49 research outputs found
Inbreeding, Microsatellite Heterozygosity, and Morphological Traits in Lipizzan Horses
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 d2) between microsatellite alleles within an individual. Both individual heterozygosity and mean d2 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 d2 (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 d2 (P <.01), and length of neck and mean d2 (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 d2 remained significant (P =.0213). Thus, no overall large effects of inbreeding, microsatellite heterozygosity, and mean d2 on morphological traits were observed in the Lipizzan horse
Inbreeding, Microsatellite Heterozygosity, and Morphological Traits in Lipizzan Horses
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 d2) between microsatellite alleles within an individual. Both individual heterozygosity and mean d2 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 d2 (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 d2 (P <.01), and length of neck and mean d2 (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 d2 remained significant (P =.0213). Thus, no overall large effects of inbreeding, microsatellite heterozygosity, and mean d2 on morphological traits were observed in the Lipizzan hors
Population genetics of the narrow endemic Hlandnikia pastinacifolia Rchb. (Apiaceae) indicates survival in situ during the pleistocene
Hladnikia pastinacifolia Rchb., a narrow endemic, has an extremely restricted distribution in Trnovski gozd
(Slovenia), despite the presence of many sites with suitable habitats. We compared the morphological traits of
plants from different populations and habitats. The overall pattern showed that the smallest plants, with low fruit
number, are found on Èaven (locus classicus or type locality); the largest individuals, with high fruit number, grow
in the Golobnica gorge. As judged by plant size and seed set, the optimal habitats are screes. We used RAPD markers
to estimate genetic variation between and within populations, as well as between and within the northern and
the southern parts of the distribution area. Hladnikia showed only a low level of RAPD variability. AMOVA partitioned
the majority of genetic diversity within selected populations. The low genetic differentiation between populations
and their genetic depauperation indicates survival in situ, since the Trnovski gozd plateau most likely was
a nunatak region in the southern Prealps during Pleistocene glaciations. Later range expansion of extant populations
was limited by poor seed dispersal. We also analyzed the cpDNA trnL-F intergenic spacer to check whether
the sequence is useful for studying the phylogenetic relationships of Hladnikia within the family Apiaceae
(Umbelliferae). Our results support the assertion that H. pastinacifolia is an old taxon
Mitochondrial DNA D-loop sequence variation among 5 maternal lines of the Zemaitukai horse breed
Genetic variation in Zemaitukai horses was investigated using mitochondrial DNA (mtDNA) sequencing. The study was performed on 421 bp of the mitochondrial DNA control region, which is known to be more variable than other sections of the mitochondrial genome. Samples from each of the remaining maternal family lines of Zemaitukai horses and three random samples for other Lithuanian (Lithuanian Heavy Draught, Zemaitukai large type) and ten European horse breeds were sequenced. Five distinct haplotypes were obtained for the five Zemaitukai maternal families supporting the pedigree data. The minimal difference between two different sequence haplotypes was 6 and the maximal 11 nucleotides in Zemaitukai horse breed. A total of 20 nucleotide differences compared to the reference sequence were found in Lithuanian horse breeds. Genetic cluster analysis did not shown any clear pattern of relationship among breeds of different type