[Variability of pericentromeric chromatin in chromosome 2 of ovarian nurse cells during inbreeding in Anopheles atroparvus V.Tiel]. / Izmenchivost' pritsentromernogo geterokhromatina khromosomy 2 pitaiushchikh kletok iaichnikov pri inbridinge u Anopheles atroparvus V. Tiel.

We investigated the variability of pericentromeric chromatin of chromosome 2 in ovarian nurse cells (trophocytes) in two laboratory lines of malaria mosquito Anopheles atroparvus V. Tiel and in their hybrids. One line had been raised by means of sib inbreeding, the other kept at constantly high population density. The inbreeding was shown to result in an increased percentage of chromosomes bearing an achromatinic zone in the centromeric region, which resulted in chromosome breakage. Toxicological tests demonstrated an increase in the sensitivity of the progeny of females with abnormal morphotypes of chromosome 2 to the entomopathogenic bacterium Bacillus thuringiensis israelensis. The appearance of the achromatinic zone is attributed to local chromatin underreplication accompanying chromosome polytenization. Possible reasons for this phenomenon and its implication for adaptation are discussed.

[The effect of infection by the entomopathogenic bacterium Bacillus thuringiensis on the spread of microsporidia in an inversion-polymorphic population of the malarial mosquito Anopheles messeae (Diptera: Culicidae)]. / Vliianie infitsirovaniia éntomopatogennoi bakteriei Bacillus thuringiensis na raspredelenie mikrosporidii v inversionno-polimorfnoi populiatsii maliariinogo komara Anopheles messeae (Diptera: Culicidae).

A specificity of distribution of the microsporidia Parathelohania sp. in a natural population of Anopheles messeae and in those, which survived after the treatment by subspecies Bacillus thuringiensis fukuokaensis, B. t. darmstadiensis and B. t. kyushuensis (pathotype B), were observed. The microsporidia Parathelohania sp. affected males and it did not show a genotypic specificity in control, but it had a genotypic specificity after the B. thuringiensis subspecies treatment.

[Escape reactions and variation in some genetic parameters in larva from the malaria mosquito Anopheles messeae]. / Reaktsiia izbeganiia i izmenchivost' po nekotorym geneticheskim parametram u lichinok maliariinogo komara Anopheles messeae.

The relationship between the escape response and four types of variations--inversion polymorphism, the number of denses in the stigmal plate ridges, their asymmetry, and stripe-nonstripe variation--was studied in larvae of malaria mosquito Anopheles messeae Fall. from natural populations. Pigmented individuals were shown to have a more reduced responce than nonpigmented ones. Asymmetry declined in the direction from unresponsive larvae to those repeatedly (responded). Number of denses was lower in larvae that responded once and higher in those with repeated response. In the latter, variation of this characteristic decreased substantially. The relation of the escape response to inversion polymorphism was most complicated. Larvae that responded a single time did not differe from unresponsive larvae in their chromosomal composition. Among larvae that responded twice, the proportion of heterozygotes 2R01 and 3L01, female XL11, and inversion XL2 increased, and the proportion of female XL01 decreased. Larvae of Anopheles beklemishevi were found to be less responsive than those of A. messeae. The responsiveness of A. messeae is mainly due to heterozygosity.

[The relationship of the larval behavioral traits of the malarial mosquito Anopheles messeae (Diptera: Culicidae) to its sensitivity to the entomopathogenic bacterium Bacillus thuringiensis subspecies israelensis]. / Sviaz' povedencheskikh priznakov lichinok maliariinogo komara Anopheles messeae (Diptera: Culicidae) s chuvstvitel'nost'iu k éntomopatogennoi bakterii Bacillus thuringiensis podvida israelensis.

Behavioural actions of the malarial mosquito Anopheles messeae larvae and their correlations with the susceptibility to the entomopathogenic bacterium Bacillus thuringiensis israelensis (Bti) were studied. The larvae were differentiated according to their feeding mode ("filter-feeders" and "scraper-feeders") and to their avoidance reaction on a concussion of water surface by water drops ("divers" and "undivers"). The "scraper-feeders" and "divers" showed a tendency of decreased susceptibility to Bti, while the "filter-feeders" and "undivers" did not. The presence of the white pigment (striped genotypes) on a dorsum of the larvae correlated with the reaction of avoidance and phyllotaxis but not with the susceptibility to Bti.

[Interaction between three types of variation and fluctuating asymmetry in the population of malaria mosquito Anopheles messeae Fall]. / Vzaimodeistvie trekh vidov izmenchivosti i fluktuiruiushchei asimmetrii v populiatsii maliariinogo komara Anopheles messaea Fall.

In the population of the malaria mosquito Anopheles messeae, interrelations of three types of variation (polymorphism for inversions, dorsal color of abdomen and thorax, and number of dents in the crests of the stigmal plate) and fluctuating asymmetry were studied. The presence of white pigmentation on the larval dorsum did not correlate with inversion polymorphism and fluctuating asymmetry, but correlated with the number of small and large dents in the crests of stigmal plate. Asymmetry was shown to have a weak positive correlation with the number of dents. In larvae having a small number of dents, a decrease in the frequency of autosomal homozygotes 3R00 and an increase in the frequency of autosomal heterozygotes 3R01 were found. The dents in the crests of the stigmal plate had two morphological forms: a large one, which is associated with arms 2R and XL, and a small one, which is associated with arms 3R, XL, and 3L. Correlation between inversion polymorphism and bilateral (fluctuating) asymmetry was more complex. The group of individuals with a difference by one dense differed from that with a difference by three or more dents in the frequency of chromosome sequences XL0, XL1, and 2R0. Chromosome sequences XL1, 2R0, 3R0, and 3L1 were classified as those increasing the developmental stability of individuals; XL2, XL0, 2R1, 3R1, and 3L0, as those decreasing it.

