Unser Haushund: Eine Spitzmaus im Wolfspelz? - Wolf-Ekkehard ...

168solution, however, blood glucose and insulin concentrations did not differ between the groups. Theseobservations are interpreted to suggest that HA individuals may be better adapted to ingest starches,whereas LA individuals may be at greater risk for insulin resistance and diabetes if chronicallyingesting starch-rich diets.” 296Und noch einmal zur Frage nach der Kopienzahl von AMY1 generell: "This geneis typically present as two diploid copies in chimpanzees. Humans average over6 copies and may have as many as 15. This is thought to be an adaptation to ahigh-starch diet that improves the ability to digest starchy foods.” 297Aber auch Umweltfaktoren sollten bei dieser Frage nicht übersehen werden (mit Santos et al.2012 wurden schon hydration status, psychosocial stress level, and short-term dietary habitskurz erwähnt). Ebenso heben Mandel et al. 2010 einige wesentliche Punkte hervor, um dann zurgenetischen Frage überzugehen (Literaturhinweise und Abbildungen dazu in der im Internet direktabrufbaren Originalarbeit) 298 :"Salivary amylase is the most abundant protein in human saliva, accounting for 40 to 50% of salivaryprotein, and has the capacity to rapidly alter the physical properties of starch within the oral cavity. Thequantity and enzymatic activity of salivary amylase, however, show significant variation amongindividuals. This is due to a number of environmental factors, including stress levels, and circadianrhythms. In addition, there is evidence that salivary amylase expression is upregulated by a diet high instarch.Ähnlich bemerken Perry et al. 2007 zu ihrer Abbildung 1 (AMY1 copy number variation andsalivary amylase protein expression.) (p. 8 Author manuscript von 2008):"A considerable amount of variation in AMY1 protein level is not explained by copy number (R2 =0.351), which may reflect other genetic influences on AMY1 expression such as regulatory region singlenucleotide polymorphisms (SNPs) or nongenetic factors that may include individual hydration status,stress level, and short-term dietary habits.”Weitere Punkte (ausführlich) zum Einfluss von Umweltfaktoren zur Amylase-Produktionspeziell bei Bonobos siehe Behringer et al. (2012): Stress affects salivary alpha-Amylase activityin bonobos. Physiology and Behavior 105: 476-482. Aus dem Abstract p. 476:"Salivary alpha-Amylase (sAA) is a starch digesting enzyme. In addition to its function in the context ofnutrition, sAA has also turned out to be useful for monitoring sympathetic nervous system activity. Recentstudies on humans have found a relationship between intra-individual changes in sAA activity andphysical and psychological stress.” […] sAA activity [in bonobos] was significantly higher in samplescollected at times when subjects had been exposed to stressors (judged by changes in behavioral patternsand cortisol levels) than in samples collected at other times.”Mandel et al. (2010) fahren im Anschluss an das obige Zitat aus ihrer Arbeit jetztzur genetischen Frage wie folgt fort:"Genetically, salivary amylase levels are influenced by individual copy number variation (CNVs) of theAMY1 gene on chromosome 1p21, which codes for salivary amylase. The AMY1 gene is one of the mostvariable CNV loci in the human genome, with a reported range of anywhere from 2 to 15 diploid copies.Importantly, oral salivary amylase concentrations positively correlate with the number of copies of theAMY1 gene.Genetic variation in AMY1 appears to have evolved independently in diverse populations across theglobe.[…] AMY1 Gene Copy Number and Salivary AmylaseDNA samples were collected from 62 subjects and analyzed by qPCR to determine gene copy number.Values were standardized to a human DNA sample with a known AMY1 gene copy number verified by296 Mandel AL, Breslin PA.(2012): High endogenous salivary amylase activity is associated with improved glycemic homeostasis followingstarch ingestion in adults. J Nutr. 142:853-858.297 http://en.wikipedia.org/wiki/Copy-number_variation (Zugriff am 21. 11. 2012)298 Abigail L. Mandel, Catherine Peyrot des Gachons, Kimberly L. Plank, Suzanne Alarcon and Paul A. S. Breslin (2010): Individual Differencesin AMY1 Gene Copy Number, Salivary α-Amylase Levels, and the Perception of Oral Starch.http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013352