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The Nivkhs are a small ethnic group indigenous of the Russian Far East, living in the Khabarovsk Territory and on Sakhalin Island, descending from the ancient inhabitants of these territories. In the Nivkhs, a specific Sakhalin-Amur anthropological type is prevalent. They are quite isolated, due to long isolation from contacts with other peoples. The gene pool of the Nivkhs and other Far Eastern and Siberian populations was characterized using a genome-wide panel of autosomal single-nucleotide polymorphic markers and Y chromosome haplogroups. Bioinformatic processing of frequencies of autosomal SNPs, Y chromosome haplogroups and YSTR haplotypes showed that the Nivkh gene pool is very different from the other populations’. Analysis of the SNP frequencies using the PCA method divided the Far Eastern populations in full accordance with the territories of their residence into the northern group of the Chukchi and Koryaks and the southern group, including the Nivkhs and Udege. The remoteness of the Nivkhs coincides with their geographic localization, with the Nivkhs and Udege demonstrating the greatest kinship. The Nivkhs have a specific component of their gene pool, which is present with much less frequency in the Udege and Transbaikal Evenks. According to the IBD blocks, the genotypes of the Nivkhs show a very small percentage of coincidence with the Udege, Koryaks, Evenks and Chukchi, the value of which is the lowest compared to the IBD blocks among all other Siberian populations. The Nivkh-specific composition of haplogroups and YSTR haplotypes was shown. In the Nivkhs, the C2a1 haplogroup is divided into three sublines, which have a fairly ancient origin and are associated with the ancestors of modern northern Mongoloids. The Nivkh haplogroup O2a1b1a2a-F238 is found among residents of China and Myanmar. The Q1a1a1-M120 line is represented among the Nivkhs, Koryaks, Evenks and Yukaghirs. Phylogenetic analysis of individual Y chromosomal haplogroups demonstrated the closeness of the Nivkh gene pool with the ancient population of the Amur and Okhotsk regions, the Koryaks, the Tungus peoples and the population of Southeast Asia. The Nivkh gene pool confirms the relative smallness of their ancestral groups without mixing with other populations.

In order to clarify the history of gene pool formation of the indigenous populations of the Northern Priokhotye (the northern coast of the Sea of Okhotsk), Y-chromosome polymorphisms were studied in the Koryaks and Evens living in the Magadan region. The results of the study showed that the male gene pool of the Koryaks is represented by haplogroups C-B90-B91, N-B202, and Q-B143, which are also widespread in other peoples of Northeastern Siberia, mainly of Paleo-Asiatic origin. High frequency of haplogroup C-B80, typical of other Tungus-Manchurian peoples, is characteristic of the Evens of the Magadan region. The shared components of the gene pools of the Koryaks and Evens are haplogroups R-M17 and I-P37.2 inherited as a result of admixture with Eastern Europeans (mainly Russians). The high frequency of such Y chromosome haplogroups in the Koryaks (16.7 %) and Evens (37.8 %) is indicative of close interethnic contacts during the last centuries, and most probably especially during the Soviet period. The genetic contribution of the European males’ Y chromosome significantly prevails over that of maternally inherited mitochondrial DNA. The study of the Y chromosome haplogroup diversity has shown that only relatively young phylogenetic branches have been preserved in the Koryak gene pool. The age of the oldest component of the Koryak gene pool (haplogroup C-B90-B91) is estimated to be about 3.8 thousand years, the age of the younger haplogroups Q-B143 and N-B202 is about 2.8 and 2.4 thousand years, respectively. Haplogroups C-B90-B91 and N-B202 are Siberian in origin, and haplogroup Q-B143 was apparently inherited by the ancestors of the Koryaks and other Paleo-Asiatic peoples from the Paleo-Eskimos as a result of their migrations to Northeast Asia from the Americas. The analysis of microsatellite loci for haplogroup Q-B143 in the Eskimos of Greenland, Canada and Alaska as well as in the indigenous peoples of Northeastern Siberia showed a decrease in genetic diversity from east to west, pointing to the direction of distribution of the Paleo-Eskimo genetic component in the circumpolar region of America and Asia. At the same time, the Evens appeared in the Northern Priokhotye much later (in the XVII century) as a result of the expansion of the Tungusic tribes, which is confirmed by the results of the analysis of haplogroup C-B80 polymorphisms.

