Judgment

To judge, in Latin judicare, is to say the law, jus dicere, whence juris-dictio. The above sentence is a possible answer to the question: what is judging? It spells out what the word to judge says, by recalling the history from which the word originates. Why would anyone ask this question? How helpful is such an answer? Everyone knows what it is to judge. Only on the ground of such self-evidence could there be that unabating debate on the \u27 justification of particular judgments, which is the day to day business of lawyering. Only because the question can be passed over can there be controversy regarding the forms and limits of adjudication in general, a preoccupation without which jurisprudence would seem to lose its main occupation. Why ask the question? Precisely because the matter is self-evident. As soon as we examine it a little, confusion begins to set in all over. Monsieur Jourdain likely would be flattered if he knew that logicians employ the word \u27Judgment in its widest sense to designate propositions of all kinds: He has been judging all along, and therefore knows already how to do it. Even Kant follows this usage when he says that we can reduce all acts of the understanding to judgments, and goes on to propose a table that classifies all possible forms of judment into four groups of three (Kritik der reinen Vernunft, * A 67- pages of the same star editions). Could it be that almost all speaking is a saying of law? A little later in the same treatise, however, Kant restricts the sense of \u27Judgment to the act of subsuming under rules, that is, of distinguishing whether something falls under a given rule or not (casus datae legis) (id. A 132-34, B 171-74). This sense is borrowed from lawyerly usage, not from logic, for, as Kant shows, logic has nothing to say regarding this operation. There are, and there can be, no rules regarding the application of rules. If Kant is right, a sizable part of what we take to be law, and almost all jurisprudence, are nothing but a futile striving to overcome this essential unruliness of judgment. How can it be that the saying of law is lawless

A window into domain amplification through Piccolo in teleost fish

I describe and characterize the extensive amplification of the zinc finger domain of Piccolo selectively in teleost fish. Piccolo and Bassoon are partially functionally redundant and play roles in regulating the pool of neurotransmitter-filled synaptic vesicles present at synapses. In mice, each protein contains two N-terminal zinc finger domains that have been implicated in interacting with synaptic vesicles. In all teleosts examined, both the Bassoon and Piccolo genes are duplicated. Both teleost bassoon genes and one piccolo gene show very similar domain structure and intron-exon organization to their mouse homologs. In contrast, in piccolo b a single exon that encodes a zinc finger domain is amplified 8 to 16 times in different teleost species. Analysis of the amplified exons suggests they were added and/or deleted from the gene as individual exons in rare events that are likely the result of unequal crossovers between homologous sequences. Surprisingly, the structure of the repeats from cod and zebrafish suggest that amplification of this exon has occurred independently multiple times in the teleost lineage. Based on the structure of the exons, I propose a model in which selection for high sequence similarity at the 5′ and 3′ ends of the exon drives amplification of the repeats and diversity in repeat length likely promotes the stability of the repeated exons by minimizing the likelihood of mispairing of adjacent repeat sequences. Further analysis of piccolo b in teleosts should provide a window through which to examine the process of domain amplification

Caenorhabditis elegans rab-3 mutant synapses exhibit impaired function and are partially depleted of vesicles

Journal ArticleRab molecules regulate vesicular trafficking in many different exocytic and endocytic transport pathways in eukaryotic cells. In neurons, rab3 has been proposed to play a crucial role in regulating synaptic vesicle release. To elucidate the role of rab3 in synaptic transmission, we isolated and characterized Caenorhabditis elegans rab-3 mutants. Similar to the mouse rab3A mutants, these mutants survived and exhibited only mild behavioral abnormalities. In contrast to the mouse mutants, synaptic transmission was perturbed in these animals

UNC-11, a Caenorhabditis elegans AP180 homologue, regulates the size and protein composition of synaptic vesicles

Journal ArticleThe unc-11 gene of Caenorhabditis elegans encodes multiple isoforms of a protein homologous to the mammalian brain-specific clathrin-adaptor protein AP180. The UNC-11 protein is expressed at high levels in the nervous system and at lower levels in other tissues. In neurons, UNC-11 is enriched at presynaptic terminals but is also present in cell bodies. unc-11 mutants are defective in two aspects of synaptic vesicle biogenesis

