Search

The relationship between the type of melanin-based plumage coloration and the strength of experimentally induced immune response was studied using as an example a pied flycatcher population from the Moscow Region. The plumage of pied flycatcher males exhibits the full spectrum of transitions from contrasting black-and-white to cryptic brownish, the latter being very similar to the coloration of females. In spite of numerous studies, the nature of this polymorphism still remains vague. Unlike many other avian species with monocyclic breeding, a considerable fraction of pied flycatchers combines two energy-consuming productive processes, breeding and molt. During the main experimental treatment we activated the humoral immunity of free-living males in chick-rearing period by injection of nonpathogenic multigenic antigen (sheep red blood cells, SRBC) and estimated the strength of the immune responses after repeated captures in 6-8 days. In addition, after each capture we estimated the numbers of leucocytes (WBC), heterophil to lymphocyte ratios (H/L) and measured night time basal metabolic rates (BMR). Non-molting males of different color types showed the same immune responses. Among molting birds, the strength of the immune response was significantly higher in pale males (morphs 4-7 by Drost's scale) than in bright males with rich melanin-based coloration (morphs 2-3). This difference resulted from two opposite processes. During molting, pale males heightened the antibody titer after immunization, while bright males tended to reduce the strength of immune response. Possibly such an asymmetry in immunocompetence at the first stage of molt reflects the different life strategies of pied flycatcher males - conspicuous birds less commonly combine breeding with molt than cryptic ones.

Estimates of a trait heritability and repeatability can get at an idea of its usefulness for being an individual characteristic and its ability to change under selection pressure. Heritability and repeatability of energetic parameters still poorly studied in birds. The most important physiological characteristic of homoiotherms is resting metabolic rate (RMR), which, in the absence of productive processes, does not exceed basal metabolic rate (BMR). We estimated BMR repeatability in free-living pied flycatchers in Moscow Region (55 degrees 44' N, 36 degrees 51' E; 1992-2008) and Tomsk (56 degrees 20' N, 84 degrees 56' E; 2008-2009) populations over intervals from 40 days to 3 years. In Moscow Region population, BMR repeatability amounted to tau = 0.34 +/- 0.10 (n=80) if measured over 1 year interval, tau = 0.60 +/- 0.15 (n=19) if measured over 2 years interval, and tau = 0.85 +/- 0.13 (n=6) if measured over 3 years interval providing that consecutive BMR measurements were done in the same period of reproductive season. In Tomsk population, BMR repeatability, measured over 1 year interval, amounted to tau = 0.49 +/- 0.11 (n=50). Repeatability is a measure of a trait constancy and sets the upper limit of its heritability. To estimate RMR heritability, cross-fostering experiments have been conducted in 2003-2005 with flycatchers of Moscow Region population. RMR of chicks positively correlated with BMR of their biological fathers, whereas such correlation in metabolic rates between chicks and their foster fathers was absent. The RMR heritability estimate turned out to be h2 = 0.43 +/- 0.17 (n=210). The obtained estimates of heritability and repeatability of fundamental energetic traits are rather high for physiological features. This suggests the existence of a potential for direct selection on BMR and evolutionary stable diversity of avian populations with regard to basal metabolic rate.

Natural populations of Drosophila melanogaster and Hirundo rustica that reside at the territories with different levels of radioactive pollution were investigated. The levels of visible mutations, sex-linked mutations and gonad reduction of Drosophila and the rate of interphase markers of chromosomal instability in erythrocytes of birds were selected as parameters for population monitoring. The results point out to possible reverse dependence among the level of chromosomal instability of birds, the rate of lethal mutations in sex chromosome of Drosophila and the density of radioactive pollution.

RAPD-PCR analysis of genetic variability of carrion crows, hooded crows and their phenotypic hybrids from the zones of overlap of their areals and hybridization of parental forms in Siberia has been carried out. According to RAPD variability the following parameters were estimated for both species and their hybrids: genetical distances (DN), polymorphism (P95), mean expected heterozygosity (H(e)), gene fixation coefficient (Fst) and the portion of interpopulation differentiation (Gst). It was shown that the rate of genetic variability in carrion crows and hooded crows is less than in the hybrids. It turned out that the hybrids were genetically closer to each other (DN = 0.295) than to both parental species (DN = 0.441 and 0.397 with C. corone and C. cornix, correspondingly). The studied individuals of C. cornix show the minimal level of heterozygosity and polymorphism (H(e) = 0.12 and P95 = = 27.8%) in comparison with C. corone and the crows of hybrid zone (H(e) = 0.18 and 0.20; P95 = 42.6% and 50.4%, correspondingly). Right's indexes of inbreeding (Fst = 0.285) and population spliting (Gst = 0.352) indicate low genetic variability in all the analysed birds. Nevertheless UPGMA and NJ dendrogrammes differentiate the individuals from the areals of carrion crows, hooded crows and from hybrid zone to different clusters. Our data correlate with molecular-genetic investigations of Corvidae carried out with other methods, and do not contradict the conception of carrion crows and hooded crows as semispecies in the context of the conception of overspecies.