The incidence and mortality of malignant neoplasms of non-reproductive organs both carcinomas and sarcomas in men is one and a half times higher than in women. This is based on genetic differences, which are superimposed by patterns of epigenetic regulation of the expression of sex chromosome genes that determine sex differences in the processes of tissue differentiation, which, in turn, mediates the formation of the hormonal status of the body. Compared to the Y chromosome, the mammalian X chromosome contains several dozen times more genes encoding major regulators of proliferation, metabolism, immunity, and tumor growth inhibitors, as well as X-linked microRNAs affecting transcription factors and cross-regulation by other non-coding RNAs. This results in a female or male gene expression profile that accounts for phenotypic differences. This peculiarity, along with the fact that in female cells on the second inactivatedX chromosome epigenetic repression of the most important genes is reversed and, accordingly, their expression level is doubled, may largely explain the sex disparity in carcinogenesis. The influence of sex hormones and disparity in the expression of antitumor immunity contribute significantly to this difference. A detailed study of the mechanisms underlying sex dimorphism in carcinogenesis will be an essential contribution to fundamental oncology and to the practice of diagnosis, prognosis and personalized treatment of malignances with regard to their gender-specific course. These studies are especially relevant in relation to insufficiently studied soft tissue sarcomas, the ratio of the frequencies of which in men and women varies greatly depending on the histological subtype of the tumor.

The results of studies in Quaternary geology, archeology, paleoanthropology and human genetics demonstrate that the ancestors of Native Americans arrived in mid-latitude North America mainly along the Pacific Northwest Coast, but had previously inhabited the Arctic and during the last glacial maximum were in a refugium in Beringia, a land bridge connecting Eurasia and North America. The gene pool of Native Americans is represented by unique haplogroups of mitochondrial DNA and the Y chromosome, the evolutionary age of which ranges from 13 to 22 thousand years. The results of a paleogenomic analysis also show that during the last glacial maximum Beringia was populated by human groups that had arisen as a result of interaction between the most ancient Upper Paleolithic populations of Northern Eurasia and newcomer groups from East Asia. Approximately 20 thousand years ago the Beringian populations began to form, and the duration of their existence in relative isolation is estimated at about 5 thousand years. Thus, the adaptation of the Beringians to the Arctic conditions could have taken several millennia. The adaptation of Amerindian ancestors to high latitudes and cold climates is supported by genomic data showing that adaptive genetic variants in Native Americans are associated with various metabolic pathways: melanin production processes in the skin, hair and eyes, the functioning of the cardiovascular system, energy metabolism and immune response characteristics. Meanwhile, the analysis of the existing hypotheses about the selection of some genetic variants in the Beringian ancestors of the Amerindians in connection with adaptation to the Arctic conditions (for example, in the FADS, ACTN3, EDAR genes) shows the ambiguity of the testing results, which may be due to the loss of some traces of the “Beringian” adaptation in the gene pools of modern Native Americans. The most optimal strategy for further research seems to be the search for adaptive variants using the analysis of paleogenomic data from the territory of Beringia, but such genetic data are still very scarce.

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study objective is to evaluate the significance of the Y chromosome microdeletions for prediction of spermatozoa retrieval during testicle biopsy in men with severe azoospermia and oligozoospermia.Materials and methods. In total, 109 men aged 21 to 56 years (mean age 32.7 ± 0.2 years) with infertility in marriage were examined. Cytogenetic, special andrological, spermiological, and molecular genetic examinations were performed to evaluate non-genetic and genetic causes of infertility.Results. Normal karyotype and absence of AZF deletions were found in 75 men, presence of deletions – in 34. The frequencies of pathozoospermia forms were comparable in these groups. Spermatozoa were retrieved during biopsy in 47 (62.7 %) patients without Y chromosome microdeletions and only in 7 (20.6 %) patients with Y chromosome microdeletions. The men with AZF deletions were divided into 2 subgroups: men with complete AZF region deletions (n = 25) and men with partial AZF deletions (n = 9). Among men with complete deletions, azoospermia was diagnosed in 25 (100 %), spermatozoa were retrieved during biopsy in 2 (8 %); among men with partial deletions, azoospermia was diagnosed in 7 (77.8 %), severe oligozoospermia in 2 (22.2 %), spermatozoa were retrieved during biopsy in 5 (56 %). Then the patients were divided according to another criterion: 54 patients from whom spermatozoa were retrieved during biopsy and 55 men with negative results. Among patients with successful result of biopsy, Y chromosome microdeletions were identified in 7 (13 %); among patient with negative biopsy result – in 27 (49 %) (р < 0.01).Conclusion. Success rate of spermatozoa retrieval during testicle biopsy is significantly higher in men without AZF deletions (р < 0.01) than in men with deletions. Molecular genetic examination of Y chromosome microdeletions is recommended for men with azoospermia and severe oligozoospermia because it allows diagnosing of cause male infertility and predicting.

