Copyright (c) 2009 All rights reserved. http://works.bepress.com/charles_detwiler Recent documents in Charles Detwiler en-us Sat, 21 Nov 2009 02:20:31 PST 3600 http://works.bepress.com/charles_detwiler/6 http://works.bepress.com/charles_detwiler/6 Fri, 20 Nov 2009 08:13:40 PST Charles R. Detwiler http://works.bepress.com/charles_detwiler/5 http://works.bepress.com/charles_detwiler/5 Thu, 10 Sep 2009 07:35:24 PDT These brief working documents are used in my Biology 101 course to encourage students to draw together what they know about science, politics, and the theology of the human will to speak to a current issue.In a team format, they are encouraged to compare these positions and select one which they (as a team) wish to identify with. The preponderance of teams are attracted to the third position. Assumptions made toward the end of this third position are accepted with little critical thought. It has been a fascinating exercise in using a biological issue to address fundamental philosophical problems we all face and don't admit to very readily. Charles Detwiler Intelligent Design http://works.bepress.com/charles_detwiler/4 http://works.bepress.com/charles_detwiler/4 Sun, 21 Jun 2009 12:39:35 PDT A deoxyribonuclease, called DNase-1, that is active at acid pH in the presence of EDTA has been studied in Drosophila melanogaster. The locus for the enzyme maps genetically to 61.8 on the right arm of the third chromosome. Cytogenetically, DNase-1 has been localized to within five to ten bands between 90C-2 and 90E. This analysis utilizes both electrophoretic variants and the Y-autosome translocations of Lindsley et al. (1972). DNase-1 is present in all stages of the life cycle, and the paternal genome actively contributes DNase-1 to the embryo between 0 and 1 hr after fertilization. Charles Detwiler http://works.bepress.com/charles_detwiler/2 http://works.bepress.com/charles_detwiler/2 Sun, 21 Jun 2009 12:39:34 PDT Charles Detwiler http://works.bepress.com/charles_detwiler/3 http://works.bepress.com/charles_detwiler/3 Sun, 21 Jun 2009 12:39:28 PDT A study was undertaken to determine the subcellular location of DNase-I, a major acid deoxyribonuclease in Drosophila melanogaster. Embryonic tissue used in these experiments was derived from a wild type strain and from a strain homozygous at the DNase-l locus (3-61.8) for the null activity allele, DNase-lnl24. The majority of total acid DNase and DNase-l activity is found in the small particulate fraction of tissue homogenates fractionated by differential centrifugation. The activity exhibits latency in these extracts indicating that it is membrane delimited. DNase-I activity also co-equilibrates in sucrose density gradients with acid phosphatase activity which, in D. melanogaster, is known to be lysosomal. These results suggest that DNase-l is localized largely within the Iysosomes of embryonic tissue. Functional implications of a lysosomal location for DNase-l are discussed. Charles Detwiler