Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose isomerase, tetrazolium oxidase, and nonenzymatic protein, Observed allele frequencies for these systems are in close agreement with Hardy-Weinberg expectations indicating that these protandric hermaphrodites are outbreeding. The genus is characterized by two distinct morphotypes which differ in shell shape and pigmentation. Genetic similarity (I) and genetic distance (D) statistics were computed for the two morphotypes and for two populations of each morphotype. The I and D values derived from intraspecific comparisons of Transennella tantilla populations are 0.99 and 0,004; for Transennella sp., the I value is also 0.99 and D is 0,002. The I and D values obtained from interspecific comparisons (T. tantilla versus T, sp.) are 0,521 and 0,650 respectively. An extensive survey of the phosphoglucose isomerase system was conducted to evaluate microgeographic variation and age-dependent frequency selection at this locus. Differences in allele frequencies were found to be non-significant, suggesting that this locus is without selective import, or that selection for a particular genotype is too slight to be detected with the sample sizes employed, The amount of genetic divergence found between the morphotypes is comparable to interspecific estimates made for a variety of invertebrate species. The results indicate that the morphological divergence apparent in the two morphotypes has been accompanied by substantial genetic differentiation.
","abstract_html":"<p>Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose isomerase, tetrazolium oxidase, and nonenzymatic protein, Observed allele frequencies for these systems are in close agreement with Hardy-Weinberg expectations indicating that these protandric hermaphrodites are outbreeding. The genus is characterized by two distinct morphotypes which differ in shell shape and pigmentation. Genetic similarity (I) and genetic distance (D) statistics were computed for the two morphotypes and for two populations of each morphotype. The I and D values derived from intraspecific comparisons of Transennella tantilla populations are 0.99 and 0,004; for Transennella sp., the I value is also 0.99 and D is 0,002. The I and D values obtained from interspecific comparisons (T. tantilla versus T, sp.) are 0,521 and 0,650 respectively. An extensive survey of the phosphoglucose isomerase system was conducted to evaluate microgeographic variation and age-dependent frequency selection at this locus. Differences in allele frequencies were found to be non-significant, suggesting that this locus is without selective import, or that selection for a particular genotype is too slight to be detected with the sample sizes employed, The amount of genetic divergence found between the morphotypes is comparable to interspecific estimates made for a variety of invertebrate species. The results indicate that the morphological divergence apparent in the two morphotypes has been accompanied by substantial genetic differentiation.</p>","abstract_has_math":false,"creators":["Rotz, William Gregory"],"institution":null,"degree_name":"Master of Science (M.S.)","degree_level":"Thesis","degree_discipline":"Graduate School","degree_department":null,"school":null,"contributors":["Steven Obrebski"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1979,"date_issued":"1979-01-01T08:00:00Z","date_published":"1979-01-01T08:00:00Z","updated_at":"2026-07-24T05:37:51Z","subjects":["Bivalvia","Electrophoresis","Biology","Life Sciences"],"languages":[],"rights":[],"rights_urls":["http://rightsstatements.org/vocab/NKC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://scholarlycommons.pacific.edu/uop_etds/2001","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Steven Obrebski"]},{"key":"dc:creator","label":"Author","values":["Rotz, William Gregory"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["1979-01-01T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Graduate School"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (M.S.)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Bivalvia","Electrophoresis","Biology","Life Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["http://rightsstatements.org/vocab/NKC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarlycommons.pacific.edu/uop_etds/2001"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose isomerase, tetrazolium oxidase, and nonenzymatic protein, Observed allele frequencies for these systems are in close agreement with Hardy-Weinberg expectations indicating that these protandric hermaphrodites are outbreeding. The genus is characterized by two distinct morphotypes which differ in shell shape and pigmentation. Genetic similarity (I) and genetic distance (D) statistics were computed for the two morphotypes and for two populations of each morphotype. The I and D values derived from intraspecific comparisons of Transennella tantilla populations are 0.99 and 0,004; for Transennella sp., the I value is also 0.99 and D is 0,002. The I and D values obtained from interspecific comparisons (T. tantilla versus T, sp.) are 0,521 and 0,650 respectively. An extensive survey of the phosphoglucose isomerase system was conducted to evaluate microgeographic variation and age-dependent frequency selection at this locus. Differences in allele frequencies were found to be non-significant, suggesting that this locus is without selective import, or that selection for a particular genotype is too slight to be detected with the sample sizes employed, The amount of genetic divergence found between the morphotypes is comparable to interspecific estimates made for a variety of invertebrate species. The results indicate that the morphological divergence apparent in the two morphotypes has been accompanied by substantial genetic differentiation.
"]},{"key":"dc:source","label":"Dc Source","values":["71"]},{"key":"dc:title","label":"Title","values":["Population genetics of the genus Transennella (Bivalvia)"]}]}],"canonical_facts":{"dc:contributor":["Steven Obrebski"],"dc:creator":["Rotz, William Gregory"],"dc:date.available":["1979-01-01T08:00:00Z"],"dc:description.abstract":["Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose isomerase, tetrazolium oxidase, and nonenzymatic protein, Observed allele frequencies for these systems are in close agreement with Hardy-Weinberg expectations indicating that these protandric hermaphrodites are outbreeding. The genus is characterized by two distinct morphotypes which differ in shell shape and pigmentation. Genetic similarity (I) and genetic distance (D) statistics were computed for the two morphotypes and for two populations of each morphotype. The I and D values derived from intraspecific comparisons of Transennella tantilla populations are 0.99 and 0,004; for Transennella sp., the I value is also 0.99 and D is 0,002. The I and D values obtained from interspecific comparisons (T. tantilla versus T, sp.) are 0,521 and 0,650 respectively. An extensive survey of the phosphoglucose isomerase system was conducted to evaluate microgeographic variation and age-dependent frequency selection at this locus. Differences in allele frequencies were found to be non-significant, suggesting that this locus is without selective import, or that selection for a particular genotype is too slight to be detected with the sample sizes employed, The amount of genetic divergence found between the morphotypes is comparable to interspecific estimates made for a variety of invertebrate species. The results indicate that the morphological divergence apparent in the two morphotypes has been accompanied by substantial genetic differentiation.
"],"dc:identifier":["https://scholarlycommons.pacific.edu/uop_etds/2001"],"dc:rights":["http://rightsstatements.org/vocab/NKC/1.0/"],"dc:source":["71"],"dc:subject":["Bivalvia","Electrophoresis","Biology","Life Sciences"],"dc:title":["Population genetics of the genus Transennella (Bivalvia)"],"thesis:degree_discipline":["Graduate School"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (M.S.)"]},"updated_at":"2026-07-24T05:37:51Z"}