The origin of humans and their settling around the globe are explored using various scientific methods. Genomic profiling data increasing in volume every day are of particular interest to researchers of these problems. In the current post-genomic era, a large amount of data on the genetic profiling of human ethnic groups has been accumulated, thereby making it possible to clarify the direction of human migration and distribution across the globe. Here, we have presented a method for studying and reconstructing the migration events based on the joint analysis of data on the genetic (Y chromosomal and mitochondrial markers and single nucleotide variation panel) and linguistic (grammar features) diversity of Eurasian populations. We have shown that, on the one hand, the direction of human migrations is associated with their contacts with neighboring ethnicities, and, on the other hand, the correlation coefficient of genetic and linguistic distances is closely related to and the shape of the points cloud on the scatter plots. The presence of a significant negative correlation is a reliable migration event signal. Moreover, we have described a few patterns of correlation expected between population's genetic pool and linguistic features. The study covers such a large territory (the whole Eurasia, except the southeastern area) for the first time and is based on the representative genetic and linguistic databases.

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spermatogenetic defects were analyzed in the cohort of 218 russian infertile men with various AZFc region deletions of the Y chromosome. Clear differences were found in both the percentage of pathozoospermia forms and sperm concentration between infertile men with complete (b2/b4) and partial (b2/b3 and gr/gr) AZFc deletions. Sperm concentration in the carriers of b2/b4, gr/gr and b2/b3 deletions, were 0.37 ± 0.13, 12.2 ± 7.1 and 30.3 ± 5.3 mln/ml, respectively. Severe spermatogenesis defects were detected in 93, 42 and 57 % patients with b2/b4, b2/b3 and gr/gr deletions, respectively. Quantitative karyological analysis of immature germ cells from ejaculate sediment revealed from incomplete spermatogenesis arrest at prepaсhytene stages to complete spermatogenesis depletion. Moderate oligozoospemia and/or astheno-, teratozoospermia were found in 7; 20; 30 %; and 0; 38; 10 % of the carriers of b2/b4, b2/b3 and gr/gr deletions, respectively.

Siberian Tatars form the largest Turkic-speaking ethnic group in Western Siberia. The group has a complex hierarchical system of ethnographically diverse populations. Five subethnic groups of Tobol-Irtysh Siberian Tatars (N = 388 samples) have been analyzed for 50 informative Y-chromosomal SNPs. The subethnic groups have been found to be extremely genetically diverse (FST = 21%), so the Siberian Tatars form one of the strongly differentiated ethnic gene pools in Siberia and Central Asia. Every method employed in our studies indicates that different subethnic groups formed in different ways. The gene pool of Isker-Tobol Tatars descended from the local Siberian indigenous population and an intense, albeit relatively recent gene influx from Northeastern Europe. The gene pool of Yalutorovsky Tatars is determined by the Western Asian genetic component. The subethnic group of Siberian Bukhar Tatars is the closest to the gene pool of the Western Caucasus population. Ishtyak-Tokuz Tatars have preserved the genetic legacy of Paleo-Siberians, which connects them with populations from Southern, Western, and Central Siberia. The gene pool of the most isolated Zabolotny (Yaskolbinsky) Tatars is closest to Ugric peoples of Western Siberia and Samoyeds of the Northern Urals. Only two out of five Siberian Tatar groups studied show partial genetic similarity to other populations calling themselves Tatars: Isker-Tobol Siberian Tatars are slightly similar to Kazan Tatars, and Yalutorovsky Siberian Tatars, to Crimean Tatars. The approach based on the full sequencing of the Y chromosome reveals only a weak (2%) Central Asian genetic trace in the Siberian Tatar gene pool, dated to 900 years ago. Hence, the Mongolian hypothesis of the origin of Siberian Tatars is not supported in genetic perspective.

A polymerase chain reaction-based test for rapid sex identification of the rainbow trout Oncorhynchus mykiss has been elaborated. Using the data deposited with the NCBI genome bank, nucleotide sequences of the specific sex-linked locus of salmonid species have been analyzed and the oligonucleotide primers have been selected. The length of the amplification products is 800 nucleotide pairs. Amplification specificity has been tested by nucleotide analysis of the amplicon sequences. All PCR products match the Y chromosome region housing the corresponding specific locus. A comparative analysis of the nucleotide sequences of the fragments carrying the rainbow trout (and other salmonid species) sex-linked marker demonstrates a high degree of identity, amounting to 95-99%. The maximal identity between the sequences (99%) is observed when analyzing representatives of the same genus, for example, Oncorhynchus. Thus, the sex is detectable by a simple PCR test, thereby allowing the male revertants emerging via hormonal sex reversion to be identified. This test is a rapid diagnostic method, since it requires only 1 day for testing and informing the fish farm on its results. Results of abdomen opening of rainbow trout revertants and examination of their hormonal status are also described.

