Dynamika wzrostu kalusa oraz regeneracja struktur embrioidalnych u kaktusa z rodzaju Gymnocalycium w zaleznosci od warunkow swietlnych

Badano wpływ jakości światła i ciemności na tempo regeneracji kalusa embriogennego Gymnocalycium mihanovichii (FRIČ ET GÜRKE) BRITTON ET ROSE f. aurantiaca in vitro. Stwierdzono, że przyrost kalusa na zmodyfikowanej pożywce MS bez regulatorów wzrostu był największy pod światłem żółtym oraz czerwonym. Największa zaś liczba kalusów zregenerowała struktury embrioidalne pod światłem żółtym, dziennym oraz czerwonym.The influence of light quality and darkness on the rate of regeneration of callus and embryogenic structures of Gymnocalycium mihanovichii (FRIČ ET GÜRKE) BRITTON ET ROSE f. aurantiaca in vitro was studied. The increment of callus on the modified MS medium without growth regulators was biggest under the yellow and red light conditions, and a high number of calli regenerated embryogenic structures under the yellow, daylight and red light conditions

Wystepowanie barwnikow w kwiatach jezyczkowatych chryzantemy wielkokwiatowej [Dendranthema grandiflora Tzvelev] w zaleznosci od rodzaju paka kwiatostanowego

Badano występowanie barwników w kwiatach języczkowatych trzech odmian chryzantemy wielkokwiatowej (Dendranthema grandiflora TZVELEV) w zależności od rodzaju pąka kwiatostanowego, w uprawie prowadzonej w szklarni od 24 kwietnia. Stwierdzono wyraźną zależność zawartości antocyjanów od rodzaju pąka kwiatostanowego u odmian 'Gonzo Rood' oraz 'Succes'. Stężenie tych barwników wzrastało w kolejno tworzących się kwiatostanach. Zawartość pozostałych barwników (flawonów i karotenoidów) nie wykazała ścisłej zależności od rodzaju pąka.The occurrence of pigments in ligulate florets of three Dendranthema grandiflora TZVELEV cultivars, grown in a greenhouse since April 24, were studied as affected by the kind of inflorescence bud. The concentration of anthocyanins was found to be considerably dependent on the kind of inflorescence bud in 'Gonzo Rood1 and 'Succes' cultivars. The concentration of these pigments increased in successively developing inflorescences, whereas the contents of other pigments (flavones and carotenoids) did not show any clear dependence on the bud kind

Regeneration of callus from root explants of Chrysanthemum × grandiflorum (Ramat.) Kitam.

Celem badań było opracowanie metody regeneracji kalusa oraz zarodków somatycznych z eksplantatów korzeniowych u chryzantem. Fragmenty korzeni inoku-lowano na pożywki MS zawierające 2,0 mg∙dm-3 6-benzyloaminopuryny (BAP) oraz od 0,0 do 0,5 mg∙dm-3 kwasu 2,4-dichlorofenoksyoctowego (2,4-D). Uzyskano regenerację kalusa oraz zarodków somatycznych u badanych odmian tylko na pożywkach zawierających jednocześnie auksynę i cytokininę. W drugim doświadczeniu kalus zregenerowany na pożywce zawierającej 0,1 mg∙dm-3 2,4-D i 2,0 mg∙dm-3 BAP przeniesiono na pożywki o zróżnicowanej zawartości regulatorów wzrostu, tiaminy i sacharozy. Określono przyrost świeżej masy kalusa oraz liczbę zarodków somatycznych. Przyrost świeżej masy kalusa najlepiej stymulowała pożywka z dodatkiem 0,6 mg∙dm-3 BAP i 2,0 mg∙dm-3 kwasu indolilo-3-octowego (IAA) oraz zawierająca 3,0 mg∙dm-3 KIN (kinetynę) i 0,5 mg∙dm-3 IAA, przy obniżonej zawartości sacharozy i podwyższonej zawartości tiaminy. W zależności od zastosowanej pożywki uzyskano do 0,92 zarodków somatycznych w przeliczeniu na eksplantat. Na podstawie przeprowadzonych badań stwierdzono, że eksplantaty korzeniowe mogą być przydatnym materiałem do regeneracji kalusa oraz zarodków somatycznych u chryzantem.Chrysanthemums are often the object of breeding using mutation as a source of variability. This method often results in the formation of periclinal chimeras, which propagated in vitro may be subjected to the separation of components. Therefore it is important to describe effective procedures to determine whether the cultivar is a chimera. The aim of experiments was to describe the method for regeneration of callus and somatic embryos from the root explants of the three chrysanthemum cultivars. In order to investigate the impact of the medium for the callus and somatic embryos formation, in the first experiment root explants included apex were collected and cultured horizontally on the media containing 2 mg∙dm-3 6-benzylaminopurine (BAP) and a 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mg∙dm-3 2,4-dichlorophenoxyacetic acid (2,4-D). After 10 weeks weight of callus and number of somatic embryos were determined. In the second experiment, callus were cultured on medium with 0.1 and 2 mg∙dm-3 BAP, next after 10 weeks callus was transferred on the three media, which differed content of BAP (0.6, 3.0 and 0.0 mg∙dm-3), kinetin (KIN) (0.0 or 3.0 mg∙dm-3) and 3-indoleacetic acid (IAA) (2.0 or 0.5 mg∙dm-3), as well as thiamin (0.1 or 0.4 mg∙dm-3) and sucrose (30 or 10 g∙dm-3). After 12 weeks the increase of the fresh weight of callus and number of somatic embryos were determined. In the first experiment callus and somatic embryos regeneration was obtained only on media containing auxin and cytokinin. In the second experiment the callus formation was stimulated the best on the medium containing 0.6 mg-dm-3 BAP and 2.0 mg-dm-3 IAA with a standard concentration of sucrose and thiamine, and on the medium enriched with 3.0 mg-dm-3 KIN and 0.5 mg-dm-3 IAA at a reduced sucrose and increased thiamine content. Also a single somatic embryos were regenerated, however, any formation of adventitious shoots was observed. Experiments have demonstrated that induction of the regeneration of the callus and somatic embryos on the root explants of the examined chrysanthemum cultivars was conditioned by the presence the auxin 2,4-D and cytokinin BAP in the medium. Depending on the medium used was obtained to 0.92 somatic embryos per explant. Chrysanthemum root explants can be useful material for the callus and somatic embryos regeneration, however, the description of efficient procedures requires further research

