Heterogeneity of human C4 gene size

In this article we present a study showing that the human C4 genes differ in length because of the presence or absence of a 6.5 kb intron near the 5 end of the gene. DNA from individuals of known HLA, factor B, and C4 haplotypes was analyzed for restriction fragment length polymorphism (RFLP) by Southern blot analysis with C4-specific cDNA probes. The RFLP patterns obtained showed that the C4 genes are either 22.5 kb or 16 kb in length. They are referred to as long and short C4 genes, respectively. A population study was carried out to examine the distribution of the gene size according to C4 allotypes and haplotypes. Long C4 genes included all C4A genes studied and also some C4B allotypes, e. g., B1 on most C4 A3B1 haplotypes. Similarly, C4B null genes were found to be of the long form. Other C4B allotypes tested were found to be coded for by short C4 genes, including B2, B1 in C4 A6B1 and C4 AQOB1 (with a single C4B gene haplotype).Abbreviations used in this paper C4 fourth component of complement - C2 second component of complement - BF factor B - MHC major histocompatibility complex - RFLP restriction fragment length polymorphism - EDTA ethylenediaminetetraacetic acid - SDS lauryl sulfate, sodium salt     

A complete sequence of the mitochondrial genome of the western lowland gorilla

The complete mitochondrial DNA (mtDNA) molecule of the gorilla was sequenced. The entire sequence, 16,412 nucleotides, was determined by analysis of natural (not polymerase chain reaction) restriction fragments covering the whole molecule. The sequence was established from one individual and thus nonchimeric. After comparison with the COII gene of gorilla specimens with known geographical origin, the sequence was identified as characteristic of the Western lowland gorilla, Gorilla gorilla gorilla. With the exception of the NADH2 gene, all genes have a methionine start codon. The inferred start codon of NADH2 is ATT (isoleucine). The COIII, NASDH4, and cytochrome b genes are not terminated by a stop codon triplet, and the COI gene is probably terminated by an AAA triplet rather than by a regular stop codon. The great majority of genic sequences (rRNAs, peptide-coding genes, tRNAs) of the complete mtDNAs of Gorilla, Pan, and Homo show a greater similarity between Pan and Homo than between either of these genera to Gorilla. The analysis of the peptide-coding genes suggest that relative to comparison between Homo and Pan a certain degree of transition saturation has taken place in codon position 3 in comparisons between Gorilla to either Homo or Pan.      

Genes,agents and the institution of responsible action

The concern of this paper is with how the accounts of human beings and their behaviour now emerging from genetics, genomics and the new human biotechnology should be related to traditional accounts in which we identify ourselves as responsible agents, capable of choice, who normally act freely and voluntarily. The paper addresses these apparently competing accounts in terms of their functions and modes of use, and thereby arrives at a general solution to this current version of the ancient problem of free will and determinism. The causal scientific discourse of genetics and the everyday discourse of responsibility and choice do different things for us, it suggests, and should not be regarded as articulating conflicting theories. Whilst the former is oriented to the task of naturalistic explanation, the latter is predominantly, if not entirely, a medium of communication through which we affect each other and thereby mutually regulate our conduct. If this is indeed the case, then interesting implications follow concerning the proper relationship of the two kinds of account, which need no longer be regarded as incompatible with each other. And insights emerge into both the limitations and the profound importance of the contribution that genetics and genomics seem destined to make to the understanding of human behaviour.     

Regulation of the spatial order of cortical microtubules in developing guard cells ofAllium

The organization of microtubules (MTs) in the cortex of cells at interphase is an important element in morphogenesis. Mechanisms controlling the initiation of MTs and their spatial ordering, however, are largely unknown. Our recent study concerning the generation of a radial array of MTs in stomatal guard cells inAllium showed that the MTs initiate in a cortical MT-organizing zone adjacent to the ventral wall separating the two young guard cells (Marc, Mineyuki and Palevitz, 1989, Planta179, 516, 530). In an attempt to detect MT-ordering mechanisms separate from the sites of MT initiation, we now employ various drugs to manipulate the geometry and integrity of the ventral wall and thereby also the associated MT-organizing zone. In the presence of cytochalasin D the ventral wall is tilted away from its normal mid-longitudinal anticlinal alignment, while treatments with the herbicide chloroisopropyl-N-phenylcarbamate (CIPC) induce the formation of a branched ventral wall. Nonetheless, in either case the MTs still form a radial array, although this is asymmetric as it is centered in accordance with the misaligned or branched ventral wall. Since the MTs maintain their original course undisturbed as they extend beyond the abnormal ventral wall, there is no evidence for the presence of an inherent MT-ordering mechanism at locations remote from MT-initiation sites. Following treatments with caffeine, which abolishes the formation of the ventral wall, the MTs revert to a transversely oriented cylindrical array as in normal epidermal cells. Thus the presence of the ventral wall, and presumably also the associated MT-organizing zone, is essential for the establishment of the radial array. The MT-organizing zone is therefore involved not only in the initiation of MTs, but also in determining their spatial order throughout the cell cortex. We thank Drs. Richard J. Cyr and Yoshi Mineyuki for providing valueable suggestions during the course of this work, and Ms. Elizabeth Bruce printing some of the figures. This research was supported by Funds from the National Science Foundation grants DCB-8703292 to B.A.P. and DCB-8803286 to B.A.P. and J.M.