A study of the properties of conditional dominant and recessive lethals in Drosophila melanogaster has demonstrated parental effects in the inheritance and manifestation of these mutations. Maternal and paternal effects are present when conditional mutations interact with (1) one another, (2) the Y chromosome, or (3) chromosomal rearrangements, as well as (4) when the visual expression of a conditional mutation is inherited or (5) during the formation ofmorphoses (monstrosities) in mutant offspring. The maternal and paternal effects do not exclude one another: the same mutation can display both patterns. The characters manifesting themselves at late developmental stages (morphoses) are inherited according to a parental effect pattern. A general concept of the parental effect is proposed and its types are classified.

The congruence between secondary sexual characters and molecular markers, linked to the Y chromosome was examined in Asian populations of five Pacific salmon species of the genus Oncorhynchus. Our results support the existence of discrepancy between secondary sexual characters and sex-linked molecular markers in all species examined, which suggests the existence of similar or identical mechanism responsible for this phenomenon in Pacific salmons. Clinal latitudinal directional variation of the character confirmed the possibility that this phenomenon could be adaptively important, including its importance for regulation of the population number. In addition to natural factors affecting the degree of discrepancy between morphobiological characters and molecular markers in the Pacific salmon populations, anthropogenic factors, in particular intense fishery of certain population or population group, is also important.

In the review, the literature evidence on DNA polymorphism obtained in the last 10-15 years using various molecular-genetic methods is summarized. All main types of DNA variation are considered but attention is focused on those extensively used in population genetics. The areas of using DNA markers are outlined and the limitations of their potential in analyzing genetic processes in populations are discussed. Particular emphasis is placed on the relationship between the earlier developed biochemical genetics based on protein polymorphism analysis and modern molecular population genetics based on DNA polymorphism. The possible role of selection in maintaining DNA variation is considered.

Molecular evolution and divergence of paralogous tandem heterochromatic repeats Stellate and Su(Ste) located on the X and Y chromosomes, respectively, are discussed. These repeats appear to emerge as a result of amplification of a unique autosomal euchromatic gene encoding the regulatory beta-subunit of the CK2 protein kinase. The autosomal gene and the clusters of heterochromatic repeats are transcribed in testes. A high level of the Stellate expression leads to partial male sterility and disturbed meiosis. The Stellate expression and its adverse effects are suppressed by homologous Su(Ste) repeats. In genome evolution, the open reading frames (ORF) of Stellate and Su(Ste) putative ancestor were maintained by translational selection. Then the coding Su(Ste) function had been damaged and switched to a new one related to antisense Su(Ste) transcription and suppression of the Stellate genes. Symmetrical (sense and antisense) Su(Ste) transcription causes the formation of a double-strand RNA, which by interference (selective switching off the homologous gene expression) suppresses the Stellate genes. The biological significance and the driving forces of evolution of the species-specific balanced interaction of Stellate and Su(Ste) repeats remain mysterious.

Using the data on five biallellic Y-chromosome loci (DYS199, 92R7, SRY1532, RBF5 and DYS287) polymorphism, genetic structures of the five Turkic-speaking ethnic groups of the Altai-Sayan highland (Tuvinians, Sojots, Shorians, Khakassians, and Southern Altaians (Altai-Kizhi), were described. The gene pools of the populations examined were characterized by the presence of pronounced paleo-Caucasoid component (92R7-T-lineages). The frequency of this component increased westward, reaching more than 70% in Shorians and Southern Altaians. Haplotype TAT-C (RBF5 locus) was observed in all populations, except Shorians, with the frequencies varying from 5.4% in Altai-Kizhi to 18.8% in Khakassians. The Alu-insertion in the DYS287 locus was revealed only in the Altaian sample with the frequency of 3.3%. It was established that the Altai-Sayan populations studied split into two statistically significantly different groups. One of the groups was represented by Tuvinians, Sojots, and Khakassians, while another one was comprised of Shorians and Altaians.

