Patterns and dynamics of sex-biased dispersal in a nocturnal primate, the grey mouse lemur, Microcebus murinus

We examined predictions on the proportion of dispersing natal males and females, dispersal distances, the age at dispersal and the potential for inbreeding over a 6-year period in a free-living population of grey mouse lemurs. We used monthly mark-recapture procedures to determine individual locations and interindividual distances. The analysis of seven polymorphic microsatellite markers for 213 (130 males, 83 females) individuals allowed us to estimate relatedness coefficients and kinship relationships. Closely related males ranged further from each other than closely related females and natal males were found further from their potential mothers than were females. Natal males were more likely to disperse from their birth sites than females, although male dispersal was not universal. Male breeding dispersal was detected in half of the long-term observations. Males therefore seem to be the predominant vectors for gene flow between populations and social units. Females usually stayed within one to two home range diameters of their potential mother, facilitating the evolution of cooperative behaviour by kin selection among females. Most dispersal took place before the mating season, indicating an age of less than 7 months for natal dispersal. The analysis of spatiotemporal coexistence revealed the potential for inbreeding in only 3.8% of the potential mother-son dyads, but in 21.9% of the potential father-daughter dyads and in 41.7% of other closely related male-female dyads. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour      

Mosaic chromosomal aberrations in synovial fibroblasts of patients with rheumatoid arthritis, osteoarthritis, and other inflammatory joint diseases

Chromosomal aberrations were comparatively assessed in nuclei extracted from synovial tissue, primary-culture (P-0) synovial cells, and early-passage synovial fibroblasts (SFB; 98% enrichment; P-1, P-4 [passage 1, passage 4]) from patients with rheumatoid arthritis (RA; n = 21), osteoarthritis (OA; n = 24), and other rheumatic diseases. Peripheral blood lymphocytes (PBL) and skin fibroblasts (FB) (P-1, P-4) from the same patients, as well as SFB from normal joints and patients with joint trauma (JT) (n = 4), were used as controls. Analyses proceeded by standard GTG-banding and interphase centromere fluorescence in situ hybridization. Structural chromosomal aberrations were observed in SFB (P-1 or P-4) from 4 of 21 RA patients (19%), with involvement of chromosome 1 [e.g. del(1)(q12)] in 3 of 4 cases. In 10 of the 21 RA cases (48%), polysomy 7 was observed in P-1 SFB. In addition, aneusomies of chromosomes 4, 6, 8, 9, 12, 18, and Y were present. The percentage of polysomies was increased in P-4. Similar chromosomal aberrations were detected in SFB of OA and spondylarthropathy patients. No aberrations were detected in i) PBL or skin FB from the same patients (except for one OA patient with a karyotype 45,X[10]/46,XX[17] in PBL and variable polysomies in long-term culture skin FB); or ii) synovial tissue and/or P-1 SFB of normal joints or of patients with joint trauma. In conclusion, qualitatively comparable chromosomal aberrations were observed in synovial tissue and early-passage SFB of patients with RA, OA, and other inflammatory joint diseases. Thus, although of possible functional relevance for the pathologic role of SFB in RA, these alterations probably reflect a common response to chronic inflammatory stress in rheumatic diseases.     

The matrix metalloproteinase 9 (mmp-9) hemopexin domain is a novel gelatin binding domain and acts as an antagonist

Matrix metalloproteinases (MMPs) are involved in the remodeling processes of the extracellular matrix and the basement membrane. Most MMPs are composed of a regulatory, a catalytic, and a hemopexin subunit. In many tumors the expression of MMP-9 correlates with local tumor growth, invasion, and metastasis. To analyze the role of the hemopexin domain in these processes, the MMP-9 hemopexin domain (MMP-9-PEX) was expressed as a glutathione S-transferase fusion protein in Escherichia coli. After proteolytic cleavage, the isolated PEX domain was purified by size exclusion chromatography. In a zymography assay, MMP-9-PEX was able to inhibit MMP-9 activity. The association and dissociation rates for the interaction of MMP-9-PEX with gelatin were determined by plasmon resonance. From the measured rate constants, the dissociation constant was calculated to be K(d) = 2,4 x 10(-8) m, demonstrating a high affinity between MMP-9-PEX and gelatin. In Boyden chamber experiments the recombinant MMP-9-PEX was able to inhibit the invasion of melanoma cells secreting high amounts of MMP-9 in a dose-dependent manner. These data demonstrate for the first time that the hemopexin domain of MMP-9 has a high affinity binding site for gelatin, and the particular recombinant domain is able to block MMP-9 activity and tumor cell invasion. Because MMP-9 plays an important role in metastasis, this antagonistic effect may be utilized to design MMP inhibition-based cancer therapy.     

