On the action of chromomycin on the eggs and embryos ofCiona intestinalis

Riassunto È stata studiata l'azione della cromomicina sulle uova diCiona intestinalis (Ascidie) in diversi stadi di sviluppo. Essa non esercita alcun effetto sull'uovo vergine o appena fecondato; modifica invece notevolmente la morfogenesi se il trattamento è portato sulle uova in gastrulazione. I risultati vengono spiegati ammettendo che la cromomicina esercita la stessa azione che la actinomicina D e cioè inibisce la sintesi del MRNA.     

A method for karyotyping mouse blastocyst embryos developing from in vivo and in vitro fertilized eggs

A method for karyotyping blastocyst-staged mouse embryos is described. The use of this protocol results in the recovery of a high percentage (greater than 70%) of readable karyotypes and can be completed rapidly.     

A method for karyotyping mouse blastocyst embryos developing from in vivo and in vitro fertilized eggs

Summary A method for karyotyping blastocyst-staged mouse embryos is described. The use of this protocol results in the recovery of a high percentage (>70%) of readable karyotypes and can be completed rapidly.This research was supported by NIH grants HD-00827 and HD-09753.     

Further studies on free amino-acids and peptides in eggs and embryos of different sea-urchin species and hybrids

Zusammenfassung Als Fortsetzung früherer Untersuchungen der freien Aminosäuren und Peptiden in Eiern und Embryonen verschiedener Seeigelarten, wurde das Muster der Ninhydrin-positiven Stoffe vonEchinocardium cordatum, Psammechinus microtuberculatus undGenocidaris maculata papierchromatographisch untersucht. DieEchinocardium-Eier zeichnen sich durch ihre hohe Konzentration an Valin (Fig. 1A, Fleck 16) und Leucin (Fleck 9) aus, welche bei allen übrigen von uns untersuchten Arten nur in sehr geringer Menge auftreten. Ferner sind sie durch das Vorkommen eines spezifischen Stoffes charakterisiert, der nur beiArbacia lixula nachgewiesen wurde (Fleck 17).Psammechinus microtuberculatus undGenocidaris maculata unterscheiden sich in den Peptiden. DiePsammechinus-Eier enthalten einen Stoff, der wahrscheinlich mit dem Tripeptid vonSphaerechinus granularis identisch ist (Fig. 1B, Fleck Nr. 23). InGenocidaris-Eiern wurde ein Peptid registriert, das auch beiParacentrotus lividus vorkommt (Fig. 1C, Fleck Nr. 21).Es wurden ferner Messungen von Eivolumen, Total-stickstoff und Totalmenge der freien Ninhydrin-positiven Substanzen des unbefruchteten Eies durchgeführt. Das Eivolumen und der Gesamtstickstoffgehalt sind beiEchinocardium cordatum am grössten, beiArbacia lixula am geringsten. DieEchinocardium-Eier sind durch ihren hohen Gehalt an freien Aminosäuren gekennzeichnet. Sie enthalten rund 7mal mehr solche Stoffe pro Ei als dieArbacia-Eier; zwischenParacentrotus lividus undSphaerechinus granularis zeigen die Messwerte keinen deutlichen Unterschied.     

Effects of puromycin on rat embryos in vitro

Summary Somite-staged rat embryos were exposed to varying concentrations of puromycin for 48 h in vitro. Medium concentrations below 0.92 M had no significant effects, while concentrations above 1.84 M were lethal. Between these extremes, there were concentration dependent increases in the incidence of malformations in a close relationship to growth retardation.     

Effects of puromycin on rat embryos in vitro

Somite-staged rat embryos were exposed to varying concentrations of puromycin for 48 h in vitro. Medium concentrations below 0.92 microM had no significant effects, while concentrations above 1.84 microM were lethal. Between these extremes, there were concentration dependent increases in the incidence of malformations in a close relationship to growth retardation.     

