Approach to human adaptability to stresses of city life

Interest of human adaptability to city life is one of the most principal topics of physiological anthropology. Especially, cultural adaptation and flowing stresses by itself is the most important viewpoint of human adaptability in the recent modern life. In this paper, the authors reviewed the keywords of physiological anthropology, especially with the focus on techno-adaptability, and presented our experimental trials to study physiological polymorphism of cardio-vascular reactivity to mental stresses. We scoped the psychological stresses by means of mental tasks as an experimental model of techno-stress. Techno-stress was defined as not only from inadequate interface of man-machine system, but also from increased social complexity owing to highly advanced technological social system. In the experimental trial, we observed different types of cardio-vascular responses to several mental tasks. Blood pressure rose significantly during the tasks. However, contribution of change in cardiac output and total peripheral resistance on it was not the same between subgroups of the subjects.     

The development of conceptual framework in physiological anthropology

From an international viewpoint, the physiological anthropology had always developed in a mosaic-like structure until the end of the nineteen-sixties. Some of the pieces of the mosaic then started to create significant elements of the theoretical concepts of this science. Generally speaking, research in physiological anthropology consists of the process of individual biology and the process of population biology. Through using these processes, physiological anthropologists have come to realize the importance of individual thinking and the inadequacy of essentialistic concept such as the ideal man, and now infer that all populations are polytypic. Physiological anthropologists have refined the conceptual framework of their science and composed a set of keywords characterizing it. These are technological adaptability, environmental adaptability, functional potentiality, whole body coordination, and physiological polytypism. These keywords are mutually interdependent and do not form any orthogonal relations.     

Functional convergence in plant responses to the environment

Much comparative ecophysiological research has focused on contrasting species-specific behavior or ecological strategies with regard to regulation of basic physiological processes such as transpiration, photosynthesis and growth, leading to an emphasis on divergence rather than convergence in plant functioning. This review highlights selected examples in which substantial functional convergence among taxonomically, phylogenetically and architecturally diverse species has been revealed by applying appropriate scaling factors and identifying universal constraints or trade-offs. Recent empirical and theoretical scaling models emphasize the strong role that plant size, architecture, allometry and chemistry play in constraining functional traits related to water and carbon economy and growth. Taken together, the findings summarized here strongly suggest that there are a limited number of physiological solutions to a given problem of plant adaptation to the environment. Comparative ecophysiological studies will therefore benefit from consideration of the constraints that plant anatomical, structural and chemical attributes place on physiological functioning.     

Prospect of manufacturing and design based on physiological polymorphism

Modern manufacturing and design should satisfy not only the requirements of high cost performance but also of the user. Besides that, the social environment which surrounds manufacturing is rapidly changing depending on new technologies. To create future products with user satisfaction, the effective use of human physiological data is essential. This is where knowledge of physiological anthropology can be applied. Physiological anthropologists have been pointing out a limit to the interpretation of the physiological data based on its average value. They have begun to notice that the physiological functions of humans show various types according to the blended effect of heredity and the surroundings. Adequate consideration of physiological polymorphism is indispensable to accomplish manufacturing that is well devised for human. In this study the concept of manufacturing and design based on physiological polymorphism is expressed. The target and the methodology for new manufacturing are discussed in seven fields, that is, welfare equipment, clothes, artificial tissue, sporting gear, furniture, building materials, and human interface. Through the above discussion, a procedure to achieve manufacturing and design based on physiological polymorphism is proposed.     

Rapid genotype analysis of the matrix metalloproteinase-1 gene 1G/2G polymorphism that is associated with risk of cancer.

A bi-allelic polymorphism in the promoter of the human matrix metalloproteinase-1 gene has been reported. It has been found to have a functional effect on the promoter strength and to be associated with risk of cancers. The polymorphism is due to an insertion/deletion of a guanine, and conventional methodologies for genotyping this polymorphism are time-consuming and expensive. A rapid genotyping method based on restriction endonuclease digestion is reported here.     

Metabolic Interrelations Underlying the Physiological and Evolutionary Advantages of Genetic Diversity

