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Summary: Background: Microplastics are environmental pollutants detected in various human organs and tissues. These particles originate from multiple sources including the degradation of larger plastic items and the intentional inclusion in consumer goods. Potential risks for human health resulting from microplastics exposure have also been reported. However, the distribution in the male reproductive system and its effect remains largely unknown. This study aims to investigate the presence of multiple microplastics in human semen and urine and their association with sperm quality in a multi-site study across China. Methods: We conducted a cross-sectional study involving 113 male participants from three regions in China. Semen and urine samples were collected and analysed using Raman microscopy to detect eight types of microplastics: polystyrene (PS), polypropylene (PP), polycarbonate (PC), polyethylene (PE), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS). Semen quality parameters, including total sperm count, concentration, motility, and morphology, were assessed. Statistical analyses, including single and multi-variable models, were used to evaluate the relationship between microplastic exposure and semen quality, with a focus on PTFE, after adjusting confounding factors of age, body mass index (BMI), smoking, alcohol drinking, and sites. Findings: Microplastics were detected in all semen and urine samples, with participants typically exposed to 3–5 different types. The detection rates of PS, PP and PE were the highest. Notably, PTFE exposure was significantly associated with decreased semen quality. Participants exposed to PTFE showed reductions in total sperm count [188.90 ± 163.71 vs. 207.67 ± 132.36 million, p = 0.091], sperm concentration [52.13 ± 47.47 vs. 58.32 ± 37.26 million/mL, p = 0.041], and progressive motility [40.29% ± 19.06 vs. 34.11% ± 17.02, p = 0.083]. The multi-linear regression analysis indicated that each additional type of microplastic exposure was associated with a significant decrease in total sperm number [β = −15.4 (95% CI: −25.6, −5.2)], sperm concentration [β = −7.2 (95% CI: −12.4, −2.0)], and progressive motility [β = −8.3 (95% CI: −13.5, −3.1)]. Latent category analysis further refined these groups by types of microplastic exposure, highlighting specific types more strongly associated with decreased semen quality (OR = 3.5, 95% CI: 1.8, 6.9, p

Metal halide perovskite solar cell (PSC) has successfully distinguished itself in optoelectronic field by virtue of the sharp rise in power conversion efficiency over the past decade. The remarkable efficiency breakthrough at such a fast speed can be mainly attributed to the comprehensive study on film deposition techniques, especially the effective management of surface and interfacial defects in recent works. Herein, we summarized the current trends in performance enhancement for PSCs, with a focus on the generally applicable strategies in high-performance works, involving deposition methods, compositional engineering, additive engineering, crystallization manipulation, charge transport material selection, interfacial passivation, optical coupling effect and constructing tandem solar cells. Promising directions and perspectives are also provided.

Highlights An ion–electron coupled thermoelectric material was successfully prepared, which theoretically proved the ion–electron thermoelectric synergy effect and this material can work for a long time, which promoted low-grade thermal energy conversion. In the new operating mode of ion–electron thermoelectric synergy effect, our ionic thermoelectrics have a high Seebeck coefficient of 32.7 mV K−1 and a high energy density of 553.9 J m−2, enabling self-power for electronic components.

Organic thermoelectric (TE) materials are considered as the next‐generation TE materials owing to their merits including high mechanical flexibility, low cost, abundant elements, and nontoxicity. However, their Seebeck coefficient is lower than that of the inorganic counterparts by around one order of magnitude, and thus they have a lower dimensionless figure of merit (ZT) value. Herein, the significant enhancement in the Seebeck coefficient and thus the overall TE properties of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) that is the most popular TE polymer by adding a zwitterion like rhodamine 101 (R101), N‐dodecyl‐N,N‐dimethyl‐3‐ammonio‐1‐propane‐sulfonate (DDMAP), or 1‐(N,N‐dimethylcarbamoyl)‐4‐(2‐sulfoethyl) pyridinium hydroxide (DMCSP) are reported. In particular, R101 can enhance the Seebeck coefficient of the acid‐then‐base‐treated PEDOT:PSS from 21.2 to 61.6 μV K−1. The PEDOT:PSS/R101 film can exhibit a power factor of 546 μW m−1 K−2 and a ZT of 0.46 that is the highest for pure organic solid films. The enhancement in the Seebeck coefficient is ascribed to the energy filtering induced by the dipole moment of zwitterion and the π–π overlapping between conjugated rhodamine 101 and PEDOT:PSS. To distinguish it from the conventional methods, this method is named as the molecular energy filtering.

