Cyclic AMP during development and ageing of the insectCeratitis capitata

Summary Cyclic AMP was determined during the development of the dipteraCeratitis capitata. The concentration of the nucleotide reaches a peak at apolysis with a sharp decline in the pharate adult stage. A gradual increase takes place through the longevity of adult stage reaching a maximum plateau at the end of life.We are indebted to Prof.A. M. Municio for advice and encouragement and Mr.V. G. Corces for technical assistance.     

Diptera of Calliphora genus, potential carriers and spreaders of swine vesicular disease virus]

Swine Vesicular Disease virus ingested by the adult fly Calliphora persists several days in the digestive tract of the insect and is eliminated in feces. The virus ingested by the insect at larval stage has been recovered from the digestive tract and feces of adult flies. Thus, the dissemination of the virus, even in a limited fashion, seems to be possible and attention is chiefly centered on the second process.     

Formation of cutaneous nerve trunks in the chick. Ultrastructural and quantitative analysis]

In chick skin structuration of nervous trunks takes place at 14-15 days of incubation, at the time of formation of the adult pattern of cutaneous innervation. At this same stage, myelogenesis begins, but develops mainly after hatching: only 4% of axons are myelinated at hatching, 40% in 6-week old Chickens and 60% in adults. This "critical" stage (14-15 days of incubation) apparently corresponds to the stabilization of cutaneous nerve supply.     

Effect of gonadal extract of Helix aspersa Müller in the dominant male stage on in-vitro gametogenesis in juvenile and adult animals]

Juvenile and adult gonads of Helix aspersa Müller have been cultivated with or without gonadal extract of animals at the male stage. With this extract a better survival of the germinative epithelium and development of the different stages of meiosis in the male cells are observed.     

The effect of proctolin on the adenylate and guanylate cyclases in the Locusta brain at various developmental stages.

Proctolin at concentrations 10(-8)-10(-7) M elevated by 40% brain adenylate cyclase activity of adult Locusta migratoria migratoriodes R.F. In moulting individuals, proctolin caused a decrease in brain adenylate cyclase activity, and it proved to be ineffective in the larvae. Proctolin caused only a slight decrease on guanylate cyclase activity of the brain at every developmental stage.     

Differences between drosophila melanogaster and its sibling species D. simulans in sensitivity to acridine orange treatment

Larvae and adults of D. melanogaster and D. simulans were fed with acridine orange, in order to test sensitivity differences between the species. Our results show that, of the two species, D. simulans is more resistant in the larval stages, and D. melanogaster is more resistant in the adult stage. Furthermore, adult males of both species are more sensitive than adult females.     

Monoamine oxidase activity of the brain of Locusta migratoria in normal conditions and after intoxication by two insecticides: chlordimeform and dieldrin]

Our investigations have shown up an MAO activity in locust brain, by the use of a radio-isotopic method, as much at larval as at adult stage. This MAO activity is in a sample of 34,3 dpm/mg of brain tissue (wet weight). Investigations have also been undertaken on effects of dieldrin and chlordimeform poisoning on this MAO activity. Even at sublethal dosages, chlordimeform causes a significant inhibition of MAO activity in vivo. This finding is in accordance with Beeman and Matsumura's work in vitro. Moreover, acute poisoning by dieldrin produces more than 60% of inhibition of MAO, 3 hours after administration of 115 microng of this insecticide by injection in the hoemocelian cavity.     

Calmodulin in epithelial intestinal cells during rat development

Calmodulin was immunocytochemically localized in the brush borders of rat intestinal epithelial cells from the tip to the base of the villi, from day 18 of fetal life up to the adult stage. The early (14th day) fetal cells, like the adult crypt cells, were not immunoreactive, although their calmodulin content was equal to that of the mature cells from the tips of the villi.     

Calmodulin in epithelial intestinal cells during rat development

Summary Calmodulin was immunocytochemically localized in the brush borders of rat intestinal epithelial cells from the tip to the base of the villi, from day 18 of fetal life up to the adult stage. The early (14th day) fetal cells, like the adult crypt cells, were not immunoreactive, although their calmodulin content was equal to that of the mature cells from the tips of the villi.     

Octopamine levels during the moult cycle and adult development in the migratory locust, Locusta migratoria.

Octopamine content of the head of the locust Locusta migratoria has been determined during the last larval stage, moulting and adult life of 3 groups of insects: female and male gregarious, solitary and CO2 solitarized. An important difference was found between these 3 groups. Octopamine contents increased in the middle of the larval life and during the adult life. The moulting time is characterized by a sharp decrease of the octopamine content which becomes identical in the 3 groups of insects. The relation between octopamine content, hormone cycles and motility is discussed.     

