DNA Fingerprinting Studies Research Articles

The Effect of Breeding Synchrony On Extra-Pair Mating Systems in Songbirds

Extra-pair mating systems are now considered to be typical of songbirds because DNA fingerprinting has revealed high rates of extra-pair fertilizations (EPFs) in so many species previously thought to be monogamous. However, there is no general framework to explain the tremendous variability among songbirds in EPF rate. Here, in a comparison of EPF rates and temporal patterns of nesting among songbirds, we show that EPFs are most common in species where females breed synchronously. We argue that for both males and females, a temporal concentration of female fertility (breeding synchrony) increases the net benefits of seeking EPFs. One implication of this finding is that tropical songbirds, most of which breed asynchronously, are predicted to have low levels of extra-pair matings. Testes size is positively correlated with frequency of EPFs, and as predicted, tropical songbirds had small testes size relative to temperate zone species. The few DNA fingerprinting studies that exist for socially monogamous tropical songbirds support the correlation between breeding synchrony and EPFs. We believe that breeding synchrony is the most important factor promoting the evolution of extra-pair mating systems.

DNA fingerprinting study on the intraspecific variation and the origin of Prunus yedoensis (Someiyoshino).

In order to investigate the intraspecific variation of Prunus yedoensis (Someiyoshino) and interspecific relationship among P. yedoensis, P. lannesiana (Oshimazakura) and P. pendula (Edohigan), DNA fingerprinting study was conducted by using two different kinds of probes, M13 repeat sequence and (GACA)4 synthetic oligonucleotide. In this study, 68 plants of P. yedoensis grown in 46 prefectures in Japan were investigated. All the P. yedoensis individuals investigated showed the completely same banding pattern, indicating their clonal origin from a single plant. On the other hand, each of P. lannesiana and P. pendula individuals investigated showed a unique banding pattern, suggesting a considerable amount of genetic variation in these two species. About 90% of bands in DNA fingerprints of P. yedoensis were detected in either P. lannesiana or P. pendula. This result supports the hypothesis that P. yedoensis is an interspecific hybrid between P. lannesiana and P. pendula. From those results, it is concluded that P. yedoensis was produced only once through hybridization between P. lannesiana and P. pendula, and that this particular hybrid plant has been spread vegetatively all over Japan.

Female-Specific Restriction Fragments Revealed by Dna-Fingerprinting and Implications for Extra-Pair Fertilisations in the Short-Tailed Shearwater (Puffinus-Tenuirostris, Procellariiformes, Procellariidae)

We report a female-specific restriction fragment in the DNA fingerprints of short-tailed shearwaters (Puffinus tenuirostris) that hybridises to a derivative of the human multilocus minisatellite probe 33.6. This genetic method of assigning sex has relevance to studies of population biology, reproductive success and mating systems in this species. The presence or absence of the female-specific restriction fragment has allowed us to reinterpret results from a previous DNA fingerprinting study of mating systems in the short-tailed shearwater.

Characterization and genetic mapping of a short, highly repeated, interspersed DNA sequence from rice (Oryza sativa L.).

A short, highly repeated, interspersed DNA sequence from rice was characterized using a combination of techniques and genetically mapped to rice chromosomes by restriction fragment length polymorphism (RFLP) analysis. A consensus sequence (GGC)n, where n varies from 13-16, for the repeated sequence family was deduced from sequence analysis. Southern blot analysis, restriction mapping of repeat element-containing genomic clones, and DNA sequence analysis indicated that the repeated sequence is interspersed in the rice genome, and is heterogeneous and divergent. About 200,000 copies are present in the rice genome. Single copy sequences flanking the repeat element were used as RFLP markers to map individual repeat elements. Eleven such repeat elements were mapped to seven different chromosomes. The strategy for characterization of highly dispersed repeated DNA and its uses in genetic mapping, DNA fingerprinting, and evolutionary studies are discussed.