Advancing Ion Selective Membranes with Micropore Ion Channels in the Interaction Confinement Regime.

Ion exchange membranes allowing the passage of charge-carrying ions have established their critical role in water, environmental, and energy-relevant applications. The design strategies for high-performance ion exchange membranes have evolved beyond creating microphase-separated membrane morphologies, which include advanced ion exchange membranes to ion-selective membranes. The properties and functions of ion-selective membranes have been repeatedly updated by the emergence of materials with subnanometer-sized pores and the understanding of ion movement under confined micropore ion channels. These research progresses have motivated researchers to consider even greater aims in the field, i.e., replicating the functions of ion channels in living cells with exotic materials or at least targeting fast and ion-specific transmembrane conduction. To help realize such goals, we briefly outline and comment on the fundamentals of rationally designing membrane pore channels for ultrafast and specific ion conduction, pore architecture/chemistry, and membrane materials. Challenges are discussed, and perspectives and outlooks are given.

Reciprocal expression of MADS-box genes and DNA methylation reconfiguration initiate bisexual cones in spruce.

The naturally occurring bisexual cone of gymnosperms has long been considered a possible intermediate stage in the origin of flowers, but the mechanisms governing bisexual cone formation remain largely elusive. Here, we employed transcriptomic and DNA methylomic analyses, together with hormone measurement, to investigate the molecular mechanisms underlying bisexual cone development in the conifer Picea crassifolia. Our study reveals a "bisexual" expression profile in bisexual cones, especially in expression patterns of B-class, C-class and LEAFY genes, supporting the out of male model. GGM7 could be essential for initiating bisexual cones. DNA methylation reconfiguration in bisexual cones affects the expression of key genes in cone development, including PcDAL12, PcDAL10, PcNEEDLY, and PcHDG5. Auxin likely plays an important role in the development of female structures of bisexual cones. This study unveils the potential mechanisms responsible for bisexual cone formation in conifers and may shed light on the evolution of bisexuality.

A Comprehensive Evolutionary Study of Chloroplast RNA Editing in Gymnosperms: A Novel Type of G-to-A RNA Editing Is Common in Gymnosperms.

Although more than 9100 plant plastomes have been sequenced, RNA editing sites of the whole plastome have been experimentally verified in only approximately 21 species, which seriously hampers the comprehensive evolutionary study of chloroplast RNA editing. We investigated the evolutionary pattern of chloroplast RNA editing sites in 19 species from all 13 families of gymnosperms based on a combination of genomic and transcriptomic data. We found that the chloroplast C-to-U RNA editing sites of gymnosperms shared many common characteristics with those of other land plants, but also exhibited many unique characteristics. In contrast to that noted in angiosperms, the density of RNA editing sites in ndh genes was not the highest in the sampled gymnosperms, and both loss and gain events at editing sites occurred frequently during the evolution of gymnosperms. In addition, GC content and plastomic size were positively correlated with the number of chloroplast RNA editing sites in gymnosperms, suggesting that the increase in GC content could provide more materials for RNA editing and facilitate the evolution of RNA editing in land plants or vice versa. Interestingly, novel G-to-A RNA editing events were commonly found in all sampled gymnosperm species, and G-to-A RNA editing exhibits many different characteristics from C-to-U RNA editing in gymnosperms. This study revealed a comprehensive evolutionary scenario for chloroplast RNA editing sites in gymnosperms, and reported that a novel type of G-to-A RNA editing is prevalent in gymnosperms.

Integrated analysis of microRNA and mRNA interactions in ovary of counter-season breeding and egg-ceased geese (Anser cygnoides).

Egg-ceasing is a phenomenon that occurs in most avian species and significantly reduces productivity. Although several factors are reported to regulate the reproduction progress, the underlying molecular mechanism of egg-ceasing remains obscure. Herein, we identified and explored the differentially expressed miRNAs and mRNAs involved in ovarian atrophy via high throughput sequencing. We identified a total of 901 mRNAs and 50 miRNAs that were differentially expressed in egg-laying and atrophic ovaries. Among them, numerous differentially expressed gene (DEG) transcripts and target genes for miRNAs were significantly enriched in Gene Ontology terms such as reproductive processes, cell proliferation, and apoptosis pathways. In addition, an interaction network was constructed by considering target relationships and correlation of the expression levels between ovary development-related genes, miRNAs and pathways. We discovered mRNA and miRNAs transcripts that are candidate regulators of ovary development in egg-ceased geese. Our findings expanded our understanding of the functional of miRNAs in ovarian atrophy and demonstrated that RNA-Seq is a powerful tool for examining the molecular mechanism in regulating egg-ceasing.

