RESUMO
This study attempts to provide a deeper insight into the current genetic status of 12 Bulgarian autochthonous sheep breeds using microsatellite (SSR) markers. A total of 600 individuals from 50 flocks were analyzed using a panel of 13 SSR markers. In total, 228 alleles were found in the studied microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphic information content (PIC) values per locus were 17.54, 5.250, and 0.799, respectively. The expected heterozygosity (He) for all breeds ranged from 0.70 to 0.82. The within-population heterozygote deficit (Fis) varied from -0.03 to 0.1, reflecting significant levels for 10 of the 12 breeds. The average genetic differentiation (Fst) was 0.046, revealing a low discrimination between the breeds. The genetic distance, principal coordinate analysis, and the structure analysis showed that two of the studied breeds-Local Stara Zagora/SZ/ and Local Karnobat/MK/-were the most distinct sheep populations. The Bayesian clustering approach suggested poor breed differentiation for the remaining 10 sheep breeds. The results suggest that proper management strategies and specific breeding policies need to be implemented in Bulgaria to avoid the intermixing of breeds and to reduce the erosion of breed purity observed in some breeds.
RESUMO
Dry direct-seeding of rice is rapidly increasing in China, but variable planting depth associated with machine sowing can lead to low seedling emergence rates. Phenotype analysis of 621 rice accessions showed that mesocotyl length (ML) was induced by deep soil covering and was important in deep-sowing tolerance in the field. Here, we performed and compared GWAS using three types of SNPs (non-synonymous SNP, non-synonymous SNPs and SNPs within promoters and 3 million randomly selected SNPs from the entire set of SNPs) and found that Non-Syn GWAS (GWAS using non-synonyomous SNP) decreased computation time and eliminated confounding by other loci relative to GWAS using randomly selected SNPs. Thirteen QTLs were finally detected, and two new major-effect genes, named OsML1 and OsML2, were identified by an integrated analysis. There were 2 and 7 non-synonymous SNPs in OsML1 and OsML2, respectively, from which 3 and 4 haplotypes were detected in cultivated rice. Combinations of superior haplotypes of OsML1 and OsML2 increased ML by up to 4 cm, representing high emergence rate (85%) in the field with 10 cm of soil cover. The studies provide key loci and naturally occurring alleles of ML that can be used in improving tolerance to dry direct-seeding.
RESUMO
BACKGROUND: Balkan endemic nephropathy (BEN) is seen in certain regions of the Balkan Peninsula. The patients are predisposed to epithelial cell tumors of the urinary tract. These tumors have not been genetically investigated so far. METHODS: We studied the loss of heterozygosity (LOH) in three BEN-associated tumors at seven microsatellite loci at 3q21.3 - 3q27.3. Comparative genomic hybridization (CGH) was also done and one of the tumors was investigated by 24-color FISH as well. RESULTS: LOH in locus D3S1299 (3q24) was established in one case. CGH showed genetic gains at 1q, 3q, 7p, 7q, 15q, and 19q in at least two of the three tumors. Genetic loss was found in one case at 4q. Most frequent aberrations detected by 24-color FISH were der(X), der(X)t(X;18), der(16), der(3)t(3;15) and der(12). CONCLUSION: The LOH suggests the presence of a new, so far unidentified tumor-suppressor gene at 3q24. In pTa BEN tumor CGH showed genome instability was extremely high. The 24-color FISH indicated highly complex chromosomal rearrangements. Chromosome 3 anomalies support our previous data on 3q24 - 3q26.3 association with BEN.
