Allozyme differentiation among gopher tortoises (Gopherus): conservation genetics and phylogenetic and taxonomic implications

1994 ◽  
Vol 72 (9) ◽  
pp. 1665-1671 ◽  
Author(s):  
David J. Morafka ◽  
Gustavo Aguirre L. ◽  
Robert W. Murphy

The genetic diversity among 18 loci within and among four species of gopher tortoises was investigated using horizontal starch gel electrophoresis. Within species variation ranged from 2 to 4% by direct count and from 2 to 8% by Hardy–Weinberg expectation. Of the loci resolved, 11–22% expressed variation. The northern and southern populations of Gopherus flavomarginatus could not be distinguished. No fixed differences were observed between G. agassizii and G. berlandieri, as reflected in a Nei genetic distance of 0.008. These latter species may be little more than allopatric populations of G. agassizii. Differentiation between the two remaining species was not extensive; G. polyphemus was only slightly distinct from G. flavomarginatus, being separated by a Nei genetic distance of only 0.006. The two pairs of species were separated by an average genetic distance of 0.200. The evolutionary rates of divergence were observed to be unequal, especially between G. polyphemus and G. flavomarginatus. The overall genetic similarity suggests a relatively recent age of origin.

Author(s):  
Iain F. Wilson ◽  
Elizabeth M. Gosling ◽  
William Tapper

Eight samples of Littorina tenebrosa and L. saxatilis (Mollusca: Gastropoda) from Ireland and Britain, including pairs of each form from two locations in Ireland, were screened for genetic variation at 12 polymorphic enzyme loci using starch gel electrophoresis. Levels of polymorphism and heterozygosity were similar in L. tenebrosa and L. saxatilis, apart from a sample of L. tenebrosa from Britain which was less polymorphic than the Irish samples. No alleles were found to be unique to either form. Phylogenetic analysis using UPGMA showed that L. saxatilis and L. tenebrosa populations clustered as a monophyletic group. Nevertheless, the mean genetic distance between parapatric populations of L. saxatilis and L. tenebrosa (D=0.076) was similar to the mean for allopatric populations of either species (D=0.080). This indicates that there is a barrier to gene flow between the two forms Despite this, L. tenebrosa does not merit specific status since populations of this snail do not cluster as a distinct group, separate from L. saxatilis populations.


1988 ◽  
Vol 66 (3) ◽  
pp. 588-594 ◽  
Author(s):  
Hong Zhu ◽  
Kenneth O. Higginbotham ◽  
Bruce P. Dancik ◽  
Stan Navratil

Mycelial extracts of 43 isolates of Suillus tomentosus (Kauffm.) Singer, Snell & Dick collected from four boreal forest regions in Alberta were subjected to starch gel electrophoresis. A total of 21 bands was resolved from eight different enzyme systems presumably representing 13 loci. Six loci were polymorphic among these isolates. Cluster and principal components analyses demonstrated that intraspecific genetic variability of this fungus existed among and within forest regions. Polymorphic loci of acid phosphatase and alkaline phosphatase exhibited the greatest genetic similarity among the isolates within forest regions. Habitat isolation and host selection could be the major sources of genetic variation among forest regions.


1976 ◽  
Vol 7 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Juhani Lokki ◽  
Pekka Lankinen ◽  
Anssi Saura ◽  
Esko Suomalainen

AbstractThe genetic variability at 20 enzyme loci in natural populations of Otiorrhynchus salicis Ström was studied by starch gel electrophoresis. Altogether 135 weevils were analyzed. The samples originated from a diploid bisexual population in Austria, from four triploid parthenogenetic populations in the Carpathian mountains, and from three triploid parthenogenetic populations in central Sweden. Altogether 16 different genotypes were found in triploid parthenogenetic populations. Two major types, comprising 39 out of the 76 parthenogenetic individuals, occur both in Scandinavia and in central Europe. The less frequent types can be derived from these through mutations. O. salicis is a flightless insect, which has been assumed to have overwintered the Würm glaciation in icefree refugia in Scandinavia. The overall genetic similarity found in the material suggests that the parthenogenetic race spread to its isolated Scandinavian area in postglacial times.


