Biology subjects

Liu, z.

Publications and source records attributed to Liu, z..

5 recordsLinked to original sources

bioRxiv2025

Drift and isolation drive genomic erosion and island speciation in a lineage of macaques

Allopatric speciation, especially on large islands and archipelagos, is a significant driver of evolutionary diversification, as geographic isolation fosters the independent evolution of populations1,2. In these isolated populations, lineage sorting and genetic drift dominate, accelerating allele fixation and reducing shared genetic variation3,4. Here, we investigated how sea-level transgression during the Early Holocene triggered rapid speciation in large vertebrates by studying macaques isolated on Dangan Island (DGD), located just 30 km from present-day Hong Kong. Whole-genome sequencing revealed that [~]10,000 years of isolation drove the macaques evolution into a distinct species, as indicated by pronounced genomic divergence (mean Fst > = 0.462 vs. mainland), 1.94 million lineage-specific variants, and complete ancestral differentiation with no evidence of post-isolation gene flow. A severe demographic collapse (effective population size, Ne {approx} 40) led to substantial genomic erosion (65.8% loss of genetic diversity). Paradoxically, this also enhanced resilience through drift-mediated genetic triage. Increased homozygosity exposed and purged lethal recessive alleles in lipid metabolism pathways (68% reduction in genetic load), while simultaneously fixing mildly deleterious variants--such as a splice-site mutation in SKAP2--thereby generating a form of genomic "burden" alongside rapid immune adaptation via 251 fixed missense mutations. These findings demonstrate that island isolation can drive vertebrate speciation within a few thousand years, with genetic drift playing a dominant role in shaping genomic architecture. Accordingly, conservation strategies should prioritize monitoring loss-of-function (LoF) variants in essential pathways and prescreening for deleterious allele combinations between donors and recipients prior to implementing genetic rescue in small, drift-sensitive populations.

genomics↗

bioRxiv2022

Specific binding of Hsp27 and phosphorylated Tau mitigates abnormal Tau aggregation-induced pathology

Amyloid aggregation of phosphorylated Tau (pTau) into neurofibrillary tangles is closely associated with Alzheimers disease (AD). Several molecular chaperones have been reported to bind Tau and impede its pathological aggregation. Recent findings of elevated levels of Hsp27 in the brains of patients with AD suggested its important role in pTau pathology. However, the molecular mechanism of Hsp27 in pTau aggregation remains poorly understood. Here, we show that Hsp27 partially co-localizes with pTau tangles in the brains of patients with AD. Notably, phosphorylation of Tau by microtubule affinity regulating kinase 2 (MARK2), dramatically enhances the binding affinity of Hsp27 to Tau. Moreover, Hsp27 efficiently prevents pTau fibrillation in vitro and mitigates neuropathology of pTau aggregation in a Drosophila tauopathy model. Further mechanistic study reveals that Hsp27 employs its N-terminal domain to directly interact with multiple phosphorylation sites of pTau for specific binding. Our work provides the structural basis for the specific recognition of Hsp27 to pathogenic pTau, and highlights the important role of Hsp27 in preventing abnormal aggregation and pathology of pTau in AD.

biochemistry↗

bioRxiv2020

DNA Methylation Reprogramming during Sex Determination and Transition in Zebrafish

It is a mystery about sex determination and sexual plasticity in species without sex chromosomes. DNA methylation is a prevalent epigenetic modification in vertebrates, which has been shown to involve in the regulation of gene expression and embryo development. However, it remains unclear about how DNA methylation regulates sexual development. To elucidate it, we used zebrafish to investigate DNA methylation reprogramming during juvenile germ cell development and adult female-to-male sex transition. We revealed that primordial germ cells (PGCs) undergo significant DNA methylation reprogramming during germline development and set to an oocyte/ovary-like pattern at 9 days post fertilization (9 dpf). When blocking DNMTs activity in juveniles after 9 dpf, the zebrafish preferably develops into females. We also show that Tet3 involves in PGC development. Notably, we find that DNA methylome reprogramming during adult zebrafish sex transition is similar to the reprogramming during the sex differentiation from 9 dpf PGCs to sperm. Furthermore, inhibiting DNMTs activity can prevent the female-to-male sex transition, suggesting that methylation reprogramming is required for zebrafish sex transition. In summary, DNA methylation plays important roles in zebrafish germline development and sexual plasticity.

developmental biology↗

bioRxiv2020

A single-cell transcriptome atlas of the aging human and macaque retina

The human retina is a complex neural tissue that detects light and sends visual information to the brain. However, the molecular and cellular processes that underlie aging primate retina remain unclear. Here, we provide a comprehensive transcriptomic atlas based on 119,520 single cells of the foveal and peripheral retina of humans and macaques covering different ages. The molecular features of retinal cells differed between the two species, suggesting the distinct regional and species specializations of the human and macaque retinae. In addition, human retinal aging occurred in a region- and cell-type- specific manner. Aging of human retina exhibited a foveal to peripheral gradient. MYO9A- rods and a horizontal cell subtype were greatly reduced in aging retina, indicating their vulnerability to aging. Moreover, we generated a dataset showing the cell-type- and region- specific gene expression associated with 55 types of human retinal disease, which provides a foundation to understand the molecular and cellular mechanisms underlying human retinal diseases. Together, these datasets are valuable for understanding the molecular characteristics of primate retina, as well as the molecular regulation of aging progression and related diseases.

neuroscience↗

bioRxiv2019

Aquaculture potential of Bohai Red and its hybrid with Agropecten irradians concentricus in southern China

Argopecten irradians concentricus (Say), one of four geographic subspecies of the bay scallop, has become the major cultured species in southern China since its introduction in 1995. However, its population has been significantly reduced due to high mortality.Also, poor growth rate has been observed following decades of culture.Therefore, the introduction or creation of new varieties is an urgent need. This study describes the first introduction of the new strain, Bohai Red, from the north to southern China. Hybridization trials were conducted between the recently introduced new strain and the local specie, A. irradians concentricus (Say). The success of hybridization was confirmed by SSR maker.The adult and juvenile Bohai Red cannot tolerate high temperatures compared to A. irradians concentricus (Say), whether in natural waters or under laboratory conditions. Fertilization rate for A. irradians concentricus (Say) x Bohai Red exceeded 80%, and hatching rate was 70%. The hybrids exhibit heterosis in survival rate, growth rate, and high-temperature tolerance, demonstrating substantial potential to replace A. irradians concentricus (Say) in southern China.

zoology↗