Polaron formation is considered to play a crucial role to enhance photoelectric performance of hybrid halide perovskites. Here, the authors report the real-time observation of polaron formation process by terahertz emission spectroscopy and reveal two different polaron modes in FAPbI3 films.

Abstract Background Woody plants provide the most abundant biomass resource that is convertible for biofuels. Since lignin is a crucial recalcitrant factor against lignocellulose hydrolysis, genetic engineering of lignin biosynthesis is considered as a promising solution. Many MYB transcription factors have been identified to involve in the regulation of cell wall formation or phenylpropanoid pathway. In a previous study, we identified that PtoMYB115 contributes to the regulation of proanthocyanidin pathway, however, little is known about its role in lignocellulose biosynthesis and biomass saccharification in poplar. Results Here, we detected the changes of cell wall features and examined biomass enzymatic saccharification for bioethanol production under various chemical pretreatments in PtoMYB115 transgenic plants. We reported that PtoMYB115 might specifically regulate lignin biosynthesis to affect xylem development. Overexpression of PtoMYB115 altered lignin biosynthetic gene expression, resulting in reduced lignin deposition, raised S/G and beta-O-4 linkage, resulting in a significant reduction in cellulase adsorption with lignin and an increment in cellulose accessibility. These alterations consequently improved lignocellulose recalcitrance for significantly enhanced biomass saccharification and bioethanol yield in the PtoMYB115-OE transgenic lines. In contrast, the knockout of PtoMYB115 by CRISPR/Cas9 showed reduced woody utilization under various chemical pretreatments. Conclusions This study shows that PtoMYB115 plays an important role in specifically regulating lignin biosynthesis and improving lignocellulose features. The enhanced biomass saccharification and bioethanol yield in the PtoMYB115-OE lines suggests that PtoMYB115 is a candidate gene for genetic modification to facilitate the utilization of biomass.

IntroductionThe prevalence of Gestational Diabetes Mellitus (GDM) is increasing globally, and high levels of triglyceride (TG) and low levels of free thyroxine (FT4) in early pregnancy are associated with an increased risk of GDM; however, the interaction and mediation effects remain unknown. The aim of the present study is to examine the impact of FT4 and TG combined effects on the prevalence of GDM and the corresponding casual paths among women in early pregnancy.Materials and methodsThis study comprised 40,156 pregnant women for whom early pregnancy thyroid hormones, fasting blood glucose as well as triglyceride were available. GDM was diagnosed using a 2-hour 75-g oral glucose tolerance test (OGTT) according to the American Diabetes Association guidelines, and the pregnant women were grouped and compared according to the results.ResultsAn L-shaped association between FT4 and GDM was observed. The prevalence of GDM increased with increasing TG levels. After accounting for multiple covariables, the highest risk for GDM was found among pregnant women of lower FT4 with the highest TG concentrations (odds ratio, 2.44, 95% CI, 2.14 to 2.80; P

