Genetic relationships of eight species of Pacific tunas (Teleostei: Scombridae) inferred from allozyme analysis

1995 ◽  
Vol 46 (7) ◽  
pp. 1021 ◽  
Author(s):  
NG Elliott ◽  
RD Ward
Keyword(s):  
Liver Enzymes ◽  
Genetic Relationships ◽  
Phylogenetic Analyses ◽  
Allozyme Variation ◽  
Allozyme Analysis ◽  
Average Heterozygosity ◽  
Katsuwonus Pelamis ◽  
Thunnus Alalunga ◽  
Auxis Thazard ◽  
Allozyme Loci

A phylogenetic analysis of eight species of Pacific tunas was made after examining allozyme variation at 23 muscle and liver enzymes encoded by 35 loci. The eight species of tuna were: Thunnus alalunga, albacore; T. obesus, bigeye; T. thynnus orientalis, northern bluefin; T. maccoyii, southern bluefin; T. albacares, yellowfin; Auxis thazard, frigate; Euthynnus affiizii kawakawa; Katsuwonus pelamis, skipjack. All species except the northern bluefin were also examined for variation at three eye-specific loci. The average heterozygosity per locus ranged from 0.038 (frigate) to 0.070 (bigeye). Genetic relationships were examined on the basis of the 35 loci screened in all species. Genetic identities among the five Thunnus species were high, averaging 0.864 and ranging from 0.788 to 0.923. Whereas the albacore appeared to be the most divergent of the Thunnus species (mean identity to other Thunnus species of 0.825, range 0.788-0.452), there was little differentiation between yellowfin, southern bluefin and northern bluefin tunas (mean identity 0.905, range 0.892-0.923), and phylogenetic analyses failed to resolve the branch order among the Thunnus species. The non-Thunnus tunas were quite divergent both from one another and from Thunnus species (mean identity 0.358, range 0.280-0.606). Diagnostic allozyme loci were identified, allowing the discrimination of all species.

scholarly journals ENZYME VARIABILITY IN THE DROSOPHILA WILLISTONI GROUP. III. AMOUNTS OF VARIABILITY IN THE SUPERSPECIES, D. PAULISTORUM

Genetics ◽  
1972 ◽  
Vol 70 (1) ◽  
pp. 87-112
Author(s):  
Rollin C Richmond
Keyword(s):  
Genetic Variation ◽  
Balancing Selection ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Metabolizing Enzymes ◽  
Group Iii ◽  
Allozyme Loci ◽  
Drosophila Paulistorum ◽  
Average Individual

ABSTRACT The semispecies composing the superspecies, Drosophila paulistorum, have been analyzed for genetic variation at 17 enzyme loci. On the average a population of D. paulistorum is polymorphic for 55–67% of its loci and an average individual is heterozygous at 21% of its loci. The pattern of genetic variability found supports the hypothesis that allozyme variation is maintained in natural populations by some form of balancing selection. Evidence is presented which supports the hypothesis that glucose-metabolizing enzymes are less genetically variable than non-glucose-metabolizing enzymes. The known genetic relationships between the semispecies of D. paulistorum are discussed in the light of the frequencies of alleles at allozyme loci.

Allozyme Variation and Population Substructuring in the Caucasian Ground Lizards Lacerta derjugini and Lacerta praticola

2011 ◽  
Vol 4 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Ross D. MacCulloch ◽  
Ilya S. Darevsky ◽  
Robert W. Murphy ◽  
Jinzhong Fu
Keyword(s):  
Genetic Diversity ◽  
Allozyme Variation ◽  
Close Proximity ◽  
Geographic Separation ◽  
Population Substructuring ◽  
Allozyme Loci ◽  
Two Populations

Genetic diversity at 35 allozyme loci was surveyed in Lacerta derjugini (3 populations) and L. praticola (2 populations). Indices of variability were consistent with those found in other Caucasian Lacerta. There was little genetic substructuring between two populations of L. praticola despite considerable geographic separation. Conversely, populations of L. derjugini in close proximity to one another exhibited considerable substructuring.

