Hyper-Cross-Linked Resin Modified by a Micropore Polymer for Gas Adsorption and Separation.

Polymerization confined to the pore was first adapted for the nanoscale structure adjustment of adsorption resin. The self-cross-linked polymer (P-1) formed in the pore of hyper-cross-linked resin (HR) by the Friedel-Crafts reaction of p-dichloroxylene (p-DCX), occupying the macropore of the HR resin and bringing about an external micropore. Compared with the raw HR resin, the volume of the micropore of HR@P-1 in 0.4 < D < 1 nm increased but the volume of the macropore has obviously decreased. After the loading of P-1 in the nanopore of HR, HR@P-1 has better gas adsorption performance. At 298 and 100 KPa, the adsorption capacity of CO2 is almost 30% higher than that of HR, reaching 35.7 cm3/g, due to the increase in the smaller micropore volume. Moreover, HR@P-1 has also been found to be the first C2H6-selective adsorption resin. The uptake of C2H6 is up to 56 cm3/g, and the IAST selectivity of C2H6/CH4 reaches 15.3. HR@P-1 can also separate syngas efficiently at ambient temperature and be regenerated by simple vacuum operation.

The glycosylation sites in RBD of spike protein attenuate the immunogenicity of PEDV AH2012/12.

Porcine epidemic diarrhea (PED) is a highly contagious swine intestinal disease caused by PED virus (PEDV). Vaccination is a promising strategy to prevent and control PED. Previous studies have confirmed that glycosylation could regulate the immunogenicity of viral antigens. In this study, we constructed three recombinant PEDVs which removed the glycosylation sites in RBD. Viral infection assays revealed that similar replication characteristics between the recombinant viruses and parental PEDV. Although animal challenging study demonstrated that the glycosylation sites in RBD do not affect the pathogenicity of PEDV, we found that removing the glycosylation sites on the RBD regions could promote the IgG and neutralization titer in vivo, suggesting deglycosylation in RBD could enhance the immunogenicity of PEDV. These findings demonstrated that removal of the glycosylation sites in RBD is a promising method to develop PEDV vaccines.

SISTER OF FCA physically associates with SKB1 to regulate flowering time in Arabidopsis thaliana.

BACKGROUND: Proper flowering time is important for the growth and development of plants, and both too early and too late flowering impose strong negative influences on plant adaptation and seed yield. Thus, it is vitally important to study the mechanism underlying flowering time control in plants. In a previous study by the authors, genome-wide association analysis was used to screen the candidate gene SISTER OF FCA (SSF) that regulates FLOWERING LOCUS C (FLC), a central gene encoding a flowering suppressor in Arabidopsis thaliana. RESULTS: SSF physically interacts with Protein arginine methyltransferase 5 (PRMT5, SKB1). Subcellular co-localization analysis showed that SSF and SKB1 interact in the nucleus. Genetically, SSF and SKB1 exist in the same regulatory pathway that controls FLC expression. Furthermore, RNA-sequencing analysis showed that both SSF and SKB1 regulate certain common pathways. CONCLUSIONS: This study shows that PRMT5 interacts with SSF, thus controlling FLC expression and facilitating flowering time control.

Immunogenicity and protective efficacy of a trimeric full-length S protein subunit vaccine for porcine epidemic diarrhea virus.

Porcine epidemic diarrhea virus (PEDV) has caused serious economic losses to the pig husbandry worldwide, and the effects of existing commercialized vaccines are suboptimal. Therefore, research to develop an efficacious vaccine for prevention and control of PEDV is essential. In this study, we designed and produced trimerized proteins of full-length PEDV spike (S) protein, S1 subunit, and a tandem of multiple epitopes of S protein using an efficient mammalian expression vector system in HEK 293F cells. The immunogenicity of two commercial adjuvants, M401 and M103, was also evaluated in mice. Enzyme-linked immunosorbent assays demonstrated that all immunized mice generated highly systemic PEDV S-specific IgG and IgA antibodies. Mice in S/M103-immunized group generated the highest neutralizing antibody titer with 1:96. Compared with control group, the subunit vaccines elicited multifunctional CD3+CD4+ and CD3+CD8+ T cells, B220+CD19+ B cells, and CD3-CD49b+ natural killer cells in the spleen. PEDV S/M103 vaccine, which had the best immune effect, was selected for further evaluation in piglets. Immunization with S/M103 vaccine induced high levels of S-specific IgG, IgA, and neutralizing antibodies, and increased the proliferation of peripheral blood mononuclear cells and the expression levels of interferon-γ and interleukin-4 in peripheral blood of piglets. Virus challenge test results showed significantly lower diarrheal index scores and fecal viral loads, and less pathological damage to the intestines in S/M103-immunized piglets than in controls, indicating that S/M103 provides good protection against the virulent virus challenge. Our findings suggest that trimeric PEDV S/M103 has potential as a clinical vaccine candidate.