Microplastics (MPs), as vectors for various pollutants in the environment, have been arousing public concern in recent years. The extensive use of antibiotics has led to their frequent detection in water environments, where they inevitably coexist with MPs and are actively adsorbed onto MPs’ surfaces. However, the information on the influence of the main environmental factors on the sorption behavior of MPs is not fully understood, and especially, information about the effect mechanism is limited. This study aims to comprehensively assess the main factors and mechanisms that affect antibiotic sorption onto microplastics. The results indicated that the adsorption of tetracycline (TC) onto PVC MPs fits the pseudo-second-order model well. The adsorption of TC onto PVC MPs decreased with increasing salinity and pH. With the help of SED analysis, the decrease at high salinity was attributed to the decreased quantities of the most distributed energy sites in high-salinity systems compared to freshwater. Additionally, the decreased adsorption capacity of TC onto MPs at high pH mainly resulted from the electrostatic repulsion between MPs and TC2−. The coexisting Cu2+ and TC could improve the affinity between PVC MPs and TC via “MPs-TC-Cu2+” and “MPs-Cu2+-TC” bridges, boosting the capacity of PVC MPs to adsorb TC. This study provides comprehensive insights into the influence and mechanism of the main factors on the environmental behaviors of the coexistence of MPs with antibiotics, which is of great importance for evaluating and controlling their risks.

Abstract Morphology optimization of active layer plays a critical role in improving the performance of organic solar cells (OSCs). In this work, a volatile solid additive‐assisted sequential deposition (SD) strategy is reported to regulate the molecular order and phase separation in solid state. The OSC adopts polymer donor D18‐Cl and acceptor N3 as active layer, as well as 1,4‐diiodobenzene (DIB) as volatile additive. Compared to the D18‐Cl:N3 (one‐time deposition of mixture) and D18‐Cl/N3 (SD) platforms, the D18‐Cl/N3(DIB) device based on DIB‐assisted SD method exhibits a finer phase separation with greatly enhanced molecular crystallinity. The optimal morphology delivers superior charge transport and extraction, offering a champion power conversion efficiency of 18.42% with significantly enhanced short‐circuit current density (Jsc) of 27.18 mA cm−2 and fill factor of 78.8%. This is one of the best performances in binary SD OSCs to date. Angle‐dependent grazing‐incidence wide‐angle X‐ray scattering technique effectively reveals the vertical phase separation and molecular crystallinity of the active layer. This work demonstrates the combination of volatile solid additive and sequential deposition is an effective method to develop high‐performance OSCs.

Multiple mutational events of insertion/deletion occurring at or around InDel sites could form multi-allelic InDels and multi-InDels (abbreviated as MM-InDels), while InDels with random DNA sequences could imply a unique mutation event at these loci. In this study, preliminary investigation of MM-InDels with random sequences was conducted using high-throughput phased data from the 1000 Genomes Project. A total of 3,599 multi-allelic InDels and 6,375 multi-InDels were filtered with multiple alleles. A vast majority of the obtained MM-InDels (85.59%) presented 3 alleles, which implies that only one secondary insertion or deletion mutation event occurred at these loci. The more frequent presence of two adjacent InDel loci was observed within 20 bp. MM-InDels with random sequences presented an uneven distribution across the genome and showed a correlation with InDels, SNPs, recombination rate, and GC content. The average allelic frequencies and prevalence of multi-allelic InDels and multi-InDels presented similar distribution patterns in different populations. Altogether, MM-InDels with random sequences can provide useful information for population resolution.

Abstract Y6 and its derivatives have greatly improved the power conversion efficiency (PCE) of organic photovoltaics (OPVs). Further developing high‐performance Y6 derivative acceptor materials through the relationship between the chemical structures and properties of these materials will help accelerate the development of OPV. Here, machine learning and quantum chemistry are used to understand the structure–property relationships and develop new OPV acceptor materials. By encoding the molecules with an improved one‐hot code, the trained machine learning model shows good predictive performance, and 22 new acceptors with predicted PCE values greater than 17% within the virtual chemical space are screened out. Trends associated with the discovered high‐performing molecules suggest that Y6 derivatives with medium‐length side chains have higher performance. Further quantum chemistry calculations reveal that the end acceptor units mainly affect the frontier molecular orbital energy levels and the electrostatic potential on molecular surface, which in turn influence the performance of OPV devices. A series of promising Y6 derivative candidates is screened out and a rational design guide for developing high‐performance OPV acceptors is provided. The approach in this work can be extended to other material systems for rapid materials discovery and can provide a framework for designing novel and promising OPV materials.

