Data/hora: 08/06/2024 09:35:53

Provedor de dados: 	74	
País: 	Brazil	
Título: 	Structural and regulatory differences in amylase isoenzymes in germinating Brazilian barley cultivars	
Autores: 	Georg-Kraemer,J.E.; Cavalli,S.S.	
Data: 	2003-01-01	
Ano: 	2003	
Palavras-chave: 	Barley; Amylases; Isoenzymes; Structural; Regulatory genetic differences.	
Resumo: 	The amylase electrophoretic patterns of 10 Brazilian brewing-barley varieties with different malting grades and diastatic power were analyzed during the 7-day germination which occurs during the malting process. Intra and inter-variety genetic variability was observed at both the structural and regulatory level. In the first few days after germination all varieties showed a few active loci, all of them with low activity. In subsequent days, new loci became active and those already detected since early germination showed increased activity. All varieties showed a continuous increase in amylase synthesis until the 3rd and/or 4th day after germination. Some varieties maintained high amylase activity until the last day of germination, while others showed a decrease in activity on the 5th or 6th day. No specific band increased or decreased its intensity independently of the others. A total of 14 loci were detected, out of which only one locus was polymorphic, indicating very low structural genetic variability, with only 2.8% polymorphic loci, an average of 1.04 alleles per loci, and an average expected heterozygosity of only 0.7%. The mean intra-variety Jaccard similarity coefficient complement (1 - S J) was 0.009. The mean intra-variety difference based on regulatory differences was higher (1 - S J = 0.17) than that obtained based on structural differences, suggesting differential gene activation. Inter-variety differentiation also showed low structural variability, with 1 - S J = 0.026 and a Nei genetic distance (D) value of 0.0076, and a remarkable increase in divergence caused by differential gene activation (1 - S J = 0.34). These results indicate that regulatory polymorphism is the principal agent responsible for amylase variability in the barley varieties analyzed.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000100012	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S1415-47572003000100012	
Formato: 	text/html	
Fonte: 	Genetics and Molecular Biology  v.26 n.1 2003	
Fonte: 	info:eu-repo/semantics/openAccess