Genetic signatures associated with the virulence of porcine epidemic diarrhea virus AH2012/12.

IMPORTANCE: Porcine epidemic diarrhea (PED) caused by PED virus (PEDV) remains a big threat to the swine industry worldwide. Vaccination with live attenuated vaccine is a promising method to prevent and control PED, because it can elicit a more protective immunity than the killed vaccine, subunit vaccine, and so on. In this study, we found two obvious deletions in the genome of a high passage of AH2012/12. We further confirmed the second deletion which contains seven amino acids at the carboxy-terminus of the S2 gene and the start codon of ORF3 can reduce its pathogenicity in vivo. Animal experiments indicated that the recombinant PEDV with deleted carboxy-terminus of S gene showed higher IgG, IgA, neutralization antibodies, and protection effects against virus challenge than the killed vaccine. These data reveal that the engineering of the carboxy-terminus of the S2 gene may be a promising method to develop live attenuated vaccine candidates of PEDV.

Application of image overlapping in percutaneous nephrolithotomy.

OBJECTIVE: To investigate the application of ultrasound and CT image overlap in percutaneous nephrolithotomy (PCNL). METHODS: A total of 140 patients with complicated kidney stones requiring PCNL were prospectively enrolled, from January 2020 to December 2022. These patients were randomly divided into 2 groups, with 70 patients each in the research group and the control group. All participants underwent dual-source, non-contrast CT scan of both kidneys and pelvis before surgery. Preoperative three-dimensional CT reconstruction and simulated puncture were performed in patients from the research group. The best puncture path was determined through ultrasound and CT image overlap. Puncture guided by regular CT and ultrasound was conducted in patients from the control group. Differences in the surgical outcomes between the two groups were compared. RESULTS: Compared to the control group, the research group had higher stone clearance rate in stage I PCNL, success rate of one-time puncture, less percutaneous channels, less reduction of hemoglobin and shorter procedure time. Complications in stage I PCNL were comparable in the two groups, and there was no significant change in the final stone clearance rates between the two groups. CONCLUSION: An optimal puncture channel can be chosen using ultrasound and CT image overlap. PCNL can be achieved with precise puncturing, thus achieving coincidence between imaging and anatomy and reducing the amount of blood loss during stage I of PCNL. It also shortens the procedure time and improves stone clearance rate of PCNL.

A mulberry 9-cis-epoxycarotenoid dioxygenase gene MaNCED1 is involved in plant growth regulation and confers salt and drought tolerance in transgenic tobacco.

The phytohormone abscisic acid (ABA) is vital in regulating root elongation, seed germination, and abiotic stress responses in plants. Conversely, the mechanisms of ABA in mulberry root growth, seed germination, and abiotic stress responses are poorly understood. Here, we reported that exogenous ABA and drought treatment inhibited the growth of mulberry seedlings but significantly increased the ratio of root/stem. Inhibition of ABA synthesis by fluridone and sodium tungstate resulted in the decrease of root/stem ratio. We also showed that the expression of MaNCED1 in the root was strongly induced by drought and salt stress. Increasing the expression of MaNCED1 in tobacco using overexpression leads to increased root elongation and reduced seed germination. Compared with the wild type, the accumulation of H2O2 and MDA was reduced, while the POD activity and proline content was increased in the transgenic plants after drought and salt treatment. Further studies revealed increased resistance to drought and salt stress in MaNCED1 overexpressed tobaccos. Meanwhile, the auxin and ethylene signal pathway-related gene expression levels increased in MaNCED1 overexpressed tobaccos. This study demonstrated the roles of mulberry MaNCED1 in regulating plant development and abiotic stress responses. It gave further insights into the coordinated regulation of ABA, auxin, and ethylene in seed growth and germination.