Allelic polymorphism of five microsatellite loci of the human Y chromosome (DYS19, DYS390, DYS391, DYS392, and DYS393) was analyzed in samples of male populations from Ukraine, Russia, and Belarus (152 subjects in total). The allelic diversity indices (Dg) were determined for all loci; they varied from 0.23 to 0.72. The mean values of this parameter in the Ukrainian, Russian, and Belarussian populations were 0.45, 0.47, and 0.52, respectively. A total of 53 different haplotypes were found in 152 subjects from three populations. The most frequent haplotype was found in 14.5% of the subjects, whereas 35 haplotypes (23%) were each found in only one person. The haplotypic diversity index (Dhp) was 0.94. The genetic distances between the populations studied and some populations of Western and Central Europe were estimated. These data were used to construct a phylogram (tree) of genetic similarity between the populations, which demonstrated that the three Eastern Slavic populations are genetically close to one another and remote from Western European populations.

The tandemly arranged MS4 repeat with monomeric units of 4.1 kb is species-specifically distributed in heterochromatin of sex chromosomes of four common vole species of genus Microtus, group arvalis [1, 2]. In this work, we studied the genomic organization of the MS4 homolog in euchromatin of the X chromosome of M. arvalis. It has been shown by analyzing the phage genomic clones that one MS4 copy makes a part of a monomeric unit exceeding 8.5 kb that also includes a new MS7 repeat and, possibly, LINE fragments. MS7 is located together with MS4 in heterochromatin of common vole sex chromosomes, but in a substantially lesser amount. Probably, as a result of an evolutionary transition of an original repeat from euchromatin of the X chromosome to heterochromatin of the Y chromosome, MS4 underwent multiple amplification, and MS7 spread throughout heterochromatin, being surrounded by the MS4 tandem arrays.

Nine rare (biallelic) mutations and six short tandem repeats (STR) mapping to the nonrecombining portion of the Y chromosome were genotyped in 734 males from different geographical regions inhabited by the contemporary Armenian population. The analysis of molecular variance (AMOVA) showed that 48.9% of total STR genetic variation was explained by the differences between the haplogroups isolated based on biallelic polymorphism, whereas only 1.3% of genetic variation could be attributed to the differences between the geographic groups.

Frequency distribution of several genetic markers was studied in ethnic Russians from the Moscow, Bryansk, Ryazan', Kostroma, Novgorod, Arkhangel'sk, and Sverdlovsk oblasts and Udmurtiya. Systems AB0, RH, HP, TF, GC, PI, C'3, ACP1, PGM1, ESD, GLO1, 6PGD, and AK were analyzed in most samples. New data on informative polymorphic genetic loci showed that the Russian gene pool mostly displays Caucasoid features. In addition, Y-chromosomal short tandem repeats (STRs) DYS19, DYS390, and YCAII were analyzed in the Russian samples. STRs of the chromosome are particularly valuable for elucidating ethnogenetic processes in Eastern Europe. Frequency distributions of the Y-chromosomal markers in Russians were intermediate between those of West European populations and eastern Finno-Ugric ethnoses of the Volga region. A marked longitudinal gradient was revealed for frequencies of several molecular markers.

The distribution of alleles and haplotypes of three diallellic Y-specific loci (YAP, DYF155S2, and Tat) in the populations of Kyrgyz, Uzbeks and Tajiks was analyzed. In Kyrgyzes and Uzbeks, a relatively high frequency of the DYF155S2 deletion (20 and 12.5%, respectively) and the C allele at the Tat locus (11.2 and 8.3%, respectively) were revealed. In the populations of southern Kyrgyzes and Uzbeks, two chromosomes carrying the YAP+ allele were detected. In both cases the YAP+ allele was found within the YAP+/DYF155S2+/TatT haplotype. The Tajik population was monomorphic in respect to the polymorphisms studied. The Tajiks demonstrated the presence of only the YAP-/DYF155S2+/TatT haplotype. This haplotype appeared to be most frequent in Kyrgyz (78.8%) and Uzbeks (83.3%). The question on the origin and the distribution of Y-chromosome variants in Eurasia are discussed.

Polymorphism of the DYS19 and DYS393 microsatellite loci and T-C transition at the RBF5 locus of the Y chromosome were analyzed in Volga-Ural populations of Bashkirs, Tatars, Chuvashes, Maris, Mordovians, Udmurts, and Komis. For the DYS19 locus, statistically significant differences were observed between Trans-Ural and Northeastern Bashkirs; between Trans-Ural Bashkirs and Tatars; and between Udmurts and other populations of the Volga-Ural region, excluding Trans-Ural Bashkirs. The DYS393 locus allele frequency distribution patterns were similar in all populations studied. The highest and the lowest frequencies of T-C transition at the RBF5 locus was detected in Udmurts (0.68) and in Mordovians (0.09), respectively. Association of C-alleles with the DYS19/DYS393 microsatellite haplotypes was investigated. The major haplotypes specific to the Turkic- and Finno-Ugric populations were revealed.

