Mitochondrial DNA length variation and heteroplasmy in populations of white sturgeon (Acipenser transmontanus).

Abstract Southern blot analysis was used to quantify the extent of mtDNA D-loop length variation in two populations of white sturgeon, Acipenser transmontanus. Over 42% of individuals were heteroplasmic for up to six different mtDNA length variants attributable to varying copy numbers of an 82-bp repeat sequence. Chi-square analyses revealed that the frequencies of length genotypes and the incidence of heteroplasmy were significantly different between Fraser and Columbia River sturgeon populations but not between restriction site haplotypes. Heteroplasmic fish have, on average, higher copy number than homoplasmic fish. Forty-five of 101 homoplasmic individuals carry only a single copy of the repeat, while none of the 73 heteroplasmic fish has the single repeat as the predominant variant. On the basis of differences in frequency distributions of copy number within and between fish, we suggest that (1) heteroplasmy is maintained by high recurrent mutation of multiple copy genomes, favoring increased copy number and (2) the mutation pressure toward higher copy number heteroplasmy is partially offset by selection to reduced genome size and segregation to the homoplasmic condition.

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Inheritance of microsatellite loci in the white sturgeon (Acipenser transmontanus)

Genome ◽

10.1139/g02-083 ◽

2002 ◽

Vol 45 (6) ◽

pp. 1064-1076 ◽

Cited By ~ 52

Author(s):

Jeff A Rodzen ◽

Bernie May

Keyword(s):

Genetic Markers ◽

Microsatellite Loci ◽

Single Copy ◽

White Sturgeon ◽

Null Alleles ◽

Acipenser Transmontanus ◽

Dominant Marker ◽

Transmission Frequency ◽

Inheritance Patterns ◽

Complex Modes

Nine tetramer motif (GATA)n microsatellite systems were developed for use in the white sturgeon, Acipenser transmontanus. We report inheritance patterns for these nine systems, which range from one possible disomic system to tetrasomy and octosomy, with some systems containing null alleles. Because of the complex modes of inheritance underlying these systems and the highly duplicated nature of the genome, we propose each allele be scored as its own dominant marker, similar to AFLPs or RAPDs. The utility of this method is validated by the observation that individual alleles within a microsatellite system generally fit the expectation for independent transmission and fit the expected transmission frequency for single copy nuclear markers.Key words: white sturgeon, Acipenser transmontanus, microsatellite, polyploid, inheritance, genetic markers.

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Heteroplasmy of short tandem repeats in mitochondrial DNA of Atlantic cod, Gadus morhua.

Genetics ◽

10.1093/genetics/132.1.211 ◽

1992 ◽

Vol 132 (1) ◽

pp. 211-220 ◽

Cited By ~ 2

Author(s):

E Arnason ◽

D M Rand

Keyword(s):

Mitochondrial Dna ◽

Copy Number ◽

Gadus Morhua ◽

Tandem Repeats ◽

Atlantic Cod ◽

Length Variation ◽

The North ◽

Loop Region ◽

D Loop ◽

Displacement Model

Abstract The mitochondrial DNA of the Atlantic cod (Gadus morhua) contains a tandem array of 40-bp repeats in the D-loop region of the molecule. Variation among molecules in the copy number of these repeats results in mtDNA length variation and heteroplasmy (the presence of more than one form of mtDNA in an individual). In a sample of fish collected from different localities around Iceland and off George's Bank, each individual was heteroplasmic for two or more mtDNAs ranging in repeat copy number from two (common) to six (rare). An earlier report on mtDNA heteroplasmy in sturgeon (Acipenser transmontanus) presented a competitive displacement model for length mutations in mtDNAs containing tandem arrays and the cod data deviate from this model. Depending on the nature of putative secondary structures and the location of D-loop strand termination, additional mechanisms of length mutation may be needed to explain the range of mtDNA length variants maintained in these populations. The balance between genetic drift and mutation in maintaining this length polymorphism is estimated through a hierarchical analysis of diversity of mtDNA length variation in the Iceland samples. Eighty percent of the diversity lies within individuals, 8% among individuals and 12% among localities. An estimate of theta = 2N(eo) mu greater than 1 indicates that this system is characterized by a high mutation rate and is governed primarily by deterministic dynamics. The sequences of repeat arrays from fish collected in Norway, Iceland and George's Bank show no nucleotide variation suggesting that there is very little substructuring to the North Atlantic cod population.

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Length variation in mitochondrial DNA of the minnow Cyprinella spiloptera.

Genetics ◽

10.1093/genetics/138.1.179 ◽

1994 ◽

Vol 138 (1) ◽

pp. 179-190 ◽

Cited By ~ 4

Author(s):

R E Broughton ◽

T E Dowling

Keyword(s):

Mitochondrial Dna ◽

Copy Number ◽

Single Copy ◽

Great Difficulty ◽

Length Variation ◽

Site Analysis ◽

The Stability ◽

Taxonomic Groups ◽

Flanking Regions ◽

Tandem Duplications

Abstract Length differences in animal mitochondrial DNA (mtDNA) are common, frequently due to variation in copy number of direct tandem duplications. While such duplications appear to form without great difficulty in some taxonomic groups, they appear to be relatively short-lived, as typical duplication products are geographically restricted within species and infrequently shared among species. To better understand such length variation, we have studied a tandem and direct duplication of approximately 260 bp in the control region of the cyprinid fish, Cyprinella spiloptera. Restriction site analysis of 38 individuals was used to characterize population structure and the distribution of variation in repeat copy number. This revealed two length variants, including individuals with two or three copies of the repeat, and little geographic structure among populations. No standard length (single copy) genomes were found and heteroplasmy, a common feature of length variation in other taxa, was absent. Nucleotide sequence of tandem duplications and flanking regions localized duplication junctions in the phenylalanine tRNA and near the origin of replication. The locations of these junctions and the stability of folded repeat copies support the hypothesized importance of secondary structures in models of duplication formation.

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Co-infection of Acipenserid herpesvirus 2 (AciHV-2) and Streptococcus iniae in cultured white sturgeon Acipenser transmontanus

Diseases of Aquatic Organisms ◽

10.3354/dao03108 ◽

2017 ◽

Vol 124 (1) ◽

pp. 11-20 ◽

Cited By ~ 11

Author(s):

E Soto ◽

C Richey ◽

B Stevens ◽

S Yun ◽

K Kenelty ◽

...

Keyword(s):

White Sturgeon ◽

Acipenser Transmontanus ◽

Streptococcus Iniae

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Ancient fish and recent invaders: white sturgeon Acipenser transmontanus diet response to invasive-species-mediated changes in a benthic prey assemblage

Marine Ecology Progress Series ◽

10.3354/meps11002 ◽

2014 ◽

Vol 514 ◽

pp. 163-174 ◽

Cited By ~ 6

Author(s):

SC Zeug ◽

A Brodsky ◽

N Kogut ◽

AR Stewart ◽

JE Merz

Keyword(s):

Invasive Species ◽

White Sturgeon ◽

Acipenser Transmontanus ◽

Benthic Prey

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Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

Water Quality Research Journal ◽

10.2166/wqrj.1998.006 ◽

1998 ◽

Vol 33 (1) ◽

pp. 95-110 ◽

Cited By ~ 8

Author(s):

W.R. Bennett ◽

A.P. Farrell

Keyword(s):

Acute Toxicity ◽

Swimming Performance ◽

Juvenile Fish ◽

Toxicity Testing ◽

White Sturgeon ◽

Acipenser Transmontanus ◽

Toxicity Tests ◽

Fraser River ◽

Acute Toxicity Tests ◽

Acute Toxicity Testing

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

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