Polyaniline (PANI) is a commonly used electrochromic material due to its tunable optical properties under an applied potential. In order to fabricate large-area electrochromic devices, PANI has to be deposited uniformly in large scale. Unfortunately, the existing deposition techniques can hardly meet the requirement. In this work, sequential solution polymerization (SSP) technique is introduced for in-situ deposition of large-area PANI films. This process involves synthesis of hydrated vanadium pentoxide (HVO), formation of V2O5 precursor film and in-situ polymerization in an aniline monomer solution. PANI films with a size of 16 × 10 cm2 are realized using bar coating in ambient. This method is facile and efficient, compatible with roll-to-roll printing technology. Electrochromic devices based on SSP PANI films exhibit high optical contract in the vis-NIR region and good cyclability. This study demonstrates that SSP shows great potential in in-situ deposition of large-area PANI films for the development of optoelectronic modules.

With the development of integrated circuits according to Moore’s law, traditional silicon-based devices have gradually reached their performance limitation. Nanoelectronics based on carbon nanomaterials provides a broad prospect for the continuation of Moore’s law. In particular, in the field of optoelectronic devices, it is necessary to further develop new types of nano-optoelectronic devices. Carbon nanotubes (CNTs) are one of the representative materials of nanoelectronics with excellent electrical and optical properties, e.g., high mobility, suitable band structure, and good infrared absorption. The application of CNTs in optoelectronic devices is a very attractive research topic, which has been developed rapidly in recent years. Until now, various prototypes of CNT-based optoelectronic devices have been developed. In this Review, we briefly introduce the structure and photoelectric properties of CNTs. Then, according to different photo-electron coupling mechanisms, four types of CNTs based on optoelectronic devices are introduced in detail, namely, solar cells, photodetectors, light-emitting diodes, and lasers. Intrinsic and composite CNT-based optoelectronic devices are presented in order to describe the development of CNT-based optoelectronic devices. Finally, different material preparation, separation, and mixing methods of CNTs are discussed, which are the methods for basic material preparation for the fabrication of high performance CNT-based optoelectronic devices. An in-depth study of the development trend of CNT-based optoelectronic devices will contribute to the future development of novel high-performance nanoelectronic devices.

Abstract Background D5S818 discrepancies have been reported in forensic parental testing due to null alleles. However, more cases may be ignored since proportional null alleles were missed without detection of heredity discrepancy between parents and offspring. Results In this study, null allele 12 at D5S818 was detected by the PowerPlex® 21 System with a higher occurrence rate on the basis of review on 2824 samples from the 1282 routine cases in Chinese Han population. Sequencing results revealed novel variant of guanine (G) into adenine (A) in the 7th [AGAT] repeats in the core repeat region accompanied by rs1187948322 in the samples with null allele 12. Conclusions Forensic STR typing may benefit from this discovery: (1) primer design of CE profiling system could be improved for sensitive population and (2) polymorphic information could be enriched for the accuracy and precision of NGS genotyping system. Peak area of D5S818 was also analyzed through different commercial STR kits. It is suggested that more attention should be paid on observed homozygosity with reduced peak area, especially for the samples from Chinese Han population.

