RESUMO
This chapter describes several aspects of tandemly organized, simple repetitive DNA sequences and their usefulness for genetic relationship analyses. After introducing the structure, the evolution and the biological meaning of such target sequences in a particularly well-studied gene, we discuss oligonucleotide probes for generating individual specific multilocus banding patterns. Thus, oligonucleotide fingerprinting allows to approach novel problems in behavioral sciences. Here, we use a passerine bird, the great tit (Parus major) as an example. Finally, genomic fingerprinting is compared to sensitive amplification methods requiring less DNA. Advantages and shortcomings of these techniques need to be evaluated in the context of the biological question(s) asked and, above all, the quality and quantity of the starting material.
Assuntos
Ciências do Comportamento , Evolução Biológica , Sequências Repetitivas de Ácido Nucleico , Animais , Aves/genética , DNA/genética , Impressões Digitais de DNA , Primers do DNA/genética , HumanosRESUMO
Females of many species mate with multiple males within a single reproductive cycle. One hypothesis to explain polyandry postulates that females benefit from increasing within-brood genetic diversity. Two mechanisms may render sire genetic diversity beneficial for females, genetic bet-hedging vs. non-bet-hedging. We analysed whether females of the socially monogamous coal tit (Parus ater) benefit via either of these mechanisms when engaging in extra-pair (i.e. polyandrous) mating. To obtain a measure of within-brood genetic diversity as a function of paternal genetic contributions, we calculated a sire diversity index based on the established Shannon-Wiener Index. In 246 broods from two consecutive years, sire genetic diversity had no effect on either the mean or the variance in brood fitness measured as offspring recruitment within 4 years after birth. The hypothesis that benefits of increasing sire diversity contribute to selection for female extra-pair mating behaviour in P. ater was therefore not supported.
Assuntos
Passeriformes/fisiologia , Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Variação Genética , Masculino , Óvulo/fisiologia , Passeriformes/genéticaRESUMO
An informativity index for multilocus DNA fingerprints, r, was developed. It is based upon the Shannon information that a paternal DNA fingerprint conveys about the offspring phenotype pattern. Both simulation and empirical data reveal that the index r is strongly correlated with the mean log likelihood ratio (paternity vs. nonpaternity) expected in trio cases of true paternity. Since r can be estimated from DNA fingerprints of unrelated individuals in advance, it will provide an easy means to assess the potential utility of a given probe/enzyme combination in kinship testing.
Assuntos
Impressões Digitais de DNA , Animais , Aves/genética , Feminino , Humanos , Masculino , Paternidade , Polimorfismo GenéticoRESUMO
In order to arrive at detailed information about the occurrence of alternative reproductive tactics in the great tit (Parus major) we examined parental lineages by multilocus fingerprinting in 51 great tit broods containing 429 nestlings. In 45% of the broods at least one nestling was found to stem from copulations with males other than the social mate of the female. Single broods contained up to 62% extra-pair young (EPY). Single locus profiling revealed how many fathers were involved in extra-pair paternity (EPP) within each brood: In most cases a single male is the genetic father of all EPY in a given brood.
Assuntos
Aves/genética , Impressões Digitais de DNA/métodos , Paternidade , Alelos , Animais , Feminino , Heterozigoto , Masculino , MutaçãoRESUMO
The power of multilocus DNA fingerprinting depends on the reliability with which the uniqueness of an individual's profile can be demonstrated. This cautionary note stresses the importance of the probe concentration in this procedure. In case of a probe shortage, DNA fragments rich in tandem repeats have the potential to impede hybridization in other parts of the gel, and thus interfere with bands that are part of a DNA fingerprinting profile.
Assuntos
Impressões Digitais de DNA/métodos , Sondas de DNA , Animais , Aves/genética , Mapeamento Cromossômico , Impressões Digitais de DNA/normas , Eletroforese em Gel de Ágar , Feminino , Masculino , Sequências de Repetição em TandemRESUMO
A simple and time-saving method for DNA preparation for efficient microsatellite analysis is described. The method is based on thermal treatment of only 1-5 microL of insect hemolymph in a Chelex 100-suspension. Since hemolymph withdrawal does not harm the insects, analysis of mating systems, population structure and phylogenetic reconstruction can be conducted with minimal experimental influence.
Assuntos
DNA/análise , Insetos/genética , Repetições de Microssatélites , Animais , Genes de Insetos , HemolinfaRESUMO
In common gull colonies on islands of the Vistula River, Poland, adoption of chicks is common. In 1997, we observed 81 chicks from 35 nests. Of these, 19 (23.4%) left their natal broods and were adopted by other pairs. Another 11 (31.4%) were driven from the foreign territory by the owners. Foreign chicks were adopted by 15 pairs (42.9%). Eleven pairs (31.4%) drove foreign chicks from the territory. To test if the frequent adoptions in these colonies could be explained by kin selection or the occurrence of kin groups, we calculated band-sharing coefficients and genetic relatedness (r) between interacting birds (neighbours and non-neighbours). Adults that adopted were most often neighbours of the biological parents of adopted chicks, whereas spatially segregated birds, nesting further away, usually drove off the chicks. Band-sharing coefficients between males, but not females, were higher with decreasing internest distances. The band-sharing coefficients for adopted chicks and foster parents were significantly higher than for adopted chicks and randomly selected, spatially segregated pairs from the same and another colony. Band-sharing coefficients of adopted chicks and adopting neighbours (males: r=0.20; females: r=0.16) also tended to be higher than those of rejected chicks and rejecting neighbours (both sexes: r=0.08). Our results suggest that kin groups of neighbours do occur in common gull colonies. Such social structure might lead to indirect inclusive fitness benefits of adopting pairs. Differences in genetic similarity between chicks and adopting or rejecting neighbours show that at least in common gulls we should consider kin altruism as a factor in adoptions. Copyright 2000 The Association for the Study of Animal Behaviour.