Induction of small-segment-translocation between wheat and rye chromosomes

A new approach to produce wheat-rye translocation, based on the genetic instability caused by monosomic addition of rye chromosome in wheat, is described. 1 283 plants from the selfed progenies of monosomic addition lines with single chromosome of inbred rye line R12 and complete chromosome complement of wheat cultivar Mianyang 11 were cytologically analyzed on a plant-by-plant basis by the improved C-banding technique. 63 of the plants, with 2n = 42, were found containing wheat-rye translocation or substitution, with a frequency of 4. 91% . Compared with the wheat parent, other 32 plants with 2n = 42 exhibited obvious phenotypic variation, but their com-ponent of rye chromosome could not be detected using the C-banding technique. In situ hybridization with a biotin-la-beled DNA probe was used to detect rye chromatin and to determine the insertion sites of rye segments in the wheat chromosomes. In 20 out of the 32 variant wheat plants, small segments of rye chromosomes were found being inserted into dif     

Philopatry in the alpine grasshopper, Podisma pedestris: a novel experimental and analytical method

Abstract.

• 1 Local dispersal and philopatric behaviour of the alpine grasshopper, Podisma pedestris, were studied at two sites in the Alpes Maritimes using a new mark—release—resight technique featuring marking in situ, and multiple resighting without handling. The time-consuming nature of the design was justified by the quantity and quality of the data yielded.
• 2 Philopatry is defined independently of any concept of home range as a phenomenon by which movements over longer periods are less than would be expected by extrapolation of measures over shorter periods.
• 3 By this definition, the grasshoppers are shown to exhibit philopatry. Nymphs comprise two heterogenous classes of those which move little and those which move considerable distances.
• 4 Daily dispersal estimates were obtained from movements of 1055 nymphs and adults at one site, and of 593 adults at another.
• 5 Differences are demonstrated in daily dispersal distances for age, sex and site combinations.
• 6 Some differences in microhabitat preference were observed.
• 7 The findings are compared with previous measurements of dispersal in this species, and the merits of the new technique are discussed.

     

高邮杂交鲫（鲫♀×白鲫）及其亲本血清生化组成的比较研究

本文对高邮杂交鲫（鲫♀×白鲫♂）及其亲本血清生化组成的定量分析。结果表明,在测定的血清总蛋白、白蛋白、胆固醇、尿素氮、葡萄糖、乳酸脱氢酶、ａ－羟丁酸脱氢酶、ａ－淀粉酶和谷草转氨酶等九个生化指标中,大部分指标高邮杂交鲫与母本无显著差异,而与父本则有极显著差异。这从代谢方面论证了高邮杂交鲫是一个偏向于母本的杂交种。     

Hybrid recombinant human leukocyte interferon inhibits differentiation in murine B-16 melanoma cells

We have investigated the effects of recombinant human leukocyte interferons (IFN-alpha A and IFN-alpha D) and various hybrid recombinant human leukocyte interferons on differentiation in B-16 mouse melanoma cells. Inhibition of both spontaneous and melanocyte hormone stimulated differentiation was observed with one hybrid construct, IFN-alpha A/D (Bgl) consisting of amino acids 1 to 62 from IFN-alpha A and amino acids 64 to 166 from IFN-alpha D. In contrast, the parental human interferons, IFN-alpha A and IFN-alpha D, when used alone or in combination, as well as other hybrid human leukocyte interferons, did not cause significant inhibition of melanogenesis in B-16 mouse cells. The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) also inhibited B-16 differentiation and the combination of TPA with IFN-alpha A/D (Bgl) or mouse L-cell interferon was synergistic in delaying melanogenesis. These studies indicate that the IFN-alpha A/D (Bgl) hybrid that exhibits antiviral activity on mouse cells can also inhibit differentiation of murine cells.     

