Paracentric inversion involving a NOR-bearing chromosome of rainbow trout (Oncorhyncus mykiss): Electron microscopy studies of the synaptonemal complex

Cytogenetic studies conduced on a sample of 19 specimens of rainbow trout (Oncorhyncus mykiss) showed that 6 presented two chromosomes with a single subterminal AgNOR on the short arms and 13 presented one chromosome with a single subterminal Ag-NOR and a second chromosome with two small subterminal Ag-NORs. Synaptonemal complex studies showed the presence of a pairing failure involving the two lateral elements (LEs) of the NOR-bearing chromosomes only in those specimens with two different NOR-bearing chromosomes, suggesting that the chromosomes with two Ag-NORs originated from a paracentric inversion involving a terminal segment of the original NOR-bearing chromosome. A comparative analysis between three normal and three heterozygous fishes suggest that in the latter group the LEs of the NOR-bearing chromosomes initiate the synaptic process in a more delayed manner, the synapsis develops more quickly, and the nucleolus stays associated with chromosomes for a longer time.

Cytotaxonomic considerations with the description of two new NOR locations for South American toads, genus Bufo (Anura: Bufonidae)

Cytogenetic studies were made on Brazilian Bufo: B. marinus, B. paracnemis, B. ictericus, B. rufus, B. arenarum, B. crucifer, Bufo granulosus, B. pygmaeus and B. margaritifer (= B. typhonius). All these species had a typical karyotype of 2n = 22. Species from the marinus and crucifer groups had NORs on Chromosome 7, species from the granulosus group had NORs on Chromosome 5, and B. margaritifer had NORs on Chromosome 10. The last two locations of NORs are described for the first time for the genus Bufo in South America.

Cytogenetic analysis of Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) with Xyp sex determination system using standard staining, C-bands, NOR and synaptonemal complex microspreading techniques

The mitotic and meiotic chromosomes of the beetles Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) were analysed using standard staining, C-banding and silver impregnation techniques. We determine the diploid and haploid chromosome numbers, the sex determination system and describe the chromosomal morphology, the C-banding pattern and the chromosome(s) bearing NORs (nucleolar organizer regions). Both species shown 2n = 20 chromosomes, the chromosomal meioformula 9 + Xyp, and regular chromosome segregation during anaphases I and II. The chromosomes of E. atomaria are basically metacentric or submetacentric and P. dermestoides chromosomes are submetacentric or subtelocentric. In both beetles the constitutive heterochromatin is located in the pericentromeric region in all autosomes and in the Xp chromosome; additional C-bands were observed in telomeric region of the short arm in some autosomes in P. dermestoides. The yp chromosome did not show typical C-bands in these species. As for the synaptonemal complex, the nucleolar material is associated to the 7th bivalent in E. atomaria and 3rd and 7th bivalents in P. dermestoides. Strong silver impregnated material was observed in association with Xyp in light and electron microscopy preparations in these species and this material was interpreted to be related to nucleolar material.

Aryltetralone lignans and 7,8-seco-lignans from Holostylis reniformis

Aryltetralone lignans and two 7,8-seco-lignans were isolated from the acetone and hexane extracts of the roots of Holostylis reniformis, together with (-)-galbacin. Their structures were determined by spectroscopic methods. © 2004 Elsevier Ltd. All rights reserved.

Isolation of lignans glycosides from Alibertia sessilis (Vell.) K. Schum. (Rubiaceae) by preparative high-performance liquid chromatography

Enantiomeric aglycone lignans contained in a mixture were separated from a fraction of the extract of the stems of Alibertia sessilis (Vell.) K. Schum. (Rubiaceae) by preparative high-performance liquid chromatography. An efficient and fast separation can be achieved with methanol-water (30:70, v/v). Their structures were identified as (+)-lyoniresinol 3α-O-β-glucopyranoside and (-)-lyoniresinol 3α-O-β-glucopyranoside, being reported for the first time in Rubiaceae.

Chromosomal similarities and differences among four Neotropical Elateridae (Conoderini and Pyrophorini) and other related species, with comments on the NOR patterns in Coleoptera

This work deals with the comparative cytogenetic analysis of four Neotropical Elateridae species and reviews the nucleolar organizer region (NOR) patterns on Coleoptera chromosomes, for the first time. The cytogenetic characterization of Conoderus malleatus (Conoderini), Pyrearinus candelarius, Pyrophorus divergens and Pyrophorus punctatissimus (Pyrophorini) was accomplished through the study of mitotic and meiotic cells submitted to standard (Giemsa) and differential staining [silver impregnation and GC-specific chromomycin A 3 (CMA 3) plus AT-specific 4′-6-diamidino-2-phenylindole (DAPI) fluorochromes]. The analysis of spermatogonial cells revealed the diploid numbers: 2n = 17 in C. malleatus and 2n = 15 in P. candelarius, P. divergens and P. punctatissimus. In these species, the X0 type sex-determination system and the acrocentric morphology of almost all chromosomes were observed. The study of meiotic cells of the four species revealed the occurrence of total synapsis between the autosomes, the presence of one terminal or interstitial chiasma in the majority of the bivalents, and the reductional behaviour and regular segregation of all chromosomes. Although the three Pyrophorini species demonstrated many similar karyotypical characteristics, there was one discrepancy, which was noted in the diplotene cells and concerns the number of bivalents with two chiasmata; P. candelarius only presented one bivalent, P. divergens showed two bivalents and P. punctatissimus exhibited up to four bivalents with two chiasmata. Testicular cells impregnated with silver nitrate demonstrated two terminal NORs located on the fourth autosomal pair of the Conoderini species and on the second autosomal pair of the three Pyrophorini representatives. Use of CMA 3/distamycin A (DA)/DAPI staining on the P. candelarius and P. punctatissimus chromosomes revealed that the CMA 3 labelled regions were coincident with the NORs. The main strategies of karyotypical differentiation that have occurred among the four Elateridae species and other related species, and the general trends of the NOR shifts during Coleoptera chromosomal evolution are discussed in this work. © 2007 The Authors.

