycin by an intracellular constitutive enzyme. Conversion of oxotomaymycin to 11-demethyltomaymycin by these same preparations could not be demonstrated. The enzymatic activity associated with the conversion of 11-demethyltomaymycin to oxotomaymycin is not limited to the 11-demethyltomaymycin to oxotomaymycin is not limited to the 11-demethyltomaymycin production phase, since trophophase cells and even cells from 11-demethyltomaymycin nonproducing cultures of S. achromogenes were equally active in converting 11-demethyltomaymycin to oxotomaymycin.