Biology subjects

Du, Z.

Publications and source records attributed to Du, Z..

At least 73 records · Page 4Linked to original sources

bioRxiv2023

Histone lactylation antagonizes senescence and skeletal muscle aging via facilitating gene expression reprogramming

One of the prominent drivers of cellular senescence and/or aging is epigenetic alteration, through which orchestrated regulation of gene expression is achieved during the processes. Accumulating endeavors have been devoted to identifying histone modifications-related mechanisms underlying senescence and aging. Here, we show that histone lactylation, a recently identified histone modification bridging metabolism, epigenetic regulation of gene expression and cellular activities in response to internal and external cues, plays a crucial role in counteracting senescence as well as mitigating dysfunctions of skeletal muscle in aged mice. Mechanistically, the abundance of histone lactylation is markedly decreased during senescence and aging but restored following manipulation of the metabolic environment. Genome-wide distribution profiling and gene expression network analysis uncover that the maintenance of histone lactylation level is critical for suppressing senescence and aging programs via targeting of proliferation- and homeostasis-related pathways. We also confirmed that the level of histone lactylation is not only controlled by glycolysis but also regulated by NAD+ content in vivo. More intriguingly, running exercise enhances the level of histone lactylation and reconstructs the cell landscape and communications of mouse skeletal muscle, leading to rejuvenation and functional improvement. Our study highlights the role of histone lactylation in regulating senescence as well as aging-related tissue function, implying that this modification could be used as a novel marker of senescence, and provides a potential target for aging intervention via metabolic manipulation.

cell biology↗

bioRxiv2023

In vivo reprogramming of wound-resident cells generates skin with hair

Summary ParagraphMammalian skin appendages, such as hair follicles and sweat glands, are complex mini-organs formed during skin development1, 2. As wounds heal, the resulting scar tissue lacks skin appendages. The clinical regeneration of skin appendages is an ongoing challenge3, 4. Skin epithelial tissues have been regenerated in vivo by cellular reprogramming5, 6, but the de novo generation of skin appendages has not previously been achieved. Here, we show that transplantation of a type of epithelial cell and two types of mesenchymal cells, reprogrammed from adult mouse subcutaneous mesenchymal cells to mimic developing skin cells, resulted in the generation of skin-appendage-like structures. Furthermore, with the development of a new AAV serotype, in vivo reprogramming of wound-resident cells with the same reprogramming factors generates skin with de novo appendages in adult mice. These findings may provide new therapeutic avenues for skin regeneration and frequent aging-associated skin appendage disorders, such as hair loss and dry skin, and may extend to other tissues and organs. This study also provides the potential for de novo generation of complex organs in vivo.

cell biology↗

bioRxiv2023

Classification of dog breeds using convolutional neural network models and support vector machine

Convolutional neural network (CNN) has been widely used for fine-grained image classification, which has proven to be an effective approach for the classification and identification of specific species. For breed classification of dog, there are several proposed methods based on dog images, however, the highest accuracy rate for dogs (about 93%) is still below expectations compared to other animals or plants (more than 95% on birds and more than 97% on flowers). In this study, we used the Stanford Dog Dataset, combined image features from four CNN models, filtered the features using principal component analysis (PCA) and gray wolf optimization algorithm (GWO), and then classified the features with support vector machine (SVM). Eventually, the classification accuracy rate reached 95.24% for 120 breeds and 99.34% for 76 selected breeds, respectively, demonstrating a significant improvement over existing methods using the same Stanford Dog Dataset. It is expected that our proposed method will further serve as a fundamental framework for accurate classification of a wider range of species.

bioinformatics↗

bioRxiv2023

Gene regulatory patterning codes in early cell fate specification of the C. elegans embryo

