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1.  Synaptonemal complex analysis of interracial hybrids between the Moscow and Neroosa chromosomal races of the common shrew Sorex araneus showing regular formation of a complex meiotic configuration (ring-of-four) 
Comparative Cytogenetics  2012;6(3):301-314.
Immunocytochemical and electron microscopic analysis of synaptonemal complexes (SCs) was carried out for the first time in homozygotes and complex Robertsonian heterozygotes (hybrids) of the common shrew, Sorex araneus Linnaeus, 1758, from a newly discovered hybrid zone between the Moscow and the Neroosa chromosomal races. These races differ in four monobrachial homologous metacentrics, and closed SC tetravalent is expected to be formed in meiosis of a hybrid. Indeed, such a multivalent was found at meiotic prophase I in hybrids. Interactions between multivalent and both autosomes and/or the sex chromosomes were observed. For the first time we have used immunocytochemical techniques to analyse asynapsis in Sorex araneus and show that the multivalent pairs in an orderly fashion with complete synapsis. Despite some signs of spermatocytes arrested in the meiotic prophase I, hybrids had large number of active sperm. Thus, Moscow – Neroosa hybrid males that form a ring-of-four meiotic configuration are most likely not sterile. Our results support previous demonstrations that monobrachial homology of metacentrics of the common shrew does not lead to complete reproductive isolation between parapatric chromosomal races of the species.
PMCID: PMC3833805  PMID: 24260670
Synaptonemal complex; MSCI; γH2AX; centromeres; Sorex araneus
2.  N′-(2-Hy­droxy­benzyl­idene)-2-(hy­droxy­imino)­propano­hydrazide 
The mol­ecule of the title compound, C10H11N3O3, adopts an all-trans conformation and is approxomately planar, the largest deviation from the least-squares plane through all non-H atoms being 0.261 (1) Å. An intra­molecular O—H⋯N hydrogen bond occurs. In the crystal, the mol­ecules are packed into layers lying parallel to the ab plane by π-stacking inter­actions between the benzene ring of one molecule and the C—N bond of the oxime group of another molecule; the shortest inter­molecular C⋯C separation within the layer is 3.412 (1) Å. The layers are connected by O—H⋯O and N—H⋯O hydrogen bonds.
PMCID: PMC3238939  PMID: 22199788
3.  1-{3-[1-(Hydroxyimino)ethyl]-4-methyl-1H-pyrazol-5-yl}ethanone 
In the title compound, C8H11N3O2, the oxime and the acetyl groups adopt a transoid conformation, while the pyrazole H atom is localized in the proximity of the acetyl group and is cis with respect to the acetyl O atom. In the crystal, dimers are formed as the result of hydrogen-bonding inter­actions involving the pyrazole NH group of one mol­ecule and the carbonyl O atom of another. The dimers are associated into sheets via O—H⋯N hydrogen bonds involving the oxime hydroxyl and the unprotonated pyrazole N atom, generating a macrocyclic motif with six mol­ecules.
PMCID: PMC3201455  PMID: 22058770
4.  μ-Peroxido-bis­[acetonitrile­bis­(ethyl­enediamine)­cobalt(III)] tetrakis(per­chlorate) 
The title compound, [Co2(O2)(CH3CN)2(C2H8N2)4](ClO4)4, consists of centrosymmetric binuclear cations and perchlorate anions. Two CoIII atoms, which have a slightly distorted octa­hedral coordination, are connected through a peroxido bridge; the O—O distance is 1.476 (3) Å. Both acetonitrile ligands are situated in a trans position with respect to the O—O bridge. In the crystal, the complex cations are connected by N—H⋯O hydrogen bonds between ethyl­endiamine NH groups and O atoms from the perchlorate anions and peroxide O atoms.
PMCID: PMC3011807  PMID: 21589305
5.  μ-Oxalato-bis­[(2,2′-bipyridyl)­copper(II)] bis(perchlorate) dimethyl­formamide disolvate monohydrate 
The title compound, [Cu2(C2O4)(C10H8N2)4](ClO4)2·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II) complex cations, perchlorate anions, and DMF and water solvate mol­ecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetra­gonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water mol­ecules are linked into recta­ngles by O—H⋯O bonds in which the perchlorate O atoms act as acceptors and the water mol­ecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7):0.547 (7), and the water molecule is half-occupied.