Epidural gas-containing pseudocyst leading to lumbar radiculopathy: A case report.

BACKGROUND: Lumbar radiculopathy is a common symptom in the clinic and is often caused by lumbar disc herniation or osteophytes compressing the nerve root; however, it is rare for nerve roots to be compressed by epidural gas. Few symptomatic epidural gas-containing pseudocyst cases have been reported. Furthermore, the reported cases were due to a mix of gas and obvious osteophytes; therefore, it was hard to rigorously conclude that gas was the factor responsible for radiculopathy. We provide evidence that because no epidural gas accumulated before radiculopathy occurred and the symptoms were relieved after removal of the gas, the epidural gas-containing pseudocyst was the root cause of radiculopathy in this case. CASE SUMMARY: An 87-year-old man with a 3-wk history of right radiating pain was admitted to our hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) examinations showed a vacuum phenomenon and huge lesions with low signal intensity located in the same area where the pain occurred. After carefully checking the images acquired in the last 3 mo, we found an abdominal CT examination performed 40 d prior because of abdominal pain. The CT images showed no gas-containing pseudocyst in the epidural space and notably, he had no leg pain at the time. To ensure a low-intensity intervention and complete decompression of the nerve, percutaneous endoscopic lumbar nerve decompression surgery was advised. A gas-containing pseudocyst was identified under endoscopy. The symptoms were relieved after surgery, and the postoperative images showed total disappearance of the vacuum phenomenon and lesions with low signal intensity on CT and MRI. Histological examination showed that the sampled gas-containing pseudocyst tissue was fibrous connective tissue. CONCLUSION: This case thoroughly illustrates that an epidural gas-containing pseudocyst can result in radiculopathic pain through a comprehensive evidence chain. Percutaneous endoscopic decompression is a minimally invasive and effective treatment method.

Disparities in Risks of Inadequate and Excessive Intake of Micronutrients during Pregnancy.

BACKGROUND: Inadequate or excessive intake of micronutrients in pregnancy has potential to negatively impact maternal/offspring health outcomes. OBJECTIVE: The aim was to compare risks of inadequate or excessive micronutrient intake in diverse females with singleton pregnancies by strata of maternal age, race/ethnicity, education, and prepregnancy BMI. METHODS: Fifteen observational cohorts in the US Environmental influences on Child Health Outcomes (ECHO) Consortium assessed participant dietary intake with 24-h dietary recalls (n = 1910) or food-frequency questionnaires (n = 7891) from 1999-2019. We compared the distributions of usual intake of 19 micronutrients from food alone (15 cohorts; n = 9801) and food plus dietary supplements (10 cohorts with supplement data; n = 7082) to estimate the proportion with usual daily intakes below their age-specific daily Estimated Average Requirement (EAR), above their Adequate Intake (AI), and above their Tolerable Upper Intake Level (UL), overall and within sociodemographic and anthropometric subgroups. RESULTS: Risk of inadequate intake from food alone ranged from 0% to 87%, depending on the micronutrient and assessment methodology. When dietary supplements were included, some women were below the EAR for vitamin D (20-38%), vitamin E (17-22%), and magnesium (39-41%); some women were above the AI for vitamin K (63-75%), choline (7%), and potassium (37-53%); and some were above the UL for folic acid (32-51%), iron (39-40%), and zinc (19-20%). Highest risks for inadequate intakes were observed among participants with age 14-18 y (6 nutrients), non-White race or Hispanic ethnicity (10 nutrients), less than a high school education (9 nutrients), or obesity (9 nutrients). CONCLUSIONS: Improved diet quality is needed for most pregnant females. Even with dietary supplement use, >20% of participants were at risk of inadequate intake of ≥1 micronutrients, especially in some population subgroups. Pregnancy may be a window of opportunity to address disparities in micronutrient intake that could contribute to intergenerational health inequalities.

[Acupuncture at xing-spring point, shu-stream point and lower he-sea point for type-2 diabetic peripheral neuropathy].