Past findings have established how the faster growth, greaterreproductive output and/or longer survival that are associatedwith heterosis and genomic diversity measured as multi-locusheterozygosity stem from slower intensities with which proteinsare renewed and replaced (=protein turnover). Slower turnoverresults in lower energy requirements and reduced metabolic sensitivityto environmental change, representing a mechanistic basis forevolutionary consequences of genetic polymorphism. To determinethe genetic and functional basis of differences in whole-bodyprotein turnover, we have begun to resolve different proteolyticpathways, searching for genetic polymorphisms with a directeffect upon proteolysis, and assessing the metabolic and physiologicalconsequences of those genetic influences in the mussel Mytilusedulis. Our recent work has established the physiological importanceof lysosomal enzymes under normal conditions of basal proteolysis,and shown that associated effects on energy flux may vary accordingto functional differences between separate enzymes. Data arepresented here which compare metabolic consequences of polymorphismin the lysosomal aminopeptidases Lap-1 and Lap-2. Findings establishthat metabolic and phenotypic effects of genetic polymorphismresult directly from genetic variation at the loci coding forthese peptidases, rather than from linked loci. They also illustratethe complexity of interrelations that ultimately influence theevolutionary consequences of genomic diversity, including associatedinfluences of both Lap-1 and Lap-2 on energy requirements andanimal condition. We impress that energy requirements for proteinturnover may represent a functional basis for epistasis, includingassociations whereby advantages of genetic polymorphism aregreatest at loci that code for enzymes acting in both proteincatabolism and energy provision.     

Does polymorphism predict physiological connectedness? A test using two encrusting bryozoans

A colonial lifestyle necessitates communication between colony members to coordinate functions and enable resource sharing through physiological integration. Colonial integration is predicted to increase with both the size of the colony and the level of specialization (polymorphism). In modular colonies, although integration might be reflected in structural characteristics such as module spacing or branching patterns, physiological integration is fundamentally dependent on the level of connectedness between modules. In cheilostome bryozoans, funicular tissue links adjacent zooids through pores within zooid walls and is the most likely means of nutrient transport within colonies. We sought to determine whether the relative numbers of pores (septulae) and pore plates (septal chambers) per zooid differed across colony regions in a monomorphic species, Watersipora subtorquata, and one showing some polymorphism, Mucropetraliella ellerii. Within each species, the morphology of pore plates corresponded to functional predictions based on their position within the zooid, and connection numbers per zooid increased with colony size. Contrary to expectations, however, the more complex species, M. ellerii, had significantly fewer porous connections per zooid than W. subtorquata. Physiological connectedness was therefore not predicted by simple assessment of polymorphism in these species and may not be sufficient to infer colonial integration in related taxa.     

Within‐population genetic effects of mtDNA on metabolic rate in Drosophila subobscura

A growing body of research supports the view that within‐species sequence variation in the mitochondrial genome (mtDNA) is functional, in the sense that it has important phenotypic effects. However, most of this empirical foundation is based on comparisons across populations, and few studies have addressed the functional significance of mtDNA polymorphism within populations. Here, using mitonuclear introgression lines, we assess differences in whole‐organism metabolic rate of adult Drosophila subobscura fruit flies carrying either of three different sympatric mtDNA haplotypes. We document sizeable, up to 20%, differences in metabolic rate across these mtDNA haplotypes. Further, these mtDNA effects are to some extent sex specific. We found no significant nuclear or mitonuclear genetic effects on metabolic rate, consistent with a low degree of linkage disequilibrium between mitochondrial and nuclear genes within populations. The fact that mtDNA haplotype variation within a natural population affects metabolic rate, which is a key physiological trait with important effects on life‐history traits, adds weight to the emergent view that mtDNA haplotype variation is under natural selection and it revitalizes the question as to what processes act to maintain functional mtDNA polymorphism within populations.     

Finding keywords for intergenic and gene regions for human genome

The analysis of functionally related sequences for conserved patterns is important for further research of different functional regions. This paper presents an analysis of genes and intergenic sequences from the point of view of linguistics analysis, where gene and intergenic regions are regarded as two different subjects written in the four-letter alphabet [A, C, G, T] and high-frequency simple sequences are taken as keywords. A measurement alpha[l(tau)] was introduced to describe the relative repeat ratio of simple sequences. Cutoff values were found for keywords selection. After eliminating "noise," 87 short sequences were selected as keywords for intergenic regions and 76 for gene regions.     

A tentative proposal on physiological polymorphism and its experimental approaches

The purpose of this paper is to propose a tentative concept of physiological polymorphism and experimental approaches to it. We think that the concept of physiological polymorphism is to categorize the diversified phenomena into various types with statistical methods and to explain the differences among the categorized types from the viewpoint of their physiological mechanisms. Furthermore, it is necessary to take into consideration the fact that physiological polymorphism is observed as a phenotype, and the phenotype results from a genotype modified by culture and environment. As an experimental approach, we studied the effects of gustatory stimulation by chocolate on the activities of the prefrontal area and found that the activities were increased in some cases and decreased in other cases. Therefore, to begin with, when we divided them into an "increasing group" and a "decreasing group," we found that the increasing group had many subjects of Type B and High anxiety, and the decreasing group had many subjects of Type A and Normal anxiety. By the chi-square test for independence, it was found that the ratio of "increase" and "decrease" was related to the trait anxiety and type A personality, respectively. Next, we divided the activities of the prefrontal area into Type A and Type B, as well as a high anxiety group and a low anxiety group. As a result, the Type B and high anxiety groups showed significantly increased activities, while the Type A and normal anxiety groups showed no changes in their activities. Consequently, this data enabled us to explain the difference in activities of the prefrontal area from the viewpoint of personality characteristics. To conclude, we were able to categorize diversified changes in the prefrontal area into certain types when a gustatory stimulus was applied, and to explain them by using personality characteristics (State Trait Anxiety Inventory, Type A behavioral pattern) that are commonly known for their reflection of genotypes.     

