This is a study of references to and invocations of'the human genome' in the context of human genome research and particularly in the course of the controversy between the international Human Genome Project and Celera Genomics. References to 'the human genome' have been met with criticism by scholars in view of the manifest diversity of human beings. In contrast, I show how references to 'the human genome' as a shared though invisible object of investigation furnished a sense of shared purpose and mutual accountability among scientific experts, which also extended to policy makers and broader audiences. In particular, I show how references to 'the human genome' served to coordinate research with human-derived DNA and that invocations of 'the human genome' among scientist cut across contexts that are conventionally classed as either scientific or commercial. An analysis ofthe examination of patent applications for three entire microbial genome sequences shows that for the US Patent and Trademark Office these only constituted a logistical challenge; the patent system was unconcerned with invocations of 'the human genome'. I further document how scientists adopted the notion of a 'draft' of 'the human genome' in interactions with broader audiences. This went hand in hand with a shift in the focus of collective activity and references to 'the human genome' as a domain of investigation to the control ofhuman genome sequence information. In this context, invocations of 'the human genome' increasingly drew on discourses of property, which allows me to offer an alternative explanation for the perceived success of human genome research. Overall, my study shows that, while invocations of 'the human genome' changed to suit different objectives, actors did not differentiate between references to 'the human genome' for one purpose or another. Unreflective references to 'the human genome' thus furnished a sense ofshared purpose and mutual accountability among them. At the same time, this collective activity can be seen as effecting significant developments ofthe notion of'the human genome'. A further technical case study investigates how variability among human-derived DNA was accommodated in the results of the Human Genome Project and of Celera Genomics and explores how this might be conceptualised with respect to 'the human genome'. Development

Genetic variation and genetic differentiation in the genus Artemia has been studied using starch gel electrophoresis of 22-23 loci (coding 16 enzymes) and cytological methods. Samples, derived from cysts, included all bisexual species (A. franciscana, A. nnnica, A. persimilis, A. salina,and A. urmiana) and various parthenogenetic forms. In bisexuals, heterozygosity values (H =0.09-0.19) were consistent with other studies of invertebrates. Among the parthenogenetics, numbers of genotypes were generally higher in diploid (autanictic) than in polyploid (apanictic) populations, and heterozygosity increased considerably and significantly with ploidy level. In some localities mixtures of reproductive systems or of different ploidies and/or clones were found. Results are discussed in relation to reproductive modes and current theories. Exceptional parthenogenetically derived males contained genotypes (and had levels of heterozygosity) similar to their asexual "sisters". Chromosome numbers for the bisexuals were 2n=42 (franciscana, monica, salina and urmiana) or 44 (persimilis). Chranaoentres were found only in American species. Ebploid meters of 42, 63, 84,and 105 were found among the parthenogenetic forms, although aneuploid polyploids were also observed. This work generally confirms recent views of geneticists about the taxonomy of the genus but distinguishes several further points. Genetic distances indicate exceptionally high degree of differentiation (mean conspecific D=0.11; mean congeneric 114.5). Phenetic and phylogenetic analysis suggests (1) parthenogenetic Anemia have a monophyletic origin, (2) the ancestral form for this line was derived from a bon on ancestor with A. urmiana, (3) pentaploids were derived from tetraploids, (4) triploids have arisen in several independent events from diploids, (5) no electrophoretic or cytological differentiation exists between A. monica and A. franciscana. Formal genetic studies demonstrate (1) normal Mendelian inheritance of the loci assayed, (2) a disanic control of the unlinked duplicated Pgi loci in A. persimilis, and (3) lack of recombination in asexual forms tested. Evolution and speciation in the genus are discussed in the light of contemporary theories.

The relative influence of stochastic and deterministic forces at the molecular level is a central question in population genetics. Two main theoretical frameworks have been proposed to account for genetic variation in natural populations revealed by molecular techniques, these are neutral and selection theories. In 1980, an allozyme database project was initiated to test a prediction from neutral theory concerning the relationship between genetic diversity and evolutionary rate. As the databases now contain allele frequency data for 1311 species of animals and 209 species of plants, they are large enough to be applied to a number of neutral theory predictions. This thesis considers the historical and philosophical background to the neutralist-selectionist controversy; details the opeation of the allozyme databases; their construction, organisation and use in analysis, and presents the results of four independent sets of analysis that test predictions from neutral theory. The overall conclusion that can be drawn from these analyses is that neutral theory is sufficient to explain the majority of allozyme variation. However, some of the results cannot be explained within this framework, which may indicate evidence of the influence of selection. The work presented in this thesis illustrates the applicability and effectiveness of the database approach in addressing the neutralist-selectionist debate. Now that the resource, the databases, has been put in place, it an be used to answer a range of questions in population and evolutionary genetics.

No description available.