OBJECTIVE: To observe the effect of acupuncture at xing-spring point, shu-stream point and lower he-sea point on neurological function and clinical symptoms in patients with type-2 diabetic peripheral neuropathy. METHODS: Sixty patients with type-2 diabetic peripheral neuropathy were randomly divided into an observation group and a control group, 30 cases in each one. Both groups were treated with basic treatment, and the observation group was additionally treated with acupuncture at Neiting (ST 44), Xiangu (ST 43), Dadu (SP 2), Taibai (SP 3), Zusanli (ST 36), etc. once every other day, 3 times a week for 4 weeks. The changes of TCM symptom score, Toronto clinical assessment (TCSS) score, visual analogue scale (VAS) score of pain and serum tumor necrosis factor α(TNF-α) level were observed before and after treatment in the two groups, and the clinical effects of the two groups were evaluated. RESULTS: Compared before treatment, the TCM syndrome score and the TCSS score in the two groups were reduced after treatment (P<0.05), and the TCM syndrome score after treatment in the observation group was lower than that in the control group (P<0.05). After treatment, the VAS in the observation group was reduced (P<0.05), and the VAS score of pain in the observation group was lower than that in the control group (P<0.05). There was no significant difference in the level of serum TNF-α within and between the two groups (P>0.05). The total effective rate was 76.7% (23/30) in the observation group, which was superior to 33.3% (10/30) in the control group (P<0.05). CONCLUSION: Acupuncture at xing-spring point, shu-stream point and lower he-sea point could effectively improve the neurological function and clinical symptoms in patients with type-2 diabetic peripheral neuropathy.

Both Conifer II and Gnetales are characterized by a high frequency of ancient mitochondrial gene transfer to the nuclear genome.

BACKGROUND: Mitochondrial gene transfer/loss is common in land plants, and therefore the fate of missing mitochondrial genes has attracted more and more attention. The gene content of gymnosperm mitochondria varies greatly, supplying a system for studying the evolutionary fate of missing mitochondrial genes. RESULTS: Here, we studied the tempo and pattern of mitochondrial gene transfer/loss in gymnosperms represented by all 13 families, using high-throughput sequencing of both DNA and cDNA. All 41 mitochondrial protein-coding genes were found in cycads, Ginkgo and Pinaceae, whereas multiple mitochondrial genes were absent in Conifer II and Gnetales. In Conifer II, gene transfer from mitochondria to the nucleus followed by loss of the mitochondrial copy was common, but complete loss of a gene in both mitochondrial and nuclear genomes was rare. In contrast, both gene transfer and loss were commonly found in Gnetales. Notably, in Conifer II and Gnetales, the same five mitochondrial genes were transferred to the nuclear genome, and these gene transfer events occurred, respectively, in ancestors of the two lineages. A two-step transfer mechanism (retroprocessing and subsequent DNA-mediated gene transfer) may be responsible for mitochondrial gene transfer in Conifer II and Gnetales. Moreover, the mitochondrial gene content variation is correlated with gene length, GC content, hydrophobicity, and nucleotide substitution rates in land plants. CONCLUSIONS: This study reveals a complete evolutionary scenario for variations of mitochondrial gene transferring in gymnosperms, and the factors responsible for mitochondrial gene content variation in land plants.

2D Heterostructured Nanofluidic Channels for Enhanced Desalination Performance of Graphene Oxide Membranes.

The two-dimensional (2D) lamellar membrane assembly technique shows substantial potential for sustainable desalination applications. However, the relatively wide and size-variable channels of 2D membranes in aqueous solution result in inferior salt rejections. Here we show the establishment of nanofluidic heterostructured channels in graphene oxide (GO) membranes by adding g-C3N4 sheets into GO interlamination. Benefiting from the presence of stable and sub-nanometer wide (0.42 nm) GO/g-C3N4 channels, the GO/g-C3N4 membrane exhibits salt rejections of ∼90% with water permeances of above 30 L h-1 m-2 bar-1, while the pure GO membrane only has salt rejections of below 30% accompanied by water permeances of below 4 L h-1 m-2 bar-1. Combining experimental and theoretical investigations, size exclusion has proved to be the dominating mechanism for high rejections, and the ultralow friction water flow along g-C3N4 sheets is responsible for permeation enhancements. Importantly, the GO/g-C3N4 membrane shows promising long-term, antioxidation, and antipressure stability.

Phylotranscriptomics reveals the complex evolutionary and biogeographic history of the genus Tsuga with an East Asian-North American disjunct distribution.

