Genetic diversity and genetic similarities between Iranian rose species
Samiei, L. ; Naderi, R. ; Khalighi, A. ; Shahnejat-Bushehri, A.A. ; Mozaffarian, V. ; Esselink, G.D. ; Kazempour Osaloo, S. ; Smulders, M.J.M. - \ 2010
Journal of Horticultural Science and Biotechnology 85 (2010)3. - ISSN 1462-0316 - p. 231 - 237.
damascena mill. accessions - microsatellite analysis - phylogenetic-relationships - genus rosa - markers - aflp - ssr - identification - differentiation - varieties
Wild rose species were collected from different regions of Iran for a rose breeding programme. They included accessions from Rosa persica, R. foetida, R. pimpinellifolia, R. hemisphaerica, R. canina, R. iberica, R. damascena, R. beggeriana, and R. orientalis. Ten microsatellite (simple sequence repeat; SSR) markers were used to analyse the genetic variation among these rose species. The SSR markers amplified alleles in all species, even if they were from different sections within the genus. An unweighted pair group method cluster analysis (UPGMA) based on similarity values revealed five main Groups. The data showed no support for any distinction between R. canina and R. iberica, as all the accessions were placed in one Group, and accessions of these two species were more closely-related to each other within a Province than to accessions of the same species in other Provinces. Accessions of sect. Pimpinellifoliae were combined with plants from sect. Rosa and Cinnamomeae in two different Groups. Genetically, R. persica clustered distinctly from all others, with few alleles shared with the other taxa. We discuss the use of SSR markers for phylogenetic analysis when these markers are amplified in all species of a genus
Rainfall-driven sex-ratio genes in African buffalo suggested by correlations between Y-chromosomal haplotype frequencies and foetal sex ratio
Hooft, W.F. van; Prins, H.H.T. ; Getz, W.M. ; Jolles, A.E. ; Wieren, S.E. van; Greyling, B.J. ; Helden, P.D. ; Bastos, A.D.S. - \ 2010
BMC Evolutionary Biology 10 (2010). - ISSN 1471-2148 - 11 p.
cattle bos-taurus - syncerus-caffer - male-fertility - meiotic drive - bovine tuberculosis - drosophila-melanogaster - microsatellite analysis - natural-populations - sperm - selection
Background - The Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the fittest haplotype would inevitably sweep to fixation. Stable Y-chromosomal polymorphism due one of these factors only seems possible when there are Y-chromosomal distorters of an equal sex ratio, which act by negatively affecting X-gametes, or Y-chromosomal suppressors of a female-biased sex ratio. These sex-ratio (SR) genes modify (suppress) gamete transmission in their own favour at a fitness cost, allowing for stable polymorphism. Results - Here we show temporal correlations between Y-chromosomal haplotype frequencies and foetal sex ratios in the KNP buffalo population, suggesting SR genes. Frequencies varied by a factor of five; too high to be alternatively explained by Y-chromosomal effects on pregnancy loss. Sex ratios were male-biased during wet and female-biased during dry periods (male proportion: 0.47-0.53), seasonally and annually. Both wet and dry periods were associated with a specific haplotype indicating a SR distorter and SR suppressor, respectively. Conclusions - The distinctive properties suggested for explaining Y-chromosomal polymorphism in African buffalo may not be restricted to this species alone. SR genes may play a broader and largely overlooked role in mammalian sex-ratio variation