A study on hybrids from reciprocal crossing of the SHR-SP and the WKY has shown that Y-chromosome and mitochondrial DNA the affect development of the spontaneous hypertension. The Y-chromosome takes part in disorders of baroreceptive sensitivity in phenylnephrine assay associated with hypertension. Although our findings suggest that structural remodelling of peripheral vascular resistance and an increase in noradrenaline-dependent vasocostriction is genetically determined in hypertensive rats, we could not corroborate the role of the Y-chromosome and mitochondrial DNA in the process. A difference was shown between male and female SHR-SP in the level of arterial pressure and in development of the vascular structure changes.

The haplotype analysis of seven Y-chromosome microsatellites in three regional populations of Tuvinians revealed high intrapopulation variation in the male gene pool of the modern population of the Tuva Republic. In total, 49 haplotypes were found in 111 individuals; only four haplotypes occurred at a frequency higher than 5%. High genetic diversity (H = 0.935) suggested a high power of discrimination for the Y-chromosome haplotypes. The analysis of molecular variance (AMOVA) and other data did not reveal subdivision of the Tuvinian population with respect to Y-chromosome haplotypes. Most haplotypes found in Tuvinians formed two lines. Line A included approximately 64% of the haplotypes found, line B, approximately 24%. A putative ancestral haplotype of line B was similar to a haplotype most common in modern Caucasoids (Md = 3), whereas a putative ancestral haplotype of line A proved to be distant from the ancestral haplotype of line A and haplotypes common for Caucasoids and Mongoloids. Estimates of the age of the Y-chromosome lines showed that the male gene pool of modern Tuvinians originated in the late Paleolithic or Neolithic period. With two methods, the age of line A was estimated at 3500 or 18,000 years and the age of line B was approximately at 5500 or 15,000 years. Considering the less conservative estimates to be more reliable, line B was assumed to originate from the ancient Caucasoid population of the Tuva region. The more widespread and evolutionarily younger line A was associated with the peopling region by ancient Mongoloid tribes of the Turkic language group in the Hun-Sarmatian period.

The allele frequency distribution of seven microsatellite loci of the nonrecombining region of the Y chromosome (Y-STRs) was analyzed in three geographically distant indigenous populations of the Tuva Republic. The populations did not differ in allele frequency distribution of the seven Y-STRs. The Y-chromosome microsatellite loci in Tuvinians showed a high diversity (H = 0.575) that was nearly identical in all three populations. The genetic distance Ddm between the three populations was low, suggesting no subdivision of the modern male population of Tuva. Estimates of the period of linear changes in Ddm showed that Y-chromosome microsatellites can be used to reconstruct evolutionary events dating back no more than 40,000-50,000 years. The problems of human population phylogeny are discussed on the basis of data on Y-chromosome STRs.

An experimental procedure describing production of insertions of Y-chromosome material into autosomes of Drosophila is presented. Irradiated Y;2 translocations served as source material. The insertion selection scheme was based on the emergence of additional progeny classes in the case of independent segregation of the detached fragments of the Y chromosome and autosome. A total of seven insertions of Y-chromosome material into the left arm of chromosome 2, specifically in regions 29F, 34A, and 36B, were obtained. All insertions were lethal in the homozygous state and caused crossing-over suppression in the left arm of chromosome 2. In addition, these mutations induced the formation of loops between the chromocenter and the region of insertion, as well as breaks in one or both homologs, which are frequently observed in preparations of polytene chromosomes. The selection scheme suggested can be used to produce insertions in any region of Drosophila melanogaster chromosomes 2 and 3, for which the Y;2 translocations exist.

Two diallelic Y-chromosome markers, the Y Alu polymorphism (YAP) and the T-C transition (Tat), were analyzed in the indigenous (Tuvinian, Buryat, Northern Altaic, and Tatar) and migrant (Slavic) populations of Siberia. A high frequency of the allele C was revealed in several indigenous populations (25-55%) and in Russians (20.8%). The YAP+ allele occurred at a surprisingly high frequency (31.4%) and was completely linked with the C allele in Buryats. The YAP+ chromosome was also found in the Tuvinian population (1.5%). The two diallelic loci showed a marked linkage disequilibrium (D = 92.4%) in the total sample. The YAP-/T and YAP-/C haplotypes prevailed in both indigenous and migrant populations: their respective frequencies were 80.4 and 19.6% in the Slavic population and 71.8 and 19.9%, respectively, in the indigenous one. The YAP+/C (7.8%) and YAP+/T (0.5%) haplotypes were found only in the indigenous population. An appreciable heterogeneity in haplotype frequency distribution between regional subpopulations was revealed in Russians, Tuvinians, and Buryats. The origin and evolution of Y-chromosome lines in Northern Asia are considered.

