Characterization of Mendelian and Non-Mendelian Mutant Strains by Micronuclear Transplantation in Paramecium tetraurelia

ABSTRACT. Mutant strain d48 and d12 cannot express serotype A. In d48, the A i-antigen gene is present in the micronucleus, but not in the macronucleus. It has recently been shown that d12 contains the A gene in its micronucleus, but its macronucleus lacks the gene. Micronuclear transplantations into enucleated cells were performed to analyze those mutants. Reciprocal transplantation between wild type and d48 confirmed that d48 contains the A gene in the micronucleus and its cytoplasm is defective. Wild type 51 enucleated cells into which were transplanted d12 micronuclei could not express A. Amiccronucleate d12 cells into which were transplanted normal micronuclei from 51 or d48 showed no expression of A. These results show that even if the micronucleus of d12 contains the A gene, it must be abnormal, and its cytoplasm is also defective the same as d48. Genetic analysis showed that heterozygote of d12 and wild type 51 or d48 caused a cure of the cytoplasmic defect of d48 and d12 during the development of macronuclei.     

Is Geomagnetic Sensitivity Real? Replication of the Walker-Bitterman Magnetic Conditioning Experiment in Honey Bees

Although the presence of geomagnetic sensitivity has been suspectedfor a long time in a variety of marine and terrestrial animals,many responses reported in the literature have been based onextensive statistical analysis of orientation results or relyon obscure behavioral activities (like cetacean strandings orhoney bee waggle dances.) None of these reports have yet approachedthe level of clarity and simplicity displayed in experimentswith the magnetotactic bacteria, which is the best example ofgeomagnetic sensitivity in any living organism. Furthermore,claims of magnetic effects on living organisms pervade the literatureof biomagnetism, but many have failed subsequent attempts atreplication. We need to develop simple and easily replicatedexperiments for marine and terrestrial animals which can bemodified to answer basic questions concerning the psychophysicsof any geomagnetic sensory system which might be present. Inthis paper, we report the first replication of the Walker-Bittermanmagnetic anomaly conditioning experiment in honey bees, as wellas one of our attempts to slightly alter their basic protocol.We also report our attempts to condition honey bees to magneticdirection in simple maze experiments, and the initial resultsof a pulse-remagnetization experiment designed to test the ferromagnetictransduction hypothesis. We conclude honey bees are sensitiveto the geomagnetic field, that the signal processing for itis more complex than previously thought, and that a ferromagnetictransducer is compatible with all known behavioral data.     

Accumulation and Spatial Distribution of Poly(A)+RNA in Oocytes and Early Embryos of Drosophila melanogaster

We describe the accumulation and distribution of poly (A)⁺RNA during oogenesis and early embryogenesis as revealed by in situ hybridization with a radio-labeled poly (U) probe. The amount of poly (A)⁺RNA in nurse cell cytoplasm continuously increased untill mid-vitellogenic stage (st. 10), then decreased with the rapid increase of poly (A)⁺RNA in the oocyte (st. 11). The localization of poly (A)⁺RNA at stage 10 was in the anterior region of the oocyte, where it is connected by cytoplasmic bridge to the nurse cells. These observations indicate that most of the poly (A)⁺RNA synthesized in the nurse cells is transferred to the oocyte through the cytoplasmic bridges at stage 10–11. During the remainder of oogenesis (st. 11–14) and during preblastodermal embryogenesis, poly (A)⁺RNA was evenly distributed over the cytoplasm of oocytes and embryos. At blastoderm stage, poly(A)⁺RNA became concentrated in the peripheral region of embryos. Though the somatic nuclei of the blastoderm contained a detectable amount of poly (A)⁺ RNA, the pole cell nuclei did not. The cytoplasmic RNA visualised by acridine orange staining and the poly (A)⁺RNA detected by hybridization with [³H]poly (U) exhibited identical distributions during oogenesis and early embryogenesis. These observations provide a basis to assess the unique distributions of specific RNA sequences involved in early development.     

Maternal Messenger RNA as a Determinant of Pole Cell Formation in Drosophila Embryos

Some polar plasm components are UV-sensitive. Messenger RNA extracted from oocytes or cleavage embryos can to induce pole cells in embryos that have been deprived of ability to form pole cells by UV-irradiation. This article reviews studies on the role of this mRNA in the developmental pathway leading to germ cell formation.     

