140 research outputs found

    Rapidly evolving marmoset MSMB genes are differently expressed in the male genital tract

    Get PDF
    BACKGROUND: Beta-microseminoprotein, an abundant component in prostatic fluid, is encoded by the potential tumor suppressor gene MSMB. Some New World monkeys carry several copies of this gene, in contrast to most mammals, including humans, which have one only. Here we have investigated the background for the species difference by analyzing the chromosomal organization and expression of MSMB in the common marmoset (Callithrix jacchus). METHODS: Genes were identified in the Callithrix jacchus genome database using bioinformatics and transcripts were analyzed by RT-PCR and quantified by real time PCR in the presence of SYBR green. RESULTS: The common marmoset has five MSMB: one processed pseudogene and four functional genes. The latter encompass homologous genomic regions of 32-35 kb, containing the genes of 12-14 kb and conserved upstream and downstream regions of 14-19 kb and 3-4 kb. One gene, MSMB1, occupies the same position on the chromosome as the single human gene. On the same chromosome, but several Mb away, is another MSMB locus situated with MSMB2, MSMB3 and MSMB4 arranged in tandem. Measurements of transcripts demonstrated that all functional genes are expressed in the male genital tract, generating very high transcript levels in the prostate. The transcript levels in seminal vesicles and testis are two and four orders of magnitude lower. A single gene, MSMB3, accounts for more than 90% of MSMB transcripts in both the prostate and the seminal vesicles, whereas in the testis around half of the transcripts originate from MSMB2. These genes display rapid evolution with a skewed distribution of mutated nucleotides; in MSMB2 they affect nucleotides encoding the N-terminal Greek key domain, whereas in MSMB3 it is the C-terminal MSMB-unique domain that is affected. CONCLUSION: Callitrichide monkeys have four functional MSMB that are all expressed in the male genital tract, but the product from one gene, MSMB3, will predominate in seminal plasma. This gene and MSMB2, the predominating testicular gene, have accumulated mutations that affect different parts of the translation products, suggesting an ongoing molecular specialization that presumably yields functional differences in accessory sex glands and testis

    Clinical and molecular characterization of diffuse large B-cell lymphomas with 13q14.3 deletion.

    Get PDF
    Background: Deletions at 13q14.3 are common in chronic lymphocytic leukemia and are also present in diffuse large B-cell lymphomas (DLBCL) but never in immunodeficiency-related DLBCL. To characterize DLBCL with 13q14.3 deletions, we combined genome-wide DNA profiling, gene expression and clinical data in a large DLBCL series treated with rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 days (R-CHOP21). Patients and methods: Affymetrix GeneChip Human Mapping 250K NspI and U133 plus 2.0 gene were used. MicroRNA (miRNA) expression was studied were by real-time PCR. Median follow-up of patients was 4.9 years. Results: Deletions at 13q14.3, comprising DLEU2/MIR15A/MIR16, occurred in 22/166 (13%) cases. The deletion was wider, including also RB1, in 19/22 cases. Samples with del(13q14.3) had concomitant specific aberrations. No reduced MIR15A/MIR16 expression was observed, but 172 transcripts were significantly differential expressed. Among the deregulated genes, there were RB1 and FAS, both commonly deleted at genomic level. No differences in outcome were observed in patients treated with R-CHOP21. Conclusions: Cases with 13q14.3 deletions appear as group of DLBCL characterized by common genetic and biologic features. Deletions at 13q14.3 might contribute to DLBCL pathogenesis by two mechanisms: deregulating the cell cycle control mainly due RB1 loss and contributing to immune escape, due to FAS down-regulation

    Clinical and molecular characterization of diffuse large B-cell lymphomas with 13q14.3 deletion

    Get PDF
    Background: Deletions at 13q14.3 are common in chronic lymphocytic leukemia and are also present in diffuse large B-cell lymphomas (DLBCL) but never in immunodeficiency-related DLBCL. To characterize DLBCL with 13q14.3 deletions, we combined genome-wide DNA profiling, gene expression and clinical data in a large DLBCL series treated with rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 days (R-CHOP21). Patients and methods: Affymetrix GeneChip Human Mapping 250K NspI and U133 plus 2.0 gene were used. MicroRNA (miRNA) expression was studied were by real-time PCR. Median follow-up of patients was 4.9 years. Results: Deletions at 13q14.3, comprising DLEU2/MIR15A/MIR16, occurred in 22/166 (13%) cases. The deletion was wider, including also RB1, in 19/22 cases. Samples with del(13q14.3) had concomitant specific aberrations. No reduced MIR15A/MIR16 expression was observed, but 172 transcripts were significantly differential expressed. Among the deregulated genes, there were RB1 and FAS, both commonly deleted at genomic level. No differences in outcome were observed in patients treated with R-CHOP21. Conclusions: Cases with 13q14.3 deletions appear as group of DLBCL characterized by common genetic and biologic features. Deletions at 13q14.3 might contribute to DLBCL pathogenesis by two mechanisms: deregulating the cell cycle control mainly due RB1 loss and contributing to immune escape, due to FAS down-regulatio

