FIGL1 prevents aberrant chromosome associations and fragmentation and limits crossovers in polyploid wheat meiosis.

Meiotic crossovers (COs) generate genetic diversity and are crucial for viable gamete production. Plant COs are typically limited to 1-3 per chromosome pair, constraining the development of improved varieties, which in wheat is exacerbated by an extreme distal localisation bias. Advances in wheat genomics and related technologies provide new opportunities to investigate, and possibly modify, recombination in this important crop species. Here, we investigate the disruption of FIGL1 in tetraploid and hexaploid wheat as a potential strategy for modifying CO frequency/position. We analysed figl1 mutants and virus-induced gene silencing lines cytogenetically. Genetic mapping was performed in the hexaploid. FIGL1 prevents abnormal meiotic chromosome associations/fragmentation in both ploidies. It suppresses class II COs in the tetraploid such that CO/chiasma frequency increased 2.1-fold in a figl1 msh5 quadruple mutant compared with a msh5 double mutant. It does not appear to affect class I COs based on HEI10 foci counts in a hexaploid figl1 triple mutant. Genetic mapping in the triple mutant suggested no significant overall increase in total recombination across examined intervals but revealed large increases in specific individual intervals. Notably, the tetraploid figl1 double mutant was sterile but the hexaploid triple mutant was moderately fertile, indicating potential utility for wheat breeding.

A horizon scan of global biological conservation issues for 2024.

We present the results of our 15th horizon scan of novel issues that could influence biological conservation in the future. From an initial list of 96 issues, our international panel of scientists and practitioners identified 15 that we consider important for societies worldwide to track and potentially respond to. Issues are novel within conservation or represent a substantial positive or negative step-change with global or regional extents. For example, new sources of hydrogen fuel and changes in deep-sea currents may have profound impacts on marine and terrestrial ecosystems. Technological advances that may be positive include benchtop DNA printers and the industrialisation of approaches that can create high-protein food from air, potentially reducing the pressure on land for food production.

MSH2 stimulates interfering and inhibits non-interfering crossovers in response to genetic polymorphism.

Meiotic crossovers can be formed through the interfering pathway, in which one crossover prevents another from forming nearby, or by an independent non-interfering pathway. In Arabidopsis, local sequence polymorphism between homologs can stimulate interfering crossovers in a MSH2-dependent manner. To understand how MSH2 regulates crossovers formed by the two pathways, we combined Arabidopsis mutants that elevate non-interfering crossovers with msh2 mutants. We demonstrate that MSH2 blocks non-interfering crossovers at polymorphic loci, which is the opposite effect to interfering crossovers. We also observe MSH2-independent crossover inhibition at highly polymorphic sites. We measure recombination along the chromosome arms in lines differing in patterns of heterozygosity and observe a MSH2-dependent crossover increase at the boundaries between heterozygous and homozygous regions. Here, we show that MSH2 is a master regulator of meiotic DSB repair in Arabidopsis, with antagonistic effects on interfering and non-interfering crossovers, which shapes the crossover landscape in relation to interhomolog polymorphism.

ASYNAPSIS 1 ensures crossover fidelity in polyploid wheat by promoting homologous recombination and suppressing non-homologous recombination.

During meiosis, the chromosome axes and synaptonemal complex mediate chromosome pairing and homologous recombination to maintain genomic stability and accurate chromosome segregation. In plants, ASYNAPSIS 1 (ASY1) is a key component of the chromosome axis that promotes inter-homolog recombination, synapsis and crossover formation. Here, the function of ASY1 has been cytologically characterized in a series of hypomorphic wheat mutants. In tetraploid wheat, asy1 hypomorphic mutants experience a reduction in chiasmata (crossovers) in a dosage-specific manner, resulting in failure to maintain crossover (CO) assurance. In mutants with only one functional copy of ASY1, distal chiasmata are maintained at the expense of proximal and interstitial chiasmata, indicating that ASY1 is required to promote chiasma formation away from the chromosome ends. Meiotic prophase I progression is delayed in asy1 hypomorphic mutants and is arrested in asy1 null mutants. In both tetraploid and hexaploid wheat, single asy1 mutants exhibit a high degree of ectopic recombination between multiple chromosomes at metaphase I. To explore the nature of the ectopic recombination, Triticum turgidum asy1b-2 was crossed with wheat-wild relative Aegilops variabilis. Homoeologous chiasmata increased 3.75-fold in Ttasy1b-2/Ae. variabilis compared to wild type/Ae. variabilis, indicating that ASY1 suppresses chiasma formation between divergent, but related chromosomes. These data suggest that ASY1 promotes recombination along the chromosome arms of homologous chromosomes whilst suppressing recombination between non-homologous chromosomes. Therefore, asy1 mutants could be utilized to increase recombination between wheat wild relatives and elite varieties for expediting introgression of important agronomic traits.