The P-body component DECAPPING5 and the floral repressor SISTER OF FCA regulate FLOWERING LOCUS C transcription in Arabidopsis.

Flowering is the transition from vegetative to reproductive growth and is critical for plant adaptation and reproduction. FLOWERING LOCUS C (FLC) plays a central role in flowering time control, and dissecting its regulation mechanism provides essential information for crop improvement. Here, we report that DECAPPING5 (DCP5), a component of processing bodies (P-bodies), regulates FLC transcription and flowering time in Arabidopsis (Arabidopsis thaliana). DCP5 and its interacting partner SISTER OF FCA (SSF) undergo liquid-liquid phase separation (LLPS) that is mediated by their prion-like domains (PrDs). Enhancing or attenuating the LLPS of both proteins using transgenic methods greatly affects their ability to regulate FLC and flowering time. DCP5 regulates FLC transcription by modulating RNA polymerase II enrichment at the FLC locus. DCP5 requires SSF for FLC regulation, and loss of SSF or its PrD disrupts DCP5 function. Our results reveal that DCP5 interacts with SSF, and the nuclear DCP5-SSF complex regulates FLC expression at the transcriptional level.

A First Report of Thyroid pneumatosis as a Complication of Ultrasound-Guided Thyroid Biopsy.

BACKGROUND: Ultrasound-guided needle biopsies, including fine-needle aspirations (FNA) and core needle biopsies (CNB), have become an effective technique in the evaluation of thyroid nodules. In this report, we discuss the first reported case, to our knowledge, of thyroid pneumatosis after ultrasound-guided FNA. CASE PRESENTATION: A 44-year-old woman underwent ultrasound-guided FNA in other hospitals after thyroid ultrasound revealed a solid lesion in the left lobe classified as TI-RADS 4. Two days later, this female presented to our hospital for an excision of a thyroid mass. Pre- and post-contrast CT scans of the thyroid showed extensive accumulation of gas in the thyroid gland and the retropharyngeal and retrotracheal space. A CT scan of the thyroid two days later revealed obvious absorption of thyroid gas and faint low-density nodules in the left lobe of the thyroid. The lesion was histopathologically confirmed as papillary carcinoma of the thyroid. CONCLUSION: We thought the aforementioned issues originating from the limited imaging capacity of ultrasound in the context of thyroid biopsy. To avoid these limitations, we highlight the need to thoroughly examine the location of a lesion prior to thyroid biopsy to understand in detail the relationship between the lesion and the adjacent tissues, especially the proximity of the lesion to the trachea, the occurrence of coughing during a biopsy (indicating puncture of the trachea) is what operators need to be aware of so that they can manage such cases. On the other hand, we recommend that pre-operative use of CT before thyroid biopsy and especially if CT is needed anyway later for nodules evaluation before surgery to ensure the CT image quality.

Correlation between the IgG/IgA Antibody Response against PEDV Structural Protein and Virus Neutralization.

Porcine epidemic diarrhea (PED) is a highly contagious intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV). Large-scale outbreaks of PEDV have caused huge economic losses to the pig industry since 2010. Neutralizing antibodies play a pivotal role in protecting piglets from enteric infections. However, there has been no systematic report on the correlations between neutralizing antibody titers (NTs) and absorbance values of IgG or IgA to all PEDV individual structural proteins in clinical serum, fecal, and colostrum samples. In this study, the spike protein S1 domain (S1), membrane protein (M), envelope protein (E), and nucleocapsid protein (N) of the variant PEDV strain AH2012/12 were expressed and purified by using the human embryonic kidney (HEK) 293F expression system. A total of 92 clinical serum samples, 46 fecal samples, and 33 colostrum samples were collected, and the correlations between IgG or IgA absorbance values and NTs were analyzed. R2 values revealed that anti-S1 IgA absorbance values show the highest agreement with NTs in all serum, fecal, and colostrum samples, followed by the N protein. The correlations between anti-E or M IgA and NTs were very low. However, in the colostrum samples, both IgG and IgA to S1 showed high correlations with NTs. In addition, compared with E and M, the highest correlations of IgA absorbance values were with N and S1 in serum and fecal samples. Overall, this study revealed the highest correlation between NTs and IgA to PEDV S1 protein. Therefore, the diagnostic method with anti-S1 IgA can be used as a powerful tool for assessing the immune status of pigs. IMPORTANCE The humoral immune response plays an important role in virus neutralization. Against PEDV, both IgG and the mucosal immune component IgA play roles in virus neutralization. However, which plays a more prominent role and whether there are differences in different tissue samples are not clearly reported. Additionally, the relationship between IgG and IgA against individual structural proteins and viral neutralization remains unclear. In this study, we systematically determined the relationship between IgG and IgA against all PEDV structural proteins and viral neutralization in different clinical samples and found the highest correlation between neutralization activity and IgA to PEDV S1 protein. Our data have important guiding implications in the evaluation of immune protection.