scholarly journals Genotyping-by-Sequencing of Gossypium hirsutum Races and Cultivars Uncovers Novel Patterns of Genetic Relationships and Domestication Footprints

2019 ◽  
Vol 15 ◽  
pp. 117693431988994
Author(s):  
Shulin Zhang ◽  
Yaling Cai ◽  
Jinggong Guo ◽  
Kun Li ◽  
Renhai Peng ◽  
...  
Keyword(s):  
Gossypium Hirsutum ◽  
Genetic Relationships ◽  
Phylogenetic Analyses ◽  
Genotyping By Sequencing ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Breeding Programs ◽  
Association Analyses ◽  
Genome Wide ◽  
Candidate Gene Locus

Determining the genetic rearrangement and domestication footprints in Gossypium hirsutum cultivars and primitive race genotypes are essential for effective gene conservation efforts and the development of advanced breeding molecular markers for marker-assisted breeding. In this study, 94 accessions representing the 7 primitive races of G hirsutum, along with 9 G hirsutum and 12 Gossypium barbadense cultivated accessions were evaluated. The genotyping-by-sequencing (GBS) approach was employed and 146 558 single nucleotide polymorphisms (SNP) were generated. Distinct SNP signatures were identified through the combination of selection scans and association analyses. Phylogenetic analyses were also conducted, and we concluded that the Latifolium, Richmondi, and Marie-Galante race accessions were more genetically related to the G hirsutum cultivars and tend to cluster together. Fifty-four outlier SNP loci were identified by selection-scan analysis, and 3 SNPs were located in genes related to the processes of plant responding to stress conditions and confirmed through further genome-wide signals of marker-phenotype association analysis, which indicate a clear selection signature for such trait. These results identified useful candidate gene locus for cotton breeding programs.

Allozyme Variation and Genetic Relationships among Species of Cimicifuga (Ranunculaceae) from Korea

2000 ◽  
Vol 161 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Hyun‐Woo Lee ◽  
Myong Gi Chung ◽  
Youngbae Suh ◽  
Chong‐Wook Park
Keyword(s):  
Genetic Relationships ◽  
Allozyme Variation

scholarly journals Genetic Differentiation Associated with Fumonisin and Gibberellin Production in JapaneseFusarium fujikuroi

2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Haruhisa Suga ◽  
Mitsuhiro Arai ◽  
Emi Fukasawa ◽  
Keiichi Motohashi ◽  
Hiroyuki Nakagawa ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Genetic Relationships ◽  
Pathogenic Fungus ◽  
Phylogenetic Analyses ◽  
Aflp Markers ◽  
Fusarium Fujikuroi ◽  
Rice Seedlings ◽  
Bakanae Disease ◽  
Content Type ◽  
Gibberellin Production

ABSTRACTFusarium fujikuroiis a pathogenic fungus that infects rice. It produces several important mycotoxins, such as fumonisins. Fumonisin production has been detected in strains of maize, strawberry, and wheat, whereas it has not been detected in strains from rice seedlings infested with bakanae disease in Japan. We investigated the genetic relationships, pathogenicity, and resistance to a fungicide, thiophanate-methyl (TM), in 51 fumonisin-producing strains and 44 nonproducing strains. Phylogenetic analyses based on amplified fragment length polymorphism (AFLP) markers and two specific genes (a combined sequence of translation elongation factor 1α [TEF1α] and RNA polymerase II second-largest subunit [RPB2]) indicated differential clustering between the fumonisin-producing and -nonproducing strains. One of the AFLP markers, EATMCAY107, was specifically present in the fumonisin-producing strains. A specific single nucleotide polymorphism (SNP) between the fumonisin-producing and nonproducing strains was also detected inRPB2, in addition to an SNP previously found inTEF1α. Gibberellin production was higher in the nonproducing than in the producing strains according to anin vitroassay, and the nonproducing strains had the strongest pathogenicity with regard to rice seedlings. TM resistance was closely correlated with the cluster of fumonisin-nonproducing strains. The results indicate that intraspecific evolution in JapaneseF. fujikuroiis associated with fumonisin production and pathogenicity. Two subgroups of JapaneseF. fujikuroi, designated G group and F group, were distinguished based on phylogenetic differences and the high production of gibberellin and fumonisin, respectively.IMPORTANCEFusarium fujikuroiis a pathogenic fungus that causes rice bakanae disease. Historically, this pathogen has been known asFusarium moniliforme, along with many other species based on a broad species concept. Gibberellin, which is currently known as a plant hormone, is a virulence factor ofF. fujikuroi. Fumonisin is a carcinogenic mycotoxin posing a serious threat to food and feed safety. Although it has been confirmed thatF. fujikuroiproduces gibberellin and fumonisin, production varies among strains, and individual production has been obscured by the traditional appellation ofF. moniliforme, difficulties in species identification, and variation in the assays used to determine the production of these secondary metabolites. In this study, we discovered two phylogenetic subgroups associated with fumonisin and gibberellin production in JapaneseF. fujikuroi.

