Crystal structures of two 4H-chromene derivatives: 2-amino-3-cyano-4-(3,4-di-chloro-phen-yl)-7-hy-droxy-4H-benzo[1,2-b]pyran 1,4-dioxane monosolvate and 2-amino-3-cyano-4-(2,6-di-chloro-phen-yl)-7-hy-droxy-4H-benzo[1,2-b]pyran.

In the title compounds, C16H9Cl2N2O2·C4H8O2 and C16H9Cl2N2O2, the bicyclic 4H-chromene cores are nearly planar with maximum deviations of 0.081 (2) and 0.087 (2) Å. In both structures, the chromene derivative mol-ecules are linked into centrosymmetric dimers by pairs of N-H⋯O hydrogen bonds, forming R2 2 (16) motifs. These dimers are further linked in the 3,4-di-chloro-phenyl derivative by N-H⋯N hydrogen bonds into double layers parallel to (100) and in the 2,6-di-chloro-phenyl derivative by O-H⋯N hydrogen bonds into ribbons along the [10] direction. In the 3,4-di-chloro-phenyl derivative, the 1,4-dioxane solvent mol-ecules are connected to the chromene mol-ecules via O-H⋯O hydrogen bonds.

Crystal structure of (E)-4-(acet-oxy-imino)-N-allyl-3-isopropyl-2,6-di-phenyl-piperi-dine-1-carbo-thio-amide.

The title compound, C26H31N3O2S, crystallizes with two mol-ecules (A and B) in the asymmetric unit. In each case, the piperidine ring exists in a twist-boat conformation. The dihedral angle between the phenyl rings is 46.16 (12)° in mol-ecule A and 44.95 (12)° in mol-ecule B. In both mol-ecules, the allyl side chain is disordered over two orientations in a 0.649 (9):0.351 (9) ratio for mol-ecule A and 0.826 (10):0.174 (10) ratio for mol-ecule B. In the crystal, neither mol-ecule forms a hydrogen bond from its N-H group, presumably due to steric hindrance. A+A and B+B inversion dimers are formed, linked by pairs of weak C-H⋯O hydrogen bonds enclosing R 2 (2)(22) ring motifs.

Crystal structure of isobutyl 4-(2-chloro-phen-yl)-5-cyano-6-{(E)-[(di-methyl-amino)-methyl-idene]amino}-2-methyl-4H-pyran-3-carboxyl-ate.

In the title compound, C21H24ClN3O3, the dihedral angle between the pyran ring (r.m.s. deviation = 0.037 Å) and the chloro-benzene ring is 88.56 (14)°. In the crystal, the mol-ecules are linked by C-H⋯O inter-actions, generating C(7) (001) chains.

(E)-3-Methyl-2,6-di-phenyl-piperidin-4-one O-(3-methyl-benzo-yl)oxime.

In the title compound, C26H26N2O2, the piperidine ring exhibits a chair conformation. The phenyl rings are attached to the central heterocycle in an equatorial position. The dihedral angle between the planes of the phenyl rings is 57.58 (8)°. In the crystal, C-H⋯O inter-actions connect the mol-ecules into zigzag chains along [001].

Methyl ({[(4E)-1,3-dimethyl-2,6-di-phenyl-piperidin-4-yl-idene]amino}-oxy)acetate.

In the title compound, C22H26N2O3, the piperidine ring exhibits a chair conformation. The phenyl rings attached to the piperidine at the 2- and 6-positions have axial orientations. These rings make a dihedral angle of 49.75 (11)°. The amino-oxy acetate group attached at the 4-position has an equatorial orientation. In the crystal, inversion dimers linked by pairs of C-H⋯π inter-actions occur.

1-(4-Meth-oxy-phen-yl)-2-[4-(tri-fluoro-meth-yl)phen-yl]-1H-phenanthro[9,10-d]imidazole.