1981 ◽  
Vol 113 (9) ◽  
pp. 857-865 ◽  
Author(s):  
M. W. Stock ◽  
P. J. Castrovillo

AbstractThe genetic make-up of representative populations of five Choristoneura species was compared using starch gel electrophoresis. Species included C. occidentalis Freeman from Idaho, C. biennis Freeman from British Columbia, C. retiniana (Walsingham) (= C. viridis Freeman) from Oregon, C. lambertiana ponderosana Obraztsov from Colorado, and C. fumiferana (Clemens) from Maine. When variation at individual gene loci was examined, intraspecific variation was often as great, and sometimes greater, than interspecific variation and few significant differences were noted among the species. The highest levels of overall genetic similarity occurred among C. occidentalis, C. biennis, and C. retiniana. Relatively greater genetic distances were found between this group and C. lambertiana and C. fumiferana. C. fumiferana was most distantly related to all other groups. Genetic identity values fell within the range more commonly associated with conspecific populations rather than with separate species.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 856F-856
Author(s):  
Mark S. Strefeler ◽  
Elizabeth Darmo ◽  
Roger L. Becker ◽  
Elizabeth J. Katovich

Starch gel electrophoresis of plant proteins was used to genetically identify purple loosestrife (Lythrum spp.) cultivars and weedy populations. Preliminary determinations were made as to what degree weedy loosestrife populations were related (or genetically similar) to populations of L. alatum, L. virgatum, and horticultural cultivars. Cluster analysis of the data indicated that native L. alatum was genetically different from all populations of purple loosestrife and cultivars examined. The L. salicaria and L. virgatum cultivars, as groups, were not genetically distinguishable from the weedy populations analyzed. Seven cultivars of L. salicaria origin analyzed as a group were not distinguishable from the eight cultivars of L. virgatum origin, indicating that separation by cultivar origin may not be feasible. While the two “groups” were not distinguishable, most individual cultivars could be distinguished from one another by isozyme phenotype. Genetic variation was high within populations of weedy purple loosestrife but low among populations, which is characteristic of polyploid, perennial plant species that are widely distributed. Geographic location did not consistently correlate with genetic similarity.


1964 ◽  
Vol 12 (01) ◽  
pp. 126-136 ◽  
Author(s):  
Karl H. Slotta ◽  
J. D Gonzalez

SummaryWhen urea or ε-amino caproic acid were used as solublizing agents for plasminogen in electrophoretic experiments, only one broad band of the proenzyme was obtained on acetate cellulose, in starch block, and in acrylamide gel. In starch gel electrophoresis, however, both forms of plasminogen – the native or euglobulin and Kline’s or Pseudoglobulin plasminogen – separated into six bands. These migrated toward the cathode at room temperature in borate or veronal buffer in the alkaline range and showed full activity in fibrinagar-streptokinase plates.


Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 595-603
Author(s):  
D Borden ◽  
E T Miller ◽  
D L Nanney ◽  
G S Whitt

ABSTRACT The isozymic patterns of tyrosine aminotransferase, NADP malate dehydrogenase, NADP isocitrate dehydrogenase, and tetrazolium oxidase were examined by starch-gel electrophoresis in Tetrahymena pyriformis, syngen 1. The genetics of the alleles controlling these enzymes was studied through a breeding program. Each enzyme locus was shown to assort vegetatively, as do other loci in this organism. A detailed analysis of the assortment process for the tyrosine aminotransferase locus indicated that the rate of stabilization of heterozygotes into pure types was essentially identical to previously-reported rates for other loci.


1963 ◽  
Vol 41 (1) ◽  
pp. 369-387 ◽  
Author(s):  
J. M. Neelin

By varying conditions of starch gel electrophoresis, factors contributing to the resolution of myogen proteins from chicken breast muscle have been studied. Variables examined included composition of the myogen extractant, protein concentration, ionic strength of electrophoretic media, pH of gel media, plane and direction of electrophoresis, and the nature of cations and anions in gel media and bridge solutions. The significance of anions was more closely studied with constant buffer systems, and gradient systems in which bridge electrolyte differed from, and gradually altered, the gel medium. Optimal separation was obtained in gradient systems with 0.10 M sodium chloride bridge solutions, and gel media of sodium cacodylate, pH 6.9, μ 0.010, which resolved 12 cationic zones, and sodium veronal, pH 7.4, μ 0.010, which resolved 10 anionic zones. These buffers in two-dimensional sequence revealed a total of about 24 components in this myogen.


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