A new antifungal phenolic glycoside derivative and iridoids and lignans from Alibertia sessilis (Vell.) K. Schum. (Rubiaceae)

A new antifungal phenolic glycoside, 3,4,5-trimethoxyphenyl-1-O-β-D- (5-O-syringoyl)-apiofuranosyl-(1→6)-β-D-glucopyranoside (1), together with four known iridoids, geniposidic acid (2), geniposide (3), 6α-hydroxygeniposide (4) and 6β-hydroxygeniposide (5); two lignans, (+)-lyoniresinol-3α-O-β-D-glucopyranoside (6), (-)-lyoniresinol- 3α-O-β-D-glucopyranoside (7); and two phenolic acids, chlorogenic (8) and salicylic acids (9) and D-manitol (10), were isolated from the ethanolic extract of the stems of Alibertia sessilis. Structures of 1 and of the known compounds were determined by spectroscopic analysis. All compounds isolated were evaluated for their antifungal activities against two phytopathogenic fungi strains Cladosporium cladosporioides and C. sphaerospermum by direct bioautography. ©2007 Sociedade Brasileira de Química.

Neither plasma progesterone concentrations nor exogenous eCG affects rates of ovulation or pregnancy in fixed-time artificial insemination (FTAI) protocols for puberal Nellore heifers

The objective was to evaluate the effects of plasma progesterone (P4) concentrations and exogenous eCG on ovulation and pregnancy rates of pubertal Nellore heifers in fixed-time artificial insemination (FTAI) protocols. In Experiment 1 (Exp. 1), on Day 0 (7 d after ovulation), heifers (n = 15) were given 2 mg of estradiol benzoate (EB) im and randomly allocated to receive: an intravaginal progesterone-releasing device containing 0.558 g of P4 (group 0.5G, n = 4); an intravaginal device containing 1 g of P4 (group 1G, n = 4); 0.558 g of P4 and PGF2α (PGF; 150 μg d-cloprostenol, group 0.5G/PGF, n = 4); or 1 g of P4 and PGF (group 1G/PGF, n = 3). On Day 8, PGF was given to all heifers and intravaginal devices removed; 24 h later (Day 9), all heifers were given 1 mg EB im. In Exp. 2, pubertal Nellore heifers (n = 292) were treated as in Exp. 1, with FTAI on Day 10 (30 to 36 h after EB). In Exp. 3, pubertal heifers (n = 459) received the treatments described for groups 0.5G/PGF and 1G/PGF and were also given 300 IU of eCG im (groups 0.5G/PGF/eCG and 1G/PGF/eCG) at device removal (Day 8). In Exp. 1, plasma P4 concentrations were significantly higher in heifers that received 1.0 vs 0.588 g P4, and were significantly lower in heifers that received PGF on Day 0. In Exp. 2 and 3, there were no significant differences among groups in rates of ovulation (65-77%) or pregnancy (Exp. 2: 26-33%; Exp. 3: 39-43%). In Exp. 3, diameter of the dominant ovarian follicle on Day 9 was larger in heifers given 0.558 g vs 1.0 g P4 (10.3 ± 0.2 vs 9.3 ± 0.2 mm; P < 0.01). In conclusion, lesser amounts of P4 in the intravaginal device or PGF on Day 0 decreased plasma P4 from Days 1 to 8 and increased diameter of the dominant follicle on Day 9. However, neither of these nor 300 IU of eCG on Day 8 significantly increased rates of ovulation or pregnancy. © 2011.

Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO2), as a function of plant provenance and plant parts

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. ¹H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO2 were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated.

An alternative route to the synthesis of lignans intermediates

The preparation of beta -hydroxylignans intermediates via Baylis-Hillman reaction is described.

Microbial transformations of Aryltetralone and Aryltetralin Lignans by Cunninghamella echinulata and Beauveria bassiana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Lignans and diterpenes of three Aristolochia species

Phytochemical examination of Aristolochia cymbifera, A. esperanzae and A. galeata led to the isolation of furofuran and dibenzylbutyrolactone type lignans, as well as of clerodane and ent-labdane type diterpenes. Structural assignments for two new ent-labdans are presented and discussed. © 1988.

Genomic profile of a Li-Fraumeni-like syndrome patient with a 45,X/46,XX karyotype, presenting neither mutations in TP53 nor clinical stigmata of Turner syndrome

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Migrantes nor(destinados): uma análise sobre o estigma e a exclusão no ambiente escolar

Pós-graduação em Docência para a Educação Básica - FC