however, until now such behaviour has not been described for marsupials. In this two-and-a-half-year study co-operative behaviour among male sugar gliders (Petaurus breviceps) was revealed. A dominant relationship to females was not observed.Male sugar gliders not only showed extensive co-operative behaviour in suppressing subordinate males, but in sharing food and nesting boxes as well as taking care of the offspring. DNA fingerprinting has been used to describe the genetic variability in relatedness of the coalition partners.Co-operative behaviour in male sugar gliders was exclusively observed among closely related individuals, therefore supporting the kin-selection theory in this small marsupial.We describe the genetic variability in relatedness, the behaviour and some physiological parameters of male sugar gliders in four captive groups to test the hypothesis that the sugar glider is an example of co-operative behaviour involving kin selection in marsupials.
The tammar wallaby (Macropus eugenii) is a small, promiscuous, macropodid marsupial. Females usually produce a single young each year and there is a clear dominance hierarchy between adult males. The dominant male usually mates first and then guards the female to prevent access to her by other males. In this study, agonistic encounters and mating behaviour were observed to determine male dominance hierarchies in six groups of captive tammars consisting of a total of 23 males and 50 females. Mating behaviour was observed immediately post-partum when females were in oestrus and was correlated with plasma testosterone concentrations. Male mating sequences were recorded, and the paternity of offspring was determined by using seven macropodid marsupial microsatellites. Rates of sexual checking and aggression by males housed with females in oestrus in the non-breeding season were lower than in the breeding season. These males also had lower concentrations of testosterone, but were still able to sire young. High testosterone concentrations neither ensured dominance nor appeared to control directly the level of sexual activity. Females usually mated with more than one male. The dominant male most often secured the initial copulation (60%), but the first-mating male did not always secure parentage, with second and third matings resulting in as many young as first matings. Using these data, we were unable to discount first sire, last sire or equal chance models of paternity in this species. Half the young (50%) were sired by the dominant a male, but of the remaining progeny, the b male sired more (35%) than g and d males (15%). Dominance therefore is only a moderately effective predictor of paternity in the tammar. Although the dominant males gained most first matings and individually sired half of the offspring, the subdominant males still contributed significantly to the population, at least in captivity. Reproduction (2005) 130 123-130
DNA fingerprinting has become an invaluable tool in the study of population genetics, paternity success, and individual identification; however, the species specificity of some methods has made the wide-range screening of many different species very time-consuming. In this study we describe the development and application of reliable and informative DNA fingerprinting techniques in a range of marsupial species using three different restriction enzyme and two oligonucleotide probe combinations. Six species from four marsupial families, the koala (Phascolarctidae), tammar wallaby (Macropodidae), southern hairy-nosed wombat (Vombatidae), kowari, and dusky and brown marsupial mice (Dasyuridae) were examined. Restriction enzymes HinfI AluI and HaeIII were used in combination with the digoxygenin (DIG)-labelled oligonucleotide probes (CAC)5 and (GGAT)4. The combinations of HinfI/(GGAT)4, AluI/ (CAC)5 and AluI/(GGAT)4 were the most informative, providing highly resolved bands, low background, and the lowest band sharing between individuals. The genetic diversity evident within the different species showed a clear relationship between the level of band sharing and population size. The greatest levels of band sharing were found in the kowaris (80%), which were part of a long-term captive colony originating from a few founders, and the lowest levels of band sharing were found in the marsupial mice (30-35%) and tammar wallaby (45%), which were caught from large outbred wild populations.
DNA fingerprinting to determine paternity in laboratory rat sperm competition experimentsPrior to this study a significant amount of research had been undertaken in the field of sperm competition in mammals. However, males of different strains have been required in each of these studies to enable paternity assignment through gene expression, which has consequently resulted in problems with differential fertilising capacity being encountered. In this study paternity assignment of progeny from sperm competition experiments with Sprague Dawley rats was achieved by multilocus DNA fingerprinting using band locus matching of individual specific banding patterns between progeny and parents. Trials with 4 restriction enzymes and 5 digoxygenin labelled probes (4 oligonucleotide and 1 cloned) achieved the highest levels of DNA fingerprint heterozygosity using AluI(CAC)' and HinfI (CAC)' combinations; however, paternity could not be determined in all offspring, due to a higher than expected degree of inbreeding within the rat population used in this study. This was demonstrated in subsequent comparisons of genetic diversity of three laboratory rat breeding populations from two different animal breeding facilities. Data from the rat mating study showed that, under conditions of direct sperm competition, second males given access to a mated oestrus female either 0.5 or 6.0 h after the first mating consistently required less time than the first to ejaculate: 7.6 min vs. 19.5 min (0.5 h delay); 7.8 min vs. 19.5 min (6.0 h delay). A second male siring advantage was identified using DNA fingerprinting in both delay groups for those offspring on which paternity could be determined: 0.5 h delay, 1st = 39%, 2nd = 61%; 6 h delay, 1st = 34%, 2nd = 66%.
Summary The domestic cat (Felis silvestris catus) is a valued companion animal throughout the world. Over 60 different cat breeds are accepted for competition by the cat fancy registries in different countries. Genetic markers, including short tandem repeats and SNPs, are available to evaluate and manage levels of inbreeding and genetic diversity, population and breed structure relationships, and individual identification for forensic and registration purposes. The International Society of Animal Genetics (ISAG) hosts the Applied Genetics in Companion Animals Workshop, which supports the standardization of genetic marker panels and genotyping for the identification of cats via comparison testing. SNP panels have been in development for many species, including the domestic cat. An ISAG approved core panel of SNPs for use in cat identification and parentage analyses is presented. SNPs (n = 121) were evaluated by different university‐based and commercial laboratories using 20 DNA samples as part of the ISAG comparison testing procedures. Different SNP genotyping technologies were examined, including DNA arrays, genotyping‐by‐sequencing and mass spectroscopy, to select a robust and efficient panel of 101 SNPs as the ISAG core panel for cats. The SNPs are distributed across all chromosomes including two on the X chromosome and an XY pseudo‐autosomal sexing marker (zinc‐finger XY; ZFXY). A population study demonstrated that the markers have an average polymorphic information content of 0.354 and a power of exclusion greater than 0.9999. The SNP panel should keep testing affordable while also allowing for the development of additional panels to monitor health, phenotypic traits, hybrid cats and highly inbred cats.
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