    Autocatalytic Activation of the Furin Zymogen Requires Removal of the Emerging Enzyme's N-Terminus from the Active Site

    Get PDF
    Before furin can act on protein substrates, it must go through an ordered process of activation. Similar to many other proteinases, furin is synthesized as a zymogen (profurin) which becomes active only after the autocatalytic removal of its auto-inhibitory prodomain. We hypothesized that to activate profurin its prodomain had to be removed and, in addition, the emerging enzyme's N-terminus had to be ejected from the catalytic cleft.We constructed and analyzed the profurin mutants in which the egress of the emerging enzyme's N-terminus from the catalytic cleft was restricted. Mutants were autocatalytically processed at only the primary cleavage site Arg-Thr-Lys-Arg(107) downward arrowAsp(108), but not at both the primary and the secondary (Arg-Gly-Val-Thr-Lys-Arg(75) downward arrowSer(76)) cleavage sites, yielding, as a result, the full-length prodomain and mature furins commencing from the N-terminal Asp108. These correctly processed furin mutants, however, remained self-inhibited by the constrained N-terminal sequence which continuously occupied the S' sub-sites of the catalytic cleft and interfered with the functional activity. Further, using the in vitro cleavage of the purified prodomain and the analyses of colon carcinoma LoVo cells with the reconstituted expression of the wild-type and mutant furins, we demonstrated that a three-step autocatalytic processing including the cleavage of the prodomain at the previously unidentified Arg-Leu-Gln-Arg(89) downward arrowGlu(90) site, is required for the efficient activation of furin.Collectively, our results show the restrictive role of the enzyme's N-terminal region in the autocatalytic activation mechanisms. In a conceptual form, our data apply not only to profurin alone but also to a range of self-activated proteinases

    Dominant Glint Based Prey Localization in Horseshoe Bats: A Possible Strategy for Noise Rejection

    Get PDF
    Rhinolophidae or Horseshoe bats emit long and narrowband calls. Fluttering insect prey generates echoes in which amplitude and frequency shifts are present, i.e. glints. These glints are reliable cues about the presence of prey and also encode certain properties of the prey. In this paper, we propose that these glints, i.e. the dominant glints, are also reliable signals upon which to base prey localization. In contrast to the spectral cues used by many other bats, the localization cues in Rhinolophidae are most likely provided by self-induced amplitude modulations generated by pinnae movement. Amplitude variations in the echo not introduced by the moving pinnae can be considered as noise interfering with the localization process. The amplitude of the dominant glints is very stable. Therefore, these parts of the echoes contain very little noise. However, using only the dominant glints potentially comes at a cost. Depending on the flutter rate of the insect, a limited number of dominant glints will be present in each echo giving the bat a limited number of sample points on which to base localization. We evaluate the feasibility of a strategy under which Rhinolophidae use only dominant glints. We use a computational model of the echolocation task faced by Rhinolophidae. Our model includes the spatial filtering of the echoes by the morphology of the sonar apparatus of Rhinolophus rouxii as well as the amplitude modulations introduced by pinnae movements. Using this model, we evaluate whether the dominant glints provide Rhinolophidae with enough information to perform localization. Our simulations show that Rhinolophidae can use dominant glints in the echoes as carriers for self-induced amplitude modulations serving as localization cues. In particular, it is shown that the reduction in noise achieved by using only the dominant glints outweighs the information loss that occurs by sampling the echo

    Variation in Size and Growth of the Great Scallop Pecten maximus along a Latitudinal Gradient

    Get PDF
    Understanding the relationship between growth and temperature will aid in the evaluation of thermal stress and threats to ectotherms in the context of anticipated climate changes. Most Pecten maximus scallops living at high latitudes in the northern hemisphere have a larger maximum body size than individuals further south, a common pattern among many ectotherms. We investigated differences in daily shell growth among scallop populations along the Northeast Atlantic coast from Spain to Norway. This study design allowed us to address precisely whether the asymptotic size observed along a latitudinal gradient, mainly defined by a temperature gradient, results from differences in annual or daily growth rates, or a difference in the length of the growing season. We found that low annual growth rates in northern populations are not due to low daily growth values, but to the smaller number of days available each year to achieve growth compared to the south. We documented a decrease in the annual number of growth days with age regardless of latitude. However, despite initially lower annual growth performances in terms of growing season length and growth rate, differences in asymptotic size as a function of latitude resulted from persistent annual growth performances in the north and sharp declines in the south. Our measurements of daily growth rates throughout life in a long-lived ectothermic species provide new insight into spatio-temporal variations in growth dynamics and growing season length that cannot be accounted for by classical growth models that only address asymptotic size and annual growth rate
    corecore