Abstract Background An STR locus with tri-allelic pattern is occasionally observed in routine forensic casework. The extra copy of TPOX locus with tri-allelic pattern in populations has been assumed to be inserted into an X chromosome, which took place forth before the Bantu expansion in Africa. Nonetheless, the exact location of the duplication and the form of rearrangement in the human genome has not been clarified yet. Results In this study, we investigated the extra copy of type 2 tri-allelic pattern at TPOX in various populations. While allele 10 is the major third allele in Africa, allele 11 appears more frequent in America and overwhelming in Chinese and Korean populations, which might attribute to the population substructures. Results from the investigation of family cases showed that the transmission of the extra allele had a similar genetic pattern of autosomal genes. Furthermore, a whole-genome sequencing followed by bioinformatics analysis revealed that the intact form of chromosomal duplication and rearrangement occurred ~ 407 kb away from the authentic TPOX locus on chromosome 2 in two cases. The breakpoints of the insertion were further validated in most other tri-allelic subjects, which can imply the identical origin from the ancestral extra copy. Nevertheless, de novo chromosomal duplication and rearrangement at thyroid peroxidase gene occur in populations. Conclusions Instead of the extra allele 10 in African populations, the main third allele at TPOX with tri-allelic pattern is allele 11 in Chinese and Korean populations. The insertion of the extra copy into chromosome 2 occurs in most subjects with tri-allelic pattern at TPOX and demonstrates the transmission of the third allele from parents to offspring. The breakpoints of the ancestral extra copy are defined, which shows evidence of its inheritance from African populations. In addition, the simple validation method would help improve tri-allelic pattern calling, distinguish de novo chromosomal rearrangements, and also count the frequencies among different geographic regions. Therefore, the statistical interpretation of tri-allelic pattern at TPOX could be enhanced during forensic practice.

Summary: Various in situ synthesis methods have been developed for the polymerization of 3,4-ethylenedioxythiophene monomers, such as electropolymerization, oxidative chemical vapor deposition, and vapor phase polymerization. Meeting industrial requirements through these techniques has, however, proven challenging. Here, we introduce an alternative method to fabricate highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) films in situ by solution means. The process involves sequential deposition of oxidants (V2O5 in this case) and monomers. Excess reactants and by-products can be completely removed from the PEDOT film by MeOH rinsing. The obtained PEDOT films possess good crystallinity and high doping level, with carrier concentration three orders of magnitude higher than that of the commercial product (PH1000, Heraeus GmbH). The electrical conductivity of the as-cast PEDOT film reaches up to 1,420 S/cm. In addition, this method is fully compatible with large-scale printing techniques. These PEDOT conducting films enable the realization of flexible touch sensors, which demonstrate superior flexibility and sensitivity. : Chemistry; Polymer Chemistry; Electronic Materials Subject Areas: Chemistry, Polymer Chemistry, Electronic Materials

Abstract Single junction binary all‐small‐molecule (ASM) organic solar cells (OSCs) with power conversion efficiency (PCE) beyond 14% are achieved by using non‐fullerene acceptor Y6 as the electron acceptor, but still lag behind that of polymer OSCs. Herein, an asymmetric Y6‐like acceptor, BTP‐FCl‐FCl, is designed and synthesized to match the recently reported high performance small molecule donor BTR‐Cl, and a record efficiency of 15.3% for single‐junction binary ASM OSCs is achieved. BTP‐FCl‐FCl features a F,Cl disubstitution on the same end group affording locally asymmetric structures, and so has a lower total dipole moment, larger average electronic static potential, and lower distribution disorder than those of the globally asymmetric isomer BTP‐2F‐2Cl, resulting in improved charge generation and extraction. In addition, BTP‐FCl‐FCl based active layer presents more favorable domain size and finer phase separation contributing to the faster charge extraction, longer charge carrier lifetime, and much lower recombination rate. Therefore, compared with BTP‐2F‐2Cl, BTP‐FCl‐FCl based devices provide better performance with FF enhanced from 71.41% to 75.36% and Jsc increased from 22.35 to 24.58 mA cm−2, leading to a higher PCE of 15.3%. The locally asymmetric F, Cl disubstitution on the same end group is a new strategy to achieve high performance ASM OSCs.