scholarly journals Some digenea parasites of tunny from the coast of Rio de Janeiro State, Brazil

2002 ◽  
Vol 62 (3) ◽  
pp. 453-457 ◽  
Author(s):  
B. M. M. FERNANDES ◽  
A. KOHN ◽  
A. L. SANTOS
Keyword(s):  
South America ◽  
Rio De Janeiro ◽  
Host Record ◽  
Thunnus Albacares ◽  
New Host ◽  
Katsuwonus Pelamis ◽  
New Host Record ◽  
Auxis Thazard ◽  
First Time ◽  
Janeiro State

Rhipidocotyle pentagonum (Ozaki, 1924) is reported for the first time in South America parasitizing Auxis thazard and in a new host Katsuwonus pelamis. Tergestia laticollis (Rudolphi, 1819) is reported for the first time in South America and in Thunnus albacares, representing a new host record. Copiatestes filiferus (Leuckart, in Sars, 1885) is recorded for the first time in Brazil and in Thunnus albacares, another new host record. Tetrochetus coryphaenae (Yamaguti, 1934) is presented for the first time in Brazil parasitizing Thunnus albacares.

scholarly journals POPULATION GENETIC CONSEQUENCES OF FEEDING HABITS IN SOME FOREST LEPIDOPTERA

Genetics ◽  
1979 ◽  
Vol 92 (3) ◽  
pp. 1005-1021
Author(s):  
Charles Mitter ◽  
Douglas J Futuyma
Keyword(s):  
Genetic Variation ◽  
Environmental Heterogeneity ◽  
Feeding Habits ◽  
Functional Relation ◽  
Allozyme Variation ◽  
Unexpected Result ◽  
Polymorphic Loci ◽  
Allozyme Loci ◽  
Race Formation ◽  
Relationship Of

ABSTRACT By surveying variation at allozyme loci in several phytophagous lepidopteran species (Geometridae), we have tested two hypotheses about the relationship of genetic variation to environmental heterogeneity: (1) that allozyme polymorphisms may exist because of associations between genotypes and "niches" (different host plants, in this instance), and (2) that the overall genetic variation of a species is correlated with environmental heterogeneity (or breadth of the species' overall ecological niche) .—Genetic differentiation among samples of oligophagous or polyphagous species taken from different host species was observed in one of three species, at only one of seven polymorphic loci. The data thus provide no evidence for pronounced genetic sub-structuring, or "host race" formation in these sexually reproducing species, although host plant-genotype associations in a parthenogenetic moth give evidence of the potential for diversifying selection.—In a comparison of allozyme variation in polyphagous ("generalized") and oligophagous ("specialized") species, heterozygosity appeared to be higher in specialized species, at all polymorphic loci but one. I t is possible that this unexpected result arises from a functional relation between breadth of diet and genetic variation.