Pattern formation originates during embryogenesis by a series of symmetry-breaking steps throughout an expanding cell lineage. In Drosophila, classic work has shown that the embryo segmentation is established by morphogens within a syncytium, and the subsequent action of the gap, pair-rule, and segment polarity genes. This classic model however does not translate directly to species that lack a syncytium - such as C. elegans - where cell fate is specified by cell-autonomous cell lineage programs and their inter-signaling. Previous single-cell RNA-Seq studies in C. elegans have analyzed cells from a mixed suspension of cells from many embryos to study late differentiation stages, or individual early stage embryos to study early gene expression in the embryo. To study the intermediate stages of early and late gastrulation (28- to 102- cells stages) missed by these approaches, here we determine the transcriptomes of the 1- to 102-cell stage to identify 119 embryonic cell-states during cell-fate specification, including equivalence-group cell identities. We find that gene expression programs are modular according to the sub-cell lineages, each establishing a set of stripes by combinations of transcription factor gene expression across the anterior-posterior axis. In particular, expression of the homeodomain genes establishes a comprehensive lineage-specific positioning system throughout the embryo beginning at the 28-cell stage. Moreover, we find that genes that segment the entire embryo in Drosophila have orthologs in C. elegans that exhibit sub-lineage specific expression. These results suggest that the C. elegans embryo is patterned by a juxtaposition of distinct lineage-specific gene regulatory programs each with a unique encoding of cell location and fate. This use of homologous gene regulatory patterning codes suggests a deep homology of cell fate specification programs across diverse modes of development.

developmental biology↗

bioRxiv2022

P bodies coat germ granules to promote transgenerational gene silencing in C. elegans

The formation of biomolecular condensates has emerged as a critical mechanism for compartmentation in living cells. Despite interactions between distinct condensates having been reported, the biological relevance of these interactions remains elusive. In germ cells, small RNA silencing factors are enriched in germ granule condensates, where distinct factors are organized into sub-compartments with specific functions linked to genome surveillance or transgenerational gene silencing. Here we showed that perinuclear germ granules are coated by P body condensates, which are known for housing translationally-inactive mRNAs and mRNA degradation factors. Disruption of P body factors, including CGH-1/DDX6 and CAR-1/LSM14, lead to dispersal of small RNA factors from perinuclear germ granules and disorganization of sub-compartments within germ granules. We further found that CAR-1 promotes the interaction between CGH-1 and germ granule factors, and these interactions are critical for the ability of CGH-1 to promote piRNA-mediated gene silencing. Importantly, we observed that cgh-1 mutants are competent in triggering gene silencing but exhibit defects in maintaining gene silencing in subsequent generations. Small RNA sequencing further showed that cgh-1 mutants exhibit defects in amplifying secondary small RNAs, known carriers of gene silencing memories. Together, our results uncover the function of P body factors in small RNA-mediated transgenerational gene silencing and highlight how the formation and function of one condensate can be regulated by an adjacent, interacting condensate in cells.

cell biology↗

bioRxiv2022

Accurate de novo prediction of RNA 3D structure with transformer network

RNA 3D structure prediction remains challenging though after years of efforts. Inspired by the recent breakthrough in protein structure prediction, we developed trRosettaRNA, a novel deep learning-based approach to de novo prediction of RNA 3D structure. Like trRosetta, the trRosettaRNA pipeline comprises two major steps: 1D and 2D geometries prediction by a transformer network; and full-atom 3D structure folding by energy minimization with constraints from the predicted geometries. We benchmarked trRosettaRNA on two independent datasets. The results show that trRosettaRNA outperforms other conventional methods by a large margin. For example, on 25 targets from the RNA-Puzzles experiments, the mean RMSD of the models predicted by trRosettaRNA is 5.5 [A], compared with 10.5 [A] from the state-of-the-art human group (i.e., Das). Further comparisons with two recently released deep learning-based methods (i.e., DeepFoldRNA and RoseTTAFoldNA) show that all three methods have similar accuracy. However, trRosettaRNA yields more accurate and physically more realistic side-chain atoms than DeepFoldRNA and RoseTTAFoldNA. Finally, we apply trRosettaRNA to predict the structures for the Rfam families that do not have known structures. Analysis shows that for 263 families, the predicted structure models are estimated to be accurate with RMSD < 4 [A]. The trRosettaRNA server and the package are available at: https://yanglab.nankai.edu.cn/trRosettaRNA/.

bioinformatics↗

bioRxiv2022

Macaque Brainnetome Atlas with Fine-grained Parcellations and Reliable Connections