A Monoclonal Antibody Toolkit for C. elegans

Antibodies are critical tools in many avenues of biological research. Though antibodies can be produced in the research laboratory setting, most research labs working with vertebrates avail themselves of the wide array of commercially available reagents. By contrast, few such reagents are available for work with model organisms.We report the production of monoclonal antibodies directed against a wide range of proteins that label specific subcellular and cellular components, and macromolecular complexes. Antibodies were made to synaptobrevin (SNB-1), a component of synaptic vesicles; to Rim (UNC-10), a protein localized to synaptic active zones; to transforming acidic coiled-coil protein (TAC-1), a component of centrosomes; to CENP-C (HCP-4), which in worms labels the entire length of their holocentric chromosomes; to ORC2 (ORC-2), a subunit of the DNA origin replication complex; to the nucleolar phosphoprotein NOPP140 (DAO-5); to the nuclear envelope protein lamin (LMN-1); to EHD1 (RME-1) a marker for recycling endosomes; to caveolin (CAV-1), a marker for caveolae; to the cytochrome P450 (CYP-33E1), a resident of the endoplasmic reticulum; to β-1,3-glucuronyltransferase (SQV-8) that labels the Golgi; to a chaperonin (HSP-60) targeted to mitochondria; to LAMP (LMP-1), a resident protein of lysosomes; to the alpha subunit of the 20S subcomplex (PAS-7) of the 26S proteasome; to dynamin (DYN-1) and to the α-subunit of the adaptor complex 2 (APA-2) as markers for sites of clathrin-mediated endocytosis; to the MAGUK, protein disks large (DLG-1) and cadherin (HMR-1), both of which label adherens junctions; to a cytoskeletal linker of the ezrin-radixin-moesin family (ERM-1), which localized to apical membranes; to an ERBIN family protein (LET-413) which localizes to the basolateral membrane of epithelial cells and to an adhesion molecule (SAX-7) which localizes to the plasma membrane at cell-cell contacts. In addition to working in whole mount immunocytochemistry, most of these antibodies work on western blots and thus should be of use for biochemical fractionation studies. for the research community. These reagents are being made available through the Developmental Studies Hybridoma Bank (DSHB)

Landscape of target: Guide homology effects on Cas9-mediated cleavage

To study target sequence specificity, selectivity, and reaction kinetics of Streptococcus pyogenes Cas9 activity, we challenged libraries of random variant targets with purified Cas9::guide RNA complexes in vitro. Cleavage kinetics were nonlinear, with a burst of initial activity followed by slower sustained cleav-age. Consistent with other recent analyses of Cas9 sequence specificity, we observe considerable (al-beit incomplete) impairment of cleavage for targets mutated in the PAM sequence or in ‘seed ’ sequences matching the proximal 8 bp of the guide. A second target region requiring close homology was located at the other end of the guide::target duplex (posi-tions 13–18 relative to the PAM). Sequences flanking the guide+PAM region had measurable (albeit mod-est) effects on cleavage. In addition, the first-base Guanine constraint commonly imposed by gRNA ex-pression systems has little effect on overall cleavage efficiency. Taken together, these studies provide an in vitro understanding of the complexities of Cas9– gRNA interaction and cleavage beyond the general paradigm of site determination based on the ‘seed’ sequence and PAM

Dosage compensation: X-repress yourself

AbstractDosage compensation in Caenorhabditis elegans involves the sex-specific recruitment to the X chromosome of a protein complex, the nature of which suggests that there are mechanistic links between chromosome segregation and global transcriptional regulation

Ctk1 promotes dissociation of basal transcription factors from elongating RNA polymerase II

As RNA polymerase II (RNApII) transitions from initiation to elongation, Mediator and the basal transcription factors TFIID, TFIIA, TFIIH, and TFIIE remain at the promoter as part of a scaffold complex, whereas TFIIB and TFIIF dissociate. The yeast Ctk1 kinase associates with elongation complexes and phosphorylates serine 2 in the YSPTSPS repeats of the Rpb1 C-terminal domain, a modification that couples transcription to mRNA 3′-end processing. The higher eukaryotic kinase Cdk9 not only performs a similar function, but also functions at the 5′-end of genes in the transition from initiation to elongation. In strains lacking Ctk1, many basal transcription factors cross-link throughout transcribed regions, apparently remaining associated with RNApII until it terminates. Consistent with this observation, preinitiation complexes formed on immobilized templates with transcription extracts lacking Ctk1 leave lower levels of the scaffold complex behind after escape. Taken together, these results suggest that Ctk1 is necessary for the release of RNApII from basal transcription factors. Interestingly, this function of Ctk1 is independent of its kinase activity, suggesting a structural function of the protein