Structural modification of (3E)-4,8-dimethyl-1,3,7-nontriene enhances its ability to kill Plutella xylostella insect pests.

BACKGROUND: Plant secondary metabolites and their modified derivatives play an important role in the discovery and development of novel insecticides. The natural plant product (3E)-4,8-dimethyl-1,3,7-nontriene (DMNT) has been proven to be able to effectively repel and kill the lepidopteran insect pest Plutella xylostella. RESULTS: In this study, four oxygenated derivatives of DMNT were synthesized by allylic hydroxylation and subsequent etherification or esterification. Bioassays on P. xylostella larvae showed that the compounds DMNT-OCH3 (2), DMNT-OCy (3) and DMNT-OAc (4) were more toxic to the larvae than DMNT alone. The most pronounced effect was observed for compound 2, which showed a 22.23% increase in lethality at a concentration of 0.25 µm. Moreover, the peritrophic matrix (PM) barrier in the insect midgut was more severely damaged by compounds 2, 3 and 4 than by DMNT. The median lethal concentration (LC50 , 48 h) of compounds 2, 3 and 4 on P. xylostella was determined to be 0.98, 1.13 and 1.11 mg mL-1 , respectively, which is much lower than the commercial insecticides eucalyptol (2.89 mg mL-1 ) and thymol (2.45 mg mL-1 ). CONCLUSION: These results suggested that oxygenated DMNT derivatives offer a significantly improved killing effect over DMNT on P. xylostella. This work has provided a basis for further design, structural modification and development of DMNT as botanical insecticides. © 2023 Society of Chemical Industry.

Combining quantitative trait locus mapping with multiomics profiling reveals genetic control of corn leaf aphid (Rhopalosiphum maidis) resistance in maize.

The corn leaf aphid (Rhopalosiphum maidis) is a major maize pest that frequently causes substantial yield losses. Exploring the genetic basis of resistance to aphids is important for improving maize yield and quality. Here, we used a maize recombinant inbred line population derived from two parents with different susceptibility to aphids, B73 (susceptible) and Abe2 (resistant), and performed quantitative trait locus (QTL) mapping using aphid resistance scores as an indicator. We mapped a stable QTL, qRTA6, to chromosome 6 using data from 2 years of field trials, which explained 40.12-55.17% of the phenotypic variation. To further investigate the mechanism of aphid resistance in Abe2, we constructed transcriptome and metabolome libraries from Abe2 and B73 leaves with or without aphid infestation at different time points. Integrating QTL mapping and transcriptome data revealed three aphid resistance candidate genes (Zm00001d035736, Zm00001d035751, and Zm00001d035767) associated with the hypersensitive response, the jasmonic acid pathway, and protein ubiquitination. Integrated transcriptomic and metabolomic analysis revealed that the differentially expressed genes and metabolites were enriched in flavonoid biosynthesis. These findings extend our understanding of the molecular mechanisms controlling aphid resistance in maize, and the QTL and candidate genes are valuable resources for increasing this resistance.

Inactivation of RPX1 in Arabidopsis confers resistance to Plutella xylostella through the accumulation of the homoterpene DMNT.