Spring arrival of the common cuckoo at breeding grounds is strongly determined by environmental conditions in tropical Africa.

Failure to adapt migration timing to changes in environmental conditions along migration routes and at breeding locations can result in mismatches across trophic levels, as occurs between the brood parasitic common cuckoo Cuculus canorus and its hosts. Using satellite tracking data from 87 male cuckoos across 11 years, we evaluate why the cuckoo has not advanced its arrival to the UK. Across years, breeding ground arrival was primarily determined by timing of departure from stopover in West Africa before northward crossing of the Sahara. Together with high population synchrony and low apparent endogenous control of this event, this suggests that a seasonal ecological constraint operating here limits overall variation in breeding grounds arrival, although this event was itself influenced by carry-over from timing of arrival into tropical Africa. Between-year variation within individuals was, in contrast, mostly determined by northward migration through Europe, probably due to weather conditions. We find evidence of increased mortality risk for (a) early birds following migration periods positively impacting breeding grounds arrival, and (b) late birds, possibly suffering energy limitation, after departure from the breeding grounds. These results help identify areas where demands of responding to global change can potentially be alleviated by improving stopover quality.

Landscape fires disproportionally affect high conservation value temperate peatlands, meadows, and deciduous forests, but only under low moisture conditions.

Landscape fires are a natural component of the Earth System. However, they are of growing global concern due to climate change exacerbating their multiple impacts on biodiversity, ecosystems, carbon storage, human health, economies, and wider society. Temperate regions are predicted to be at greatest risk of increasing fire activity due to climate change, where fires can seriously impact important ecosystems for biodiversity and carbon storage, such as peatlands and forests. There is insufficient literature on the background prevalence, distribution, and drivers of fires in these regions, especially within Europe, to assess and mitigate their risks. Using a global database of fire patches based on the MODIS FireCCI51 product, we address this knowledge gap by quantifying the current prevalence and size of fires in Polesia, a 150,000 km2 area comprising a mosaic of peatland, forest, and agricultural habitats in northern Ukraine and southern Belarus. Between 2001 and 2019, fires burned 31,062 km2 of land, and were most frequent in spring and autumn. Although most fires started in agricultural land, fires disproportionately affected natural and semi-natural land cover types, particularly in protected areas. Over one fifth of protected land burned. Coniferous forests were the most common land cover type in protected areas, but fires mostly occurred in meadows, open peatlands (especially fen and transition mires), and native deciduous forests. These land cover types were highly susceptible to fires under low soil moisture conditions, but the risk of fire was low under average or higher soil moisture conditions. Restoring and maintaining natural hydrological regimes could be an effective nature-based solution to increase the resilience of fire-vulnerable ecosystems and support global biodiversity and carbon storage commitments under the United Nations Framework Conventions on Climate Change and Convention on Biological Diversity.

Collation of a century of soil invertebrate abundance data suggests long-term declines in earthworms but not tipulids.

Large-scale declines in terrestrial insects have been reported over much of Europe and across the world, however, population change assessments of other key invertebrate groups, such as soil invertebrates, have been largely neglected through a lack of available monitoring data. This study collates historic data from previously published studies to assess whether it is possible to infer previously undocumented long-term changes in soil invertebrate abundance. Earthworm and tipulid data were collated from over 100 studies across the UK, spanning almost 100 years. Analyses suggested long-term declines in earthworm abundance of between 1.6 to 2.1% per annum, equivalent to a 33% to 41% decline over 25 years. These appeared greatest in broadleaved woodlands and farmland habitats, and were greater in pasture than arable farmland. Significant differences in earthworm abundance between habitats varied between models but appeared to be highest in urban greenspaces and agricultural pasture. More limited data were available on tipulid abundance, which showed no significant change over time or variation between enclosed farmland and unenclosed habitats. Declines in earthworm populations could be contributing to overall declines in ecosystem function and biodiversity as they are vital for a range of ecosystem services and are keystone prey for many vertebrate species. If robust, our results identify a previously undetected biodiversity decline that would be a significant conservation and economic issue in the UK, and if replicated elsewhere, internationally. We highlight the need for long-term and large-scale soil invertebrate monitoring, which potentially could be carried out by citizen/community scientists.