[Distribution of natural parasites--fungi and microsporidia--in a population of malarial mosquito larva (Diptera: Culicidae) before and after infection by the entomopathogenic bacteria Bacillus thuringiensis israelensis]. / Raspredelenie estestvennykh parazitov--gribov i mikrosporidii--v populiatsii lichinok maliariinykh komarov (Diptera: Culicidae) do i posle infitsirovaniia éntomopatogennoi bakteriei Bacillus thuringiensis israelensis.

The distribution specificity of fungi and microsporidies in natural population of Anopheles messeae Fall. and A. beklemishevi Stegny et Kab. and those which survived after treatment them by Bacillus thuringiensis israelensis (Bti) were observed. Parasitic fungus nonselectively affected individuals of both species and all inversion genotypes of A. messeae. Microsporidia Parathelohania messeae affected males and it has not species and genotypic specificity. The 4-th instar larvae of both species infected by parasitic fungus after treatment them by Bti did not survive. The level of microsporidian infection of A. messeae and A. beklemishevi after Bti treatment was reduced from 1.1 +/- 0.5 to 0.5 +/- 0.3% and from 1.3 +/- 1.3 to 0.7 +/- 0.5% accordingly. A. beklemishevi was registered as Parathelohania messeae host for the first time. The harmonious relationships between malaria mosquitoes and their parasites in natural populations may be destructed by the Bti treatments.

[Sensitivity of larvae of the malaria mosquito Anopheles messae with various inversion genotypes to the entomopathogenic bacteria Bacillus thuringiensis israelensis as a function of dose]. / Chuvstvitel'nost' lichinok maliariinogo komara Anopheles messaea s raznymi inversionnymi genotipami k éntomopatogennoi bakterii Bacillus thuringiensis israelensis v zavisimosti ot dozy.

The influence of the entomopathogenic bacterium Bacillus thuringiensis israelensis (Bti) on the chromosomal composition of a natural population of fourth instar larvae of the malaria mosquito (Anopheles messeae Fall.) was investigated. The two doses used in the experiment yielded different death rates. A dose of 6.17 micrograms Bti per 1 mg of host mass led to a death rate of 41.1 +/- 3.0%. The chromosomal composition of the population remained unchanged, but the proportion of XL11-2R11 females decreased, and the diversity of genotypes increased due to a slight increase in proportions of heterozygotes 2R01 and 3R01. A dose of 12.34 micrograms/mg caused a death rate of 71.9 +/- 2.7%. The percentages of chromosomal variants XL1(2), 2R1, 3R1, and 3L1, as well as heterozygotes 2R01 and 3R01, decreased, thereby lessening the diversity of inversion genotypes in the population. The pathogen-related mortality is considered a quantitative index of the selection strength.

[The effect of Culex family mosquito larva on the sensitivity of Anopheles mosquitos with various karyotypes to the entomopathogenic bacteria Bacillus thuringiensis subsp. Israelensis]. / Vliianie lichinok komarov roda Culex na chuvstvitel'nost' komarov roda Anopheles s razlichnymi kariotipami k éntomopatogennoi bakterii Bacillus thuringiensis subsp. Israelensis.

Culex (C. modestus) and Anopheles (A. beklemishevi and A. messeae) larvae mosquito were treated with Bacillus thuringiensis subsp. israelensis (Bti) bacterium together and separately. It was determined that the presence of C. modestus reduced the mortality of Anopheles larvae and altered the results of the selection of genotypes resistant to Bti of the polymorphic species of A. messeae, C. modestus larvae consumed the pathogen more rapidly and protected the sensitive individuals of A. messeae with "northern" chromosomal inversions from destruction. The correlation of the selection of cohabiting Anopheles and Culex mosquitoes as well as the relation between the specific diversity and the stability of communities are discussed.

[Inversion polymorphism in the malaria mosquito Anopheles messeae. XI. The group effect of larval infection with Bacillus thuringiensis subsp. israeliensis bacteria]. / Inversionnyi polimorfizm maliariinogo komara Anopheles messeae. Soobshchenie XI. Gruppovoi éffekt pri infitsirovanii lichinok bakterei B.Th.s.i.

Genetic consequences of the group and individual infections of Anopheles messeae larvae with bacteria Bacillus thuringiensis subsp. israelensis (Bti) were examined. The group effect of infections was manifested by increase in mortality and the speed-up of selection of chromosomal inversions resistant to Bti. Connection between the group and individual selections during the process of populations' adaptation is under discussion.

[Search for producers of restriction endonucleases with a given specificity]. / Poisk produtsentov éndonukleaz restriktsii zadannoi spetsifichnosti.

Six site-specific restriction endonucleases were isolated from Bacillus thuringiensis strains chosen of 58 strains ought purposefully for production of restriction enzymes. All six strains produce isoschisomers of Sau3A.

[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)]. / Inversionny i polimorfizm maliariinogo komara Anopheles messeae. Soobshchenie X. Ustoichivost' lichinok s raznymi genotipami k toksinam kristalloobrazuiushchei bakterii 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.