Abstract Piezoresponse force microscopy (PFM), as a powerful nanoscale characterization technique, has been extensively utilized to elucidate diverse underlying physics of ferroelectricity. However, intensive studies of conventional PFM have revealed a growing number of concerns and limitations which are largely challenging its validity and applications. In this study, an advanced PFM technique is reported, namely heterodyne megasonic piezoresponse force microscopy (HM‐PFM), which uses 106 to 108 Hz high‐frequency excitation and heterodyne method to measure the piezoelectric strain at nanoscale. It is found that HM‐PFM can unambiguously provide standard ferroelectric domain and hysteresis loop measurements, and an effective domain characterization with excitation frequency up to ≈110 MHz is demonstrated. Most importantly, owing to the high‐frequency and heterodyne scheme, the contributions from both electrostatic force and electrochemical strain can be significantly minimized in HM‐PFM. Furthermore, a special measurement of difference‐frequency piezoresponse frequency spectrum (DFPFS) is developed on HM‐PFM and a distinct DFPFS characteristic is observed on the materials with piezoelectricity. By performing DFPFS measurement, a truly existed but very weak electromechanical coupling in CH3NH3PbI3 perovskite is revealed. It is believed that HM‐PFM can be an excellent candidate for the ferroelectric or piezoelectric studies where conventional PFM results are highly controversial.

Summary: Here we introduce a σ-hole-containing volatile solid additive, 1, 4-diiodotetrafluorobenzene (A3), in PM6:Y6-based OSCs. Aside from the appropriate volatility of A3 additive, the synergetic halogen interactions between A3 and photoactive matrix contribute to more condensed and ordered molecular arrangement in the favorable interpenetrating donor/acceptor domains. As a result, greatly accelerated charge transport process with suppressed charge recombination possibility is observed and ultimately a champion PCE value of 16.5% is achieved. Notably, the A3 treated OSCs can maintain a high efficiency of over 16.0% in a wide concentration range of A3 additive between 10 and 35 mg/mL. The A3-treated device shows excellent stability with an efficiency of 15.9% after 360-h storage. This work demonstrates that the σ-hole interaction can be applied to enhance the OSC performance and highlights the importance of non-covalent interactions in the optoelectronic materials. : Energy Materials; Organic Chemistry; Supramolecular Chemistry Subject Areas: Energy Materials, Organic Chemistry, Supramolecular Chemistry

Abstract Background Short tandem repeats (STRs) are essential genetic markers for forensic applications and population estimations; thus the population genetics of STR loci have been extensively studied and discussed. Methods In the present study, we detected 21 autosomal noncombined DNA index system (non‐CODIS) STR loci in a Chinese Han population from Shanghai, calculated their forensic parameters and analyzed their genetic relationships with reported reference populations in mainland China. Results A total of 173 alleles were observed, with corresponding allele frequencies from 0.0020 to 0.5512. The cumulative power of discrimination (CPD) and the cumulative probability of exclusion (CPE) values of the 21 STR loci were 0.999999999999999999997337058271 and 0.99999953732495, respectively. The results of interpopulation differentiation, phylogenetic, multidimensional scaling, and structure analyses indicated a closer genetic relationship of the studied population with Han populations from other regions of China than with other populations. Conclusions The 21 STR loci exhibited high genetic polymorphism in the studied Shanghai_Han population and could be used for forensic applications and population genetic studies.

Bioelectronics, an emerging discipline formed by the biology and electronic information disciplines, has maintained a state of rapid development since its birth. Amongst the various functional bioelectronics materials, bacteriorhodopsin (bR), with its directional proton pump function and favorable structural stability properties, has drawn wide attention. The main contents of the paper are as follows: Inspired by the capacitive properties of natural protoplast cell membranes, a new bio-capacitor based on bR and artificial nanochannels was constructed. As a point of innovation, microfluidic chips were integrated into our device as an ion transport channel, which made the bio-capacitor more stable. Meanwhile, a single nanopore structure was integrated to improve the accuracy of the device structure. Experiments observed that the size of the nanopore affected the ion transmission rate. Consequently, by making the single nanopore’s size change, the photocurrent duration time (PDT) of bR was effectively regulated. By using this specific phenomenon, the original transient photocurrent was successfully transformed into a square-like wave.