Loss of function of NaPiIIa causes nephrocalcinosis and possibly kidney insufficiency

BACKGROUND Inherited metabolic disorders associated with nephrocalcinosis are rare conditions. The aim of this study was to identify the genetic cause of an Israeli-Arab boy from a consanguineous family with severe nephrocalcinosis and kidney insufficiency. METHODS Clinical and biochemical data of the proband and family members were obtained from both previous and recent medical charts. Genomic DNA was isolated from peripheral blood cells. The coding sequence and splice sites of candidate genes (CYP24A1, CYP27B1, FGF23, KLOTHO, SLC34A3 and SLC34A1) were sequenced directly. Functional studies were performed in Xenopus laevis oocytes and in transfected opossum kidney (OK) cells. RESULTS Our patient was identified as having nephrocalcinosis in utero, and at the age of 16.5 years, he had kidney insufficiency but no bone disease. Genetic analysis revealed a novel homozygous missense mutation, Arg215Gln, in SLC34A1, which encodes the renal sodium phosphate cotransporter NaPiIIa. Functional studies of the Arg215Gln mutant revealed reduced transport activity in Xenopus laevis oocytes and increased intracellular cytoplasmic accumulation in OK cells. CONCLUSIONS Our findings show that dysfunction of the human NaPiIIa causes severe renal calcification that may eventually lead to reduced kidney function, rather than complications of phosphate loss

Nanomechanics of multidomain neuronal cell adhesion protein contactin revealed by single molecule AFM and SMD

Contactin-4 (CNTN4) is a complex cell adhesion molecule (CAM) localized at neuronal membranes, playing a key role in maintaining the mechanical integrity and signaling properties of the synapse. CNTN4 consists of six immunoglobulin C2 type (IgC2) domains and four fibronectin type III (FnIII) domains that are shared with many other CAMs. Mutations in CNTN4 gene have been linked to various psychiatric disorders. Toward elucidating the response of this modular protein to mechanical stress, we studied its force-induced unfolding using single molecule atomic force microscopy (smAFM) and steered molecular dynamics (SMD) simulations. Extensive smAFM and SMD data both indicate the distinctive mechanical behavior of the two types of modules distinguished by unique force-extension signatures. The data also reveal the heterogeneity of the response of the individual FNIII and IgC2 modules, which presumably plays a role in the adaptability of CNTN4 to maintaining cell-cell communication and adhesion properties under different conditions. Results show that extensive sampling of force spectra, facilitated by robot-enhanced AFM, can help reveal the existence of weak stabilizing interactions between the domains of multidomain proteins, and provide insights into the nanomechanics of such multidomain or heteromeric proteins