Haematological characteristics of albacore, Thunnus alalunga (Bonnaterre), and skipjack, Katsuwonus pelamis (Linnaeus)

1980 ◽  
Vol 16 (4) ◽  
pp. 383-395 ◽  
Author(s):  
N. Alexander ◽  
R. M. Laurs ◽  
A. McIntosh ◽  
S. W. Russell
Keyword(s):  
Katsuwonus Pelamis ◽  
Thunnus Alalunga

Breeding System, Karyotype and Variation Within and Between Populations of Rutidosis leptorrhynchoides F Muell (Asteraceae, Inuleae)

1991 ◽  
Vol 39 (1) ◽  
pp. 85 ◽  
Author(s):  
P Leeton ◽  
YJ Fripp
Keyword(s):  
Chromosome Number ◽  
Breeding System ◽  
Geographic Distance ◽  
Endangered Plant ◽  
Allozyme Analysis ◽  
Self Incompatibility ◽  
Eastern Australia ◽  
Incompatibility System ◽  
Leaf Dimensions ◽  
Allozyme Loci

The endangered plant species, Rutidosis leptorrhynchoides (button wrinklewort), is now known from only a few populations in each of two regions separated by approximately 500 km in south-eastern Australia. Plants were examined from several populations from each region. No differences in chromosome number or morphology were observed among plants or populations. All counts were diploid, 2n = 26. Viable progeny were obtained following self-pollination and allozyme analysis indicated that these progeny were the result of selfing and not agamospermy. This species is not an obligate outcrosser and does not have a classical pre-zygotic self-incompatibility system. However, outcross pollen may have an advantage over self pollen and this species may thus be preferentially outcrossing. The pollen: ovule ratios (mean 3186 ± 48.5) were consistent with this hypothesis. Allele frequencies at allozyme loci diferred little between populations, with an estimated 97% of the variation within populations. There was no correlation between genetic distance and geographic distance. In contrast, for the leaf dimensions of plants germinated and raised together in a glasshouse there were differences between plants from the two regions. It is recommended that populations from both regions should be conserved.

Seasonal variation and clonal selection in cyclically parthenogenetic rose aphids (Macrosiphum rosae)

1985 ◽  
Vol 27 (2) ◽  
pp. 224-232 ◽  
Author(s):  
L. R. Rhomberg ◽  
S. Joseph ◽  
R. S. Singh
Keyword(s):  
Genetic Variation ◽  
Seasonal Variation ◽  
Clonal Selection ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Polymorphic Loci ◽  
Esterase Loci ◽  
Allozyme Loci ◽  
Macrosiphum Rosae ◽  
Asexual Cycle

Patterns of geographic and seasonal genetic variation were assessed in natural populations of cyclically parthenogenetic rose aphids Macrosiphum rosae (L.). Nine populations were studied for a red–green colour morph and 30 allozyme loci (20 coding for enzymes and 10 for abundant proteins). Genetic variation was found at 5 of 20 enzyme loci (20%); all 10 abundant proteins proved monomorphic. The average heterozygosity was 4.3%. At some polymorphic loci genotypic frequencies showed significant deviations from Hardy–Weinberg proportions. Six local populations from Hamilton, Ontario, were studied for seasonal variation at the colour locus and at two polymorphic esterase loci (Est-2 and Est-4). All three loci showed large changes in genotypic frequencies over the season during the asexual cycle, but only for Est-4 were changes consistent among populations. This locus undergoes a regular seasonal cycle, the directional changes during the asexual phase presumably being balanced by changes during the sexual phase. The frequencies of three-locus genotypes within each locality fluctuated dramatically over the course of a season, reflecting the domination of local infestations by a few particularly successful clones. We speculate that because of such clonal competition followed by extensive migration, much of the selectively neutral variation is purged from aphid populations. The remaining polymorphic loci, which are mostly di- or tri-allelic, are subject to balancing natural selection at the gene or at closely linked loci. The Est-4 in rose aphids is an example of such a selectively maintained polymorphism.Key words: aphids, allozyme variation, seasonal variation, parthenogenesis, clonal selection, population structure.

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