SM Journal of Biology

Current Issue

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From Allelic Heterogeneity to Biomechanical Phenotypes: A Functional New Genomic Model of ABCC11 Polymorphisms and their Role in Human Chemical Ecology

The ABCC11 gene, through a single nucleotide polymorphism (SNP; rs17822931), is established as a primary determinant of human axillary secretion. Such a composition dictates the presence of both a binary phenotype of earwax (dry/wet) and the absence or presence thereof of characteristic body odor. However, significant phenotypic heterogeneity exists within genotypic groups, suggesting a more complex genetic architecture. This paper proposes a functional genomic model that expands upon the current biochemical pathway to position the biomechanical properties of the secretion as a critical phenotypic trait. We hypothesize that beyond the foundational secretion of odorant precursors, the ABCC11 genotype, influenced by allelic heterogeneity and modifier genes, actually impacts ecological behaviors and human interactions. Such biomechanical properties of the viscosity, rheology, and water content of apocrine secretions. Directly impact the kinetics of odorant release, persistence on the skin, and dispersion through the air, thereby modulating the efficacy of chemical signal transmission. We outline a research program to characterize the ABCC11 variation, functionally validate novel alleles, define associated metabolomic and biomechanical phenotypes, and test their ecological consequences in behavioral assays. This model integrates population genetics, cell biology, materials science, and ethology to provide a holistic understanding of the role of ABCC11 in human chemical transmission.

Sameer Meralli**


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Microbiological Response to Copper Contamination in a Irrigation Silt Soil

Soil contamination by copper (Cu) causes a severe loss of crop production in China due to rapid industrialization. A laboratory
incubation experiment with varied levels of Cu was conducted to study toxic effects of Cu contamination on microbiological properties
of Irrigation silt soil. Basal respiration (BR), microbial biomass C (Cmic), and microbial quotient (MQ) were stimulated low levels of
external Cu loadings (<50 mg kg-1), but were inhibited at higher rates (>400 mg kg-1). Microbial metabolic quotient (MMQ) was
significantly enhanced. Increasing Cu loading decreased enzyme activities, by 65.6% for phosphatase, 99.5% for invertase, and
74.7% for urease. Color development rate and richness were accelerated, and Shannon diversity and Shannon evenness increased
at low levels of external Cu loadings (<50 mg kg-1), but the reverse was true at higher Cu rate (400 mg kg-1), as estimated by the
Biolog procedure. External Cu loading affected the amounts of individual fatty acids and their ratios. The saturated fatty acids were
increased by 144% and 74%, respectively at the rates of 100 and 400 mg kg-1 Cu, as compared to the control. Gram negative
bacteria were increased by 10.1% and 20.6%, and actinomycete by 10% and 8% respectively, whereas fungi were decreased
11.8% and 66.1%, respectively at the loading rates of 100 and 400 mg kg-1 Cu. These results indicate that microbial biomass, basal
respiration rate, and enzyme activities and microbial community structure in the Irrigation silt soil are sensitive to Cu contamination
and can serve as indicators of Cu contamination.

Kaiyi Fan1*, Mengze Wang2,3, Jun Yao2, Bo Ma2, Ning Min2 and Tatyana Kouznetsova3