Utility of barley and wheat simple sequence repeat (SSR) markers for genetic analysis of Hordeum chilense and tritordeum

A selection of 36 wheat and 35 barley simple sequence repeat markers (SSRs) were studied for their utility in Hordeum chilense. Nineteen wheat and nineteen barley primer pairs amplified consistent H. chilense products. Nine wheat and two barley SSRs were polymorphic in a H. chilense mapping population, producing codominant markers that mapped to the expected homoeologous linkage groups in all but one case. Thirteen wheat and 10 barley primer pairs were suitable for studying the introgression of H. chilense into wheat because they amplified H. chilense products of distinct size. Analysis of wheat/H. chilense addition lines showed that the H. chilense products derived from the expected homoeologous linkage groups. The results showed that wheat and barley SSRs provide a valuable resource for the genetic characterization of H. chilense, tritordeums and derived introgression lines. Received: 20 November 2000 / Accepted: 12 April 2001     

Intrachromosomal mapping of the nucleolar organiser region relative to three marker loci on chromosome 1B of wheat (Triticum aestivum)

Summary Restriction enzyme digestion of the ribosomal RNA genes of the nucleolar organisers of wheat has revealed fragment length polymorphisms for the nucleolar organiser on chromosome 1B and the nucleolar organiser on 6B. Variation between genotypes for these regions has also been demonstrated. This variation has been exploited to determine the recombination frequency between the physically defined nucleolar organiser on 1B (designatedNor1) and other markers; two loci,Glu-B1 andGli-B1 which code for endosperm storage proteins andRf3, a locus restoring fertility to male sterility conditioned byT. timopheevi cytoplasm.Gli-B1 andRf3 were located on the short-arm satellite but recombine with the nucleolar organiser giving a gene order ofNor1 — Rf3 — Gli-B1. Glu-B1 is located on the long arm of 1B but shows relatively little recombination withNor1, which is, in physical distance, distal on the short arm. This illustrates the discrepancy between map distance and physical distance on wheat chromosomes due to the distal localisation of chiasmata. The recombination betweenNor1 andRf3 indicates that, contrary to previous suggestions, fertility restoration is not a property of the nucleolar organiser but of a separate locus.     

The taste of polycose in hamsters

Hamsters show a preference for Polycose, a mixture of starch-derived glucose polymers, that is as strong as their preference for sucrose. However, in the hamster, taste aversions to Polycose may be less easily acquired than taste aversions to sucrose and the qualitative aspects of Polycose are unknown in this species. In order to examine the taste of Polycose in the hamster, we utilized a taste-aversion protocol with two conditioning trials. Animals were trained to avoid one of three different conditioning stimuli: 50 mM sucrose, 100 mM Polycose and a mixture of 50 mM sucrose with 100 mM Polycose. Control animals were conditioned with deionized water. After the second conditioning trial, generalization testing began for the three conditioning stimuli plus 3 mM citric acid, 300 mM KCI and 30 mM NaCl. The results showed that aversions to Polycose, sucrose or the Polycose/sucrose mixture cross- generalized, demonstrating that Polycose and sucrose share a common taste percept in the hamster. None of the aversions generalized to NaCl, citric acid or KCI. In addition, comparisons among the patterns of taste generalizations indicated that the tastes of Polycose and sucrose also had distinct qualitative components. Finally, although the taste of 100 mM Polycose was more salient than the taste of 50 mM sucrose, the taste of sucrose could still be detected in a mixture with Polycose.      

The green fluorescent protein (GFP) as a vital screenable marker in rice transformation

 An engineered green fluorescent protein (GFP) from the jellyfish Aequora victoria was used to develop a facile and rapid rice transformation system using particle bombardment of immature embryos. The mgfp4 gene under the control of the 35s Cauliflower Mosaic Virus promoter produced bright-green fluorescence easily detectable and screenable in rice tissue 12–22 days after bombardment. Visual screening of transformed rice tissue, associated with a low level of antibiotic selection, drastically reduced the quantity of tissue to be handled and the time required for the recovery of transformed plants. GFP expression was observed in primary transformed rice plants (T₀) and their progeny (T₁). We describe various techniques to observe GFP in vitro and in vivo. The advantages of this new screenable marker in rice genetic engineering programmes are discussed. Received: 6 October 1997 / Accepted: 9 October 1997     

Regulation of embryonic cell division by a Xenopus gastrula-specific protein kinase.

We describe a novel protein kinase, Pk9.7, and its role in cell division in the Xenopus embryo. Pk9.7 is transcribed only during blastula and gastrula stages. Expression of Pk9.7 in Xenopus oocytes induces meiotic maturation, while overexpression in embryos blocks blastomere cleavage in a MAP kinase-independent fashion. In both Pk9.7-injected oocytes and mitotic cells of cleavage-blocked embryos, chromosomes appear detached from abnormal spindles, and in oocytes additional microtubule structures are formed, suggesting that one function of Pk9.7 is to regulate formation of, and chromosome attachment to, the spindle. Consistent with this, Pk9.7 co-immunoprecipitates tubulin and phosphorylates it in vitro. Pk9.7 expression coincides with the switch from maternal to zygotic control of the cell cycle, and with the switch from microtubule independence to microtubule dependence. Our results suggest that Pk9.7 plays a role in these processes.     

Persistence of specific bactericidal antibodies at 5 years of age after vaccination against serogroup B meningococcus in infancy and at 40 months

Background:

The multicomponent serogroup B meningococcal (4CMenB) vaccine induces antibodies against indicator strains of serogroup B meningococcus under various schedules. We investigated the persistence of antibodies in 5-year-old children 18–20 months after their last dose (at about 3.5 years of age).