PMCID: PMC3008067  PMID: 21588513
6.  2-Hydroxy­amino-2-oxoacetohydrazide 
In the title compound, C2H5N3O3, the hydroxamic group adopts an anti orientation with respect to the hydrazide group. In the crystal, mol­ecules are connected by N—H⋯O and O—H⋯N hydrogen bonds into zigzag chains along the c axis.
PMCID: PMC2979297  PMID: 21579115
7.  Bis{2-hydroxy­imino-N′-[1-(2-pyrid­yl)ethyl­idene]propanohydrazidato}zinc(II) dihydrate 
The title compound, [Zn(C10H11N4O2)2]·2H2O, was prepared by the reaction between Zn(CH3COO)2·2H2O and 2-hydroxy­imino-N′-[1-(2-pyrid­yl)ethyl­idene]propano­hydrazide (Hpop). The central ZnII atom has a distorted tetra­gonal-bipyramidal coordination geometry formed by two amide O atoms and four N atoms of two azomethine and two pyridine groups. In the crystal, complex mol­ecules form layers parallel to the crystallographic b direction. The layers are connected by O—H⋯N and O—H⋯O hydrogen bonds involving the solvent water mol­ecules.
PMCID: PMC2979945  PMID: 21579695
8.  (2E)-2-Hydroxy­imino-N′-[(E)-2-pyridyl­methyl­ene]propanohydrazide 
In the title compound, C9H10N4O2, the pyridine ring is twisted by 16.5 (1)° from the mean plane defined by the remaining non-H atoms. An intra­molecular N—H⋯N inter­action is present. In the crystal, inter­molecular O—H⋯N and N—H⋯O hydrogen bonds link mol­ecules into layers parallel to the bc plane. The crystal packing exhibits π–π inter­actions indicated by the short distance of 3.649 (1) Å between the centroids of the pyridine rings of neighbouring mol­ecules.
PMCID: PMC2970200  PMID: 21577872
9.  2-Hydroxy­imino-N′-[1-(2-pyrid­yl)ethyl­idene]propanohydrazide 
The title compound, C10H12N4O2, features an intra­molecular N—H⋯N hydrogen bond formed between the imine NH and oxime N atoms. The oxime group and the amide C=O bond are anti to each other. In the crystal, mol­ecules are connected by O—H⋯O hydrogen bonds into supra­molecular zigzag chains along the c axis.
PMCID: PMC2969988  PMID: 21577640
10.  Phenotypic Variation across Chromosomal Hybrid Zones of the Common Shrew (Sorex araneus) Indicates Reduced Gene Flow 
PLoS ONE  2013;8(7):e67455.
Sorex araneus, the Common shrew, is a species with more than 70 karyotypic races, many of which form parapatric hybrid zones, making it a model for studying chromosomal speciation. Hybrids between races have reduced fitness, but microsatellite markers have demonstrated considerable gene flow between them, calling into question whether the chromosomal barriers actually do contribute to genetic divergence. We studied phenotypic clines across two hybrid zones with especially complex heterozygotes. Hybrids between the Novosibirsk and Tomsk races produce chains of nine and three chromosomes at meiosis, and hybrids between the Moscow and Seliger races produce chains of eleven. Our goal was to determine whether phenotypes show evidence of reduced gene flow at hybrid zones. We used maximum likelihood to fit tanh cline models to geometric shape data and found that phenotypic clines in skulls and mandibles across these zones had similar centers and widths as chromosomal clines. The amount of phenotypic differentiation across the zones is greater than expected if it were dissipating due to unrestricted gene flow given the amount of time since contact, but it is less than expected to have accumulated from drift during allopatric separation in glacial refugia. Only if heritability is very low, Ne very high, and the time spent in allopatry very short, will the differences we observe be large enough to match the expectation of drift. Our results therefore suggest that phenotypic differentiation has been lost through gene flow since post-glacial secondary contact, but not as quickly as would be expected if there was free gene flow across the hybrid zones. The chromosomal tension zones are confirmed to be partial barriers that prevent differentiated races from becoming phenotypically homogenous.
PMCID: PMC3707902  PMID: 23874420

Results 1-10 (10)