Mitochondrial DNA structure and colony expansion dynamics of New Zealand fur seals (Arctocephalus forsteri) around Banks Peninsula

New Zealand fur seals are one of many pinniped species that survived the commercial sealing of the eighteenth and nineteenth centuries in dangerously low numbers. After the enforcement of a series of protection measures in the early twentieth century, New Zealand fur seals began to recover from the brink of extinction. We examined the New Zealand fur seal populations of Banks Peninsula, South Island, New Zealand using the mitochondrial DNA control region. We identified a panmictic population structure around Banks Peninsula. The most abundant haplotype in the area showed a slight significant aggregated structure. The Horseshoe Bay colony showed the least number of shared haplotypes with other colonies, suggesting a different origin of re-colonisation of this specific colony. The effective population size of the New Zealand fur seal population at Banks Peninsula was estimated at approximately 2500 individuals. The exponential population growth rate parameter for the area was 35, which corresponds to an expanding population. In general, samples from adjacent colonies shared 4.4 haplotypes while samples collected from colonies separated by between five and eight bays shared 1.9 haplotypes. The genetic data support the spill-over dynamics of colony expansion already suggested for this species. Approximate Bayesian computations analysis suggests re-colonisation of the area from two main clades identified across New Zealand with a most likely admixture coefficient of 0.41 to form the Banks Peninsula population. Approximate Bayesian computations analysis estimated a founder population size of approximately 372 breeding individuals for the area, which then rapidly increased in size with successive waves of external recruitment. The population of fur seals in the area is probably in the late phase of maturity in the colony expansion dynamic.     

Construction of plasmid cloning vectors for lactic streptococci which also replicate in Bacillus subtilis and Escherichia coli

The cryptic Streptococcus cremoris Wg2 plasmid pWV01 (1.5 megadaltons) was genetically marked with the chloramphenicol resistance (Cmr) gene from pC194. The recombinant plasmid (pGK1, 2.4 megadaltons) replicated and expressed Cmr in Bacillus subtilis. From this plasmid an insertion-inactivation vector was constructed by inserting the erythromycin resistance (Emr) gene from pE194 cop-6. This plasmid (pGK12, 2.9 megadaltons) contained a unique BclI site in the Emr gene and unique ClaI and HpaII sites outside both resistance genes. It was stably maintained in B. subtilis at a copy number of approximately 5. pGK12 also transformed Escherichia coli competent cells to Cmr and Emr. The copy number in E. coli was about 60. Moreover, pGK12 transformed protoplasts of Streptococcus lactis. In this host both resistance genes are expressed. pGK12 is stably maintained in S. lactis at a copy number of 3.     

Mutations in the NB-ARC domain of I-2 that impair ATP hydrolysis cause autoactivation

Resistance (R) proteins in plants confer specificity to the innate immune system. Most R proteins have a centrally located NB-ARC (nucleotide-binding adaptor shared by APAF-1, R proteins, and CED-4) domain. For two tomato (Lycopersicon esculentum) R proteins, I-2 and Mi-1, we have previously shown that this domain acts as an ATPase module that can hydrolyze ATP in vitro. To investigate the role of nucleotide binding and hydrolysis for the function of I-2 in planta, specific mutations were introduced in conserved motifs of the NB-ARC domain. Two mutations resulted in autoactivating proteins that induce a pathogen-independent hypersensitive response upon expression in planta. These mutant forms of I-2 were found to be impaired in ATP hydrolysis, but not in ATP binding, suggesting that the ATP- rather than the ADP-bound state of I-2 is the active form that triggers defense signaling. In addition, upon ADP binding, the protein displayed an increased affinity for ADP suggestive of a change of conformation. Based on these data, we propose that the NB-ARC domain of I-2, and likely of related R proteins, functions as a molecular switch whose state (on/off) depends on the nucleotide bound (ATP/ADP).     

The range of action of the mother and the avoidance of big novel objects in long-tailed macaques

Most surrogate-reared long-tailed macaques persistently avoid a big novel object, whereas most mother-reared subjects approach it. A striking difference between these attachment figures is that the mothers moved about with their infants, whereas the surrogates were fixed to the wall In this experiment, we aimed to find out whether mobility of the attachment figure plays a part in the development of an infant’s responses to big novel objects. We studied the effects of mobility of the attachment figure by restraining mothers in their range of action. We confined mothers of the experimental group in a small part of the home cage. Their infants could leave the cage in which their mothers were restrained. Infants that were growing up with unrestrained mothers made up the control group. At two different ages all infants encountered a big novel object. We used two different objects. We found that the range of action of the mother did not significantly affect the responses of infants to big novel objects. As in the previous studies, most of the mother-reared monkeys approached the objects. The age at which an infant was first exposed to an object did not significantly affect its behavior toward it. Further, the two different objects evoked the same reactions.     

