Mitochondrial DNA restriction fragment length polymorphisms in field isolates of the Aspergillus niger aggregate

1994 ◽  
Vol 40 (8) ◽  
pp. 612-621 ◽  
Author(s):  
János Varga ◽  
Ferenc Kevei ◽  
Aldwin Vriesema ◽  
Fons Debets ◽  
Zofia Kozakiewicz ◽  
...  

The mitochondrial DNAs (mtDNAs) and the ribosomal repeat unit (ribosomal DNA, rDNA) of black Aspergillus isolates collected in various parts of the world were examined. Wide-ranging mtDNA variation was observed in natural populations of the Aspergillus niger aggregate. Most isolates were classifiable as A. niger or Aspergillus tubingensis according to their rDNA and mtDNA patterns. The mtDNA variation was distributed unevenly in the populations studied. The mtDNAs of most of the isolates collected in Australia were of the A. tubingensis type, with an unexpectedly high degree of variation, while the rDNA of these isolates exhibited the same A. tubingensis pattern as that of isolates from other locations. Some other local populations displayed very little polymorphism in their mtDNA and rDNA. Hybridization experiments in which cloned A. niger and Aspergillus nidulans mtDNA fragments were used revealed that the two main mtDNA groups corresponding to A. niger and A. tubingensis are more distantly related than concluded earlier. Six of the 13 Brazilian isolates examined exhibited mtDNA and rDNA types different from those of all the other strains and could not be classified into the above species. Classical taxonomic examination of these strains is in progress.Key words: Aspergillus niger aggregate, mitochondrial DNA, RFLP.

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.


1996 ◽  
Vol 26 (3) ◽  
pp. 428-432 ◽  
Author(s):  
Andrew J. David ◽  
Daniel E. Keathley

Fifteen interspecific hybrids of Serbian spruce (Piceaomorika (Panc) Purkyne) and white spruce (Piceaglauca (Moench) Voss) representing five separate crosses, including reciprocals, were used to demonstrate maternal inheritance of mitochondrial DNA. Total DNA was extracted from foliage samples of Serbian spruce (S), white spruce (W), and both S(♂) × W(♀) and W(♂) × S(♀) hybrids, digested and probed with one of two maize mitochondrial genes, ATPaseα or COXII. ATPaseα generated diagnostic Serbian and white spruce genotypes for all five enzymes tested, while COXII differentiated between the two species for four of five enzymes. Maternal inheritance was indicated in all hybrids for every diagnostic enzyme–probe combination. No paternal or nonparental bands were detected. A dilution experiment indicated that the Serbian and white spruce mitochondrial DNA restriction fragment length polymorphisms could be detected in as little as 60 and 500 ng of total DNA, respectively. It appears that the mechanism that controls the inheritance of mitochondria in Picea is still functional in wide interspecific crosses.


Genetics ◽  
1985 ◽  
Vol 109 (1) ◽  
pp. 195-213
Author(s):  
Jeffrey D Palmer ◽  
Richard A Jorgensen ◽  
William F Thompson

ABSTRACT Variation in 30 chloroplast DNAs, representing 22 wild and cultivated accessions in the genus Pisum, was analyzed by comparing fragment patterns produced by 16 restriction endonucleases. Three types of mutations were detected. First, an inversion of between 2.2 kilobase pairs (kb) and 5.2 kb distinguished a population of P. humile from all other Pisum accessions examined. Second, deletions and insertions of between 50 and 1200 base pairs produced small restriction fragment length variations in four regions of the 120-kb chloroplast genome. Two of these regions—one of which is located within the sequence that is inverted in P. humile—showed a high degree of size polymorphism, to the extent that size differences were detected between individuals from the same accession. Finally, a total of only 11 restriction site mutations were detected among the 165 restriction sites sampled in the 30 DNAs. Based on these results and previous data, we conclude that the chloroplast genome is evolving very slowly relative to nuclear and mitochondrial DNAs. The Pisum chloroplast DNA restriction site mutations define two major lineages: One includes all tested accessions of P. fulvum, which is known to be cytogenetically quite distinct from all other Pisum taxa. The second includes 12 of 13 cultivated lines of the garden pea (P. sativum) and a wild population of P. humile from northern Israel. These observations strongly reinforce an earlier conclusion that the cultivated pea was domesticated primarily from northern populations of P. humile. A 13th P. sativum cultivar has a chloroplast genome that is significantly different from those of the aforementioned lines and somewhat more similar to those of P. elatius and southern populations of P. humile. This observation indicates that secondary hybridization may have occurred during the domestication of the garden pea.


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