The disjunct distribution between East Asia and North America is one of the best established biogeographic patterns. A robust phylogeny is fundamental for understanding the biogeographic histories of taxa with this distribution pattern. Tsuga (hemlock) is a genus of Pinaceae with a typical intercontinental disjunct distribution in East Asia and eastern and western North America, and its phylogeny has not been completely reconstructed in previous studies. In this study, we reconstructed a highly resolved phylogeny of Tsuga using 881 nuclear genes, 60 chloroplast genes and 23 mitochondrial genes and explored its biogeographic and reticulate evolutionary history. The results of phylogenetic analysis, molecular dating and ancestral area reconstruction indicate that Tsuga very likely originated from North America in the late Oligocene and dispersed from America to East Asia via the Bering Land Bridge during the middle Miocene. In particular, we found complex reticulate evolutionary pattern among the East Asian hemlock species. T. sieboldii possibly originated from hybridization with the ancestor of T. chinensis from mainland China and T. forrestii as the paternal donor and the ancestor of T. diversifolia and T. ulleungensis as the maternal donor. T. chinensis (Taiwan) could have originated by hybridization together with T. sieboldii and then evolved independently after dispersal to the Taiwan Island, subsequently experiencing mitochondrial DNA introgression with T. chinensis from mainland China. Moreover, our study found that T. chinensis from western China is more closely related to T. forrestii than to T. chinensis from eastern China. The nonmonophyletic T. chinensis needs taxonomic reconsideration.

Unbiased Subgenome Evolution in Allotetraploid Species of Ephedra and Its Implications for the Evolution of Large Genomes in Gymnosperms.

The evolutionary dynamics of polyploid genomes and consequences of polyploidy have been studied extensively in angiosperms but very rarely in gymnosperms. The gymnospermous genus Ephedra is characterized by a high frequency of polyploidy, and thus provides an ideal system to investigate the evolutionary mode of allopolyploid genomes and test whether subgenome dominance has occurred in gymnosperms. Here, we sequenced transcriptomes of two allotetraploid species of Ephedra and their putative diploid progenitors, identified expressed homeologs, and analyzed alternative splicing and homeolog expression based on PacBio Iso-Seq and Illumina RNA-seq data. We found that the two subgenomes of the allotetraploids had similar numbers of expressed homeologs, similar percentages of homeologs with dominant expression, and approximately equal numbers of isoforms with alternative splicing, showing an unbiased subgenome evolution as in a few polyploid angiosperms, with a divergence of the two subgenomes at ∼8 Ma. In addition, the nuclear DNA content of the allotetraploid species is almost equal to the sum of two putative progenitors, suggesting limited genome restructuring after allotetraploid speciation. The allopolyploid species of Ephedra might have undergone slow diploidization, and the unbiased subgenome evolution implies that the formation of large genomes in gymnosperms could be attributed to even and slow fractionation following polyploidization.

The flattened and needlelike leaves of the pine family (Pinaceae) share a conserved genetic network for adaxial-abaxial polarity but have diverged for photosynthetic adaptation.

BACKGROUND: Leaves have highly diverse morphologies. However, with an evolutionary history of approximately 200 million years, leaves of the pine family are relatively monotonous and often collectively called "needles", although they vary in length, width and cross-section shapes. It would be of great interest to determine whether Pinaceae leaves share similar morpho-physiological features and even consistent developmental and adaptive mechanisms. RESULTS: Based on a detailed morpho-anatomical study of leaves from all 11 Pinaceae genera, we particularly investigated the expression patterns of adaxial-abaxial polarity genes in two types of leaves (needlelike and flattened) and compared their photosynthetic capacities. We found that the two types of leaves share conserved spatial patterning of vasculatures and genetic networks for adaxial-abaxial polarity, although they display different anatomical structures in the mesophyll tissue differentiation and distribution direction. In addition, the species with needlelike leaves exhibited better photosynthetic capacity than the species with flattened leaves. CONCLUSIONS: Our study provides the first evidence for the existence of a conserved genetic module controlling adaxial-abaxial polarity in the development of different Pinaceae leaves.

A novel mixed matrix membrane framework for ultrafast cation sieving.

This work reported a new mixed matrix membrane architecture. Within this structure, cross-linked sulfonated polymers uniformly distributed into the two dimensional channels stacked by graphene oxide sheets. The resulting membranes show ultrafast perm-selectivity towards mono/multiple-valence cations.

