Genomic Mechanisms of Physiological and Morphological Adaptations of Limestone Langurs to Karst Habitats.

Knowledge of the physiological and morphological evolution and adaptation of nonhuman primates is critical to understand hominin origins, physiological ecology, morphological evolution, and applications in biomedicine. Particularly, limestone langurs represent a direct example of adaptations to the challenges of exploiting a high calcium and harsh environment. Here, we report a de novo genome assembly (Tfra_2.0) of a male François's langur (Trachypithecus francoisi) with contig N50 of 16.3 Mb and resequencing data of 23 individuals representing five limestone and four forest langur species. Comparative genomics reveals evidence for functional evolution in genes and gene families related to calcium signaling in the limestone langur genome, probably as an adaptation to naturally occurring high calcium levels present in water and plant resources in karst habitats. The genomic and functional analyses suggest that a single point mutation (Lys1905Arg) in the α1c subunit of the L-type voltage-gated calcium channel Cav1.2 (CACNA1C) attenuates the inward calcium current into the cells in vitro. Population genomic analyses and RNA-sequencing indicate that EDNRB is less expressed in white tail hair follicles of the white-headed langur (T. leucocephalus) compared with the black-colored François's langur and hence might be responsible for species-specific differences in body coloration. Our findings contribute to a new understanding of gene-environment interactions and physiomorphological adaptative mechanisms in ecologically specialized primate taxa.

Spatiotemporal trajectories of reactivation of somatosensory cortex by direct and secondary pathways after dorsal column lesions in squirrel monkeys.

After lesions of the somatosensory dorsal column (DC) pathway, the cortical hand representation can become unresponsive to tactile stimuli, but considerable responsiveness returns over weeks of post-lesion recovery. The reactivation suggests that preserved subthreshold sensory inputs become potentiated and axon sprouting occurs over time to mediate recovery. Here, we studied the recovery process in 3 squirrel monkeys, using high-resolution cerebral blood volume-based functional magnetic resonance imaging (CBV-fMRI) mapping of contralateral somatosensory cortex responsiveness to stimulation of distal finger pads with low and high level electrocutaneous stimulation (ES) before and 2, 4, and 6weeks after a mid-cervical level contralateral DC lesion. Both low and high intensity ES of digits revealed the expected somatotopy of the area 3b hand representation in pre-lesion monkeys, while in areas 1 and 3a, high intensity stimulation was more effective in activating somatotopic patterns. Six weeks post-lesion, and irrespective of the severity of loss of direct DC inputs (98%, 79%, 40%), somatosensory cortical area 3b of all three animals showed near complete recovery in terms of somatotopy and responsiveness to low and high intensity ES. However there was significant variability in the patterns and amplitudes of reactivation of individual digit territories within and between animals, reflecting differences in the degree of permanent and/or transient silencing of primary DC and secondary inputs 2weeks post-lesion, and their spatio-temporal trajectories of recovery between 2 and 6weeks. Similar variations in the silencing and recovery of somatotopy and responsiveness to high intensity ES in areas 3a and 1 are consistent with individual differences in damage to and recovery of DC and spinocuneate pathways, and possibly the potentiation of spinothalamic pathways. Thus, cortical deactivation and subsequent reactivation depends not only on the degree of DC lesion, but also on the severity and duration of loss of secondary as well as primary inputs revealed by low and high intensity ES.

Multiparametric MRI reveals dynamic changes in molecular signatures of injured spinal cord in monkeys.

PURPOSE: To monitor the spontaneous recovery of cervical spinal cord injury (SCI) using longitudinal multiparametric MRI methods. METHODS: Quantitative MRI imaging including diffusion tensor imaging, magnetization transfer (MT), and chemical exchange saturation transfer (CEST) were conducted in anesthetized squirrel monkeys at 9.4T. The structural, cellular, and molecular features of the spinal cord were examined before and at different time points after a dorsal column lesion in each monkey. RESULTS: Images with MT contrast enhanced visualization of the gray and white matter boundaries and the lesion and permitted differentiation of core and rim compartments within an abnormal volume (AV). In the early weeks after SCI, both core and rim exhibited low cellular density and low protein content, with high levels of exchanging hydroxyl, amine, and amide protons, as evidenced by increased apparent diffusion coefficient, decreased fractional anisotropy, decreased MT ratio, decreased nuclear Overhauser effect, and large CEST effects. Over time, cellular density and fiber density increased, whereas amide, amine, and hydroxyl levels dropped significantly, but at differing rates. Histology confirmed the nature of the AV to be a cyst. CONCLUSION: Multiparametric MRI offers a novel method to quantify the spontaneous changes in structure and cellular and molecular compositions of SC during spontaneous recovery from injury.

Comparison and Analysis of Computational Methods for Identifying N6-Methyladenosine Sites in Saccharomyces cerevisiae.

BACKGROUND: N6-methyladenosine (m6A) plays critical roles in a broad range of biological processes. Knowledge about the precise location of m6A site in the transcriptome is vital for deciphering its biological functions. Although experimental techniques have made substantial contributions to identify m6A, they are still labor intensive and time consuming. As complement to experimental methods, in the past few years, a series of computational approaches have been proposed to identify m6A sites. METHODS: In order to facilitate researchers to select appropriate methods for identifying m6A sites, it is necessary to conduct a comprehensive review and comparison of existing methods. RESULTS: Since research works on m6A in Saccharomyces cerevisiae are relatively clear, in this review, we summarized recent progress of computational prediction of m6A sites in S. cerevisiae and assessed the performance of existing computational methods. Finally, future directions of computationally identifying m6A sites are presented. CONCLUSION: Taken together, we anticipate that this review will serve as an important guide for computational analysis of m6A modifications.

The efficacy and safety of health qigong for anti-aging: Protocol for a systematic review and meta-analysis.

BACKGROUND: Aging is a phenomenon that human's physiology and psychology is progressive decline for natural environment. Health Qigong, as a convenient and effective exercise therapy,is widely used for anti-aging. However, there are no systematic reviews or meta-analysises to evaluate the efficacy and safety of Health Qigong on anti-aging. METHODS: We will systematically search for 7 English databases(PubMed, Excerpta Medica Database, MEDLINE, Web of Science, Cochrane Library, SpringerLink, and WHO International Clinical Trials Registry Platform) and 4 Chinese databases(namely the China National Knowledge Infrastructure Database, the Wanfang Database, the Chinese Scientific Journal Database, and the Chinese BioMedical Literature Database) from their inceptions to August 2020. Randomized controlled trials (RCTs) using Health Qigong to anti-aging will be included. After the selection and extraction of eligible studies, a meta-analysis will be undertaken to assess the efficacy and safety of Health Qigong on anti-aging. Moreover, study selection, data extraction, and the evaluation of the methodological quality of trials will each be independently completed by at least 2 researchers. The Review Manager Software V.5.3 will be employed for meta-analysis to assess the risk of bias, data synthesis, and subgroup analysis. RESULTS: This review will provide the latest knowledge and evidence on the efficacy and safety of Health Qigong for anti-aging through the analysis of various evaluation scales. CONCLUSION: The conclusion of this review will help clinicians provide effective exercise therapy for anti-aging. REGISTRATION NUMBER: INPLASY202090017.