Regeneration of Picea omorika plants via organogenesis

Picea omorika plants were regenerated from embryo and seedling shoot tip cultures. Adventitious and axillary shoots were produced on 1/2 MS medium containing benzyladenine and kinetin. Benzyladenine was more effective in bud induction, whereas kinetin hastened shoot development. Excised shoots were elongated on 1/3 MS medium without growth regulators, multiplied with kinetin and rooted with or without indole-3-butyric acid.Abbreviations BA N⁶-benzyladenine - 2IP N ⁶-(²-isopenteny) adenine - NAA -naphthaleneacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid     

Genetic transformation of alfalfa somatic embryos and their clonal propagation through repetitive somatic embryogenesis

Genetically transformed alfalfa (Medicago sativa L., cv. Zajearska 83) plantlets were obtained by inoculating somatic embryos with Agrobacterium tumefaciens strains A281/pGA472 and LBA4404/pBI121. Single somatic embryos, 5–7 mm long, were released from a repetitively embryogenic culture, wounded, and cocultivated with the bacteria. The agar-solidified culture medium contained mineral salts, vitamins, 40 g l^–1 sucrose, 1 g l^–1 yeast extract and 0.05 mg l^–1 BA. Five clones, transformed with A281/pGA472, and 4 clones transformed with LBA4404/pBI121, were selected for proliferation by repetitive somatic embryogenesis, on media containing 100 mg l^–1 of kanamycin. The transformation of kanamycin-resistant clones was confirmed by assaying the activity of neomycin phosphotransferase II and/or -glucuronidase enzymes, and by the Southern blot analysis. It is suggested that the transformation/regeneration system based on somatic embryogenesis may be suitable for establishing transgenic alfalfa lines. The relatively low frequency of embryo transformation is compensated for by abundant proliferation in secondary somatic embryogenesis.Abbreviations BA 6-benzyladenine - GUS -glucuronidase - Km kanamycin - NPTII neomycin phosphotransferase II - X-gluc 5-bromo-4-chloro-3-indolyl--glucuronic acid - BM basal medium     

Ultrastructural observations on the presence of stereocilia in myoblasts of Scyllium stellare

Many Authors described primary 9+0 cilia in different tissue of different animal species. In relation to the study on the ultrastructural architecture of the embryonic heart of a elasmobranch "Scyllium stellare", we saw some primary 9+0 cilia in very undifferentiated heart tissue. The hearts dissected from the Scyllium stellare embryo at 6 months of gestation, were processed for the observations at the transmission electron microscope. The cilia are found in deep invagination of the plasma membrane, near the Golgi complex and in the perinuclear region. Various functions have been postulated for the primary 9+0 cilia.     

Influence of maternal adrenalectomy on the ultrastructure of the adrenal gland in neonatal rats

Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.     

Recombinant chromosome as a result of pericentric inversion of X chromosome

Summary A structural X chromosome abnormality was found in the karyotype of a tall patient with gonadal dysgenesis and with no extragenital anomalies. Based on her mother's karyotype, which showed a pericentric inversion of the X chromosome: 46,X,inv(X)(p22q24), as well as from G and R banding, we concluded that the abnormal X chromosome of our patient was a recombinant chromosome that had originated as a result of one crossing over in the inversion loop during gametogenesis in her mother. The recombinant X chromosome had a partial deletion of Xq and a partial duplication of Xp: 46,X,rec(X),dup p,inv(X)(p22q24). After BUDR incorporation, the abnormal X chromosome of the patient and that of her mother showed a late replication. The karyotype-phenotype correlation and the nonrandom inactivation of the inverted X chromosome in the mother are discussed.     

Chromosomal and histological changes in the reproductive organs of infertile men

Summary The chromosomal changes in the process of spermatogenesis in 27 infertile men have been examined. Normal chromosomal meiotic activity was found in 44% of cases, various chromosomal anomalies were seen in 18%, and no cells in meiosis were detected in 37% of cases.     

Age-related changes in chromatin of liver cell nuclei of different ploidity

Summary A comparsion of the Feulgen hydrolysis curves and the chromatin compactness of the liver cell nuclei of young and old rats was made. It was found that the rate of DNA depurination and chromatin compactness are higher in the liver cell nuclei of old rats, both in di-and tetraploidal cells. The effect of fixation upon the course of the hydrolysis curves is discussed.This investigation was supported by grant 474/VI Committee of Cell Pathology, Polish Academy of Sciences     

The effect of phosphatidylcholine depletion on biochemical and physical properties of a Neurospora crassa membrane mutant

By using the choline starvation process it is possible to deplete the membranes of Neurospora crassa choline auxotroph $\text{chol-1}$ of phosphatidylcholine, without affecting the viability of germinated spores or whole mycelium. Spin label probes were used to examine the possible dependence of the physical state of cellular lipids on the presence of phosphatidylcholine in the membranes.Increased freedom of rotational motion of lipid soluble probes was regularly detected in choline-starved mycelium. The accumulation of neutral lipids (mostly triglycerides) in bulk form was also observed during the choline starvation process. The experiments with isolated and separated lipid classes indicated that the observed increase in fluidity of lipids in choline-starved mycelium is partly due to the difference in physical properties between bulk lipids and membrane lipids. Spin label probe 2N4 ($\text{2-}\text{propyl}\text{-2,5,5-}\text{trimethyl-oxazolidine}\text{-N-}\text{oxyl}$), which can partition at the membrane-water interface, exhibited easier partitioning among membrane lipids of choline-starved mycelium.     

The effect of sodium on depolarization-induced calcium uptake and acetylcholine release by synaptosomes

The influence of external sodium concentration on potassium (depolarizing agent)-stimulated calcium uptake and Ca⁺-dependent acetylcholine release by rat cerebral cortex synaptosomes has been studied. It was found that increased sodium concentration decreases both the Ca²⁺ uptake and the acetylcholine release, whereas a low external sodium concentration is stimulatory.