Genotype frequency distributions of 28 SNP markers in two commercial lines and five Chinese native chicken populations.

BACKGROUND: Modern breeding in the poultry industry mainly aims to produce high-performance poultry lines and breeds in two main directions of productivity, meat and eggs. To understand more about the productive potential of lowly selected Chinese native chicken populations, we selected 14 representative SNP markers strongly associated with growth traits or carcass traits and 14 SNP markers strongly associated with egg laying traits through previous reports. By using the MassArray technology, we detected the genotype frequency distributions of these 28 SNP markers in seven populations including four lowly selected as well as one moderately selected Sichuan native chicken populations, one commercial broiler line and one commercial layer line. RESULTS: Based on the genotype frequency distributions of these 28 SNP markers in 5 native chicken populations and 2 commercial lines, the results suggested that these Chinese indigenous chicken populations have a relatively close relationship with the commercial broiler line but a marked distinction from the commercial layer line. Two native chicken breeds, Shimian Caoke Chicken and Daheng Broilers, share similar genetic structure with the broiler line. CONCLUSIONS: Our observations may help us to better select and breed superior domestic chickens and provide new clues for further study of breeding programs in local chicken populations.

The complete mitochondrial genome of Taxus cuspidata (Taxaceae): eight protein-coding genes have transferred to the nuclear genome.

BACKGROUND: Gymnosperms represent five of the six lineages of seed plants. However, most sequenced plant mitochondrial genomes (mitogenomes) have been generated for angiosperms, whereas mitogenomic sequences have been generated for only six gymnosperms. In particular, complete mitogenomes are available for all major seed plant lineages except Conifer II (non-Pinaceae conifers or Cupressophyta), an important lineage including six families, which impedes a comprehensive understanding of the mitogenomic diversity and evolution in gymnosperms. RESULTS: Here, we report the complete mitogenome of Taxus cuspidata in Conifer II. In comparison with previously released gymnosperm mitogenomes, we found that the mitogenomes of Taxus and Welwitschia have lost many genes individually, whereas all genes were identified in the mitogenomes of Cycas, Ginkgo and Pinaceae. Multiple tRNA genes and introns also have been lost in some lineages of gymnosperms, similar to the pattern observed in angiosperms. In general, gene clusters could be less conserved in gymnosperms than in angiosperms. Moreover, fewer RNA editing sites were identified in the Taxus and Welwitschia mitogenomes than in other mitogenomes, which could be correlated with fewer introns and frequent gene losses in these two species. CONCLUSIONS: We have sequenced the Taxus cuspidata mitogenome, and compared it with mitogenomes from the other four gymnosperm lineages. The results revealed the diversity in size, structure, gene and intron contents, foreign sequences, and mutation rates of gymnosperm mitogenomes, which are different from angiosperm mitogenomes.

Phylogenomics disentangles the evolutionary history of spruces (Picea) in the Qinghai-Tibetan Plateau: Implications for the design of population genetic studies and species delimitation of conifers.

A laborious and difficult task in current tree of life reconstruction is to resolve evolutionary relationships of closely related congeneric species that originated from recent radiations. This is particularly difficult for forest species with long generation times and large effective population sizes such as conifers. The Qinghai-Tibetan Plateau (QTP) and adjacent areas are considered a species diversity center of Picea, harboring 11 species (including 5 varieties) of this genus, but evolutionary relationships of these species are far from being resolved due to recent radiations, morphological convergence, and frequent interspecific gene flow. In this study, we use these spruce species to test whether phylotranscriptomic analysis, combined with population genetic analysis, can disentangle their evolutionary relationships, and to explore whether reticulate evolution has occurred among them. Phylogenomic analyses indicate that all spruce species in the QTP and neighboring areas, except P. asperata and P. crassifolia, cluster together, and in particular, nearly all taxa (including varieties) reflect reciprocally monophyletic lineages, although the two species P. likiangensis and P. brachytyla are not monophyletic. We found that, compared to herbaceous plants, many more genes (a minimum of 600 OGs for Picea) are required to resolve interspecific relationships of conifers. Contrary to previous studies, our data do not support a hybrid origin of P. purpurea, but suggests a hybrid origin for P. brachytyla var. brachytyla and P. likiangensis var. rubescens. We emphasize that the species or species complex used for population genetic and phylogeographical studies should be monophyletic.

