BACKGROUND Globozoospermia is a severe form of teratozoospermia (incidence < 0.1%) in infertile men that is characterized by round headed sperm and acrosomeless in semen. OBJECTIVE To compare the semen parameters, protamine deficiency, and apoptosis in ejaculated spermatozoa between globozoospermic and normozoospermic men. MATERIALS AND METHODS Thirty six semen samples were divided into two...

Detailed studies on the 13C and 1H NMRspectra of chromomycins A2 and A3, olivomycins A and B, and their derivatives clarified the assignment of manysignals which had been unassigned or erroneously reported in the literatures. The revised assignments for chromomycin A3 and olivomycin A include the assignment of a key 13C signal used to discuss the saccharide linkage in question. Structure analys...

Cytogenetic studies were carried out on Rhamdella microcephala collected from the headwaters of the Machado river, a tributary of the Sapucaí river, Minas Gerais, Brazil. Sixteen specimens exhibited 2n556 chromosomes, with 18 metacentrics, 30 submetacentrics and 8 subtelocentric-acrocentrics (FN584). The nucleolar organizing regions (NORs) were identified in the interstitial position on the lon...

Anti-cancer antibiotics, chromomycin A3 (CHR) and mithramycin (MTR) inhibit DNA directed RNA synthesis in vivo by binding reversibly to template DNA in the minor groove with GC base specificity, in the presence of divalent cations like Mg2+. Under physiological conditions, (drug)2Mg2+ complexes formed by the antibiotics are the potential DNA binding ligands. Structures of CHR and MTR differ in ...

Cytogenetic studies were carried out on eighteen wild specimens of Pterophyllum scalare from Jari River, in Pará state, and the results were compared to literature. Mitotic chromosomes were obtained from kidney cells and the analysis was done using: C-banding, Ag-NOR staining, Chromomycin A3/DAPI sequential staining and fluorochrome in situ hybridization with human telomere probes. All individu...

background: chromomycin a3 (cma3) staining has been used to assess protamine deficiency. the aim of this study was to determine credibility of cma3 along with semen parameters for assessment of fertility potential. materials and methods: semen analysis and cma3 staining were carried out on 234 fertile and 178 subfertile individuals. semen analysis was assessed according to who criteria. protami...

Intercalating, minor groove binding, and covalently bonding drugs were evaluated by mobility shift assays for their ability to interfere with transcription factors binding to their respective DNA recognition sequences. The Cys2His2 zinc finger proteins EGR1, WT1, and NIL2A, the basic leucine-zipper protein wbJun/wbFos, and the minor groove binding protein hTBP were chosen as representative tran...

BACKGROUND It has been claimed that by using different washing methods, the sperms can be separated according to size, motility, density, chromosomal content and surface markings and charge. These methods also reduce sperm chromatin deficiencies and screen the sperms before applying in assisted reproduction techniques. OBJECTIVE This study compared simple density gradient methods and a combin...

Cytogenetic and molecular investigations on the holocentric chromosomes of the aphid Macrosiphum euphorbiae (Thomas, 1878)have been carried out using silver staining and C-banding (followed by chromomycin A3 and DAPI staining) in order to improve our knowledge about the structure of aphid chromosomes. The C-banding pattern is peculiar since only the two X chromosomes and a single pair of autoso...

Yondelis (trabectedin) is an antitumor ecteinascidin that binds covalently to the 2-amino group of the central guanine in the minor groove of selected DNA pyrimidine-G-G and purine-G-C triplets. Chromomycin A3 is an aureolic acid derivative that binds noncovalently to the DNA minor groove in G/C-rich triplet sites as a metal-chelated dimer. Despite their different binding modes, the cytotoxicit...