The lepidopteran crop pest Plutella xylostella causes severe constraints on Brassica cultivation. Here, we report a novel role for RPX1 (resistance to P. xylostella) in resistance to this pest in Arabidopsis thaliana. The rpx1-1 mutant repels P. xylostella larvae, and feeding on the rpx1-1 mutant severely damages the peritrophic matrix structure in the midgut of the larvae, thereby negatively affecting larval growth and pupation. This resistance results from the accumulation of defence compounds, including the homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), due to the upregulation of PENTACYCLIC TRITERPENE SYNTHASE 1 (PEN1), which encodes a key DMNT biosynthetic enzyme. P. xylostella infestation and wounding induce RPX1 protein degradation, which may confer a rapid response to insect infestation. RPX1 inactivation and PEN1 overexpression are not associated with negative trade-offs for plant growth but have much higher seed production than the wild-type in the presence of P. xylostella infestation. This study offers a new strategy for plant molecular breeding against P. xylostella.

Linkage mapping combined with GWAS revealed the genetic structural relationship and candidate genes of maize flowering time-related traits.

BACKGROUND: Flowering time is an important agronomic trait of crops and significantly affects plant adaptation and seed production. Flowering time varies greatly among maize (Zea mays) inbred lines, but the genetic basis of this variation is not well understood. Here, we report the comprehensive genetic architecture of six flowering time-related traits using a recombinant inbred line (RIL) population obtained from a cross between two maize genotypes, B73 and Abe2, and combined with genome-wide association studies to identify candidate genes that affect flowering time. RESULTS: Our results indicate that these six traits showed extensive phenotypic variation and high heritability in the RIL population. The flowering time of this RIL population showed little correlation with the leaf number under different environmental conditions. A genetic linkage map was constructed by 10,114 polymorphic markers covering the whole maize genome, which was applied to QTL mapping for these traits, and identified a total of 82 QTLs that contain 13 flowering genes. Furthermore, a combined genome-wide association study and linkage mapping analysis revealed 17 new candidate genes associated with flowering time. CONCLUSIONS: In the present study, by using genetic mapping and GWAS approaches with the RIL population, we revealed a list of genomic regions and candidate genes that were significantly associated with flowering time. This work provides an important resource for the breeding of flowering time traits in maize.

Preference Test of Plutella xylostella Larvae upon DMNT Treatment.

We describe a method to test the preference of insects in response to (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT). We use a device that includes a horizontal glass tube, two grooves (with activated carbon), air flow, rubber stoppers/tubes, transparent glass containers (optional), and a holder for the glass tube (optional). Equal amounts of activated carbon in the groove (removable) are placed at both ends to avoid air contamination. The air flow is generated by an air pump. In the closed device, different samples are placed at each end of the glass tube. The air pump at the top of the glass tube forms an air flow that converges to the middle site of the glass tube. In each test, insect larvae are located in the middle of the glass test tube. If the test samples release DMNT that can be sensed by insects, the insects will selectively move to one specific end of the glass tube. The number of insects that move to each end will be recorded for further studies. This method can also be used to test the preference of insects in response to other volatile compounds.

SRT1720 enhances maturity and quality of oocytes in aged mice.

This study aims to investigate the morphology and distribution of mitochondria, spindles, and chromosomes in oocytes of aged mice and examine the effects of SRT1720 on oocyte maturation. C57BL/6J mice were divided into young (4-8 weeks) and aged groups (48-52 weeks). In vitro maturation media contained (0.05, 0.1, and 1.0 µM) SRT1720 and 0.1-µM dimethyl sulfoxide (DMSO control). The rate of chromosome misalignment and spindle misorientation in oocytes of aged mice were significantly higher than that of young mice (P < 0.01). Fluorescence intensity of mitochondria from oocytes of aged mice was significantly lower than that of young mice (P < 0.01). SRT1720 at 0.1 µM significantly improved oocyte maturation, fertilization, and blastocyst formation in aged mice compared with young mice (P < 0.01). Additionally, immunofluorescence intensity of mitochondria, normal spindle morphology, and chromosome alignment were notably enhanced with SRT1720 when compared with the DSMO control group for metaphase II (MII)-stage oocytes matured in vitro (P < 0.01); 0.1-µM SRT1720 enhanced the expression level of SRIT1 in oocytes from aged mice. In summary, the aged mice oocytes showed increased nuclear and cytoplasmic defects, whereas SRT1720 enhanced oocyte maturation and quality. We concluded that 0.1-µM SRT1720 was an appropriate concentration for in vitro maturation media.

