THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (III): THE NUCLEAR MATRIX AND THE NUCLEAR LAMINA

A large variety of nuclear fibrous proteins (such as actin, myosin, lamin B, transcription factors, topoisomerases, etc) represent constitutive elements of complex structures present in the eukaryotic nuclei: the nuclear matrix and the nuclear lamina, repectively. These nuclear compartments, with fibrous network-like structure, play crucial roles in structural organization of nuclei, chromatin remodeling, DNA transcription, signals transduction, cell cycle regulation, embryonic development and other nuclear basic processes

THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (II): CHROMOSOME TERRITORIES AND THE INTERCHROMATIN DOMAINS

chromosomes territories (CTs), interchromatin network model (ICN), insulator elements, interchromatin (interchromosomal) compartment (IC

THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (IV): THE NUCLEAR ENVELOPE

The nuclear envelope (NE), a double membrane structure, separates the nucleoplasm from cytosol. Each of the two membranes of the NE (the inner nuclear membrane, INM and the outer nuclear membrane, ONM) contain a particular protein complement, with specific domains, which accomplish various and critical functions: the lamin and chromatin anchoring at NE, the localization and movement of nucleus within cells, the control of transciption, etc. The nuclear pores complexes (NPCs) of the NE are large and complicated proteic structures, essentially involved in bidirectional transport of molecules between nucleus and cytoplasm. Some nuclear envelope molecular components are subjected to various genetic disorders known as envelopathies, which result in general syndroms, more or less severe

THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (II): CHROMOSOME TERRITORIES AND THE INTERCHROMATIN DOMAINS

chromosomes territories (CTs), interchromatin network model (ICN), insulator elements, interchromatin (interchromosomal) compartment (IC

MITOSIS ANA-THELOPHASE CHROMOSOMAL ABERRATIONS INDUCED BY UV IRRADIATION UNDER THE ANTIOXIDATIVE PROTECTION OF VITAMIN C, BY CALENDULA OFFICINALIS L.

due to the stratospheric ozone layer depletion, the researches focused in the last decades on the study of solar radiations reaching Earth surface. The target of the study was to establish the biological response of Calendula officinalis L. to UV irradiation, under the anti-oxidative protection of vitamin C, (which helps next to UV induced anti-oxidative enzymes, in the protection against a large variety of products capable to induce free radicals formation). Our investigations were focused on detecting chromosomal aberrations which occurs during cells in division in meristem root tips, under UV irradiation for 15 or 30 minutes, in the presence or absence of vitamin C, reported to the non- irradiated control samples. Regarding the mitotic index, it could be noticed an inhibition of cell division frequency under UV stress for all irradiated variants, not depending of presence or absence of vitamin C, positively correlated with the increase of irradiation period. Maximal chromosomal aberrations frequency, were induced by UV radiations in the root tips of seedlings germinated in the absence of vitamin C, decreasing in the presence of vitamin C, due to the antioxidant protective role of this. In the absence of UV irradiation, the chromosomal aberrations frequency was lower comparing with irradiated variants, for all seedlings, even if germinated in the presence or absence of vitamin C. Between chromosomal aberrations were detected: bridges, expulsed and retardate chromosomes, fragments

Some citogenetic effects of sodium azide treatments in caraway root meristems

Sodium azide (NaN3) still remains a popular plant mutagen. In the present investigation, its effects on the cytogenetic changes were studied in root tip cells of Carum carvi L., an important economical and medicinal crop plant. The study revealed that sodium azide decreased mitotic index, and caused increase of chromosomal aberrations. Altogether, sodium azide treated root tip cells exhibited an increased incidence of bridges, lagging and/or expulsed chromosomes and C-metaphases

Carassius genetic diversity investigation from Tautesti Lake (Iasi County)

n this experiment we investigated the genetic diversity of Carassius gibelio Bloch, individuals, from Tautesti (Iasi County) pond, using the sequencing of cytochrome b as a codominat-marker. The analysis of cytochrome b first part gene coding region has permitted to establish if there is a wild population or the pond was repopulated in the last years

CYTOGENETIC EFFECTS INDUCED BY 4-CHLOROHYDRATE-BROMO-6-METHYL-3-DIMETHYLAMINO-3-CHROMANONE IN OCIMUM BASILICUM L. SPECIES

: In this study, a series of modifications issued at the material genetic level of meristematic cells of root tips of Ocimum basilicum L. are presented, as consequence of the treatment with 4-chlorohydrate-bromo-6-methyl-3- dimethylamino-3-chromanone. The 1/10000 dilution induces the increase of frequency of mitotic dividing cells. The cells with chromosome aberrations are in greater number in treated variants, comparatively with control. The aberration spectrum is enough large and comprises: ana-telophases with bridges, lagging chromosomes, expelled chromosomes, multipolar ana-telophases, as well as binucleate cells and interphases with micronucleuses

INFLUENCE OF SUMIDAN ON MITOTIC DIVISION IN TRIGONELLA FOENUM GRAECUM L. SPECIES

: This paper includes the cytogenetic effects induced by sumidan insectofungicide in meristematic cells of Trigonella foenum graecum L. root tips. The increase of pesticide concentration determined the decrease of mitotic index, while the frequency and the type of chromosome aberrations are much greater in treated variants, comparatively with control

EVALUATION OF THE AMPLITUDE OF CYTOGENETIC DAMAGE INDUCED BY TWO FOOD ADDITIVES IN WHEAT

Sulfites and metabisulfites, nitrates and nitrites are among the most utilized food additives. They can determine negative reactions in human body, but some of them showed genotoxic and carcinogenic action in various test-systems. In this study, we analyzed the amplitude of the cytogenetic changes induced by the exposure to different concentrations (0.1%, 0.5%, and 1.0%) of sodium nitrate (E251; SN) and sodium metabisulfite (E223; SMB) in wheat root tips meristems, by scoring the mitotic index and the frequency of division phases, the rates of ana-telophase chromosome aberrations, and of metaphase disturbances. Also, the influence on plantlet length was analyzed in young plantlets. The two chemicals increased the amount of chromosome aberrations, depending on concentration and time exposure