In the title compound, C29H19F3N2O, a phenanthroline-fused imidazole tetra-cyclic system, the fused benzene rings deviate slightly from the central ring and make dihedral angles with this ring of 3.47 (8) and 3.05 (8)°. The tri-fluoro-methyl-phenyl ring is roughly coplanar with the phenanthroline-fused imidazole tetra-cyclic system [dihedral angle = 11.02 (6)°], while the meth-oxy-phenyl ring is almost perpendicular [dihedral angle = 87.65 (6)°]. There are intra-molecular C-H ⋯π inter-actions involving the meth-oxy-phenyl ring and the central phenanthroline ring, as well as an inter-molecular C-H⋯π inter-action involving the phenanthroline ring. In addition, there is an inter-molecular π-π inter-action involving the central phenanthroline ring and the tri-fluoro-methyl-phenyl ring [centroid-centroid distance = 3.685 (2) Å], as well as C-H⋯N inter-actions linking the mol-ecules into dimers.

1-(4-Methyl-phen-yl)-2-[4-(trifluoro-methyl)phen-yl]-1H-phenanthro[9,10-d]imida-zole.

In the title compound, C29H19F3N2, the tetra-cyclic ring system is essentially planar [maximum deviation from the best plane = 0.076 (1) Å] and makes dihedral angles of 78.10 (5) and 33.71 (4)° with the methyl-phenyl and fluoro-phenyl rings, respectively. An intra-molecular C-H⋯π inter-action occurs. In the crystal, pairs of C-H⋯π inter-actions link inversion-related mol-ecules.

1-Phenyl-2-p-tolyl-1H-benzimidazole.

In the title compound, C20H16N2, the benzimidazole ring system forms dihedral angles of 28.50 (7) and 72.44 (7)° with the tolyl and phenyl rings, respectively. In the crystal, mol-ecules are linked into chains along the a-axis direction by weak C-H⋯N inter-actions. The crystal structure also features C-H⋯π inter-actions.

1-(3,5-Dimethyl-phen-yl)-2-(4-fluoro-phen-yl)-1H-phenanthro[9,10-d]imidazole.

In the title compound, C29H21FN2, the phenanthro tricyclic ring system is essentially planar with a maximum deviation of 0.030 (2) Šand makes dihedral angles between of 77.96 (6) and 37.18 (7)° with the dimethyl-phenyl and fluoro-phenyl rings, respectively. The crystal packing features weak C-H⋯π inter-actions involving the dimethyl-phenyl and other phenyl rings.

2-(4-Fluoro-phen-yl)-1-(4-meth-oxy-phen-yl)-1H-phenanthro[9,10-d]imidazole.

In the title compound, C28H19FN2O, the phenanthrene fused with an imidazole ring, constituting an essentially planar tetra-cyclic system [maximum deviation = 0.032 (2) Å], makes dihedral angles of 60.83 (4) and 80.55 (4)° with the fluoro-benzene and meth-oxy-benzene rings, respectively. The dihedral angle between the the meth-oxy-benzene and fluoro-benzene rings is 69.45 (6)°. In the crystal, C-H⋯O hydrogen bonds connect the mol-ecules into infinite strands along the b axis. The crystal structure is further consolidated by C-H⋯π inter-actions.

Glycine-d-tartaric acid (1/1).

In the title co-crystal, C(2)H(5)NO(2)·C(4)H(6)O(6), the gylcine mol-ecule is present in the zwitterion form. In the tartaric acid mol-ecule there is a short intra-molecular O-H⋯O contact. In the crystal, the tartaric acid mol-ecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked via a number of O-H⋯O and N-H⋯O hydrogen bonds involving the two components, forming a three-dimensional network.

1-Phenyl-2-[4-(trifluoro-meth-yl)phen-yl]-1H-benzimidazole.

In the title mol-ecule, C(20)H(13)F(3)N(2), the benzimidazole unit is close to being planar [maximum deviation = 0.012 (1) Å] and forms dihedral angles of 31.43 (7) and 61.45 (9)° with the 4-(trifluoromethyl)phenyl and 1-phenyl rings, respectively; the dihedral angle between these rings is 60.94 (10)°. In the crystal, C-H⋯F hydrogen bonds link the mol-ecules into chains along the c-axis direction. The CF(3) group is rotationally disordered with an occupancy ratio of 0.557 (8):0.443 (8) for the F atoms.

