Kin selection can explain the evolution of cooperative breeding and the distribution of relatives within a population may influence the benefits of cooperative behaviour. We provide genetic data on relatedness in the cooperatively breeding cichlid Neolamprologus pulcher. Helper to breeder relatedness decreased steeply with increasing helper age, particularly to the breeding males. Helper to helper relatedness was age-assortative and also declined with age. These patterns of relatedness could be attributed to territory takeovers by outsiders when breeders had disappeared (more in breeding males), betweengroup dispersal of helpers and reproductive parasitism. In six of 31 groups females inherited the breeding position of their mother or sister. These matrilines were more likely to occur in large groups. We conclude that the relative fitness benefits of helping gained through kin selection vs. those gained through direct selection depend on helper age and sex.

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Mammals have been cloned from adult donor cells. Here we report the first cases of mitochondrial DNA (mtDNA) heteroplasmy in adult mammalian clones generated from fetal and adult donor cells. The heteroplasmic clones included a healthy cattle equivalent of the sheep Dolly, for which a lack of heteroplasmy was reported.

Samples from 717 sheep of 11 Austrian sheep breeds were genotyped for 25 microsatellite loci. Twenty-one loci showing no deviation from Hardy-Weinberg equilibrium were used to calculate pairwise genetic distances (Nei's minimum distance and Reynolds' distance). All breeds could be clearly distinguished through these genetic distances. The shortest genetic distance was found between Alpines Steinschaf (AS) and Waldschaf (WS). Within the so-called 'Steinschaf' group [AS, Montafoner Steinschaf (MS), Krainer Steinschaf (KS) and Tiroler Steinschaf (TS)] the MS adopted an extreme status with the largest distance to the other breeds in the group. This finding resulted in the decision to consider the MS no longer as subpopulation of Alpines Steinschaf but as an independent breed. A correct breed assignment using a Bayesian approach was possible for only 66% of all individuals belonging to Alpines Steinschaf, but for at least 90% of individuals for all other breeds investigated.

While the negative effects of inbreeding and reduced heterozygosity on fecundity and survival are well established, only a few investigations have been carried out concerning their influence on morphological traits. This topic is of particular interest for a small and closed population such as the Lipizzan horse. Thus, 27 morphological traits were measured in 360 Lipizzan mares and were regressed on the individual inbreeding coefficients, as well as on the individual heterozygosity and mean squared distances (mean d(2)) between microsatellite alleles within an individual. Both individual heterozygosity and mean d(2) were based on 17 microsatellite loci dispersed over 14 chromosomes. The results obtained by multivariate analysis reveal significant effects of stud (P <.0001), age at measurement (P <.0001), and mean d(2) (P =.0143). In univariate analyses, significant associations were obtained between length of pastern-hindlimbs and inbreeding coefficient (P <.01), length of cannons-hindlimb and mean d(2) (P <.01), and length of neck and mean d(2) (P <.001). After adjustment of single-test P values for multiple tests (Hochberg's step-up Bonferroni method), only the association of the length of neck and mean d(2) remained significant (P =.0213). Thus, no overall large effects of inbreeding, microsatellite heterozygosity, and mean d(2) on morphological traits were observed in the Lipizzan horse.