Endowing g-C3 N4 Membranes with Superior Permeability and Stability by Using Acid Spacers.

g-C3 N4 membranes were modulated by intercalating molecules with SO3 H and benzene moieties between layers. The intercalation molecules break up the tightly stacking structure of g-C3 N4 laminates successfully and accordingly the modified g-C3 N4 membranes give rise to two orders magnitude higher water permeances without sacrificing the separation efficiency. The sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO)/g-C3 N4 with a thickness of 350 nm presents an exceptionally high water permeance of 8867 L h-1 m-2 bar-1 and 100 % rejection towards methyl blue, while the original g-C3 N4 membrane with a thickness of 226 nm only exhibits a permeance of 60 L h-1 m-2 bar-1 . Simultaneously, SO3 H sites firmly anchor nitrogen with base functionality distributing onto g-C3 N4 through acid-base interactions. This enables the nanochannels of g-C3 N4 based membranes to be stabilized in acid, basic, and also high-pressure environments for long periods.

Phylotranscriptomics resolves interspecific relationships and indicates multiple historical out-of-North America dispersals through the Bering Land Bridge for the genus Picea (Pinaceae).

A robust phylogeny is prerequisite to understand the evolution and biogeography of organisms. However, ancient and recent evolutionary radiations occurred in many plant lineages, which pose great challenges for phylogenetic analysis, especially for conifers characterized by large effective population sizes and long generation times. Picea is an important component of the dark coniferous forests in the Northern Hemisphere. Previous studies improved our understanding of its evolutionary history, but its interspecific relationships and biogeographic history remain largely unresolved. In the present study, we reconstructed a well-resolved phylogeny of Picea by comparative transcriptomic analysis based on a complete species sampling. The phylogenetic analysis, together with molecular dating and ancestral area reconstruction, further supports the North American origin hypothesis for Picea, and indicates that this genus experienced multiple out-of-North America dispersals by the Bering Land Bridge. We also found that spruces in the Japanese Archipelago have multiple origins, and P. morrisonicola from the Taiwan Island has a close relationship with species from the Qinghai-Tibetan Plateau and adjacent regions. Our study provides the first complete phylogeny of Picea at the genomic level, which is important for future studies of this genus.

Polymorphism in MC1R, TYR and ASIP genes in different colored feather chickens.

Coat color genetics successfully adapted and applied to different animal species, which provides a good demonstration of the concept of comparative genetics. In this study, we sequenced 945 bp fragments of melanocortin 1 receptor (MC1R) gene, 421 bp fragments of exon 1 of tyrosinase (TYR) gene and 266 bp fragments of exon 3 of agouti signaling protein (ASIP) gene for 250 individuals with five plumage color patterns. We detected a total of three SNPs (T398A, T637C, and G920C) in MC1R and built six haplotypes (H1-H6) based on the three SNPs. H5 and H6 haplotypes were mainly concentrated in white and grey chicken. And diplotypes H2H3 occurred in white feather and black-speckle feather with the same frequency. Moreover, a total of three SNPs (C47G, T120C, and T172C) in TYR were found and built six haplotypes (P1-P6) based on the three SNPs. Among them, haplotype P2, P3 and P6 were not occurred in black chicken, the diplotypes P1P6 and P4P6 were only distributed in white, gray and black-speckled feather. We only detected one SNP (T168C) in ASIP gene and found that genotype TT was advantage genotype in the different plumage color groups of chickens. Collectively, our study suggested an association between plumage color and genetic variation of MC1R, TYR and ASIP in chicken.

[Genetic regulation of broodiness in poultry].

Broodiness is a behavior commonly occurring in the poultry industry, which is characterized by inappetence, egg-laying cessation and incubation. Different from laying fowls, the ovary and oviduct of broodiness fowls is degenerate. Broodiness is a low heritability trait, which is controlled by multiple genes in autosomes and influenced by three factors, including environment, endocrine and genetics. In addition to the observation of behavioral characteristics, the current research of broodiness focuses on evaluating the genetic mode, endocrine factors, nesting candidate genes and their polymorphisms in poultry. Given the rapid development of high-throughput sequencing, the joint analyses of genomics, transcriptomics and proteomics have been used to screen out the candidate genes, pathways and molecular mechanism of broodiness. In this review, we summarize the candidate genes, microRNAs and pathways involved in broodiness to provide a reference for further research on poultry broodiness.