The rhesus macaque (Macaca mulatta) is a crucial experimental animal that shares many genetic, brain organizational, and behavioral characteristics with humans. A macaque brain atlas that identifies anatomically and functionally distinct regions is fundamental to biomedical and evolutionary research. However, even though connectivity information is vital for understanding brain functions, a connectivity-based whole-brain atlas of the macaque has not previously been made. In this study, we created a new whole-brain map, the Macaque Brainnetome Atlas (MacBNA), based on the anatomical connectivity profiles provided by high angular and spatial resolution ex vivo diffusion MRI data. The new atlas consists of 248 cortical and 56 subcortical regions as well as their structural and functional connections. The parcellation and the diffusion-based tractography were comprehensively evaluated with multi-contrast MRI, invasive neuronal-tracing, and Nissl-stained images collected from a single subject and with open-access datasets from other cohorts. As a demonstrative application, the structural connectivity divergence between macaque and human brains was mapped using the Brainnetome atlases of those two species to uncover the genetic underpinnings of the evolutionary changes in brain structure. The resulting resource includes (1) the thoroughly delineated Macaque Brainnetome Atlas (MacBNA), (2) regional connectivity profiles, (3) the postmortem high resolution macaque diffusion and T2-weighted MRI dataset (Brainnetome-8), and (4) multi-contrast MRI, block-face, and section images collected from a single macaque. MacBNA can serve as a common reference frame for mapping multifaceted features across modalities and spatial scales and for integrative investigation and characterization of brain organization and function. Therefore, it will enrich the collaborative resource platform for nonhuman primates and facilitate translational and comparative neuroscience research.

neuroscience↗

bioRxiv2022

SRSF2 is required for mRNA splicing and spermatogenesis

RNA splicing plays significant roles in fundamental biological activities. However, our knowledge about the roles of alternative splicing and underlying mechanisms during spermatogenesis is limited. Here, we report that Serine/arginine-rich splicing factor 2 (SRSF2), also known as SC35, plays critical roles in alternative splicing and male reproduction. Male germ cell-specific deletion of Srsf2 by Stra8-Cre caused complete infertility and defective spermatogenesis. Further analyses revealed that deletion of Srsf2 disrupted differentiation and meiosis initiation of spermatogonia. Mechanistically, by combining RNA-seq data with LACE-seq data, we showed that SRSF2 regulatory networks play critical roles in several major events including reproductive development, spermatogenesis, meiotic cell cycle, synapse organization, DNA recombination, chromosome segregation, and male sex differentiation. Furthermore, SRSF2 affected expression and alternative splicing of Stra8, Stag3 and Atr encoding critical factors for spermatogenesis in a direct manner. Taken together, our results demonstrate that SRSF2 has important functions in spermatogenesis and male fertility by regulating alternative splicing.

developmental biology↗

bioRxiv2022

High-precision neural stimulation by a highly efficient candle soot fiber optoacoustic emitter

Highly precise neuromodulation with a high efficacy poses great importance in neuroscience. Here, we developed a candle soot fiber optoacoustic emitter (CSFOE), capable of generating a high pressure of over 10 MPa, enabling highly efficient neuromodulation in vitro. The design of the fiber optoacoustic emitter, including the choice of the material and the thickness of the layered structure, was optimized in both simulations and experiments. The optoacoustic conversion efficiency of the optimized CSFOE was found to be ten times higher than the other carbon-based fiber optoacoustic emitters. Driven by a single laser, the CSFOE can perform dual-site optoacoustic activation of neurons, confirmed by calcium (Ca) imaging. Our work opens potential avenues for more complex and programmed control in neural circuits using a simple design for multisite neuromodulation in vivo.

neuroscience↗

bioRxiv2022

Three-dose vaccination-induced immune responses protect against SARS-CoV-2 Omicron-BA.2