Due to the complete absence of ribosomal DNA (genetic symbol bb-), the Xbb- chromosome of Drosophila is lethal both in homozygous conditions and in compound with the Xbb- chromosome. However, in the cross between the C(1)RM/Ybb- females and the Xbb-/BSYbb+ males, characterized by the development of lethal Xbb-/Ybb- zygotes, two fertile males were detected. These males possessed all the markers of the Xbb- chromosome but lacked the Y chromosome BS marker. Genetic analysis of their progeny showed that genes responsible for restoration of viability and fertility of these exceptional males were associated with the X chromosome. The crossover tests showed that in one case these genes were tightly linked to the w locus (the bbAM1 allele), and in the second case they were located 12.6 map units to the right of the Tu locus (the bbAM7 allele). It has also been shown that the bb locus was transposed to the X chromosome within the short arm of Y chromosome. Transposition of the BSYbb+ chromosome-specific rDNA sequences to the X chromosome was confirmed by means of Southern blotting. These data indicate that replacement of the bb locus is realized by transposition rather than recombination.

Insertion of the Y-material into the 34A Is(Y;2L)419 region diminished recombinational length of the left arm of chromosome 2 (2L) from 49.1 to 15.0 cM. This decrease was compensated by the increase of recombinational length in the other chromosomal arms due to interchromosomal effect. The increase in the X chromosome was 11.4 cM; it was 2.0 cM in chromosome 2R; and 17.3 cM in chromosome 3. The insertion-induced decrease of the 2L recombinational length could be eliminated by evoking interchromosomal effects from other chromosomes. The presence of the inversion in the X chromosome increased the 2L recombinational length from 15.0 to 30.2 cM, while its association with the In(3LR)D inversion increased this length to 45.6 cM. The interchromosomal effects in the inductor chromosome were induced by distortion of pairing rather than by the low recombinational length of this chromosome. For example, the interchromosomal effect of the insertion on the X chromosome was higher in the Is(Y;2L)/+; In(3LR)/+ females than in the Is(Y;2L)/+; +/+ females (15.4 versus 11.5 cM), though the 2L recombinational length in the females with the former genotype (30.2 cM) was twofold higher than in females with the latter genotype (15.0 cM). It is suggested that chromosomal rearrangement hampers the development of local contacts in the homologues. This delay affects crossing over in the given pair of homologues in two ways: directly via diminishing the number of exchange sites, and indirectly through regulatory delay of crossing over determination in the meiocyte. The effects of the insertion on crossing over in nonhomologous chromosomes are implemented by through the second way.

Transposition of the P[1ArB] vector was used to generate three mutations inducing sterility in homozygous males: ms(3)P50, ms(3)P122, and ms(3)P115 located within 67A4-B13, 92A2-14, and 75D regions on the polytene map. Staining for beta-galactosidase synthesized by P[1ArB] allowed us to study enhancer activity of these ms genes in the testicles. Their activity correlated to the presence of the YS arm but was little affected by the presence of YL arm of Y chromosome.

Sex differentiation provides for testing evolutionary innovations in the male genome before they are transferred to the female genetic system. This is possible with dichronous (asynchronous) evolution, when evolution in males precedes that in females [3-7]. Hence, along with common autosomal genes for stable characters, exclusively male and exclusively female genes must exist. The male genes are already acquired by the male genome but are not yet transferred to the female one. The female genes are already lost by the male genome but still remain in the female genome. They constitute temporary evolutionary genotypic sexual dimorphism. Common genes cannot exhibit genotypic sexual dimorphism; they show only constant phenotypic hormonal sexual dimorphism. On the basis of the interpretation of genotypic sexual dimorphism as a consequence of sex dichronism, the evolutionary role of sex chromatins is clarified and a new concept for them is suggested. According to this concept, the Y chromosome is the "conductor" of ecological information into the genome, the "place of birth" and testing of new genes, the accelerator and regulator of genotypic sexual dimorphism. By contrast, the X chromosome of the heterogametic sex provides the transportation of new genes from the Y chromosome to autosomes. This chromosome stabilizes, relaxes, and suppresses genotypic sexual dimorphism and accumulates genes that will be eliminated. This concept sheds light on many problems: the chromosomal localization of genes and their transfer to other chromosomes, the inactivation of chromosomes, mobile genes, mutation bursts, insertional mutagenesis, the association of the Y chromosome with stress, retroviruses, etc. In particular, it explains why genes "jump," why transpositions of mobile elements depend on ecological stress, why different genes mutate simultaneously, etc.

