The central gene cluster of chromosome III was one of the ®rst regions to be sequenced by the Caenorhabditis elegans genome project. We have performed an essential gene analysis on the left part of this cluster, in the region around dpy-17III balanced by the duplication sDp3. We isolated 151 essential gene mutations and characterized them with regard to their arrest stages. To facilitate positioning of these mutations, we generated six new de®ciencies that, together with preexisting chromosomal rearrangements, subdivide the region into 14 zones. The 151 mutations were mapped into these zones. They de®ne 112 genes, of which 110 were previously unidenti®ed. Thirteen of the zones have been anchored to the physical sequence by polymerase chain reaction de®ciency mapping. Of the 112 essential genes mapped, 105 are within these 13 zones. They span 4.2 Mb of nucleotide sequence. From the nucleotide sequence data, 920 genes are predicted. From a Poisson distribution of our mutations, we predict that 234 of the genes will be essential genes. Thus, the 105 genes constitute 45% of the estimated number of essential genes in the physically de®ned zones and between 2 and 5% of all essential genes in C. elegans.

The central gene cluster of chromosome III was one of the first regions to be sequenced by the Caenorhabditis elegans genome project. We have performed an essential gene analysis on the left part of this cluster, in the region around dpy-17III balanced by the duplication sDp3. We isolated 151 essential gene mutations and characterized them with regard to their arrest stages. To facilitate positioning of these mutations, we generated six new deficiencies that, together with preexisting chromosomal rearrangements, subdivide the region into 14 zones. The 151 mutations were mapped into these zones. They define 112 genes, of which 110 were previously unidentified. Thirteen of the zones have been anchored to the physical sequence by polymerase chain reaction deficiency mapping. Of the 112 essential genes mapped, 105 are within these 13 zones. They span 4.2 Mb of nucleotide sequence. From the nucleotide sequence data, 920 genes are predicted. From a Poisson distribution of our mutations, we predict that 234 of the genes will be essential genes. Thus, the 105 genes constitute 45% of the estimated number of essential genes in the physically defined zones and between 2 and 5% of all essential genes in C. elegans.

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In the early twentieth century, harmony, the sacred, and even time were seen as impediments to artistic freedom, though for the ancients, harmony was the integrating force of the cosmos. Giorgio Agamben’s recent writings on the sacred and on messianic time shed new light on the emergence of polyphony. He warns that capitalism, subsuming sacral power, reduces art either to spectacle or to object for consumption.

In Canada, brucellosis and tuberculosis threaten an estimated 4500 wood bison (Bison bison athabascae), a species considered at risk by the Committee on the Status of Endangered Wildlife In Canada (COSEWIC). To help rescue this species, our Wood Bison Reproductive Research group proposes to employ advanced reproductive technologies. Unfortunately, little is known about the reproductive physiology of the wood bison, which hinders the application of these reproductive technologies. In order to modify advanced reproductive techniques developed in cattle for use in wood bison, the large amounts of semen, embryos, and oocytes from wood bison required are not available. The purpose of this study was to compare semen collected from the more abundant and closely related plains bison (Bison bison bison) with that of wood bison. Semen from 3 wood and 4 plains bison were collected by electro-ejaculation during the summer of 2007. Andrological parameters of morphology and motility were recorded on fresh semen, extended semen, and post-thawed semen samples. A Student's t-test was used to compare the results of these two groups. Semen was cryopreserved using two commercially available cryopreservation media (Andromed and Triladyl, Minitube Canada, Ingersoll, Ontario, Canada). Sperm morphology and motility were not different between electro-ejaculated samples from plains and wood bison (P > 0.05). Also, no difference was found in the survival rate of sperm from the electro-ejaculated samples between plains and wood bison after freezing and then thawing using an egg-yolk based extender (Triladyl) or an extender containing no products of animal origin (Andromed). A difference between cryopreservation media was found; post-thaw motility of Triladyl-treated sperm was higher (29%) than that of the Andromed-treated sperm (12%). Due to lack of previous success with preserving electro-ejaculated semen in media free of animal-origin products, motility assays were performed to evaluate if spermatozoa retrieved from epididymides of plains bison can be cryopreserved in Andromed. Interestingly, cyropreserved epididymal spermatozoa had a higher motility than cryopreserved electro-ejaculated sperm after freezing-thawing procedures using a medium containing no products of source animal (respectively, 30% v. 7%). This result suggests that there may be a factor secreted by the reproductive accessory glands that interferes with the post-thaw survivability of bison sperm. In conclusion, this study supports the hypothesis that semen from plains bison behaves similarly to that of wood bison semen during cryopreservation and therefore could be used to establish protocols for advanced reproductive technologies in wood bison. This project was supported by Canadian Adaptation and Rural Development in Saskatchewan.