Mitochondrial-DNA Restriction-Site Polymorphisms in the Teleost Fundulus heteroclitus Support Secondary Intergradation

Evolution ◽  
1990 ◽  
Vol 44 (1) ◽  
pp. 27 ◽  
Author(s):  
Lucia Irene Gonzalez-Vilasenor ◽  
Dennis A. Powers
1982 ◽  
Vol 2 (1) ◽  
pp. 30-41
Author(s):  
N A Oliver ◽  
D C Wallace

Two mitochondrially synthesized marker polypeptides, MV-1 and MV-2, were found in human HeLa and HT1080 cells. These were assigned to the mitochondrial DNA in HeLa-HT1080 cybrids and hybrids by demonstrating their linkage to cytoplasmic genetic markers. These markers include mitochondrial DNA restriction site polymorphisms and resistance to chloramphenicol, an inhibitor of mitochondrial protein synthesis. In the absence of chloramphenicol, the expression of MV-1 and MV-2 in cybrids and hybrids was found to be directly proportional to the ratio of the parental mitochondrial DNAs. In the presence of chloramphenicol, the marker polypeptide linked to the chloramphenicol-sensitive mitochondrial DNA continued to be expressed. This demonstrated that resistant and sensitive mitochondrial DNAs can cooperate within a cell for gene expression and that the CAP-resistant allele was dominant or codominant to sensitive. Such cooperation suggests that mitochondrial DNAs can be exchanged between mitochondria.


1982 ◽  
Vol 2 (1) ◽  
pp. 30-41 ◽  
Author(s):  
N A Oliver ◽  
D C Wallace

Two mitochondrially synthesized marker polypeptides, MV-1 and MV-2, were found in human HeLa and HT1080 cells. These were assigned to the mitochondrial DNA in HeLa-HT1080 cybrids and hybrids by demonstrating their linkage to cytoplasmic genetic markers. These markers include mitochondrial DNA restriction site polymorphisms and resistance to chloramphenicol, an inhibitor of mitochondrial protein synthesis. In the absence of chloramphenicol, the expression of MV-1 and MV-2 in cybrids and hybrids was found to be directly proportional to the ratio of the parental mitochondrial DNAs. In the presence of chloramphenicol, the marker polypeptide linked to the chloramphenicol-sensitive mitochondrial DNA continued to be expressed. This demonstrated that resistant and sensitive mitochondrial DNAs can cooperate within a cell for gene expression and that the CAP-resistant allele was dominant or codominant to sensitive. Such cooperation suggests that mitochondrial DNAs can be exchanged between mitochondria.


1986 ◽  
Vol 43 (10) ◽  
pp. 1866-1872 ◽  
Author(s):  
Lucia Irene González-Villaseñor ◽  
Amanda M. Burkhoff ◽  
Víctor Corces ◽  
Dennis A. Powers

Analysis of mitochondrial DNA endonuclease restriction patterns is a powerful tool for studying related species and variation within species. The ethidium bromide staining technique has limited the number of digestions of mitochondrial DNA per individual. Because 32P-end-labeling also imposes severe limitations, we have resorted to cloning the fish (Fundulus heteroclitus) mitochondrial genome in the lambda replacement vector EMBL-3. The clone was used as a radioactive probe via Southern blotting to detect mitochondrial DNA restriction fragments obtained by multiple restriction endonuclease digestions from small amounts of tissue. This technique offers much greater sensitivity than ethidium bromide staining. Moreover, it eliminates the expense and time to obtain highly purified mitochondrial DNA for the 32P-end-labeling procedure. It is also useful when the mtDNA is prepared from frozen tissue which has been a problem with the 32P-end-labeling technique. Because the cloned mitochondrial DNA has a high degree of cross-hybridization with the mitochondrial DNA of certain other fishes, it can be used to probe the mitochondrial DNA restriction patterns of a variety of fish species. However, its usefulness is restricted by the degree of relatedness to the species being cloned.


Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 173-178 ◽  
Author(s):  
William E. A. Hintz ◽  
James B. Anderson ◽  
Paul A. Horgen

The ribosomal DNA (rDNA) repeat of Agaricus brunnescens (= A. bisporus) was cloned and mapped for six restriction endonucleases. The map positions of the 26S, 18S, and 5.8S rRNA genes on the 9.2 kilo base pairs (kbp) repeat were determined by alignment of sites conserved in the rRNA genes of other fungi. The rDNA restriction site maps for six isolates of A. brunnescens, five isolates of A. bitorquis, and three isolates of A. campestris were compared using cloned A. brunnescens (Ag 50) rDNA as a hybridization probe. The rDNA restriction patterns for all six A. brunnescens isolates were identical. The A. bitorquis and A. campestris isolates were subdivided into two groups each, according to rDNA restriction-site polymorphisms. The A. brunnescens and A. bitorquis rDNAs were distinguished by a 0.7 kbp length difference in the noncoding spacer between the 18S and 26S rRNA genes. Despite the almost perfect conservation of the coding region between species, the noncoding spacers of A. campestris and the other two Agaricus species were too divergent to propose a simple series of mutational events to account for the differences. Interstrain and interspecies variation in the mitochondrial DNA was also surveyed. Strain-specific mitochondrial DNA restriction patterns were recognized and fewer differences were observed between the A. brunnescens and A. bitorquis isolates than between A. campestris and the other two species.Key words: Agaricus brunnescens (= A. bisporus), Agaricus, rDNA, mitochondrial DNA, restriction fragment length polymorphism analysis.


Genetics ◽  
1988 ◽  
Vol 118 (2) ◽  
pp. 261-266
Author(s):  
S H Clark ◽  
A J Hilliker ◽  
A Chovnick

Abstract This report presents the results of a recombination experiment designed to question the existence of special sites for the initiation or termination of a recombination heteroduplex within the region of the rosy locus. Intragenic recombination events were monitored between two physically separated rosy mutant alleles ry301 and ry2 utilizing DNA restriction site polymorphisms as genetic markers. Both ry301 and ry2 are known from previous studies to be associated with gene conversion frequencies an order of magnitude lower than single site mutations. The mutations are associated with large, well defined insertions located as internal sites within the locus in prior intragenic mapping studies. On the molecular map, they represent large insertions approximately 2.7 kb apart in the second and third exons, respectively, of the XDH coding region. The present study monitors intragenic recombination in a mutant heterozygous genotype in which DNA homology is disrupted by these large discontinuities, greater than the region of DNA homology and flanking both sides of the locus. If initiation/or termination requires separate sites at either end of the locus, then intragenic recombination within the rosy locus of the heterozygote should be eliminated. Contrary to expectation, significant recombination between these sites is seen.


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