[Retracted] miR­22 inhibits proliferation and invasion in estrogen receptor α­positive endometrial endometrioid carcinomas cells.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the cell­cycle data shown in Fig. 4A and Transwell cell migration data shown in Fig. 5A were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 9: 2393­2399, 2014; DOI: 10.3892/mmr.2014.2123].

Retroperitoneal dendritic cell sarcoma: A case report.

RATIOANLE: Interdigitating dendritic cell sarcoma (IDCS) is a rare sarcoma that originates from interdigitating dendritic cells in lymphoid tissue, the imaging characteristics of which are poorly defined. Pathological examination can identify the tumor, but reports on the imaging characteristics of IDCS are limited. PATIENT CONCERNS: Here, we report a case of IDCS in a 48-year-old female involving the retroperitoneal area. The patient had a lumbar mass on her right lower back for 4 years, and which started increasing in size 1 year before. DIAGNOSES: An irregular soft tissue mass (10.1cm × 8.5 cm in size) in the right lower back of retroperitoneum was detected by CT examination with unclear borders, uneven density, and necrosis. The solid components of the mass were significantly enhanced on postcontrast imaging. The soft tissue was irregular and uneven. Cystic solid masses were observed on MRI examination in the right retroperitoneum, lateral abdominal wall, waist, and back. Necrosis, hemorrhage, and cystic transformation were observed inside the lesion. The cyst wall, separation, and wall nodules were significantly enhanced on the postcontrast image. No distant metastasis was observed. Postoperative pathology confirmed the diagnosis of IDCS. INTERVENTIONS: The patient underwent surgical resection. The resected margin was positive, and the patient received adjuvant radiotherapy 2 months after the surgery. OUTCOMES: Twelve months after radiotherapy, the patient's chest CT showed multiple metastases in both lungs. The patient was started on combination chemotherapy of doxorubicin and ifosfamide, and the follow-up is still ongoing. LESSONS: Imaging provides a unique advantage to determine the extent of the IDCS, the invasion of adjacent tissues, and the presence or absence of distant metastases.

Volatile DMNT directly protects plants against Plutella xylostella by disrupting the peritrophic matrix barrier in insect midgut.

Insect pests negatively affect crop quality and yield; identifying new methods to protect crops against insects therefore has important agricultural applications. Our analysis of transgenic Arabidopsis thaliana plants showed that overexpression of pentacyclic triterpene synthase 1, encoding the key biosynthetic enzyme for the natural plant product (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), led to a significant resistance against a major insect pest, Plutella xylostella. DMNT treatment severely damaged the peritrophic matrix (PM), a physical barrier isolating food and pathogens from the midgut wall cells. DMNT repressed the expression of PxMucin in midgut cells, and knocking down PxMucin resulted in PM rupture and P. xylostella death. A 16S RNA survey revealed that DMNT significantly disrupted midgut microbiota populations and that midgut microbes were essential for DMNT-induced killing. Therefore, we propose that the midgut microbiota assists DMNT in killing P. xylostella. These findings may provide a novel approach for plant protection against P. xylostella.

Molecular variation in a functionally divergent homolog of FCA regulates flowering time in Arabidopsis thaliana.

The identification and functional characterization of natural variants in plants are essential for understanding phenotypic adaptation. Here we identify a molecular variation in At2g47310 that contributes to the natural variation in flowering time in Arabidopsis thaliana accessions. This gene, which we term SISTER of FCA (SSF), functions in an antagonistic manner to its close homolog FCA. Genome-wide association analysis screens two major haplotypes of SSF associated with the natural variation in FLC expression, and a single polymorphism, SSF-N414D, is identified as a main contributor. The SSF414N protein variant interacts more strongly with CUL1, a component of the E3 ubiquitination complex, than the SSF414D form, mediating differences in SSF protein degradation and FLC expression. FCA and SSF appear to have arisen through gene duplication after dicot-monocot divergence, with the SSF-N414D polymorphism emerging relatively recently within A. thaliana. This work provides a good example for deciphering the functional importance of natural polymorphisms in different organisms.