2-(4-Meth-oxy-phen-yl)-1-phenyl-1H-benzimidazole.

In the title compound, C(20)H(16)N(2)O, the 1H-benzimidazole ring forms dihedral angles of 48.00 (6) and 64.48 (6)°, respectively with the benzene and phenyl rings, which are inclined to one another by 58.51 (7)°. In the crystal, weak C-H⋯π inter-actions are the only inter-molecular inter-actions present.

Genetic variability and genetic structure of wild and semi-domestic populations of tasar silkworm (Antheraea mylitta ) ecorace Daba as revealed through ISSR markers.

The genetic diversity in the wild and semi-domestic populations of Daba ecorace of Antheraea mylitta was studied to ascertain the distribution of variability within and among populations of semi-domestic bivoltine (DB), trivoltine (DT) and nature grown wild populations (DN) with inter-simple sequence repeat (ISSR) markers. A total of 138 markers were produced among 56 individuals of the three populations, of which 98% were polymorphic. For the individual populations, the percentage polymorphism was 58.69, 52.9 and 77.54 for DB, DT and DN, respectively. Average number of observed (1.791+/- 0.408) and effective alleles (1.389+/-0.348) was also high in the wild populations in comparison to the bivoltine and trivoltine semi-domestic populations. Genetic diversity (H(t)) in DB, DT and DN was 0.180+/- 0.033, 0.153+/- 0.032 and 0.235+/- 0.033, respectively and within-population genetic diversity (H(s)) ranged from 0.166 to 0.259 with a mean of 0.189. Mean gene differentiation (G(ST)) was found to be 0.25. Shanon's diversity index was 0.278, 0.237 and 0.361 for DB, DT and DN and overall it was 0.391. Gene flow (N(m)) among the populations was 1.509. The dendrogram produced by UPGMA with Dice's genetic distance matrices resulted in the formation of three major clusters separating the three populations. Considerable intra- and inter-population variability is found in all three populations. The population structure analysis further suggests that the semi-domestic populations of Daba ecorace are at the threshold of differentiating themselves. The high genetic variability present within wild Daba population of A. mylitta is of much importance for conservation as well as utilization in systematic breeding program.

Molecular analysis of divergence in tachinid Uzi (Exorista sorbillans) populations in India.

Exorista sorbillans is a tachinid endoparasitoid of silkworm, Bombyx mori, and is globally known as uzi. It causes economic injury to the cocoon crop in silkworm cultivating areas of India, except those above 400 m above mean sea level (AMSL) in the foothills of the Himalayas (Darjeeling). It is reported that the sericulture tract of south India became infected with this pest only since 1980 through an accidental transportation of cocoons from West Bengal. To ascertain whether the genome of this parasitoid is differentiating into discrete gene pools in contrasting geo-climatic conditions, molecular profiling of four populations (Es (Annatapur), Es(Ramanagaram), Es (Channapatna) and Es(Kodathi) from south India and Es(Murshidabad) from Murshidabad, West Bengal was undertaken with 13 ISSR, 3 RAPD and six non-random primers designed from various repeat sequences of B. mori . MANOVA indicated significance for the Roy's largest root estimate (55.4; F =18.47; p = 0.002) for the variability contributed by the replication. Further, hierarchical clustering done on the basis of Euclidean distance matrix and Nei's unbiased Phylip clustering put Es(Murshidabad) at the maximum distance from those of south India and 29 markers could also be identified which significantly differentiateEs(Murshidabad) from others. However, Nei's statistics for gene diversity in sub-populations reveal considerably high gene-flow (3.44 and 2.51) among the populations around Bangalore. The gene-flow between Es(Murshidabad) and other population is lowest but cannot be ignored. The comparison of endosymbiont specific 16SrRNA and fts Z gene (partial) sequences through clustalW (gcgMSF) revealed a closer relationship of Es(Murshidabad) with Es(Annatapur) and Es (Ramanagaram) and is not congruent with the relationships discussed above. The significance of this maiden study with a tachinid fly-pest is discussed in the context of understanding the diversification of Uzi fly-pest and also establishing this pest as a relevant biological material for studying microevolution in future.