Interactions among oscillatory pathways in NF-kappa B signaling

Background  

Sustained stimulation with tumour necrosis factor alpha (TNF-alpha) induces substantial oscillations—observed at both the single cell and population levels—in the nuclear factor kappa B (NF-kappa B) system. Although the mechanism has not yet been elucidated fully, a core system has been identified consisting of a negative feedback loop involving NF-kappa B (RelA:p50 hetero-dimer) and its inhibitor I-kappa B-alpha. Many authors have suggested that this core oscillator should couple to other oscillatory pathways.     

Qualitative and quantitative late blight resistance in the potato cultivar Sarpo Mira is determined by the perception of five distinct RXLR effectors

Potato defends against Phytophthora infestans infection by resistance (R)-gene-based qualitative resistance as well as a quantitative field resistance. R genes are renowned to be rapidly overcome by this oomycete, and potato cultivars with a decent and durable resistance to current P. infestans populations are hardly available. However, potato cultivar Sarpo Mira has retained resistance in the field over several years. We dissected the resistance of 'Sarpo Mira' in a segregating population by matching the responses to P. infestans RXLR effectors with race-specific resistance to differential strains. The resistance is based on the combination of four pyramided qualitative R genes and a quantitative R gene that was associated with field resistance. The qualitative R genes include R3a, R3b, R4, and the newly identified Rpi-Smira1. The qualitative resistances matched responses to avirulence (AVR)3a, AVR3b, AVR4, and AVRSmira1 RXLR effectors and were overcome by particular P. infestans strains. The quantitative resistance was determined to be conferred by a novel gene, Rpi-Smira2. It was only detected under field conditions and was associated with responses to the RXLR effector AvrSmira2. We foresee that effector-based resistance breeding will facilitate selecting and combining qualitative and quantitative resistances that may lead to a more durable resistance to late blight.     

Cross-species bacterial artificial chromosome-fluorescence in situ hybridization painting of the tomato and potato chromosome 6 reveals undescribed chromosomal rearrangements

Ongoing genomics projects of tomato (Solanum lycopersicum) and potato (S. tuberosum) are providing unique tools for comparative mapping studies in Solanaceae. At the chromosomal level, bacterial artificial chromosomes (BACs) can be positioned on pachytene complements by fluorescence in situ hybridization (FISH) on homeologous chromosomes of related species. Here we present results of such a cross-species multicolor cytogenetic mapping of tomato BACs on potato chromosomes 6 and vice versa. The experiments were performed under low hybridization stringency, while blocking with Cot-100 was essential in suppressing excessive hybridization of repeat signals in both within-species FISH and cross-species FISH of tomato BACs. In the short arm we detected a large paracentric inversion that covers the whole euchromatin part with breakpoints close to the telomeric heterochromatin and at the border of the short arm pericentromere. The long arm BACs revealed no deviation in the colinearity between tomato and potato. Further comparison between tomato cultivars Cherry VFNT and Heinz 1706 revealed colinearity of the tested tomato BACs, whereas one of the six potato clones (RH98-856-18) showed minor putative rearrangements within the inversion. Our results present cross-species multicolor BAC–FISH as a unique tool for comparative genetic studies across Solanum species.     

Complete Suppression of the Gut Microbiome Prevents Acute Graft-Versus-Host Disease following Allogeneic Bone Marrow Transplantation

The hypothesis that elimination of facultative and strict anaerobic microorganisms from the gastro-intestinal tract by antimicrobial drugs in the period of time around allogeneic bone marrow transplantation (BMT) prevents acute graft-versus-host disease (GVHD), was examined in a cohort of 112 children grafted between 1989 and 2002 for hematological malignancies. All patients received T-cell replete marrow from human leukocyte antigens (HLA) matched sibling donors under identical transplantation conditions. To eliminate microorganisms from the gastro-intestinal tract, total gastro-intestinal decontamination (GID) was applied by high doses of non-absorbable antimicrobial drugs while the graft recipient was maintained in strict protective isolation. About half of the children (51%) proved to be successfully decontaminated, and about half (49%) unsuccessfully. One recipient got acute GVHD in the first group and 8 in the second group (p = 0.013). The degree of success of total GID was decisive for the occurrence of acute GVHD, irrespective of the presence of other risk factors such as higher age of recipient and/or donor, female donor for male recipient and carriership or reactivation of herpesviruses. Our results demonstrate that successful total GID of the graft recipient prevents moderate to severe acute GVHD. We suppose that substantial translocation of gastro-intestinal microorganisms or parts of these, functioning as microbial-associated molecular patterns (MAMP''s), triggering macrophages/dendritic cells via pattern recognizing receptors (PRR''s) is prohibited. As a consequence the initiation and progression of an inflammatory process leading to acute GVHD is inhibited.