Effects of ethanol and acetaldehyde on cultured pre-implantation mouse embryos

Summary Pre-implantation 2-cell stage mouse embryos, obtained from superovulated CF-1 mice, were exposed to ethanol and acetaldehyde through the culture medium for 60 min followed by a 105-h incubation period. Control and ethanol exposed embryos survived equally well in ethanol concentrations as high as 800mg/100 ml medium and acetaldehyde levels up to 10 mg/100 ml medium.     

Effects of ethanol and acetaldehyde on cultured pre-implantation mouse embryos

Pre-implantation 2-cell stage mouse embryos, obtained from superovulated CF-1 mice, were exposed to ethanol and acetaldehyde through the culture medium for 60 min followed by a 105-h incubation period. Control and ethanol exposed embryos survived equally well in ethanol concentrations as high as 800 mg/100 ml medium and acetaldehyde levels up to 10 mg/100 ml medium.     

Effects of gamma-rays on the developing embryos of Calotes versicolor.

The gamma-ray irradiation causes mortality, retardation in development and growth rate, haemorrhage, axial defects and unilateral microphthalmia. Histological examination of microphthalmic embryos revealed a partial division of the left optic cup and a 'double lens'.     

Effects of dibutyryl cyclic AMP on cultured brain cells from chick embryos of different ages

Summary The effect of dibutyryl cyclic AMP on cultivated astroblasts from 8-, 12- and 15-day-old chick embryo brain has been studied. The results show that these cells must have reached some degree of maturation in ovo to become morphologically differentiated by the cyclic nucleotide.     

Effects of beta-hydroxybutyrate on rat embryos grown in culture

In order to investigate further the relationship between maternal diabetes and fetal malformation, rat embryos were grown in vitro in the presence of beta-hydroxybutyrate, one of the ketone bodies produced by diabetics. At 10 mM, beta-hydroxybutyrate produced minor abnormalities and at 20 mM it produced major abnormalities in rat embryos.     

Effects of lithium chloride on normal and neoplastic cells in vitro

Résumé L'action du lithium (LiCl) a été étudiée comparativement sur des cellules néoplasiques humaines KB et normales de rein de singe. Les résultats obtenus démontrent que le LiCl en concentrations égales et supérieures à 5.10^–2 M entraîne une inhibition significative de la prolifération des deux types cellulaires. D'autre part, pour des temps d'exposition supérieurs à 24h, cet effet cytoinhibiteur s'accompagne d'une diminution de la quantité des RNA cytoplasmiques. Ces effets du LiCl apparaissent sélectifs par rapport à ceux du NaCl utilisés en concentrations équimoléculaires.     

Effects of dibutyryl cyclic AMP on cultured brain cells from chick embryos of different ages.

The effect of dibutyryl cyclic AMP on cultivated astroblasts from 8-, 12- and 15-day-old chick embryo brain has been studied. The results show that these cells must have reached some degree of maturation in ovo to become morphologically differentiated by the cyclic nucleotide.     

Effects of low temperatures on survival of frozen-thawed mouse embryos

Summary Almost no damage to mouse morulae was observed between 0 and –40°C, and freezing damage to embryos in DMSO, glycerol or ethylene glycol occurred after exposure to –60, –50 or –50°C, respectively. Cooling embryos in DMSO or glycerol to temperatures below –50 to –60°C increased freezing damage. To the contrary, in the presence of ethylene, glycol, no more damage occurred after exposure to temperatures below –50°C.     

Effects of chronic lithium administration on concanavalin A binding to plasma membranes from the corpus striatum of rat brain

Summary The effects of chronic in vivo lithium administration on mannose-containing components of plasma membranes from rat corpus striatum were examined by a³H-concanavalin A binding displacement method. No difference in Con A binding was observed between sodium or lithium-treated rats during a 1-month period.We thank Dr S. Gershon of this research unit for his encouragement and support during these studies.