A novel missense mutation in <em>CACNA1A</em> evaluated by <em>in silico</em> protein modeling is associated with non-episodic spinocerebellar ataxia with slow progression.

Spinocerebellar ataxia type 6 (SCA6), episodic ataxia type 2 (EA2) and familial hemiplegic migraine type 1 (FHM1) are allelic disorders of the gene CACNA1A encoding the P/Q subunit of a voltage gated calcium channel. While SCA6 is related to repeat expansions affecting the C-terminal part of the protein, EA2 and FHM phenotypes are usually associated with nonsense and missense mutations leading to impaired channel properties. In three unrelated families with dominant cerebellar ataxia, symptoms cosegregated with CACNA1A missense mutations of evolutionary highly conserved amino acids (exchanges p.E668K, p.R583Q and p.D302N). To evaluate pathogenic effects, in silico, protein modeling analyses were performed which indicate structural alterations of the novel mutation p.E668K within the homologous domain 2 affecting CACNA1A protein function.The phenotype is characterised by a very slowly progressive ataxia, while ataxic episodes or migraine are uncommon. These findings enlarge the phenotypic spectrum of CACNA1A mutations

Genetic diversity among Brazilian soybean cultivars based on SSR loci and pedigree data

In this study, simple sequence repeats (SSR) loci and pedigree data were used to investigate the genetic relationship in a group of 168 Brazilian soybean cultivars. Eighteen SSR loci produced an average of 5.06 alleles and a mean gene diversity of 0.58 for the cultivars studied. Genetic distance (GD) was determined using the modified Roger's Wright distance, and a final dendrogram was in agreement with the cultivar pedigree. A distance matrix based on the coefficient of parentage scores was also generated for the cultivars, which ranged from 0 to 1, with a mean of 0.18, whereas SSR-based genetic similarity (1- GD) ranged from 0.01 to 0.90, with a mean of 0.25. Mantel's Z test showed that the similarity matrices generated from both the data sets were low, but significantly correlated (r = 0.31, p<0.001). The results showed that SSR data and pedigree analyses could help to quantify more accurately the degree of relationship among the soybean cultivars.<br>Locos microssatélites e dados de genealogia foram utilizados para avaliar a diversidade genética de um grupo de 168 cultivares brasileiras de soja. Os dezoito locos utilizados apresentaram em média 5,06 alelos por loco e coeficiente de diversidade genética médio de 0,58. O dendrograma final resultante da matriz de distância genética de Roger modificado por Wright, apresentou boa concordância com a ancestralidade dos grupos formados. Também foi estimado os coeficientes de parentesco entre as cultivares, sendo observada variação de 0 a 1 com média de 0,18, enquanto que as similaridades para os locos microssatélites (1- GD) variou de 0,01 a 0,90 com média de 0,25. A correlação entre as duas matrizes obtidas determinada pelo teste Z de Mantel apresentou valor baixo, 0,31, mas significativo (p<0,001). Os resultados obtidos sugerem que os locos microssatélites aliados às informações de genealogia proporcionam melhor análise da diversidade genética de cultivares de soja

Assessment of genetic diversity by simple sequence repeat markers among forty elite varieties in the germplasm for malting barley breeding*

The genetic diversity and relationship among 40 elite barley varieties were analyzed based on simple sequence repeat (SSR) genotyping data. The amplified fragments from SSR primers were highly polymorphic in the barley accessions investigated. A total of 85 alleles were detected at 35 SSR loci, and allelic variations existed at 29 SSR loci. The allele number per locus ranged from 1 to 5 with an average of 2.4 alleles per locus detected from the 40 barley accessions. A cluster analysis based on the genetic similarity coefficients was conducted and the 40 varieties were classified into two groups. Seven malting barley varieties from China fell into the same subgroup. It was found that the genetic diversity within the Chinese malting barley varieties was narrower than that in other barley germplasm sources, suggesting the importance and feasibility of introducing elite genotypes from different origins for malting barley breeding in China