[The frequency of heteroploidy in spermatozoa of patients with infertility]. / Analiz chastoty geteroploidii v spermatozoidakh cheloveka pri narusheniiakh fertil'nosti.

The incidence of heteroploid spermatozoa was studied by mono- and dual-colored fluorescence in situ hybridization in semen samples from donors and patients with normal and impaired spermatogenesis. The frequency of heteroploid sperm in the ejaculate was linearly and inversely correlated with sperm parameters (sperm concentration in the ejaculate and proportion of motile and morphologically normal spermatozoa). The level of heterploidy was the most significant in the semen samples from patients with oligoasthenoteratospermia and oligoasthenospermia.

[The specific blocks of heterochromatin on metaphase chromosomes of horse and Prjewalski horse detected by in situ digestion with restriction endonucleases]. / Osobye bloki geterokhromatina, vyiavliaemye v metafaznykh khromosomakh domashnei loshadi i loshadi Przheval'skogo v rezul'tate obrabotki chromosom restriktazami in situ.

Restriction endonuclease in situ digestion of metaphase chromosomes gives an opportunity to reveal strips with different structure within GC-rich pericentric heterochromatin of the domestic horse and the wild Przewalski horse. Blocks of heterochromatin, which are insensitive to HaeIII and brightly stained with chromomycin A3 after restriction enzyme digestion, are localized on the border with euchromatin in the majority of chromosomes of Equus caballus and E. przewalskii. In contrast to chromosome 5 of E. caballus, acrocentric chromosomes of E. prezewalskii which are homologous to this chromosome have RE-CMA-blocks. We discuss a possible nature of the specific heterochromatin, which is insensitive to restriction enzyme digestion, and its role in the karyotype evolution.

[Quantitative characteristics of the differential banding pattern prometaphase chromosomes of the domestic horse (Equus caballus)]. / Kolichestvennaia kharakteristika differentsial'noi ischerchennosti prometafaznykh khromosom domashnei loshadi (Equus caballus).

A high-resolution cytogenetic map (670 bands per haploid set) of RBA-banded chromosomes has been constructed in the domestic horse Equus caballus. The size and distribution of the replication-based R(G)-bands were analyzed using the computer program VideoTest-Karyo. The obtained data were compared to the results of cytogenetic mapping in other mammalian species and human.

[Distribution of T-bands and telomeric (TTAGGG)n nucleotide repeats on chromosomes of Bos taurus]. / Raspredelenie T-diskov i telomernykh (TTTAGGG)n blokov nukleotidov na khromosomakh Bos taurus

Distribution of T-bands on mitotic chromosomes of Bos taurus was studied. Association of T-bands with telomeres and enrichment of T-bands with genes, with a known localization is described. After THA-banding on the chromosomes of cattle, telomeric and pericentromeric regions of all autosomes showed bright fluorescence. The exception was for chromosome 7, which did not have telomeric T-bands. Interstitial T-bands were detected only on chromosomes 7, 16, and Y (7q13, 7q15, 7q22, 7q24, 16q21, and Yp12). A total proportion of centromeric, telomeric, and interstitial T-bands was 11.19, 9.97, and 2.02% of the length of the haploid chromosome set, respectively. By means of fluorescent in situ hybridization (FISH), the presence of the telomeric repeat (TTAGGG)n was shown not only in telomeric regions of all autosome, but also in all pericentromeric regions. The obtained data are indicative of the specificity of T-banding on the chromosomes of Bos taurus.

[Heterochromatin and euchromatin regions in the chromosomes of various representatives of the subfamily Bovinae]. / Geterokhromatinovye i éukhromatinovye raiony khromosom nekotorykh predstavitelei podsemeistva Bovinae.

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.

[Analysis of the distribution of ribosomal RNA genes on chromosomes of the domestic horse (Equus caballus) using fluorescent in situ hybridization]. / Analiz raspredeleniia genov ribosomnykh RNK na khromosomakh domashnei loshadi (Equus caballus) s pomoshch'iu fluorestsentnoi in situ gibridizatsii.