BackgroundThe ongoing outbreak of SARS-CoV-2 Omicron BA.2 infections in Hong Kong, the model city of universal masking of the world, has resulted in a major public health crisis. Although the third vaccination resulted in strong boosting of neutralization antibody, vaccine efficacy and corelates of immune protection against the major circulating Omicron BA.2 remains to be investigated. MethodsWe investigated the vaccine efficacy against the Omicron BA.2 breakthrough infection among 470 public servants who had received different SARS-CoV-2 vaccine regimens including two-dose BNT162b2 (2xBNT, n=169), three-dose BNT162b2 (3xBNT, n=170), two-dose CoronaVac (2xCorV, n=34), three-dose CoronaVac (3xCorV, n=67) and third-dose BNT162b2 following 2xCorV (2xCorV+1BNT, n=32). Humoral and cellular immune responses after three-dose vaccination were further characterized and correlated with clinical characteristics of BA.2 infection. FindingsDuring the BA.2 outbreak, 27.7% vaccinees were infected. The timely third-dose vaccination provided significant protection with lower incidence rates of breakthrough infections (2xBNT 49.2% vs 3xBNT 13.1%, p <0.0001; 2xCorV 44.1% vs 3xCoV 19.4%, p=0.003). Investigation of immune response on blood samples derived from 92 subjects in three-dose vaccination cohorts collected before the BA.2 outbreak revealed that the third-dose vaccination activated spike (S)-specific memory B cells and Omicron cross-reactive T cell responses, which correlated with reduced frequencies of breakthrough infections and disease severity rather than with types of vaccines. Moreover, the frequency of S-specific activated memory B cells was significantly lower in infected vaccinees than uninfected vaccinees before vaccine-breakthrough infection whereas IFN-{gamma}+ CD4 T cells were negatively associated with age and viral clearance time. Critically, BA.2 breakthrough infection boosted cross-reactive memory B cells with enhanced cross-neutralizing antibodies to Omicron sublineages, including BA.2.12.1 and BA.4/5, in all vaccinees tested. InterpretationOur results imply that the timely third vaccination and immune responses are likely required for vaccine-mediated protection against Omicron BA.2 pandemic. Although BA.2 conferred the highest neutralization resistance compared with variants of concern tested before the emergence of BA.2.12.1 and BA.4/5, the third dose vaccination-activated S-specific memory B cells and Omicron cross-reactive T cell responses contributed to reduced frequencies of breakthrough infection and disease severity. Neutralizing antibody potency enhanced by BA. 2 breakthrough infection with previous 3 doses of vaccines (CoronaVac or BNT162b2) may reduce the risk for infection of ongoing BA.2.12.1 and BA.4/5. FundingHong Kong Research Grants Council Collaborative Research Fund, Health and Medical Research Fund, Wellcome Trust, Shenzhen Science and Technology Program, the Health@InnoHK, Innovation and Technology Commission of Hong Kong, China, National Program on Key Research Project, Emergency Key Program of Guangzhou Laboratory, donations from the Friends of Hope Education Fund and the Hong Kong Theme-Based Research Scheme.

immunology↗

bioRxiv2022

Structural connectivity gradient associated with a dichotomy reveals the topographic organization of the macaque insular cortex

Histology studies revealed that the macaque insular cortex was characterized by the gradual organizations containing agranular, dysgranular and granular insula. However, no consensus has been reached on the elaborate subdivisions of macaque insula. Until now, no neuroimaging study to our knowledge combining connectivity-based gradients and parcellation has been performed to investigate the topographic organization of the macaque insular cortex. In this study, we used high-resolution ex vivo diffusion-weighted imaging data to explore the macaque insular cortexs global gradient organization and subdivisions. We found a rostrocaudal organization of the dominant gradient in the macaque insula using a diffusion map embedding. Meanwhile, extracting the 25% top and bottom components from the dominant and second gradient, which explained variance over 60% in total within ten gradients, the connectivity-based parcellation method was performed to subdivide each component into two subregions confirmed by the cross-validation analysis. Furthermore, permutations tests identified that two subregions from each component showed significant differences between their connectivity fingerprints. Finally, we found that the dominant and second gradients were significantly correlated with the T1w/T2w and cortical thickness maps in the macaque insula. Taken together, the global gradients combining the subdivisions examined the topographic organization of the macaque insular cortex based on the structural connectivity, which may contribute to a better understanding of the intricate insular cortex anatomy.

neuroscience↗

bioRxiv2022

Allele-specific activation, enzyme kinetics, and inhibitor sensitivities of EGFR exon 19 deletion mutations in lung cancer

Oncogenic mutations within the epidermal growth factor receptor (EGFR) are found in 15-30% of all non-small cell lung carcinomas. The term exon 19 deletion (ex19del) is collectively used to refer to more than 20 distinct genomic alterations within exon 19 that comprise the most common EGFR mutation subtype in lung cancer. Despite this heterogeneity, clinical treatment decisions are made irrespective of which EGFR ex19del variant is present within the tumor, and there is a paucity of information regarding how individual ex19del variants influence protein structure and function. Herein, we identify allele-specific functional differences among ex19del variants attributable to recurring sequence and structure motifs. We build all-atom structural models of 60 ex19del variants identified in patients and combine ~400 s of molecular dynamics simulations with biochemical and biophysical experiments to analyze three ex19del mutations (E746_A750, E746_S752>V, and L747_A750>P). We demonstrate that sequence variation in ex19del alters oncogenic cell growth, dimerization propensity, and tyrosine kinase inhibitor (TKI) sensitivity. We show that in contrast to E746_A750 and E746_S752>V, the L747_A750>P variant forms highly active ligand-independent dimers. E746_S752>V displays the least TKI sensitivity among the variants tested, which enzyme kinetic analysis and TKI inhibition experiments suggest is due to increased ATP Km relative to the common E746_A750 variant. Through these analyses, we propose an expanded framework for interpreting ex19del variants and new considerations for therapeutic intervention. SignificanceEGFR mutations are detected in approximately 30% of all lung adenocarcinomas, and the most common EGFR mutation occurring in ~50% of patients is termed "exon 19 deletion" (ex19del). Despite the existence of dozens of different genomic variants comprising what is generically referred to clinically as ex19del, clinicians currently do not distinguish between ex19del variants in considering treatment options, and the differences between ex19del variants are largely unstudied in the broader scientific community. Herein, we describe functional differences between distinct EGFR ex19del variants attributable to the structural features of each variant. These findings suggest a possible explanation for observed differences in patient outcomes stratified by ex19del subtype and reinforce the need for allele-specific considerations in clinical treatment decision making.