A novel two-step mechanism for removal of a mitochondrial signal sequence involves the mAAA complex and the putative rhomboid protease Pcp1

The yeast protein cytochrome c peroxidase (Ccp1) is nuclearly encoded and imported into the mitochondrial intermembrane space, where it is involved in degradation of reactive oxygen species. It is known, that Ccp1 is synthesised as a precursor with a N-terminal pre-sequence, that is proteolytically removed during transport of the protein. Here we present evidence for a new processing pathway, involving novel signal peptidase activities. The mAAA protease subunits Yta10 (Afg3) and Yta12 (Rca1) were identified both to be essential for the first processing step. In addition, the Pcp1 (Ygr101w) gene product was found to be required for the second processing step, yielding the mature Ccp1 protein. The newly identified Pcp1 protein belongs to the rhomboid-GlpG superfamily of putative intramembrane peptidases. Inactivation of the protease motifs in mAAA and Pcp1 blocks the respective steps of proteolysis. A model of coupled Ccp1 transport and N-terminal processing by the mAAA complex and Pcp1 is discussed. Similar processing mechanisms may exist, because the mAAA subunits and the newly identified Pcp1 protein belong to ubiquitous protein families.     

Peptide differential display: a novel approach for phase transition in locusts

Today, the question of the physiological cause of phase transition, the transition from the solitary to the gregarious phase, in locusts remains unanswered. We hereby present a novel approach by which we have attempted to determine whether different phases express or release different peptides in similar physiological conditions. For this purpose, a peptidomic analysis of the corpora cardiaca and hemolymph of crowded and isolated locusts of Schistocerca gregaria was performed using high performance liquid chromatography and matrix-assisted laser desorption ionisation time of flight mass spectrometry. A comparison between the two conditions reveals differences in the number and amount of peptides present in the corpora cardiaca and the hemolymph. Further research will have to identify these phase specific differences and their role in locust phase polymorphism.     

The Streptomyces coelicolor ssgB gene is required for early stages of sporulation

ssgB was identified as a novel early sporulation gene in Streptomyces coelicolor. An ssgB deletion mutant failed to sporulate, over-produced actinorhodin, and its colonies were significantly larger than those of the parental strain, suggesting an important role for the ssgB gene product in the process of growth cessation prior to sporulation-specific cell division. This places ssgB temporally before the paralogous sporulation gene ssgA. Analysis of ssgB mutant hyphae by electron microscopy and by confocal fluorescence microscopy showed that it was defective in the initiation of sporulation, as no sporulation septa could be identified, and DNA segregation had not yet been initiated in the mutant.     

Capillary electrophoretic separation and quantification of flavone-O- and C-glycosides in Achillea setacea W. et K

A simple method for the rapid separation and quantification of flavone-O- and C-glycosides in A. setacea W. et K. by capillary zone electrophoresis (CZE) with UV detection is described. Using 25 mM sodium borate with 20% (v/v) of methanol (pH 9.3) as running buffer sufficient separation of the analytes was achieved within 19 min. For the quantitative determination isorhamnetin-3-O-rutinoside was used as internal standard. The method was successfully applied to a rapid characterisation of the flavonoid complex and a precise quantification of the single and total amount of the flavonoids in different samples of A. setacea.     

Isolation,structural characterization,and antiviral activity of positional isomers of monopegylated interferon alpha-2a (PEGASYS)

Interferon alpha-2a plays an essential role in the treatment of chronic hepatitis C, but it is limited in its efficacy by the short in vivo half-life. To improve the half-life and efficacy, interferon alpha-2a is conjugated with a 40-kDa branched polyethylene glycol moiety (PEG-IFN, PEGASYS). From this preparation the positional PEG-IFN isomers were isolated and characterized by different analytical methods and antiviral assay. Two chromatographic steps were used to separate and purify nine isomers. The analytical methods IE-HPLC, RP-HPLC, SE-HPLC, SDS-PAGE, and MALDI-TOF MS indicated that each of these nine isomers is conjugated to the branched polyethylene glycol chain at a specific lysine. No isomer with a modification at the amino terminus was observed. All positional isomers induced viral protection of MDBK cells in the antiviral assay. When comparing the quantitative potency of the individual isomers with the whole mixture of PEG-IFN, significant differences in the specific activities were observed: PEG-Lys(31) and PEG-Lys(134) showed higher activities than the mixture, PEG-Lys(164) was equal to the mixture, whereas the activities of PEG-Lys(49), PEG-Lys(70), PEG-Lys(83), PEG-Lys(112), PEG-Lys(121), and PEG-Lys(131) were lower.