Text mining biomedical literature for discovering gene-to-gene relationships: a comparative study of algorithms

Partitioning closely related genes into clusters has become an important element of practically all statistical analyses of microarray data. A number of computer algorithms have been developed for this task. Although these algorithms have demonstrated their usefulness for gene clustering, some basic problems remain. This paper describes our work on extracting functional keywords from MEDLINE for a set of genes that are isolated for further study from microarray experiments based on their differential expression patterns. The sharing of functional keywords among genes is used as a basis for clustering in a new approach called BEA-PARTITION in this paper. Functional keywords associated with genes were extracted from MEDLINE abstracts. We modified the Bond Energy Algorithm (BEA), which is widely accepted in psychology and database design but is virtually unknown in bioinformatics, to cluster genes by functional keyword associations. The results showed that BEA-PARTITION and hierarchical clustering algorithm outperformed k-means clustering and self-organizing map by correctly assigning 25 of 26 genes in a test set of four known gene groups. To evaluate the effectiveness of BEA-PARTITION for clustering genes identified by microarray profiles, 44 yeast genes that are differentially expressed during the cell cycle and have been widely studied in the literature were used as a second test set. Using established measures of cluster quality, the results produced by BEA-PARTITION had higher purity, lower entropy, and higher mutual information than those produced by k-means and self-organizing map. Whereas BEA-PARTITION and the hierarchical clustering produced similar quality of clusters, BEA-PARTITION provides clear cluster boundaries compared to the hierarchical clustering. BEA-PARTITION is simple to implement and provides a powerful approach to clustering genes or to any clustering problem where starting matrices are available from experimental observations.     

Physiological indicators of fitness in benthic invertebrates: a useful measure for ecological health assessment and experimental ecology

Physiological indicators of fitness present a measure of an organism’s response to a changing environment. An analysis of how these organisms allocate and store their energy resources provides an understanding of how they cope with such environmental changes. Each individual has to balance the investment necessary to acquire a certain resource with the energy gained by it. This trade-off can be monitored by measuring several physiological indicators of fitness such as energy storage components, metabolic state or RNA/DNA ratio. Because environmental adaptations and ecological strategies of survival are best examined within the natural environment, our research has to rely on the physiological indicators that are easily accessible in the field. The physiological indicators presented here are significant for an individual’s fitness and in turn lead to reliable values in field-collected samples. Based on our own expertise and on a literature survey, the physiological relevance of the presented indicators is explained. Furthermore, some consideration to the analytical methods used to obtain the physiological indicators is given, and possible errors introduced at the sampling site and during the laboratory procedures are discussed. This work demonstrates that the integration of ecological and physiological expertise facilitates the identification of future ecological problems much earlier than separate approaches of both disciplines alone.     

沙蟋翅多型性的调控机理

沙蟋Gryllus firmus Zera&Denno成虫的后翅有长翅和短翅2种类型,是翅多型性机理研究的极佳模式昆虫。长翅成虫从第5日龄开始迁飞,而短翅成虫的主要特点是繁殖。除了翅的表型差异外,长翅成虫的飞行肌发达,呈褐色;卵巢幼小,直到飞行停止后(大约在10d以后)才开始发育。而短翅成虫的飞行肌退化并呈乳白色;卵巢在第4日龄就发育成熟,表现为卵巢硕大。对翅多型性机理的深入研究,将有利于了解沙蟋迁飞和扩散的内在机理,为准确地预测预报该虫的发生提供重要的理论和实际依据。文章概述沙蟋翅多型性与外界环境的相互关系,以及体内生化代谢和内分泌激素等的变化对该虫迁飞和生殖的影响和作用,进而探讨翅多型的遗传机制和进化意义等问题。     

The TT genotype of methylenetetrahydrofolate reductase 677C>T polymorphism increases the susceptibility to pediatric ischemic stroke: meta-analysis of the 822 cases and 1,552 controls

