Somatic embryogenesis and plant regeneration inAcanthopanax sciadophylloides

Somatic embryos ofAcanthopanax sciadophylloides Franch. et Sav. were differentiated from both zygotic and somatic embryos and calli, and plants were regenerated from these somatic embryos. A zygotic embryo, enclosed within a small portion of the endosperm, was incubated on Murashige and Skoog (MS) media supplemented with various combinations (range 0–10.0 mg/l) of 6-benzylaminopurine (BAP) and 2,4-dichlorophenoxyacetic acid (2,4-D). After 4 months, swelling of the zygotic embryos and callus formation was observed. When the swollen embryos were transferred to MS medium supplemented with 0.5 mg/l of 2,4-D, somatic embryos were formed in one to two months. After subculture on the same medium, new embryos were differentiated from various parts of the older somatic embryos. The calli were cultured on medium supplemented with 2.0 mg/l of 2,4-D and BAP for three weeks. Proliferated calli were transferred to medium supplemented with 1.0 mg/l of 2,4-D and BAP. Somatic embryos were differentiated from the calli within one to two months. Somatic embryos were germinated on half-strength MS medium without plant growth regulators and the plantlets were grown in soil. A part of this paper was presented at the 106th Annual Meeting of the Japanese Forestry Society (1995) & First Asia-Pacific Symposium on Forest Tree Genetic Improvement (Beijing).     

Genetic and environmental variances on growth and reproductive traits of silver crucian carp Carassius langsdorfii using communal and separate rearing systems

SUMMARY: Five clonal lines of silver crucian carp Carassius langsdorfii were produced from natural maternal fish to estimate the variance and heritability of total length, bodyweight and gonadosomatic index (GSI). The larvae on the 10th day after hatching were reared together in a common rearing system with five duplicate systems. Another system was prepared using a separate system with two replications in each family. Estimation of variance and heritability were done in the first, third, fifth and 10th month for total length and bodyweight. Microsatellite DNA markers were used to identify the clonal lines in each communal rearing tank. Average heritabilities in the first month were 0.105 for total length (ranging from 0.21 to 0.03) and 0.127 for bodyweight (ranging from 0.22 to 0.06) then decreased in the third, fifth and 10th month. In contrast, intermediate levels of heritability from separate systems were observed. Likewise, relative heritability of GSI in the 10th month presented a high level in both rearing systems. Those heritabilities indicated that growth, total length, bodyweight and reproductive performances of silver crucian carp were affected by genetic influence. The results suggest that clonal lines of silver crucian carp are suitable as experimental animals for evaluations of environmental change and various pollutants through quantitative traits such as growth, reproductive and other physiological traits.     

Sporadic congenital transmission of avian leukosis virus in hens discharging the virus into the oviducts.

The efficacy of the albumen test for infectious avian leukosis virus (ALV) was examined in detecting congenitally transmitting hens. Seventy-three White Leghorn non-viremic hens with antibody to ALV were used. Eleven of the hens shed infectious ALV into their egg albumen, whereas only 7 of the 11 ALV-positive hens shed ALV antigens. The egg albumen test for infectious ALV was shown to be more effective in detecting the congenitally transmitting hens than that for ALV antigens. Then, twenty of the 62 hens which shed no infectious ALV into the albumen were studied for transmission of ALV to their embryos and for discharging ALV into the oviduct and vagina. Six of the 50 embryos from 4 hens were found to be infected with ALV but all of the 227 embryos from remaining 16 hens were free from the infection. Discharge of the virus into the oviduct and vagina was found both in the 4 transmitting hens and in 6 of the 16 non-transmitting hens. These results suggest that the hens discharging ALV into the oviduct, even though they do not shed ALV into egg albumen, may transmit the virus sporadically to their embryos.     

Outbreaks of egg-drop syndrome-1976 in Japan and its etiological agent

A condition similar to egg-drop syndrome-1976 (EDS-76) occurred in 14 broiler breeding flocks in 2 farms in Japan from December 1978 to January 1980, and it was diagnosed as EDS-76 by serologic and virological investigations. Egg production fell suddenly when the hens were 30 to 55 weeks of age, and the depression lasted 3 to 7 weeks. Production fell 6 to 25%. Depressed egg production was accompanied by the laying of shell-less, soft-shelled, and thin-shelled eggs associated with loss of egg-shell pigment. Eleven isolates of hemagglutinating adenovirus were isolated from cloacal swabs (10 isolates) and a uterus (1 isolate) of hens in one farm. One isolate, cloned and named JPA-1, had the same antigenicity in serologic tests and the same biological and physicochemical properties as the BC14 strain of EDS-76 virus.     

Lectin histochemical study on the olfactory bulb of the newt, Cynops pyrrhogaster

The function and/or morphological features of the vomeronasal olfactory system remain unclear in aquatic animals, although the system appeared first in urodeles based on phylogenic data. We examined the lectin binding patterns in the olfactory bulb of a semi-aquatic urodele, the Japanese red-bellied newt, Cynops pyrrhogaster, using 22 different lectins. Eleven of the lectins showed specific binding to the nerve fibres and glomeruli in the olfactory bulb. Among these, Wheat germ agglutinin, pokeweed and peanut agglutinin preferentially bound the main olfactory bulb, reflecting variation in the expression of glycoconjugates between the main and accessory olfactory bulbs. By contrast, the types of lectins bound to the Cynops olfactory bulb were considerably different from those reported in other urodele families. These results suggest a histochemical distinction between the main and accessory olfactory bulbs, and that glycoconjugate expression may differ significantly among urodele families.     

Interleukin-2 receptor beta chain gene: generation of three receptor forms by cloned human alpha and beta chain cDNA's

Interleukin-2 (IL-2) binds to two distinct receptor molecules, the IL-2 receptor alpha (IL-2R alpha, p55) chain and the newly identified IL-2 receptor beta (IL-2R beta, p70-75) chain. The cDNA encoding the human IL-2R beta chain has now been isolated. The overall primary structure of the IL-2R beta chain shows no apparent homology to other known receptors. Unlike the IL-2R alpha chain, the IL-2R beta chain has a large cytoplasmic region in which a functional domain (or domains) mediating an intracellular signal transduction pathway (or pathways) may be embodied. The cDNA-encoded beta chain binds and internalizes IL-2 when expressed on T lymphoid cells but not fibroblast cells. Furthermore, the cDNA gives rise to the generation of high-affinity IL-2 receptor when co-expressed with the IL-2R alpha chain cDNA.     

Interaction of the IL-2 receptor with the src-family kinase p56lck: identification of novel intermolecular association

In the interleukin-2 (IL-2) system, intracellular signal transduction is triggered by the beta chain of the IL-2 receptor (IL-2R beta); however, the responsible signaling mechanism remains unidentified. Evidence for the formation of a stable complex of IL-2R beta and the lymphocyte-specific protein tyrosine kinase p56lck is presented. Specific association sites were identified in the tyrosine kinase catalytic domain of p56lck and in the cytoplasmic domain of IL-2R beta. As a result of interaction, IL-2R beta became phosphorylated in vitro by p56lck. Treatment of T lymphocytes with IL-2 promotes p56lck kinase activity. These data suggest the participation of p56lck as a critical signaling molecule downstream of IL-2R via a novel interaction.