Evolutionary and comparative anatomical investigations of the autonomic cardiac nervous system in the African Cercopithecidae

The purpose of this study was to clarify the general architecture and morphological variations of the autonomic cardiac nervous system (ACNS) in the African Cercopithecidae (Old World monkeys), and to discuss the evolutionary changes between this system in African/Asian Cercopithecidae and humans. A detailed macroscopic comparative morphological investigation of the ACNS was performed by examining the left and right sides of 11 African cercopithecid specimens, including some previously unreported species (Abyssinian colobus, Angola pied colobus, Savanna monkey, and lesser white-nosed guenon). The common characteristics of the ACNS in the African Cercopithecidae are described in detail. Consequently, homologies of the ACNS between Asian (macaques) and African Cercopithecidae, and differences between the Asian/African Cercopithecidae and humans, were found. In particular, differences in the sympathetic (cardiac) systems of the Cercopithecidae and humans were recognized, despite the similar morphology of the parasympathetic vagal (cardiac) system. These differences include the composition of the cervicothoracic ganglion, the lower positions of the middle cervical and cervicothoracic ganglia, and the narrow range for the origin of the cardiac nerves in the Cercopithecidae, compared with that in humans. In conclusion, these findings are considered with regard to the morphology of the last common ancestors of the Cercopithecidae.     

Relationships between BK virus lineages and human populations

BK polyomavirus (BKV) is ubiquitous in human populations, infecting children asymptomatically and then persisting in the kidney, in which it can cause nephropathy in renal transplant patients. BKV isolates are classified into four subtypes (I-IV) using serological or genotyping methods, and subtype I is further divided into four subgroups, Ia, Ib-1, Ib-2, and Ic, based on DNA sequence variations. To clarify whether there is an association between BK virus lineages and human populations, we examined BKV-positive urine samples collected from immunocompetent individuals at various locations in Europe, Africa, and Asia. Partial BKV DNA sequences (n=299) in these samples were determined and subjected to phylogenetic and single nucleotide polymorphism analysis to classify BKV isolates around the world. The validity of the classification was confirmed by analyses based on complete BKV DNA sequences. Subtype I was the major subtype throughout the studied regions, and subtype IV was prevalent only in Asia and Europe. Subtype-I subgroups showed close relationships to major geographical areas. It has recently been shown that JC virus (a human polyomavirus closely related to BKV) co-evolved with human populations, and the present study thus suggests that host-linked evolution is the general mode of polyomavirus evolution. Additionally, our results indicate certain unique aspects of the relationship between BKV and humans.     

Deuterium NMR of Raft Model Membranes Reveals Domain-Specific Order Profiles and Compositional Distribution

In this report, we applied site-specifically deuterated N-stearoylsphingomyelins (SSMs) to raft-exhibiting ternary mixtures containing SSM, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and cholesterol (Chol) and successfully acquired deuterium quadrupole coupling profiles of SSM from liquid-ordered (L_o) and liquid-disordered (L_d) domains. To our knowledge, this is the first report that shows detailed lipid chain dynamics separately and simultaneously obtained from coexisting L_o and L_d domains. We also found that the quadrupole profile of the L_o phase in the ternary system was almost identical to that in the SSM-Chol binary mixture, suggesting that the order profile of the binary system is essentially applicable to more complicated membrane systems in terms of the acyl chain order. We also demonstrated that ²H NMR spectroscopy, in combination with organic synthesis of deuterated components, could be used to reveal the accurate mole fractions of each component distributed in the L_o and L_d domains. As compared with the reported tie-line analysis of phase diagrams, the merit of our ²H NMR analysis is that the domain-specific compositional fractions are directly attainable without experimental complexity and ambiguity. The accurate compositional distributions as well as lipid order profiles in ternary mixtures are relevant to understanding the molecular mechanism of lipid raft formation.     

Axillary Meristem Formation in Rice Requires the WUSCHEL Ortholog TILLERS ABSENT1

Axillary shoot formation is a key determinant of plant architecture. Formation of the axillary shoot is regulated by initiation of the axillary meristem or outgrowth of the axillary bud. Here, we show that rice (Oryza sativa) TILLERS ABSENT1 (TAB1; also known as Os WUS), an ortholog of Arabidopsis thaliana WUS, is required to initiate axillary meristem development. We found that formation of the axillary meristem in rice proceeds via a transient state, which we term the premeristem, characterized by the expression of OSH1, a marker of indeterminate cells in the shoot apical meristem. In the tab1-1 (wus-1) mutant, however, formation of the axillary meristem is arrested at various stages of the premeristem zone, and OSH1 expression is highly reduced. TAB1/WUS is expressed in the premeristem zone, where it shows a partially overlapping pattern with OSH1. It is likely, therefore, that TAB1 plays an important role in maintaining the premeristem zone and in promoting the formation of the axillary meristem by promoting OSH1 expression. Temporal expression patterns of WUSCHEL-RELATED HOMEOBOX4 (WOX4) indicate that WOX4 is likely to regulate meristem maintenance instead of TAB1 after establishment of the axillary meristem. Lastly, we show that the prophyll, the first leaf in the secondary axis, is formed from the premeristem zone and not from the axillary meristem.     

Monitoring oxygen consumption of single mouse embryos using an integrated electrochemical microdevice

Oxygen consumption (respiration activity) has been found to be the most remarkable criterion for determining the viability of an embryo produced in vitro. In this study, we propose an accurate, simple, and user-friendly device for measurement of the oxygen consumption of single mammalian embryos. An integrated electrode array was fabricated to determine the oxygen consumption of a single embryo, including the blastocyst stage, which has an inhomogeneous oxygen consumption rate, using a single measurement procedure. A single mouse embryo was positioned in a microwell at the center of an integrated electrode array, using a mouthpiece pipette, and immobilized by a cylindrical micropit with good reproducibility. The oxygen consumption of two-cell, morula, and blastocyst stages was measured amperometrically using the device. The recorded current profile was corrected to take into consideration transient background current during the measurement. A calculation method for oxygen consumption based on spherical diffusion centered on the defined point of the device was developed. This procedure is quite simple because it is not necessary to estimate the radius of the embryo being measured. The calculated values of oxygen consumption for two-cell, morula, and blastocyst stages were 1.36 ± 0.33 × 10⁻¹⁵ mol s⁻¹, 1.38 ± 0.58 × 10⁻¹⁵ mol s⁻¹, and 3.44 ± 2.07 × 10⁻¹⁵ mol s⁻¹, respectively. The increasing pattern of oxygen consumption from morula to blastocyst agreed well with measurements obtained using conventional scanning electrochemical microscopy (SECM).