Molecular genetic approach for identifying markers associated with yield traits in the silkworm, Bombyx mori using RFLP-STS primers.

Bombyx mori, the mulberry silkworm, exhibits wide variability in yield and developmental attributes. The genetics of yield expression, shown to be of polygenic nature, is poorly studied in silkworm. To identify markers associated with 10 selected yield traits, multiple regression analysis (MRA) and discriminant function analysis (DFA) were applied on 64 markers generated with eight RFLP-derived sequence-tagged-site (STS) primers on the genomic DNA of 20 silkworm stocks of different origin and diverse yield potential. The analyses led to the identification of ten markers showing significant association with the different yield traits. The markers could classify the stocks according to yield potential, irrespective of their origin and status of diapause. Trait means were significantly different for stocks with and with out the associated marker. The inheritance of a marker G2(1300bp), selected at the first step of MRA for five yield traits was shown to segregate in 1:1 ratio in the F2 progeny from a cross between two divergent stocks. The relevance of the STS primers is discussed in the context of applying multiple regression model for identifying markers associated with yield expression and suitability for molecular breeding work in B. mori for yield improvement.

Identification of ISSR markers associated with productivity traits in silkworm, Bombyx moni L.

Bombyx mori L., commonly recognised around the world as the mulberry silkworm, is characterized by a wide variability in yield and developmental traits, which have been proven through conventional genetic analysis to be of polygenic nature. A large number of morpho-biochemical traits and RFLP and RAPD markers are mapped on different linkage groups, but to this point very little attention has been given to unravelling the genetics of yield traits. To address this issue, polymorphic profiles of 147 markers generated with 12 ISSR primers on the genomic DNA of 20 silkworm stocks of diverse yield status were subjected to multiple regression and discriminant function analyses (DFA). This led to the identification of eight markers generated by six primers, which demonstrated high beta-coefficient indices of -0.451 to -0.940. Furthermore, a significant difference between the yield traits for stocks with and without the specific marker could also be established. The inheritance pattern of one marker, L13800bp, identified at the first step of selection of markers through stepwise regression analyses for five yield parameters is discussed in the context of applying multiple regression analysis for establishing association, if not linkage, between a group of DNA markers and a particular yield trait of polygenic nature and using such markers in molecular marker-assisted breeding programs.

Prenatal diagnosis of mosaic tetrasomy 5p.

We report the prenatal diagnosis of a fetus with tetrasomy 5p mosaicism resulting from a supernumerary isochromosome for the short arm of chromosome 5. The pregnancy was terminated and fetal autopsy revealed minor facial abnormalities (long philtrum, up-slanting palpebral fissures and a broad nasal bridge). Cultures were established from fetal skin, kidney, and pancreas for cytogenetic analysis; the i(5p) was observed only in the skin fibroblasts. To our knowledge, this is the fourth report of mosaic tetrasomy 5p and the first report of prenatal diagnosis of this abnormality.

Amplification of the MLL region in acute myeloid leukemia.

We report amplification of the MLL gene region (11q23-->11qter) in a 72-year-old woman with myelodysplastic syndrome progressing to acute myelomonocytic leukemia and in a 51-year-old man with a history of hairy cell leukemia and secondary myelodysplasia progressing to acute myelogenous leukemia. The amplicons containing MLL were shown by molecular cytogenetics to extend from chromosomal region 11q23 to the distal long arm of chromosome 11 and to be present in the first patient in five copies on a large ring chromosome and present in the second patient also in five copies on two derived chromosomes. Other karyotypic findings in the first patient included del(5q), +8, and der(21)t(17;21), resulting in the loss of a copy of 17p, whereas deletion 7q was observed in the second patient. Southern-blot analysis for the second patient was consistent with MLL amplification but did not demonstrate rearrangement of the germ-line MLL band. Amplification of MLL and the 11q23 region has been documented in only a few cases and appears to be yet another mechanism by which MLL contributes to the leukemia phenotype.