Methods:

We assessed 5-year-old children who received the 4CMenB vaccine or a recombinant protein vaccine in a previous randomized trial. We also recruited 50 vaccine-naive 5-year-olds and administered 2 doses of 4CMenB to each child. We measured serum bactericidal antibody titres against 4 indicator strains of serogroup B meningococcus matched to each individual vaccine component and against 4 mismatched strains.

Results:

Of those who received the 4CMenB vaccine at 2, 4, 6, 12 and 40 months (n = 16), the percentage with protective antibody titres (≥ 1:4) at 60 months ranged from 44% to 88% against matched strains and from 13% to 81% against mismatched strains. Loss of protective titres was also observed for those who received the 4CMenB vaccine at 12, 40 and 42 months (n = 5) (80%–100% against matched strains, 60%–100% against mismatched strains) or at 40 and 42 months (n = 29) (31%–100% against matched strains, 41%–81% against mismatched strains). Administering the 4CMenB vaccine to 5-year-old children yielded protective titres against matched strains in 92%–100% and against mismatched strains in 59%–100%. The majority of these children reported injection-site pain (40/50 [80%] after dose 1, 39/46 [85%] after dose 2) and erythema (47/50 [94%] and 40/46 [87%], respectively); rates of fever were low (5/50 [10%] and 2/46 [4%], respectively).

Interpretation:

Waning of immunity by 5 years of age occurred after receipt of the 4CMenB vaccine in infancy, even with an additional booster at 40 months. The 4CMenB vaccine is immunogenic and was fairly well tolerated by 5-year-old children, although injection-site pain was noteworthy. Trial registration: ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT01027351","term_id":"NCT01027351"}}NCT01027351The multicomponent serogroup B meningococcal (4CMenB) vaccine is licensed in the European Union, Australia and Canada to prevent serogroup B meningococcal disease. It was developed using “reverse vaccinology,” in which candidate antigens were identified by interrogating the whole meningococcal genome.¹ The 4CMenB vaccine consists of 3 surface proteins (factor H binding protein [fHbp], Neisseria adhesin A [NadA] and Neisseria heparin-binding antigen [NHBA]), along with a fourth component, the outer membrane vesicle, which acts as both antigen and adjuvant.¹Group B meningococcal disease is a potentially devastating condition, with an average case fatality rate of 5.2% (data for England and Wales²), and over a third of survivors are left with measurable functional deficits.³ The incidence of laboratory-confirmed cases is about 1 per 100 000 population in England⁴ and 0.33 per 100 000 population in Canada.⁵ The recommendation of the United Kingdom Joint Committee on Vaccination and Immunisation that the 4CMenB vaccine be introduced into the routine UK immunization schedule should, if implemented, lead to a reduction in this morbidity and mortality.⁶ Data on the persistence of antibody responses following infant or toddler immunization, and after subsequent boosting, remain limited yet will be important for guiding implementation of this recommendation.We present here the results of a follow-on study investigating the persistence of antibodies 18–20 months after the last dose in 5-year-old children previously immunized under a variety of schedules with 4CMenB vaccine or another investigational vaccine (recombinant protein serogroup B meningococcal [rMenB] vaccine), which lacks the outer membrane vesicle component of the 4CMenB vaccine. Since the original infant study,⁷ 4CMenB vaccine has emerged as the preferred vaccine, because addition of the outer membrane vesicle component improves the breadth of strain coverage;⁸ however, the extension study continued follow-up for all of the original children, and all results are therefore presented here.     

黑麦6R抗白粉病基因向小麦的渗进与鉴定

为了将黑麦６Ｒ染色体上抗小麦白粉病的基因导入小麦,选用了一个６Ｒ／６Ｄ代换系Ｍ２４为亲本之一,分别与小麦栽培品种和第６部分同源群缺体系杂交,杂种出现６Ｒ或／或６Ａ,６Ｂ,６Ｄ单,双或三单体等各种情况,取其花药进行培养,共获得２４１个再生植株,对其中３２个抗白粉病的花粉植株经染色体计数,Ｃ－分带,基因组原位杂交,同工酶等电聚焦电泳和或／ＲＦＬＰ分子标记检测,发现有６株仍保持为６Ｒ／６Ｄ代换系,有１０     

Purification of galectin-3 from ovine placenta: developmentally regulated expression and immunological relevance

Galectins, beta-galactoside-binding lectins, are extensively distributed in the animal kingdom and share some basic molecular properties. Galectin-3, a member of this family, is generally associated with differentiation, morphogenesis, and metastasis. In this study, galectin-3 was isolated from ovine placental cotyledons round the middle of the gestation period by lactose extraction followed by affinity chromatography on lactosyl-agarose, and separated from galectin-1 by size exclusion chromatography on a Superose 12 column. Under native conditions this lectin behaved as a monomer with an apparent molecular weight of approximately 29,000 and an isoelectric point of 9.0. The partial amino acid sequence of the peptides obtained by tryptic digestion of this protein followed by HPLC separation showed striking homology with other members of the galectin-3 subfamily. Furthermore, ovine placental galectin-3 exhibited specific mitogenic activity toward rat spleen mononuclear cells. Besides, this protein strongly reacted with a rabbit antiserum raised against a chicken galectin. Results obtained by Western blot analysis showed that its expression was greatly decreased in term placenta with respect to the middle of the gestation period, suggesting a regulated expression throughout development.