Use of an Artificial Intelligence Conversational Agent (Chatbot) for Hip Arthroscopy Patients Following Surgery.

Purpose: The purpose of this study was to evaluate the use of an AI conversational agent during the postoperative recovery of patients undergoing elective hip arthroscopy. Methods: Patients undergoing hip arthroscopy were enrolled in a prospective cohort for their first 6 weeks following surgery. Patients used standard SMS text messaging to interact with an artificial intelligence (AI) chatbot ("Felix") used to initiate automated conversations regarding elements of postoperative recovery. Patient satisfaction was measured at 6 weeks after surgery using a Likert scale survey. Accuracy was determined by measuring the appropriateness of chatbot responses, topic recognition, and examples of confusion. Safety was measured by evaluating the chatbot's responses to any questions with potential medical urgency. Results: Twenty-six patients were enrolled with a mean age of 36 years, and 58% (n = 15) were male. Overall, 80% of patients (n = 20) rated the helpfulness of Felix as good or excellent. In the postoperative period, 12/25 (48%) patients reported being worried about a complication but were reassured by Felix and, thus, did not seek medical attention. Of a total of 128 independent patient questions, Felix handled 101/128 questions appropriately (79%), either by addressing them independently, or facilitating contact with the care team. Felix was able to adequately answer the patient question independently 31% of the time (n = 40/128). Of 10 patient questions that were thought to potentially represent patient complications, in 3 cases Felix did not adequately address or recognize the health concern-none of these situations resulted in patient harm. Conclusion: The results of this study demonstrate that the use of a chatbot or conversational agent can enhance the postoperative experience for hip arthroscopy patients, as demonstrated by high levels of patient satisfaction. Levels of Evidence: Level IV, therapeutic case series.

Use of Treatments after Recovery from Thumb Carpometacarpal Arthritis Surgery.

BACKGROUND: Which treatments patients continue to use more than 1 year after primary thumb carpometacarpal arthritis surgery, and how such use relates to patient-reported outcomes, is largely unknown. METHODS: The authors identified patients who had isolated primary trapeziectomy alone or with ligament reconstruction ± tendon interposition and were 1 to 4 years postoperative. Participants completed a surgical site-focused electronic questionnaire about what treatments they still used. Patient-reported outcome measures were the Quick Disability of the Arm, Shoulder, and Hand questionnaire and visual analog/numerical rating scales for current pain, pain with activities, and typical worst pain. RESULTS: A total of 112 patients met inclusion and exclusion criteria and participated. At a median of 3 years after surgery, over 40% reported current use of at least one treatment for their thumb carpometacarpal surgical site, with 22% using more than one treatment. Of those who still used treatments, 48% used over-the-counter medications, 34% used home or office-based hand therapy, 29% used splinting, 25% used prescription medications, and 4% used corticosteroid injections. A total of 108 participants completed all patient-reported outcome measures. With bivariate analyses, the authors found that use of any treatment after recovering from surgery was associated with statistically and clinically significantly worse scores for all measures. CONCLUSIONS: Clinically relevant proportions of patients continue to use various treatments a median of 3 years after primary thumb carpometacarpal arthritis surgery. Continued use of any treatment is associated with significantly worse patient-reported outcomes for function and pain.

Treatment-induced neural reorganization in aphasia is language-domain specific: Evidence from a large-scale fMRI study.

