{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/45555"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/45555","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Chromosome identification and analysis in selected lines of laboratory mice","abstract":"Chromosome preparations from 102 ICR albino mice were examined using a modified trypsin Giemsa staining technique. The mice were from four lines selected for maximum rate of post-weaning gain (28 generations), one line selected for minimum rate of post-weaning gain (25 generations), and two unselected control lines. Mitotic metaphase chromosome preparations were obtained from bone marrow cells of adult male and female mice. Two similar treatments were utilized in obtaining the chromosome preparations. The first treatment consisted of: 50 minute colchicine pretreatment, 30 minute hypotionic pretreatment, four-glacial acetic acid-methnanol fixation periods, 15 second trypsin period and 15 minute Giemsa staining period. The second treatment varied from the first, basically, in the length of hypotonic pretreatment, and length and number of fixation periods. A mean number of 40 telocentric chromosomes with very similar banding patterns was observed in all lines. Relative chromosome lengths for each chromosome were obtained. The lengths for the various lines, control, high and low, were compared by means of a pooled \"t\" test. Non-significant a₂ levels were obtained for the pairwise comparisons of the lines. Significant a₂ levels were obtained for the effects of the two treatments, trypsin and no trypsin. Karyotypes for each line were made with no chromosomal abnormalities detected in any of the lines. The selection regime followed has produced significant genetic change in several characteristics of these mice. However, these changes have apparently not been accompanied by observable alterations at the chromosomal level.","abstract_html":"Chromosome preparations from 102 ICR albino mice were examined using a modified trypsin Giemsa staining technique. The mice were from four lines selected for maximum rate of post-weaning gain (28 generations), one line selected for minimum rate of post-weaning gain (25 generations), and two unselected control lines. Mitotic metaphase chromosome preparations were obtained from bone marrow cells of adult male and female mice. Two similar treatments were utilized in obtaining the chromosome preparations. The first treatment consisted of: 50 minute colchicine pretreatment, 30 minute hypotionic pretreatment, four-glacial acetic acid-methnanol fixation periods, 15 second trypsin period and 15 minute Giemsa staining period. The second treatment varied from the first, basically, in the length of hypotonic pretreatment, and length and number of fixation periods. A mean number of 40 telocentric chromosomes with very similar banding patterns was observed in all lines. Relative chromosome lengths for each chromosome were obtained. The lengths for the various lines, control, high and low, were compared by means of a pooled "t" test. Non-significant a₂ levels were obtained for the pairwise comparisons of the lines. Significant a₂ levels were obtained for the effects of the two treatments, trypsin and no trypsin. Karyotypes for each line were made with no chromosomal abnormalities detected in any of the lines. The selection regime followed has produced significant genetic change in several characteristics of these mice. However, these changes have apparently not been accompanied by observable alterations at the chromosomal level.","abstract_has_math":false,"creators":["Schmitt, Athanasia Nancy Panos"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Zoology","degree_department":"Zoology","school":null,"contributors":[],"advisors":[],"committee_chairs":["Vinson, William E.","White, John M."],"committee_members":["Davis, Brian K.","Saacke, Richard G.","Paterson, Robert A."],"year":1976,"date_issued":"1976-06-05","date_published":"1976-06-05","updated_at":"2026-07-22T22:19:06Z","subjects":["chromosomal indentification"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-11092012-040112"],"render_values":[{"text":"etd-11092012-040112","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/45555","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Vinson, William E.","White, John M."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Davis, Brian K.","Saacke, Richard G.","Paterson, Robert A."]},{"key":"dc:contributor.department","label":"Department","values":["Zoology"]},{"key":"dc:creator","label":"Author","values":["Schmitt, Athanasia Nancy Panos"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:49:16Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:49:16Z","2012-11-09"]},{"key":"dc:date.issued","label":"Date","values":["1976-06-05"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Zoology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["chromosomal indentification"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-11092012-040112"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/45555"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Chromosome preparations from 102 ICR albino mice were examined using a modified trypsin Giemsa staining technique. The mice were from four lines selected for maximum rate of post-weaning gain (28 generations), one line selected for minimum rate of post-weaning gain (25 generations), and two unselected control lines. Mitotic metaphase chromosome preparations were obtained from bone marrow cells of adult male and female mice. Two similar treatments were utilized in obtaining the chromosome preparations. The first treatment consisted of: 50 minute colchicine pretreatment, 30 minute hypotionic pretreatment, four-glacial acetic acid-methnanol fixation periods, 15 second trypsin period and 15 minute Giemsa staining period. The second treatment varied from the first, basically, in the length of hypotonic pretreatment, and length and number of fixation periods. A mean number of 40 telocentric chromosomes with very similar banding patterns was observed in all lines. Relative chromosome lengths for each chromosome were obtained. The lengths for the various lines, control, high and low, were compared by means of a pooled \"t\" test. Non-significant a₂ levels were obtained for the pairwise comparisons of the lines. Significant a₂ levels were obtained for the effects of the two treatments, trypsin and no trypsin. Karyotypes for each line were made with no chromosomal abnormalities detected in any of the lines. The selection regime followed has produced significant genetic change in several characteristics of these mice. However, these changes have apparently not been accompanied by observable alterations at the chromosomal level."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Chromosome identification and analysis in selected lines of laboratory mice"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Vinson, William E.","White, John M."],"dc:contributor.committeemember":["Davis, Brian K.","Saacke, Richard G.","Paterson, Robert A."],"dc:contributor.department":["Zoology"],"dc:creator":["Schmitt, Athanasia Nancy Panos"],"dc:date.accessioned":["2014-03-14T21:49:16Z"],"dc:date.available":["2014-03-14T21:49:16Z","2012-11-09"],"dc:date.issued":["1976-06-05"],"dc:description.abstract":["Chromosome preparations from 102 ICR albino mice were examined using a modified trypsin Giemsa staining technique. The mice were from four lines selected for maximum rate of post-weaning gain (28 generations), one line selected for minimum rate of post-weaning gain (25 generations), and two unselected control lines. Mitotic metaphase chromosome preparations were obtained from bone marrow cells of adult male and female mice. Two similar treatments were utilized in obtaining the chromosome preparations. The first treatment consisted of: 50 minute colchicine pretreatment, 30 minute hypotionic pretreatment, four-glacial acetic acid-methnanol fixation periods, 15 second trypsin period and 15 minute Giemsa staining period. The second treatment varied from the first, basically, in the length of hypotonic pretreatment, and length and number of fixation periods. A mean number of 40 telocentric chromosomes with very similar banding patterns was observed in all lines. Relative chromosome lengths for each chromosome were obtained. The lengths for the various lines, control, high and low, were compared by means of a pooled \"t\" test. Non-significant a₂ levels were obtained for the pairwise comparisons of the lines. Significant a₂ levels were obtained for the effects of the two treatments, trypsin and no trypsin. Karyotypes for each line were made with no chromosomal abnormalities detected in any of the lines. The selection regime followed has produced significant genetic change in several characteristics of these mice. However, these changes have apparently not been accompanied by observable alterations at the chromosomal level."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-11092012-040112"],"dc:identifier.uri":["http://hdl.handle.net/10919/45555"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["chromosomal indentification"],"dc:title":["Chromosome identification and analysis in selected lines of laboratory mice"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Zoology"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:06Z"}