Macrophage Activation by Tetrahymena pyriformis II. Active Protein Fractions from Tetrahymena

ABSTRACT. Water-soluble and 0.6 M KCl-soluble protein fractions prepared from Tetrahymena pyriformis , when inoculated into mice, could effectively induce activated macrophages having the ability to kill Toxoplasma gondii in vitro. This effect was not induced by other proteins tested, such as bovine serum albumin, pepsin from porcine stomach mucosa and chicken egg-white lysozyme, nor by muramyl dipeptide (MDP), a potent immunoadjuvant. Five fractions obtained by DEAE-Sephadex chromatography of the water-soluble protein fraction were compared with regard to induction of toxoplasmacidal activity in macrophages. The first peak was most effective for activation of macrophages. Five fractions obtained by chromatography of the 0.6 M KCl-soluble protein fraction were also examined and it was found that the first peak had the activity. No marked difference in activity was observed between the active fractions of water-soluble and 0.6 M KCl-soluble protein fractions. For practical use, we focused on the water-soluble active fraction. The minimum effective dose of the active fraction was 100 μg and the fraction could activate macrophages directly in vitro. Four fractions obtained by gel filtration of the active fraction on Sephadex G-200 were compared and the first peak had the activity. The first peak contained a single protein, revealed by SDS-polyacrylamide gel electrophoresis; its apparent molecular weight was 64,000.     

PHYSIOLOGICAL.STUDIES OF A CHIMAERA FORMED BY GRAFTING NIGHTSHADE UPON TOMATO I. RESPIRATORY ACTIVITY OF LEAVES

1. Leaves of a chimaera which are composed of the tissues fromLycopersicum esculentum var. kinnari (L. e.) covered by twolayers of cells from Solatium villosum (S. v.) were comparedwith those of control plants, L. e. and S. v. with respect tothe respiratory activity. 2. As for the respiratory activity of leaf strips, the chimaerawas more active than either L. e.. or S. v. 3. To respiratory inhibitors examined leaf strips of the chimaeraresponded rather similarly to those of S. v. but differentlyfrom those of L. e. 4. Of various substrates tested, glycolic, ascorbic and chlorogenicacids were actively oxidized by cell-free extracts of leavesfrom every plant. The first two were especially good substratesfor S. v.: L. e. attacked most the third, and the chimaera oxidizedjust as well the first two as S. v. did and the third as L.e. did. 5. Ascorbic acid and chlorogenic acid contents of the leaf extractswere not correlated with the activities of the extracts of oxidizingthese substances. 6. Physiological interactions were suggested between the twotissues of different origins in the chimaera. (Received December 2, 1963; )     

CHANGES IN ACTIVITY OF DGLUCOSE-6-PHOSPHATE: NADP AND 6-PHOSPHO-D-GLUCONATE: NADP OXIDOREDUCTASES IN RELATION TO LIGNIFICATION OF BAMBOO

D-Glucose-6-phosphate: NADP oxidoreductase (glucose-6-phosphatedehydrogenase; EC 1.1.1.49 [EC] ) and 6-phospho-D-gluconate: NADPoxidoreductase (6-phosphogluconate dehydrogenase; EC 1.1.1.44 [EC] )were found to be present in immature bamboo. Optimal pHs ofthe glucose-6-phosphate- and 6-phosphogluconate dehydrogenaseswere found to be 8.0 and 8.5, respectively. Both enzymes were demonstrated to be NADP-specific and NADPcould not be replaced by NAD. Fructose-6-phosphate was indirectlyutilized after convrsion to glucose-6-phosphate by glucose-6-phosphateisomerase coexisting in the enzyme preparation. Pattern of enzyme activity and of respiratory breakdown of glucose-1-¹⁴Cand glucose-6-¹⁴C were investigated in connection with lignificationof bamboo and discussed in comparison with sugar metabolismof fungi-infected plant tissues. As for the changes in the enzymeactivity with growth of bamboo, it was recognized that therewas a tendency that the activity of both enzymes increased andwas maintained at a certain level even in the aged tissues.In addition there was a drop of the C₆/C₁ ratio toward the tissuesof lower parts containing considerable amount of lignin andthis phenomenon was the same as that observed in pentose phosphatemetabolism of fungi-infected plant tissues. (Received September 5, 1966; )     

Do battles lead to coexistence? Role of interference competition in structuring the insect community on fermented tree sap

Abstract.  1. In insect communities on fermented tree sap, agonistic interactions occur frequently among the component species. This study examined the effects of such interference competition on community structure and species co-occurrence on a spatio-temporally small scale.
2. Experimental removal of giant hornets ( Vespa mandarinia ), one of the most dominant species, showed no effect on either species richness or total abundance of the remaining insects. Significant increases in abundance were detected for five out of 19 taxa: V. ducalis , V. crabro , Lasius japonicus , Cryptarcha lewisi , and a group of micro sap beetles ( Epuraea spp., Haptoncus spp., and Haptoncurina spp.).
3. Behavioural observations indicated that interference did not alter the staying time at a patch (an exuding spot on a tree) for V. mandarinia , Rhomborrhina japonica , and Neope goschkevitschii . Interference-mediated departure from a patch was less frequent than departure without interference for all nine species observed, except for R. japonica . These behavioural contexts varied yearly for several species.
4. These results suggest that interference competition is a minor determinant of overall community structure, despite its conspicuousness. This weak effect of interference may be attributed to the short stay of dominant species and to individual behavioural responses, such as competitor avoidance. The variable influence of interference might be related to differences in species attributes, such as dominance hierarchies.