Inhibition of parathormone-stimulated bone resorption by type I interferon

The effect of Type I interferon on bone resorption was studied by measuring its effect on parathormone-stimulated calcium release from neonatal murine calvaria in vitro. A pure human recombinant leukocyte interferon hybrid of the A and D subtypes was used, which has high antiviral activity on mouse cells. Calcium release was inhibited in a dose dependent fashion with 50% inhibition at about 10(-10) M or 600 U/ml, and the inhibition was reversible. The presence of interferon was required before or during the activation phase of the resorptive response, when the formation of osteoclasts from precursor cells would occur. When added to actively resorbing bone it had no effect. The data suggest that Type I interferon can inhibit the parathormone-regulated development of active osteoclasts, possibly by inhibiting osteoclast precursor differentiation.     

Molecular mass analysis of murine immunosuppressive immunoglobulin G-binding factors (IgG-BFs) produced by T-cell hybrids

Induced and constitutive murine IgG-binding factors (IgG-BFs) have been purified by affinity chromatography from supernatants of T-cells preincubated with or without murine monoclonal IgG1 and IgG2b, respectively. IgG-BF Mr values have been studied by SDS-polyacrylamide gel electrophoresis (PAGE) after treatment with SDS under conditions which do not noticeably alter their immunosuppressive activities on the secondary in vitro IgG antibody response. Suppression was recovered at Mr values of 80000, 40000 and 20000. When induced IgG-BF was tested, the isotype-specific suppressive activity was found only at 40 kDa. The 20-kDa moiety appeared to derive from the 40-kDa component and the material found at 80 kDa exerted non-specific immunosuppressive effects. We conclude therefore that isotype-specific IgG-BF has an apparent Mr of 40000.     

Decreased UDP-GlcNAc:Glycopeptideβ-2-N-Acetylglucosaminyltransferase II activity in a ricin-resistant mutant of baby hamster kidney (BHK) cells

The ricin-resistant mutant baby hamster kidney (BHK) cell line RIC^R21 is unable to make the sialylated bi- or triantennary complexN-glycans found in wild type cells and accumulates instead non-bisected hybrid structures containing three Man residues and one or two sialylated antennae (Hugheset al 1983, Carbohydr Res 120215-34). Specific assays forN-acetylglucosaminyltransferases I, II, III and IV were applied to Triton X-100 extracts of wild type BHK, RIC^R14 and RIC^R21 cells. It was shown that RIC^R21 cell extracts had a decreasedN-acetylglucosaminyltransferase II specific activity (17 to 27% of wild type values). It is suggested that in wild type cellsN-acetylglucosaminyltransferase II action proceeds quickly, leading to complexN-glycan synthesis, while in RIC^R21 cells potential substrates forN-acetylglucosaminyltransferase II move into the trans-Golgi compartment before the transferase can act, thereby leading to hybrid structures.     

Cytogenetic study of an interspecific cross of Nicotiana debneyi X N. umbratica

Summary Interspecific F₁ hybrids of Nicotiana debneyi Domin (2n=48) and N. umbratica Burbidge (2n=46), both belonging to the section Suaveolentes, showed a high degree of meiotic chromosome pairing. Two of the five F₂ plants obtained exhibited chromosome mosaicism. The first colchiploid generation (C₁) had the expected chromosome number of 2n=94 while C₂ showed 2n=88, a loss of three pairs of chromosomes. This same chromosome number continued in further colchiploid generations, followed up to C₅, except for a few plants in C₃ which showed chromosome mosaicism. The F₁ phenotype was stable through C₁ to C₅ and fertility was normal in colchiploids through all generations in spite of the loss of three pairs of chromosomes and chromosome mosaicism. This stability and fertility apparently reflect the tolerance of the genomes to the genetic adjustment of chromosome complements which is believed to be associated with the originally polyploid nature of the parental species and the chromosome doubling brought about in the amphidiploids.     

In vitro construction of a recombinant adenovirus Ad2:Ad5

A hybrid virus containing the left half of the Ad5 genome and the right half of the Ad2 genome has been constructed by ligating together in vitro the BamHI.-A fragment of Ad5 (map co-ordinates 0–59.5) to the-SawHI-A fragment of Ad2 (map coordinates 59.5–100), and using this DNA to transfect susceptible cells. Viable progeny virus has been obtained which grows as well as the parental virus without any requirement for helper virus, and probably contains a hybrid hexon polypeptide consisting of the major part of the Ad5 hexon with an Ad2 carboxy terminus.