Studies investigating the effects of language intervention on the re-organization of language networks in chronic aphasia have resulted in mixed findings, likely related to-among other factors-the language function targeted during treatment. The present study investigated the effects of the type of treatment provided on neural reorganization. Seventy individuals with chronic stroke-induced aphasia, recruited from three research laboratories and meeting criteria for agrammatism, anomia or dysgraphia were assigned to either treatment (N = 51) or control (N = 19) groups. Participants in the treatment group received 12-weeks of language intervention targeting sentence comprehension/production, naming, or spelling. At baseline and post-testing, all participants performed an fMRI story comprehension task, with blocks of auditorily-presented stories alternated with blocks of reversed speech. Participants in the treatment, but not control, group significantly improved in the treated language domain. FMRI region-of-interest (ROI) analyses, conducted within regions that were either active (or homologous to active) regions in a group of 22 healthy participants on the story comprehension task, revealed a significant increase in activation from pre-to post-treatment in right-hemisphere homologues of these regions for participants in the sentence and spelling, but not naming, treatment groups, not predicted by left-hemisphere lesion size. For the sentence (but not the spelling) treatment group, activation changes within right-hemisphere homologues of language regions were positively associated with changes in measures of verb and sentence comprehension. These findings support previous research pointing to recruitment of right hemisphere tissue as a viable route for language recovery and suggest that sentence-level treatment may promote greater neuroplasticity on naturalistic, language comprehension tasks, compared to word-level treatment.

The coordinated regulation of early meiotic stages is dominated by non-coding RNAs and stage-specific transcription in wheat.

Reproductive success hinges on precisely coordinated meiosis, yet our understanding of how structural rearrangements of chromatin and phase transitions during meiosis are transcriptionally regulated is limited. In crop plants, detailed analysis of the meiotic transcriptome could identify regulatory genes and epigenetic regulators that can be targeted to increase recombination rates and broaden genetic variation, as well as provide a resource for comparison among eukaryotes of different taxa to answer outstanding questions about meiosis. We conducted a meiotic stage-specific analysis of messenger RNA (mRNA), small non-coding RNA (sncRNA), and long intervening/intergenic non-coding RNA (lincRNA) in wheat (Triticum aestivum L.) and revealed novel mechanisms of meiotic transcriptional regulation and meiosis-specific transcripts. Amidst general repression of mRNA expression, significant enrichment of ncRNAs was identified during prophase I relative to vegetative cells. The core meiotic transcriptome was comprised of 9309 meiosis-specific transcripts, 48 134 previously unannotated meiotic transcripts, and many known and novel ncRNAs differentially expressed at specific stages. The abundant meiotic sncRNAs controlled the reprogramming of central metabolic pathways by targeting genes involved in photosynthesis, glycolysis, hormone biosynthesis, and cellular homeostasis, and lincRNAs enhanced the expression of nearby genes. Alternative splicing was not evident in this polyploid species, but isoforms were switched at phase transitions. The novel, stage-specific regulatory controls uncovered here challenge the conventional understanding of this crucial biological process and provide a new resource of requisite knowledge for those aiming to directly modulate meiosis to improve crop plants. The wheat meiosis transcriptome dataset can be queried for genes of interest using an eFP browser located at https://bar.utoronto.ca/efp_wheat/cgi-bin/efpWeb.cgi?dataSource=Wheat_Meiosis.

Identification, characterization, and rescue of CRISPR/Cas9 generated wheat SPO11-1 mutants.

Increasing crop yields through plant breeding is time consuming and laborious, with the generation of novel combinations of alleles being limited by chromosomal linkage blocks and linkage-drag. Meiotic recombination is essential to create novel genetic variation via the reshuffling of parental alleles. The exchange of genetic information between homologous chromosomes occurs at crossover (CO) sites but CO frequency is often low and unevenly distributed. This bias creates the problem of linkage-drag in recombination 'cold' regions, where undesirable variation remains linked to useful traits. In plants, programmed meiosis-specific DNA double-strand breaks, catalysed by the SPO11 complex, initiate the recombination pathway, although only ~5% result in the formation of COs. To study the role of SPO11-1 in wheat meiosis, and as a prelude to manipulation, we used CRISPR/Cas9 to generate edits in all three SPO11-1 homoeologues of hexaploid wheat. Characterization of progeny lines shows plants deficient in all six SPO11-1 copies fail to undergo chromosome synapsis, lack COs and are sterile. In contrast, lines carrying a single copy of any one of the three wild-type homoeologues are phenotypically indistinguishable from unedited plants both in terms of vegetative growth and fertility. However, cytogenetic analysis of the edited plants suggests that homoeologues differ in their ability to generate COs and in the dynamics of synapsis. In addition, we show that the transformation of wheat mutants carrying six edited copies of SPO11-1 with the TaSPO11-1B gene, restores synapsis, CO formation, and fertility and hence opens a route to modifying recombination in this agronomically important crop.

A global biological conservation horizon scan of issues for 2023.