The 677C>T polymorphism within methylenetetrahydrofolate reductase (MTHFR) gene is related to an elevated level of homocysteine. Thus it may be considered as a genetic risk factor in ischemic stroke. Apparently studies of this type of polymorphism in childhood stroke have shown conflicting results. We performed meta-analysis of all the data that are available in relation with MTHFR polymorphism and the risk of ischemic stroke in children. We searched PubMed (last search dated December 2010) using "MTHFR polymorphism", "ischemic stroke" "child", "children", "pediatric stroke" as keywords and reference lists of studies and reviews on the topic. Finally, 15 case-control studies corresponded to the inclusion criteria for meta-analysis. These studies involved the total number of 822 children and adolescents after ischemic stroke and 1,552 control subjects. Fixed or random effects models were used depending on the heterogeneity between the studies. The association between ischemic stroke and 677C>T polymorphism within MTHFR gene was observed in three of the studies. The pooled analysis showed that TT genotype of MTHFR gene is more common in stroke patients than in controls (p = 0.0402, odds ratio = 1.57, 95 % confidence interval 1.02-2.41). The Egger's test did not reveal presence of a publication bias. The results based on a sizeable group of cases and controls have proved that the 677C>T polymorphism in MTHFR gene is associated with the development of ischemic stroke in children.     

Comparison of DNA and protein polymorphisms between humans and chimpanzees

To examine the nucleotide diversity at silent (synonymous + intron + untranslated) and non-silent (nonsynonymous) sites in chimpanzees and humans, genes at six nuclear loci from two chimpanzees were sequenced. The average silent diversity was 0.19%, which was significantly higher than that in humans (0.05%). This observation suggests a significantly larger effective population size and a higher extent of neutral polymorphism in chimpanzees than in humans. On the other hand, the non-silent nucleotide diversity is similar in both species, resulting in a larger fraction of neutral mutations at non-silent sites in humans than in chimpanzees. Other types of polymorphism data were collected from the literature or databases to examine whether or not they are consistent with the nuclear DNA sequence polymorphism observed here. The nucleotide diversity at both silent and non-silent sites in mitochondrial (mt) DNA genes was compatible with that of the nuclear genes. Microsatellite loci showed a similar high extent of heterozygosity in both species, perhaps due to the combined effect of a high mutation rate and a recent population expansion in humans. At protein loci, humans are more heterozygous than chimpanzees, and the estimated fraction of neutral alleles in humans (0.84) is much larger than that in chimpanzees (0.26). These data show that the neutral fraction in non-silent changes is relatively large in the human population. This difference may be due to a relaxation of the functional constraint against proteins in the human lineage. To evaluate this possibility, it will be necessary to examine nucleotide sequences in relation to the physiological or biochemical properties of proteins.     

Spatiotemporal environmental heterogeneity and the maintenance of the tailspot polymorphism in the variable platyfish (Xiphophorus variatus)

Genetic variation is critical for adaptive evolution. Despite its importance, there is still limited evidence in support of some prominent theoretical models explaining the maintenance of genetic polymorphism within populations. We examined 84 populations of Xiphophorus variatus, a livebearing fish with a genetic polymorphism associated with physiological performance, to test: (1) whether niche differentiation explains broad‐scale maintenance of polymorphism, (2) whether polymorphism is maintained among populations by local adaptation and migration, or (3) whether heterogeneity in explicit environmental variables could be linked to levels of polymorphism within populations. We found no evidence of climatic niche differentiation that could generate or maintain broad geographic variation in polymorphism. Subsequently, hierarchical partitioning of genetic richness and partial mantel tests revealed that 76% of the observed genetic richness was partitioned within populations with no effect of geographic distance on polymorphism. These results strongly suggest a lack of migration‐selection balance in the maintenance of polymorphism, and model selection confirmed a significant relationship between environmental heterogeneity and genetic richness within populations. Few studies have demonstrated such effects at this scale, and additional studies in other taxa should examine the generality of gene‐by‐environment interactions across populations to better understand the dynamics and scale of balancing selection.     

Perspectives on environmental adaptability and physiological polymorphism in thermoregulation

The environmental adaptability of human beings has progressed according to various environments experienced in the course of evolution. Therefore, various phenotypes for environmental adaptability exist and are considered to be physiological polymorphism. Physiological polymorphism in thermoregulation is influenced by genotype, individual characteristics, environmental factors, cultural factors, etc. Moreover, it is thought that physiological polymorphism is evidenced more clearly in physiological responses to extreme situations and/or changing conditions than in environments where homeostasis is easily maintained. In the field of physiological anthropology, I think that it is important not only to discover the physiological responses that demonstrate polymorphism, but also to hypothesize about the mechanisms and the processes by which such polymorphisms were formed, and their meaning for human beings. Such discussions may be supposed to lead to an evaluation of the environmental adaptability of humans from the viewpoint of physiological anthropology.