Biomaterial Database

Genetic and environmental components of thyroxine variation in Mennonites from Kansas and Nebraska. 1998

L J Martin, and M H Crawford

Department of Anthropology, University of Kansas, Lawrence 66045, USA.

Thyroxine is an endocrine hormone that regulates cellular and organismic metabolism. Current research on thyroxine has primarily examined its adaptive potential and genetic inheritance patterns. To date, no studies have attempted to investigate the interaction between the genetic and environmental components of thyroxine variation. This approach is useful because hormones are on feedback regulation; thus interaction occurs between the environment and gene expression. The purposes of this research are to characterize the genetic and environmental components of thyroxine variation using univariate statistics and to estimate the genetic and cultural heritabilities through path analysis. For univariate analyses, analyses of variance are used to determine whether or not age, sex, or community affiliation are covariates of thyroxine level. Significant differences existed in thyroxine level based on sex and community affiliation (p < 0.05). The genetic and environmental components of thyroxine variation were partitioned through path analysis. Heritability was estimated at 0.317 +/- 0.109 for the genetic component and at 0.060 +/- 0.029 for the environmental component. The environmental variables that contributed to the variation in thyroxine level were caffeine consumption, blood calcium level, and biceps skinfold thickness.

UI	MeSH Term	Description	Entries
D007615	Kansas	State bounded on the north by Nebraska on the east by Missouri, on the south by Oklahoma, and on the west by Colorado.
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009329	Nebraska	State bounded on the north by South Dakota, on the east by Iowa and Missouri, on the south by Kansas and Colorado, and on the west by Colorado and Wyoming.
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D002110	Caffeine	A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.	1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002835	Christianity	The religion stemming from the life, teachings, and death of Jesus Christ: the religion that believes in God as the Father Almighty who works redemptively through the Holy Spirit for men's salvation and that affirms Jesus Christ as Lord and Savior who proclaimed to man the gospel of salvation. (From Webster, 3d ed)	Stigmata,Christian Ethics,Christian Ethic,Ethic, Christian,Ethics, Christian
D003466	Cultural Characteristics	Those aspects or characteristics which identify a culture.	Ethnic Boundary Maintenance,Boundary Maintenance, Ethnic,Boundary Maintenances, Ethnic,Characteristic, Cultural,Characteristics, Cultural,Cultural Characteristic,Ethnic Boundary Maintenances,Maintenance, Ethnic Boundary,Maintenances, Ethnic Boundary
D005006	Ethnicity	A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.	Ethnic Groups,Nationality,Ethnic Group,Nationalities