INTROGRESSION BETWEEN TWO CUTTHROAT TROUT SUBSPECIES WITH SUBSTANTIAL KARYOTYPIC, NUCLEAR AND MITOCHONDRIAL GENOMIC DIVERGENCE

Genetics ◽  
1985 ◽  
Vol 111 (4) ◽  
pp. 905-915
Author(s):  
Ulf Gyllensten ◽  
Robb F Leary ◽  
Fred W Allendorf ◽  
Allan C Wilson
Keyword(s):  
Random Mating ◽  
Sequence Divergence ◽  
Cutthroat Trout ◽  
Secondary Contact ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Hybrid Swarm ◽  
Genetic Barrier ◽  
Allozyme Loci ◽  
Salmo Clarki

ABSTRACT The authors used allozymes encoded by nuclear genes and restriction enzyme analysis of mitochondrial DNA (mtDNA) to study secondary contact between westslope (Salmo clarki lewisi) and Yellowstone cutthroat trout (Salmo clarki bouvieri) in Forest Lake, Montana. Eleven diagnostic allozyme loci identified this as a random-mating hybrid swarm. No parental, first-generation hybrid or backcross genotypes were detected in the sample (N = 33), and genotype distributions at all the variable loci conform to binomial expectations. There is little linkage disequilibrium between the diagnostic loci, indicating that the nuclear genomes of the two subspecies are largely randomly associated. The allozymes and mtDNA give identical estimates of the proportional genetic contribution of each subspecies. Thus, males and females from both subspecies have contributed equally to this hybrid swarm. Although these subspecies have accumulated substantial genetic divergence between their nuclear (Nei's D = 0.34) and mitochondrial (2% sequence divergence) genomes, this has not resulted in a genetic barrier to exchange between them.

Mitochondrial DNA variation in Atlantic and Pacific walruses

1994 ◽  
Vol 72 (6) ◽  
pp. 1035-1043 ◽  
Author(s):  
Matthew A. Cronin ◽  
Susan Hills ◽  
Erik W. Born ◽  
John C. Patton
Keyword(s):  
Mitochondrial Dna ◽  
Chukchi Sea ◽  
Sequence Divergence ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Chain Reaction ◽  
Dna Variation ◽  
Odobenus Rosmarus ◽  
Sampling Locations ◽  
Polymerase Chain

We used restriction enzyme analysis of polymerase chain reaction amplified mitochondrial DNA to assess genetic differentiation of two subspecies of walruses: Atlantic walruses (Odobenus rosmarus rosmarus) from Greenland and Pacific walruses (O. r. divergens) from the Chukchi Sea. Each subspecies has distinct monophyletic mitochondrial DNA haplotypes. Mitochondrial DNA sequence divergence between Atlantic and Pacific subspecies was 1.0–1.6%. Several haplotypes were observed for each subspecies. Haplotype frequencies varied among sampling locations of Atlantic walruses, suggesting that mitochondrial DNA may be useful for walrus stock identification.

scholarly journals INTRA- AND INTERSPECIFIC VARIATION OF THE MITOCHONDRIAL GENOME IN RATTUS NORVEGICUS AND RATTUS RATTUS: RESTRICTION ENZYME ANALYSIS OF VARIANT MITOCHONDRIAL DNA MOLECULES AND THEIR EVOLUTIONARY RELATIONSHIPS

Genetics ◽  
1981 ◽  
Vol 97 (1) ◽  
pp. 125-143
Author(s):  
Gregory G Brown ◽  
Melvin V Simpson
Keyword(s):  
Rattus Norvegicus ◽  
Rattus Rattus ◽  
Sequence Divergence ◽  
Interspecific Variation ◽  
Restriction Endonuclease Analysis ◽  
Rrna Genes ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Base Pairs ◽  
Geographic Origins

ABSTRACT Restriction endonuclease analysis has revealed extensive mtDNA polymorphism in two species of rats, Rattus rattus and Rattus norvegicus. Sequence divergence values for the eight detected R. norvegicus variants range from 0.2% to 1.8% and for the eight R. rattus variants, from 0.2% to 9.6%. Three of the most closely related R. norvegicus mtDNA's appear to differ by deletions/insertions of about 4 base pairs apiece. Restriction sites for seven enzymes have been mapped for 11 of these variants. The 31 intraspecific and 41 interspecific variant sites appear to be evenly distributed on the mtDNA molecule outside of the rRNA cistrons. The location of sites present in all the DNAs suggests that the rRNA genes and possibly the light strand origin of replication may be more highly evolutionarily conserved than other parts of the molecule. The sequence divergences among the mtDNAs of animals whose geographic origins are separated by major barriers, such as oceans, were significantly greater than those among animals found within large land masses, such as the continental United States. Dendrograms (phenograms), which have been constructed to depict the relationships among the various DNAs, indicate that East Asian members of the R. rattus species are more closely related to American rats of this species than to other Asian R. rattus animals from Sri Lanka. Moreover, it appears that R. norvegicus comprises a group taxonomically distinct from any of the R. rattus subspecies.

scholarly journals Molecular evolution of Drosophila metallothionein genes.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 921-932 ◽  
Author(s):  
B W Lange ◽  
C H Langley ◽  
W Stephan
Keyword(s):  
Natural Populations ◽  
Sequence Divergence ◽  
Copper Tolerance ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Nucleotide Polymorphism ◽  
Heavy Metal Detoxification ◽  
Recent Origin ◽  
Selection For ◽  
Tandem Duplications