Role of granular cells in the placement and distribution of synapses between ascending fibers and Purkinje cells of the rat cerebellum]

The study of rats irradiated during development shows that the establishment of the one-to-one relationship in the adult between climbing fibers and Purkinje cells which follows the immature multiply innervated stage mainly depends on granule cells formed before day 8. Climbing fibers ending upon a multiply innervated cell are intermingled on the same dendritic segments.     

Critical period and ecdysone titers in the pupae ofPieris brassicae

Summary The ecdysone titer in the haemolymph of pupae of Pieris brassicae shows a sharp peak (1.90 g/ml) on days 5 and 6 of the pupal stage. Isolated abdomens were able to form adult abdomens at 72 h, this being 2 or 3 days before maximum ecdysone levels and at a time when the concentration of hormone in the abdominal haemolymph was only 0.23 g/ml.     

Octopamine levels during the moult cycle and adult development in the migratory locust,Locusta migratoria

Summary Octopamine content of the head of the locustLocusta migratoria has been determined during the last larval stage, moulting and adult life of 3 groups of insects: female and male gregarious, solitary and CO₂ solitarized. An important difference was found between these 3 groups. Octopamine contents increased in the middle of the larval life and during the adult life. The moulting time is characterized by a sharp decrease of the octopamine content which becomes identical in the 3 groups of insects. The relation between octopamine content, hormone cycles and motility is discussed.     

Appearance of growth-inhibiting activity (G1 chalone) during ontogenetic development of rat and chick epidermis in vivo and in vitro.

A comparative study was carried out between the stage of embryonic development of epidermis and its content of growth-inhibitory activity (G1 chalone). Injections of aqueous extracts from keratinized fetal rat or chick embryo epidermis led to a depression of DNA-synthesis in adult mouse epidermis, whereas extracts from undifferentiated epidermis did not contain such an activity.     

Development of nucleoside phosphotransferase activity in the cerebral hemispheres of embryonal and adult chick

Summary In the cerebral hemispheres of the chick embryo, the level of nucleoside phosphotransferase activity is much higher than that of thymidine kinase and it increases progressively during development up to the adult stage. Therefore nucleoside phosphotransferase is not coupled with DNA synthesis.     

Study of gangliosides in normal (C57B1/6J) and quaking mice. Presence and characterization of a labile ganglioside in alkaline solution]

In the adult Quaking mutant, there is an increase in some polysialogangliosides (GT1 and Gq) and a 50% decrease in BM1 content. Thus, the latter ganglioside, which is a constituent of mature myelin, could be linked to one of the late steps of the myelination process. A novel ganglioside ALG1, which appears during the postnatal development of brain, has been isolated and purified; it contains an alkali labile linkage and after alkaline treatment yields GT1b. Comparison between normal Mice and Quaking mutants does not show any significant quantitative differences, under our conditions. At the stage at which it appears, it could be linked to steps of brain maturation other than myelimation.     

Molecular and Cellular Basis of Regeneration and Tissue Repair

Although early after birth the central nervous system is more plastic than in the adult, it already displays limited regenerative capability. This becomes severely impaired at specific stages of embryonic development; however, the precise cellular and molecular basis of this loss is not fully understood. The chick embryo provides an ideal model for direct comparisons of regenerating and non-regenerating spinal cord within the same species because of its accessibility in ovo, the extensive knowledge of chick neural development and the molecular tools now available. Regenerative ability in the chick is lost at around E13, a relatively advanced stage of spinal cord development. This is most likely due to a complex series of events: there is evidence to suggest that developmentally regulated changes in the early response to injury, expression of inhibitory molecules and neurogenesis may contribute to loss of regenerative capacity in the chick spinal cord.     

Microdensitometric analysis of denervation effects on newt limb blastema cells

Summary This report examines the fate of cycling cells in normal and denervated blastemas of adult newts. Cells are found to accumulate in G₁ in blastemas which are nerve independent. No stage specific accumulation different from controls is found in limbs with nerve-dependent blastemas.     

Identification of JH III as the princpal juvenile hormone inLocusta migratoria

Summary JH titers in the hemolymph of nymphal and adult femaleLocusta migratoria migratorioides (R. and F.) were determined using a selective mass spectrosc opic detection technique. Only JH III could be found in either stage, with no detectable JH I (or II). Titers observed were 10–1000-fold lower than those found via a recently reported radioimmunoassay procedure.     

Appearance of growth-inhibiting activity (G1 chalone) during ontogenetic development of rat and chick epidermis in vivo and in vitro

Summary A comparative study was carried out between the stage of embryonic development of epidermis and its content of growth-inhibitory activity (G₁ chalone). Injections of aqueous extracts from keratinized fetal rat or chick embryo epidermis led to a depression of DNA-synthesis in adult mouse epidermis, whereas extracts from undifferentiated epidermis did not contain such an activity.This investigation was supported by the Deutsche Forschungsgemeinschaft.