Christian Hagger

Heritability of flight distance for Cydia pomonella

Cydia pomonella L. (Lepidoptera: Tortricidae) is considered to be rather sedentary, but some individuals undertake flights of several kilometres in the field. This paper investigates the genetic influence on this variability. The flight capacity was measured in the laboratory by a flight mill and its heritability was estimated for two different strains. The laboratory strain was kept for more than 45 generations and the field strain from Embrach (northern Switzerland) was recently collected in the field.

Genetic Analysis of White Facial and Leg Markings in the Swiss Franches-Montagnes Horse Breed

White markings and spotting patterns in animal species are thought to be a result of the domestication process. They often serve for the identification of individuals but sometimes are accompanied by complex pathological syndromes. In the Swiss Franches-Montagnes horse population, white markings increased vastly in size and occurrence during the past 30 years, although the breeding goal demands a horse with as little depigmented areas as possible. In order to improve selection and avoid more excessive depigmentation on the population level, we estimated population parameters and breeding values for white head and anterior and posterior leg markings. Heritabilities and genetic correlations for the traits were high (h(2) > 0.5). A strong positive correlation was found between the chestnut allele at the melanocortin-1-receptor gene locus and the extent of white markings. Segregation analysis revealed that our data fit best to a model including a polygenic effect and a biallelic locus with a dominant-recessive mode of inheritance. The recessive allele was found to be the white trait-increasing allele. Multilocus linkage disequilibrium analysis allowed the mapping of the putative major locus to a chromosomal region on ECA3q harboring the KIT gene.

Y chromosome polymorphism in various breeds of cattle (Bos taurus) in Switzerland.

The evolutionary development of mammals involves mutations and fixations of chromosomal types. The Y chromosome polymorphism in cattle is important for the breeding strategy, since chromosomal incompatibilities in crossings result in fertility problems. In bulls of various breeds in Switzerland, data on chromosome status have been collected for over 20 years. Data from 7 years were analysed in this study through chromosome measurements and their normalization. Some highly significant differences were found between the 7 groups of breeds, especially between Holsteins and the original Swiss breeds Braunvieh and Simmental. Fleckvieh (purebred or crossbred) did not differ significantly from Black or Red Holsteins. The results were discussed with respect to fertility problems. The observed Y chromosome polymorphism should be taken into account in breeding, and research in this field should be continued.