Karyotypes of two African mouse species, Mus mahomet, 2n = 36, NFa = 34 (34A + XA + YA) and Mus sp. A, 2n = 34, NFa = 32 (32A + XA + YA), from five localities of the Bale Mountains National Park, Ethiopia, were analyzed. In both species all autosomes contained C-positive pericentromeric blocks. In M. mahomet, heterochromatin blocks of different chromosomes varied in size. In addition, the X chromosomes of both species contained a pericentromeric block and showed more intensive staining throughout the chromosome. The Y chromosome was two times larger in Mus sp. A than in M. mahomet and C-positive in both species. Comparative analysis of G-banding patterns revealed a similarity with respect to nine autosomes and the X chromosome. Autosome 1 of Mus sp. A was demonstrated to result from centromere-telomere fusion of two M. mahomet acrocentrics. The other five autosomes represent different linkage groups determining a specificity of the karyotypes. The karyotypes of M. mahomet and Mus sp. A were also compared with that of M. musculus. The evolution of M. mahomet and Mus sp. A karyotypes was shown to have involved structural rearrangements in 10 and 12 autosomes, respectively. The high karyological divergence confirmed molecular phylogenetic data. The cytogenetic differences T of M. musculus C from M. mahomet and Mus sp. A are high enough to different genera.

Heterochromatin distribution was studied in three species of subfamily Bovinae: bison (Bison bison), European bison (Bison bonasus), and gayal (Bos frontalis). In all of the studied species, C- and CMA3-banding and in situ hybridization with satellite DNAII (satDNAII) revealed the conservative distribution of heterochromatic regions in autosomes; sex chromosomes did not contain the classical constitutive heterochromatin. The Y chromosome was the most variable element of the karyotypes of both bison species and the gayal. A mechanism for formation of the acrocentric Y chromosome in B. bison was suggested. This hypothetical mechanism included breakage of the p arm at the telomeric region and subsequent translocation and inversion. The map of B. bison chromosomes (491 bands per haploid set) is presented. The data obtained are discussed in terms of speciation and the evolution of Bovinae karyotypes.

A set of eight strains differing in recombinational length of the left arm of chromosome 2(2L) was obtained by means of inserting genetic material of the Y chromosome into the 34A region and two inversions, In(1)dl-49 + BM1 and In(3LR)D, demonstrating interchromosomal effects on crossing over. The length of 2L ranged from 15.0 to 64.9 cM. Interchromosomal effects on crossing over differed in extent and in distribution over 2L between females carrying wild-type chromosome 2 and the chromosome with inserts. Tetrad analysis showed that the 2L recombinational length was increased up to the normal level (females +/+; +/+, +/+) or more due to increased proportions of single- or double-exchange tetrads, respectively. A model of pairing and crossing over proposed earlier was used to interpret crossing-over patterns. The model implies that initial pairing of homologous chromosomes involves the formation of local contacts between them. The number of exchanges in a bivalent is determined by the number of local contacts at the onset of an event termed the determination of crossing-over sites (DCS). Interference is determined by the mechanism of contact formation. The extent of interference varies both temporally and spatially (within a chromosome), decreasing from the periphery to a contact site as the time from contact formation increases.

Different hypotheses for genetic control of sexual differentiation in humans are discussed. Information on structure and manifestation of genes determining development of internal and external male genitals is considered. The process of discovering the gene responsible for differentiation of the indifferent fetal gonad into testes is described. The etiological problems of sexual development disorders are considered on the basis of knowledge obtained by modern molecular and genetic methods.

Genetic analysis of line T32 of Drosophila melanogaster, which is able to reproduce at 32 degrees C, was conducted. To estimate the contributions of chromosomes Y, X, 2, and 3 to the determination of the trait of male sterility at 31 degrees C, lines were synthesized in which chromosomes of T32 and Canton S were substituted with marked chromosomes. Estimation of frequencies of sterile males in lines with substituted chromosomes indicates that genes controlling male fertility at high temperatures are located mainly in chromosome 3. The Y-chromosome of line T32 was shown to significantly affect male fertility at high temperature.