Sucrose transporters (SUTs) play key roles in allocating the translocation of assimilates from source to sink tissues. Although the characteristics and biological roles of SUTs have been intensively investigated in higher plants, this gene family has not been functionally characterized in cotton. In this study, we performed a comprehensive analysis of SUT genes in the tetraploid cotton Gossypium hirsutum. A total of 18 G. hirsutum SUT genes were identified and classified into three groups based on their evolutionary relationships. Up to eight SUT genes in G. hirsutum were placed in the dicot-specific SUT1 group, while four and six SUT genes were, respectively, clustered into SUT4 and SUT2 groups together with members from both dicot and monocot species. The G. hirsutum SUT genes within the same group displayed similar exon/intron characteristics, and homologous genes in G. hirsutum At and Dt subgenomes, G. arboreum, and G. raimondii exhibited one-to-one relationships. Additionally, the duplicated genes in the diploid and polyploid cotton species have evolved through purifying selection, suggesting the strong conservation of SUT loci in these species. Expression analysis in different tissues indicated that SUT genes might play significant roles in cotton fiber elongation. Moreover, analyses of cis-acting regulatory elements in promoter regions and expression profiling under different abiotic stress and exogenous phytohormone treatments implied that SUT genes, especially GhSUT6A/D, might participate in plant responses to diverse abiotic stresses and phytohormones. Our findings provide valuable information for future studies on the evolution and function of SUT genes in cotton.

Cotton is one of the most important economic crops worldwide. As the global demands rising, cotton yield improvement is the most important goal of cotton breeding. Hybrids have great potential for increasing yield, however, the genetic mechanism of hybrids is still not clear. To investigate the genetic basis of cotton hybrids, we resequenced 9053 and sGK9708 with 62.13x coverage depth, the parents of the elite hybrid cotton CCRI63 that has obvious heterosis in lint percentage (LP) and boll weight (BW). Based on the cotton reference genome (TM-1), 1,287,661 single nucleotide polymorphisms (SNPs) and 152,479 insertions/deletions (InDels) were identified in 9053, and 1,482,784 SNPs and 152,985 InDels in sGK9708. Among them, 8649 SNPs and 629 InDels in the gene coding regions showed polymorphism between parents. Moreover, these variations involved 5092 genes, and 3835 of these genes were divided into 10 clusters based on the gene expression profiles. The genes in Cluster 3 and 7 were specifically expressed in the ovule and fiber development stage, suggesting that they might relate to LP and BW. We further co-localized the polymorphic SNPs and InDels with the reported quantitative trait loci (QTLs) of LP and BW, and identified 68 genes containing the polymorphic SNPs or InDels within these QTL intervals and as being related to fiber development. This suggested that the outstanding traits of CCRI63 such as LP and BW might be generated by accumulating the favorable variations from the parents. The results generated herein provide a genetic basis for cotton hybrids and genetic markers for marker-assisted selection breeding of cotton.

The SWEET (sugars will eventually be exported transporters) proteins are sugar efflux transporters containing the MtN3_saliva domain, which affects plant development as well as responses to biotic and abiotic stresses. These proteins have not been functionally characterized in the tetraploid cotton, Gossypium hirsutum, which is a widely cultivated cotton species. In this study, we comprehensively analyzed the cotton SWEET gene family. A total of 55 putative G. hirsutum SWEET genes were identified. The GhSWEET genes were classified into four clades based on a phylogenetic analysis and on the examination of gene structural features. Moreover, chromosomal localization and an analysis of homologous genes in Gossypium arboreum, Gossypium raimondii, and G. hirsutum suggested that a whole-genome duplication, several tandem duplications, and a polyploidy event contributed to the expansion of the cotton SWEET gene family, especially in Clade III and IV. Analyses of cis-acting regulatory elements in the promoter regions, expression profiles, and artificial selection revealed that the GhSWEET genes were likely involved in cotton developmental processes and responses to diverse stresses. These findings may clarify the evolution of G. hirsutum SWEET gene family and may provide a foundation for future functional studies of SWEET proteins regarding cotton development and responses to abiotic stresses.