Abstract The metallothionein genes of Drosophila melanogaster, Mtn and Mto, may play an important role in heavy metal detoxification. Several different tandem duplications of Mtn have been shown to increase cadmium and copper tolerance, as well as Mtn expression. In order to investigate the possibility of increased selection for duplications of these genes in natural populations exposed to high levels of heavy metals, we compared the frequencies of such duplications among flies collected from metal-contaminated and non-contaminated orchards in Pennsylvania, Tennessee and Georgia. Restriction enzyme analysis was used to screen 1666 wild third chromosomes for Mtn duplications and a subset (327) of these lines for Mto duplications. The frequency of pooled Mtn duplications found ranged from 0% to 20%, and was not significantly higher at the contaminated sites. No Mto duplications were identified. Estimates of sequence diversity at the Mtn locus among a subsample (92) of the duplication survey were obtained using four-cutter analysis. This analysis revealed a low level of polymorphism, consistent with both selection at the Mtn locus, and a fairly recent origin for the duplications. To further examine this hypothesis, we sequenced an Mtn allele of Drosophila simulans and measured the amount of nucleotide sequence divergence between D. simulans and its sibling species D. melanogaster. The levels of silent nucleotide polymorphism and divergence in the Mtn region were compared with those in the Adh region, using the neutrality test of R.R. Hudson, M. Kreitman and M. Aguadé.

EFFECT OF VARIOUS HORMONES ON THE KIDNEY RESPIRATION RATES IN THE CUTTHROAT TROUT (SALMO CLARKI CLARKI)

1960 ◽  
Vol XXXIII (III) ◽  
pp. 428-436 ◽  
Author(s):  
W. N. Holmes
Keyword(s):  
Single Dose ◽  
Respiration Rate ◽  
Cutthroat Trout ◽  
Adaptive Mechanism ◽  
Respiration Rates ◽  
Salmo Clarki

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

scholarly journals A molecular characterization ofClostridium difficileisolates from humans, animals and their environments

1993 ◽  
Vol 111 (2) ◽  
pp. 257-264 ◽  
Author(s):  
G. O'Neill ◽  
J. E. Adams ◽  
R. A. Bowman ◽  
T. V. Riley
Keyword(s):  
Fragment Length Polymorphism ◽  
Hospital Environment ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Direct Transmission ◽  
Chromosomal Dna ◽  
Veterinary Clinic ◽  
Enhanced Chemiluminescence ◽  
Typing Methods ◽  
Rflp Typing

SummaryIt is generally accepted that most patients withClostridium difficile-associated diarrhoea acquire the organism from the environment. Recently we demonstrated that household pets may constitute a significant reservoir ofC. difficilethrough gastrointestinal carriage in up to 39% of cats and dogs. These findings suggested that direct transmission from household pets, or contamination of the environment by them, may be a factor in the pathogenesis ofC. difficile-associated diarrhoea. To investigate this possibility, we examined isolates ofC. difficilefrom humans, pets and the environment by restriction enzyme analysis (REA) and restriction fragment length polymorphism (RFLP) typing using enhanced chemiluminescence. Both REA and RFLP typing methods usedHindIII digests of chromosomal DNA. A total of 116 isolates ofC. difficilefrom pets (26), veterinary clinic environmental sites (33), humans (37) and hospital environmental sites (20) was examined. REA was far more discriminatory than RFLP typing and for all isolates there were 34 REA types versus 6 RFLP types. There was good correlation between the REA types found in isolates from pets and from the veterinary clinic environment, and between isolates from humans and from those found in the hospital environment. There was, however, no correlation between REA type ofC. difficilefound in pets and isolates of human origin. We conclude that there may still be a risk of humans acquiringC. difficilefrom domestic pets as these findings may be the result of geographical variation.

scholarly journals Specific Detection of Xanthomonas axonopodis pv. dieffenbachiae in Anthurium (Anthurium andreanum) Tissues by Nested PCR

2006 ◽  
Vol 72 (2) ◽  
pp. 1072-1078 ◽  
Author(s):  
Isabelle Robène-Soustrade ◽  
Philippe Laurent ◽  
Lionel Gagnevin ◽  
Emmanuel Jouen ◽  
Olivier Pruvost
Keyword(s):  
Diagnostic Tool ◽  
Nested Pcr ◽  
Restriction Analysis ◽  
Detection Threshold ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Amplification Product ◽  
Xanthomonas Axonopodis ◽  
Sequence Characterized Amplified Region ◽  
Pcr Test

ABSTRACT Efficient control of Xanthomonas axonopodis pv. dieffenbachiae, the causal agent of anthurium bacterial blight, requires a sensitive and reliable diagnostic tool. A nested PCR test was developed from a sequence-characterized amplified region marker identified by randomly amplified polymorphic DNA PCR for the detection of X. axonopodis pv. dieffenbachiae. Serological and pathogenicity tests were performed concurrently with the nested PCR test with a large collection of X. axonopodis pv. dieffenbachiae strains that were isolated worldwide and are pathogenic to anthurium and/or other aroids. The internal primer pair directed amplification of the expected product (785 bp) for all 70 X. axonopodis pv. dieffenbachiae strains pathogenic to anthurium tested and for isolates originating from syngonium and not pathogenic to anthurium. This finding is consistent with previous studies which indicated that there is a high level of relatedness between strains from anthurium and strains from syngonium. Strains originating from the two host genera can be distinguished by restriction analysis of the amplification product. No amplification product was obtained with 98 strains of unrelated phytopathogenic bacteria or saprophytic bacteria from the anthurium phyllosphere, except for a weak signal obtained for one X. axonopodis pv. allii strain. Nevertheless, restriction enzyme analysis permitted the two pathovars to be distinguished. The detection threshold obtained with pure cultures or plant extracts (103 CFU ml−1) allowed detection of the pathogen from symptomless contaminated plants. This test could be a useful diagnostic tool for screening propagation stock plant material and for monitoring international movement of X. axonopodis pv. dieffenbachiae.

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