RAPD-PCR analysis of the genetic diversity of the carrion crow (Corvus corone) and jungle crow (C. macrorhynchos) living in the continental parts of their species ranges and on some Russian and Japanese Far Eastern islands has been performed. Taxon-specific molecular markers have been found for each species. The genetic diversity of the carrion crow is considerably less than that of the jungle crow at the same genetic distance (P95 = 68.2%, DN = 0.27 and P95 = 88.4%, DN = 0.24, respectively). In both species, the genetic polymorphism of island samples is almost two times greater than that of continental samples (62 and 31.8%, respectively, for C. corone and 81.5 and 47.2%, respectively, for C. macrorhynchos). In addition, differences in genetic diversity between males and females (P95 = 55.1 and P95 = 72.1, respectively) has been found in the carrion crow but not in the jungle crow. The gene diversity of C. macrorhynchos is greater than that of C. corone: the mean numbers of alleles per locus are 2 and 1.81, effective numbers of alleles are 1.62 and 1.43, and the mean expected heterozygosities are 0.39 and 0.30, respectively. The phenograms and phylograms significantly segregate the clusters of the carrion and jungle crows. The clustering patterns of carrion crows corresponds to the intraspecies taxonomic and geographic differentiation: subspecies C. c. corone and C.c. orientalis living in the western and eastern parts of the species range, respectively, form different subclusters. The cluster of the jungle crow does not exhibit differentiation into subspecies C. m. mandshuricus and C. m. japonensis; molecular genetic differences between them are small.

A novel repeated sequence of chaffinch (Fringilla coelebs) designated as GS was isolated from genomic DNA after in vitro amplification of satellite DNA sequences using GSP-PCR technique. The proportion of this repeat in the chaffinch genome constitutes about 2%. Monomers are 176 to 199 bp in size and contain a short cluster of the TTAGGG telomeric tandem repeat. The oligomer of the telomeric hexanucleotide is flanked by the sequences that are significantly different in different monomers. The GS sequences are organized as tandemly repeated units and located in a number of chromomycin-positive blocks on the long arms of macrochromosomes 1, 2, 3, 5, and 6, as well as on several microchromosomes. The sequences homologous to the GS satellite of chaffinch were not found in the genomes of redwing (Turdus iliacus) and house sparrow (Passer domesticus).

Karyotypes were studied in the hooded and carrion crows, their naturally occurred hybrids, the jungle crow, the azure-winged magpie (2n = 80 in all aforementioned birds), and the magpie (2n = 82). Corvine birds of Primorskii Krai were karyotyped for the first time. In addition to the similarity in the diploid chromosome sets, corvine birds were shown to have a similar structure of karyotype: in all studied birds, 14 macrochromosomes (Mchs) classified into three groups according to their size were detected. By karyotype structure, birds belonging to the same genus are similar. Some intergeneric differences are due to a change in the position of centromeres of the largest and sex chromosomes. Karyotypes of interspecific hybrids of crows are remarkable for the presence of heteromorphic (t/st) chromosome pair 2 in some individuals, which apparently does not affect their fecundity. Using differential C-banding, the sex chromosome W in female magpies was identified. In addition, heteromorphism was detected in C-bands of homologs of Mch pair 4 in the hooded crow. In the jungle crow, the azure-winged magpie, and the magpie, bright QH-bands and numerous G-bands were detected on Mchs and on some microchromosomes only. Active Ag-NOR-bands were detected on one macrochromosome pair in the magpie. In all, the karyotype structure of corvine birds is comparable to the basic structural scheme of the karyotype in the order Passeriformes, which confirms the concept of conservatism of the avian karyotype.

To establish phylogenetic relationships within the corvine birds at the interspecific and intergeneric levels, the sequence of the mitochondrial DNA cytochrome b gene was analyzed. The NJ, UPGMA, and MP trees showed similar clustering. Relationships between the jungle crow, on the one hand, and the rook and Australian raven, on the other hand, were closer than between the jungle crow and the hooded and carrion crows. Mitochondrial genome of Australian raven displayed the closest similarity to the ancestral genome of the genus Corvus. Populations inhabiting the eastern part of the carrion crow C. corone orientations area were statistically significantly subdivided into three lineages. These data also confirmed the hypothesis on the location of the carrion crow ancestral lineage in the southeastern part of the area. In general, the transition and transversion substitution levels, their relationships, and distribution over codon positions were similar to that already reported for birds. Synonymous transitions in the third codon position were the prevailing substitution type. Using standard calibration scales, the time of divergence between species and genera within the corvine family was estimated to be 3.1-4 and 3.8-8.8 Myr, respectively. The divergence time between the examined corvine birds and birds of paradise constituted from 8 to 10 Myr.

Distribution of mitochondrial DNA cytochrome b gene haplotypes in two crow species was examined by means of sequencing of the 336-bp gene fragment. The topology of the NJ and UPGMA trees showed that the carrion crow range was split into two parts due to the presence of significantly diverged ancestral lineage localized in the southeastern part of the range. The carrion crow populations, inhabiting a territory ranging from France to northern Sakhalin, along with interspersed hooded crow populations and hybrid Siberian populations, shared a common haplotype. The border between two carrion crow lineages revealed is located in central Sakhalin. The subdivision of two weakly differentiated lineages within the jungle crown range, also observed within this territory, coincided with the subspecies division of this species. The estimated genetic distances indicate the isolation of the subgenus Coloeus. These data also suggest the convergent similarity between the chough Pyrrhocorax pyrrhocorax and the Corvus genus, as well as the conspecificity of Corvus corone corone and C. c. cornix.