Distribution of blocks of ribosomal RNA genes along metaphase chromosomes of 26 horses from five breeds was determined by means of a modified method of fluorescence in situ hybridization (FISH) in combination with simultaneous R- banding. Gene loci coding for rRNA were mapped to the region of secondary constriction on the short arm of chromosome 1, and to the pericentromeric regions of chromosomes 27, 28, and 31. The nucleolar organizer region (NOR) on chromosome 27 was not described earlier. Interindividual and interchromosomal NOR polymorphism was detected With the use of a semiquantitative score estimation of fluorescence hybridization signals.

[Patterns in the condensation of bovine chromosomes in the prophase-late metaphase of mitosis]. / Zakonomernosti kompaktizatsii khromosom krupnogo rogatogo skota v profaze--pozdnei metafaze mitoza.

A comparative analysis of Bos taurus L. cytogenetic maps of different resolution levels was used to study principles of fusion R(G)-bands during chromosome condensation from prophase to the late metaphase. Three different types of fusion have been demonstrated, differing in quantity of interacting bands and fusion mechanism. Preferential condensation zones with constant localization was found. By means of the fusion index, faster condensation of R-bands than that of G-bands was revealed. Relevant data on B. taurus and Homo sapiens were compared. The obtained results are discussed in terms of common problems of mitotic chromosome R(G)-banding nature in warm-blooded animals.

[The detection of the location in cattle chromosomes of a gene presumably determining testis development]. / Vyiavlenie lokalizatsii v khromosomakh krupnogo rogatogo skota gena, predpolozhitel'no opredeliaiushchego razvitie testisov.

The localization of the putative testis determining gene (TDF) was established with isotopic and nonisotopic methods of in situ hybridization in prometaphasic chromosomes of cattle. The results of both the methods were seen to coincide. The sites of hybridization have been revealed in X-chromosome (R-bands, q2.1 and q2.3.1). TDF was also localized in the proximal part of the long Y-chromosome arm.

[The heterochromatin regions of the mitotic chromosomes in cattle]. / Geterokhromatinovye uchastki mitoticheskikh khromosom krupnogo rogatogo skota.

Cytochemical and molecular peculiarities of heterochromatic regions of bovine chromosomes have been studied, using specific fluorochrome staining induced decondensation, in situ hybridization, pretreatment of restriction enzymes. The heterochromatin of autosomes demonstrated a strong homogeneity. In chromosome Y two small specific heterochromatic regions were found lacking a long repeated tandem block of nucleotides enriched in GC base pairs and having no tandem block of Bkm repeats (10(4) b.p.). This class repeats are probably interspersed in the bovine genome. A rather seldom character of mammalian karyotypes is the absence of cytochemical heterochromatin in the X chromosome.

[Cytogenetic mapping of cattle (Bos taurus L.). Quantitative analysis of the RBA-map of prometaphase chromosomes]. / Tsitogeneticheskoe kartirovanie krupnogo rogatogo skota (Bos taurus L.). Kolichestvennyi analiz RBA-karty prometafaznykh khromosom.

Using the decondensing effect of ethidium bromide and replicative (RBA) staining a high resolution map of cattle chromosomes was produced. The extent and distribution pattern of R(G) blocks were estimated quantitatively. The data thus obtained are correlated with the results of cytogenetic mapping in other mammalian species and in man.

[An analysis of the action of nonspecific and restriction nucleases on metaphase chromosomes in situ]. / Analiz deistviia nespetsificheskikh i restriktsionnykh nukleaz na metafaznye khromosomy in situ.

Patterns of differential staining of Drosophila, mouse, rat, cattle and pig chromosomes were examined after the treatment with nucleases (DNAase I, DNAase II) and restriction enzymes (AluI, HpaII, MspI, BpE, EcoRI). The above effects depend on the species used, on the enzymes and substitution of thymine for bromodeoxyuridine in the chromosomal DNA. It is supposed that such a phenomenon may not only result from the irregular distribution of specific restriction sites along chromosomes but also depend on the specificity of supramolecular organization of the chromosomal DNA.