Ribosomal DNA repeat unit polymorphism in 49 Vicia species

The frequencies of polymorphic restriction fragments for the nuclear ribosomal DNA repeat were compared for 12 provenances of red spruce (Picearubens Sarg.) and 34 provenances of black spruce (Piceamariana (Mill.) B.S.P.). Within an individual as many as five distinct ribosomal DNA repeat unit types could be distinguished. Canonical correlation analysis revealed significant variation of restriction fragment frequencies with a geographic variate comprising latitude and longitude of provenances. Geographic origins accounted for 24.7% of the variation in polymorphic restriction fragments in black spruce and 31.8% of the variation in polymorphic restriction fragments in red spruce. Discriminant analysis, using the restriction fragment frequencies for the ribosomal DNA, was used to develop a classification model for the two species. Tenfold verification of the model produced an average correct classification of 99% for black spruce and 96% for red spruce. Plots of canonical scores for the first and second canonical variâtes clearly separated red spruce from black spruce. This study presents a novel combination of restriction fragment frequency data and multivariate analysis to distinguish species that may not always be differentiated using morphological traits.

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Restriction fragment length polymorphisms within the ribosomal DNA repeat unit of British entomopathogenic nematodes (Rhabditida: Steinernematidae)

Parasitology ◽

10.1017/s0031182000074242 ◽

1992 ◽

Vol 105 (2) ◽

pp. 317-323 ◽

Cited By ~ 20

Author(s):

A. P. Reid ◽

W. M. Hominick

Keyword(s):

Restriction Fragment ◽

Ribosomal Dna ◽

Fragment Length ◽

Genomic Dna ◽

Entomopathogenic Nematodes ◽

Repeat Unit ◽

Geographical Location ◽

Steinernema Feltiae ◽

Dna Repeat ◽

Restriction Fragment Length

SUMMARYGenomic DNA extracted from entomopathogenic nematodes isolated from 89 soil samples taken throughout the United Kingdom was hybridized with the ribosomal DNA clone from Caenorhabditis elegans (pCe7). When the DNA was digested with EcoR I and Hind III in a double digest, 5 distinct RFLP (restriction fragment length polymorphism) types were observed. While the prevalence of the 5 types was not equal, no correlation with geographical location, soil type or habitat could be detected. Subsequent hybridizations of total genomic DNA from the various RFLP types divided them into 2 groups. The most prevalent group, identified as Steinernema feltiae ( = bibionis), contained 2 of the RFLP types (Al and A2). The other group contained the remaining 3 RFLP types (B1, B2 and B3). Although similar to S. feltiae ( = bibionis), the members of the B-types can be distinguished from this species on morphological grounds and preliminary crossbreeding experiments have demonstrated that the 2 groups are reproductively isolated.

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Peer Review #2 of "Comparative analysis of the ribosomal DNA repeat unit (rDNA) of Perna viridis (Linnaeus, 1758) and Perna canaliculus (Gmelin, 1791) (v0.4)"

10.7287/peerj.7644v0.4/reviews/2 ◽

2019 ◽

Keyword(s):

Comparative Analysis ◽

Peer Review ◽

Ribosomal Dna ◽

Repeat Unit ◽

Perna Viridis ◽

Perna Canaliculus ◽

Dna Repeat

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