cancer biology↗

bioRxiv2021

Nasal prevention of SARS-CoV-2 infection by intranasal influenza-based boost vaccination

BackgroundVaccines in emergency use are efficacious against COVID-19, yet vaccine-induced prevention against nasal SARS-CoV-2 infection remains suboptimal. MethodsSince mucosal immunity is critical for nasal prevention, we investigated an intramuscular PD1-based receptor-binding domain (RBD) DNA vaccine (PD1-RBD-DNA) and intranasal live attenuated influenza-based vaccines (LAIV-CA4-RBD and LAIV-HK68-RBD) against SARS-CoV-2. FindingsSubstantially higher systemic and mucosal immune responses, including bronchoalveolar lavage IgA/IgG and lung polyfunctional memory CD8 T cells, were induced by the heterologous PD1-RBD-DNA/LAIV-HK68-RBD as compared with other regimens. When vaccinated animals were challenged at the memory phase, prevention of robust SARS-CoV-2 infection in nasal turbinate was achieved primarily by the heterologous regimen besides consistent protection in lungs. The regimen-induced antibodies cross-neutralized variants of concerns. Furthermore, LAIV-CA4-RBD could boost the BioNTech vaccine for improved mucosal immunity. InterpretationOur results demonstrated that intranasal influenza-based boost vaccination is required for inducing mucosal and systemic immunity for effective SARS-CoV-2 prevention in both upper and lower respiratory systems. FundingThis study was supported by the Research Grants Council Collaborative Research Fund (C7156-20G, C1134-20G and C5110-20G), General Research Fund (17107019) and Health and Medical Research Fund (19181052 and 19181012) in Hong Kong; Outbreak Response to Novel Coronavirus (COVID-19) by the Coalition for Epidemic Preparedness Innovations; Shenzhen Science and Technology Program (JSGG20200225151410198); the Health@InnoHK, Innovation and Technology Commission of Hong Kong; and National Program on Key Research Project of China (2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); and donations from the Friends of Hope Education Fund. Z.C.s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).

immunology↗

bioRxiv2021

Multi-Functionalized Self-Bonding MXene for Minimal-invasive Jet-injected Neural Interface and Tissue Healing

Implantable central and peripheral neural interfaces have great potential in treating various nerve injuries and diseases. Still, limitations of surgery trauma, handling inconvenience, and biocompatibility issues of available materials and techniques significantly hinder the peripheral nerve interface for research and clinical purposes. MXenes have great potential as bioelectronics materials for excellent hydrophilicity, conductivity, and biocompatibility. However, their application in bioelectronic interface has been limited due to the poor oxidation stability and fast tissue clearance. Here, we developed a minimal-invasive jet-injected neural interface using MXene nanosheets with strong redox stability, tissue adhesion, conductivity, and good self-bonding properties. We also develop a minimal-invasive jet injector to implant the optimized MXene suspension into the damaged sciatic nerve and establish a neural interface through tissue adhesion and self-bonding. We use this neural interface to promote nerve regeneration and perform electrophysiology recording on moving mice. We prove that the nanosheets can mitigate cellular inflammation, promote tissue healing, and record high-quality electrophysiology signals for predicting joint movement. Thus, our material and implantation strategy together form a novel minimal-invasive neural interface, facilitating the collection and analysis of large-scale living body data to solve the challenge of neurological diseases of the peripheral or even the central nervous system.

bioengineering↗

bioRxiv2021

SARS-CoV-2 hijacks neutralizing dimeric IgA for enhanced nasal infection and injury