Intraspecific genetic differentiation between populations of <I>Artemia franciscana </I>from San Francisco Bay (SFB) and Vietnam (feral) as well as evolutionary divergence between Asian <I>Artemia</I> species have been investigated using allozymes, reproductive characters and mitochondrial DNA. Allozyme analysis (20 loci) of <I>A. franciscana</I>, SFB and derived (over a period of one to seven years) Vietnamese populations reveals considerable genetic differences between samples, cultured at combinations of two salinities (80 ppt, 120 ppt) and three temperatures (26<SUP>o</SUP>C, 30<SUP>o</SUP>C, 34<SUP>o</SUP>C). Combined probability values (pooled over all polymorphic loci) of tests for allele frequency homogeneity between all salinity/temperature combinations range from <10<SUP>-4</SUP> to 0.033. In addition, cluster analysis applied to all levels of comparison (within and between temperatures and salinities) shows evidence of differentiation of Vietnamese <I>Artemia</I> from the wild (SFB) stock as early as within a year after inoculation. Rapid divergence between SFB and Vietnamese <I>Artemia</I> is also evident from an analysis of reproductive (fecundity) traits. Vietnamese populations seem to be better adapted to increased temperature, as gauged by the significantly higher reproductive output they display compared to San Francisco Bay <I>Artemia</I>. Correlations between individual heterozygosity and fitness also confirm, albeit in a few cases, the existence of a strong genetic component involved in the determination of reproductive profiles. Similar patterns of genetic differentiation to those obtained by allozymes and reproductive traits are revealed by mitochondrial DNA RFLP markers. However, unlike allozymes, there is strong evidence of a reduction in haplotype diversity from 40.6% in SFB <I>Artemia</I> to 10.5% in the established Vietnamese strain.

Masculinization and feminization of the Jitralada strain of <i>Oreochromis niloticus</i> (L.) could be induced with a high level of success by oral administration of a 40-mg kg<SUP>-1</SUP> of 17-α-methyltestosterone and 40-mg mg^-1 of ethynyl-estradiol, respectively, to the first-feeding fry for a period of 21 days. On the other hand, optimization of dosage and means of application of 17-β-oestradiol or <i>Pueraria mirifica</i> roots are still needed in inducing reliable feminization of this strain. Differences in the results obtained are discussed and it is concluded that there are significant genetic differences between strains in the readiness with which sex reversal can be brought about. The modification and application of starch gel and SDS-polyacrylamide gel electrophoresis are proved useful and powerful in the investigation of biochemical studies of tilapia. The use of fin tissue in starch gel electrophoresis was advantageous and gave adequate data for the identification of <i>tilapiine</i> fish. Allozymes studies of the Jitralada strain of <i>O.niloticus</i> (L.) in Northeastern Thailand provided clear evidence of gene leakage and introgression from <i>O.mossambicus</i> at the Chaiyaphum Inland Fisheries Station. The results of inheritance studies on F<SUB>1</SUB> hybrids between <i>O.niloticus</i> and <i>O.aureus</i> and back-crosses, at the <i>ADA</i>* locus and blood serum protein, fit well to Mendelian inheritance. Expression of the <i>ADA</i>* locus is found to be controlled by a single autosomal gene. The pattern of blood serum protein of <i>O.spilurus, O.aureus, O.niloticus</i> and F<SUB>1</SUB> hybrids between <i>O.niloticus</i> and <i>O.aureus</i> from 8% SDS-polyacrylamide gel electrophoresis were investigated. A band of 63 kDa in molecular weight was present only in F<SUB>1</SUB> female hybrids between <i>O.niloticus</i> and <i>O.aureus</i>. A model is proposed to explain this phenomenon.

The stock structure of three sturgeon species from the South Caspian Sea was studied. PCR-based mtDNA analysis (RFLP) was used for the study of population differentiation in the Russian sturgeon (<I>Acipenser gueldenstaedti</I>). The mtDNA ND5/6 gene regions was amplified using PCR techniques followed by RFLP analysis. 39 different composite haplotypes were detected among 62 specimens. 29 haplotypes were rare occurring only once in two regions (west and east areas of the Southern Caspian Sea). The average nucleotide and haplotype diversities within populations are estimated to be 0.028727 ± 0.000 and 0.9645 ± 00042 respectively and divergence between populations to be 0.00052. A highly significant difference in the distribution of haplotypes was observed between the west and east areas, suggesting the possible existence of different stocks. RAPD markers were used to discriminate different kinds of black caviar and sturgeon meat. A polymorphic band from RAPD amplification of DNA from two out of five sturgeon species was purified, cloned and sequenced. SCAR primers were designed and used to amplify caviar DNA from five sturgeon species. A marker of potential economic importance was discovered that is able to distinguish three species from their caviar and also is able to distinguish ship sturgeon caviar from osetra caviar (Russian and Persian sturgeon). This marker could assist international conservation and legal efforts to save what is left of the commercial ship sturgeon populations which are endangered and whose caviar is at present substituted for the more expensive osetra caviar. A partial sequence of the mtDNA ND5 gene region was used for population study in Persian sturgeon (west and east areas of Southern Caspian Sea). The results showed that although this approach was informative for phylogenetic study in sturgeon it was less informative for population study in Persian sturgeon.

No description available.

No description available.

No description available.