Robust severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in nasal turbinate (NT) accounts for high viral transmissibility, yet whether neutralizing IgA antibodies can control it remains unknown. Here, we evaluated receptor binding domain (RBD)-specific monomeric B8-mIgA1 and B8-mIgA2, and dimeric B8-dIgA1 and B8-dIgA2 against intranasal SARS-CoV-2 challenge in Syrian hamsters. These antibodies exhibited comparably potent neutralization against authentic virus by competing with human angiotensin converting enzyme-2 (ACE2) receptor for RBD binding. While reducing viruses in lungs, pre-exposure intranasal B8-dIgA1 or B8-dIgA2 led to 81-fold more infectious viruses and severer damage in NT than placebo. Virus-bound B8-dIgA1 and B8-dIgA2 could engage CD209 as an alternative receptor for entry into ACE2-negative cells and allowed viral cell-to-cell transmission. Cryo-EM revealed B8 as a class II neutralizing antibody binding trimeric RBDs in 3-up or 2-up/1-down conformation. Therefore, RBD-specific neutralizing dIgA engages an unexpected action for enhanced SARS-CoV-2 nasal infection and injury in Syrian hamsters.

microbiology↗

bioRxiv2021

OPAM, an Open source, 3D printed Low-cost Micro-Manipulator for Single Cell Manipulation

We introduce OPAM, an Open source, low-cost (under $150), 3D-Printed, stepper motor driven, Arduino based, single cell Micromanipulator (OPAM). Modification of a commercial stepper motor led to dramatically increased stability and maneuverability of the motor, based on which the micromanipulator was designed. All components of this micromanipulator can be 3D printed using an entry-level 3D printer and assembled with ease. With this single cell manipulator, successful targeted single cell capture and transfer was confirmed under the microscope, which showed great promise for single cell related experiments.

bioengineering↗

bioRxiv2021

The creation of functioning gastrojejunostomy following magnetic compression

BackgroundMagnetic compression for creating gastrojejunostomy has many advantages according to previous studies. However, following mechanical device release after healing, the anastomotic stenosis becomes the pivotal point. MethodsRectangle-shaped magnets were used for magnetic compression in rabbits. Both paclitaxel-loaded magnets and a strategy of pyloric ligation were chosen to improve the gastrojejunostomy. Based on these choices, the half-capsule was applied to occlude the pylorus after anastomotic formation. The size and patency of the anastomoses were analyzed to evaluate the efficacy of these approaches. A histological examination was also performed. ResultsThe positive effect of ligating the pylorus on gastrojejunostomy was significantly greater than that achieved using paclitaxel-loaded magnets during either short- or long-term follow-up. There were fewer scar tissue and collagen fibers at the anastomotic site in the treatment group than in the control group. The anastomotic aperture was of great interest at 9 months after the ligation of the pylorus following magnetic compression. In the view of the jejunum, although the aperture was barely visible, gastric juice was continuously spilling through it like a spring, and the aperture was clearly visible from the stomach side. All half-capsules failed to block the pylorus. ConclusionThe effect of paclitaxel on maintaining gastrojejunostomy patency was temporary. The ligation of the pylorus ensured the long-term patency of gastrojejunostomy, and the aperture was comparable to the pylorus which could play an anti-reflux role. Further studies for the sort of gastrointestinal aperture are being planned.

physiology↗

bioRxiv2021

New insights into the earlier evolutionary history of epiphytic macrolichens

Lichens are well known as pioneer organisms colonizing bare surfaces such as rocks and therefore have been hypothesized to play a role in the early formation of terrestrial ecosystems. Given the rarity of fossil evidence, our understanding of the evolutionary history of lichen-forming fungi is primarily based on molecular dating approaches. These studies suggest extant clades of macrolichens diversified after the K-Pg boundary. Here we corroborate the mid-Mesozoic fossil Daohugouthallus ciliiferus as an epiphytic macrolichen that predates the K-Pg boundary by 100 Mys. Based on new material and geometric morphometric analysis, we demonstrate that the Jurassic fossil is morphologically most similar to Parmeliaceae, but cannot be placed in Parmeliaceae or other similar family-level clades forming macrolichens as these evolved much later. Consequently, a new family, Daohugouthallaceae, is proposed here to accommodate this fossil, which reveals macrolichens may have been diverse long before the Cenozoic diversification of extant lineages.

paleontology↗