We present the results of our 14th horizon scan of issues we expect to influence biological conservation in the future. From an initial set of 102 topics, our global panel of 30 scientists and practitioners identified 15 issues we consider most urgent for societies worldwide to address. Issues are novel within biological conservation or represent a substantial positive or negative step change at global or regional scales. Issues such as submerged artificial light fisheries and accelerating upper ocean currents could have profound negative impacts on marine or coastal ecosystems. We also identified potentially positive technological advances, including energy production and storage, improved fertilisation methods, and expansion of biodegradable materials. If effectively managed, these technologies could realise future benefits for biological diversity.

Lateral Femoral Trochlea Flap Reconstruction of the Proximal Capitate: An Assessment of Congruity and Description of Technique.

PURPOSE: We examined morphologic similarities of the medial lateral femoral trochlea (MFT) and lateral femoral trochlea (LFT) osteochondral flaps for reconstruction of the proximal capitate. METHODS: Magnetic resonance imaging scans of the wrists and ipsilateral knees of 10 young healthy volunteers were obtained. Three morphologic parameters were investigated, comparing the MFT and LFT harvest sites to the capitate proximal pole. The correspondingly relevant surgical planes were compared. The coronal plane radius of curvature (ROC) of the capitate was compared with the sagittal planes of the MFT and LFT. The sagittal plane ROC of the capitate was compared to the axial planes of the MFT and LFT. The angular relationship between the dorsal cortical surface of the capitate and the proximal pole cartilage (proximal dorsal capitate pitch) was compared to the corresponding angles between the cortical bone and convex cartilage on the LFT and MFT. RESULTS: The average ratios of ROC for the coronal planes of the capitate to the MFT (0.61) and LFT (0.58) were similar. The average ratios of ROC for the sagittal planes of the capitate to the MFT (0.57) and LFT (0.86) were also similar. The proximal dorsal capitate pitch demonstrated greater similarity to the corresponding shape of the LFT (angular ratio, 1.01) than to that of the MFT (angular ratio, 0.74). CONCLUSIONS: The LFT and MFT demonstrate similar congruity to the proximal capitate in the sagittal and coronal planes of the wrist. The LFT dorsal pitch closely approximates the relationship of the proximal capitate pole to its dorsal cortical surface. CLINICAL RELEVANCE: In capitate fracture, fracture nonunion, or avascular necrosis, both the MFT and LFT demonstrate similarity to the proximal convex capitate morphology. The relationship between the cortical and chondral surfaces of the LFT is morphologically very similar to that of the proximal capitate.

Patient-Reported Lower Extremity Outcomes Following Fibula or Medial Femoral Condyle Free Flaps for Upper Extremity Defects.

BACKGROUND: Free fibula flap (FFF) and medial femoral condyle (MFC) flap are commonly used for upper extremity osseous reconstruction, yet donor-site morbidity has never been systematically compared. METHODS: Patients who underwent an FFF or MFC for upper extremity extra-carpal osseous reconstruction at 3 academic hand centers were retrospectively identified. Only patients who underwent reconstruction for a defect in which either flap type is routinely used or has been described in the literature were deemed eligible. Patients who agreed to participate were asked to complete the Lower Extremity Functional Scale (LEFS) and Lower Limb Core Scale (LLCS). The reported population norm median score of LEFS is 77 points. The LLCS population norm mean score is 90.52 points. RESULTS: Twenty-one patients (10 MFC, 11 FFF) were enrolled. The median LEFS score for patients after MFC was 76 (interquartile range [IQR], 49-80) points and 75 (IQR, 56-79) points after FFF. The median LLCS score for patients after MFC was 96.4 (IQR, 87.9-100) points and 100 (IQR, 91-100) points after FFF. Median LEFS scores were slightly below the population norm, whereas median LLCS scores were above the norm for both FFF and MFC. All patients stated they would have the surgery again and that any dysfunction or pain in the leg was justified by the benefit in the arm. CONCLUSIONS: When considering whether to use an MFC or FFF for upper extremity reconstruction, both flap types appear to result in modest and comparable donor-site morbidity.

Magnetic Resonance Imaging to Investigate the Clinical Applicability of the Medial Femoral Trochlea Osteochondral Flap Within the Wrist.

BACKGROUND: The medial femoral trochlea (MFT) osteochondral flap is employed for reconstruction of unsalvageable scaphoid proximal pole nonunions. The convex surface of the cartilage-bearing proximal trochlea is used to replace the similarly contoured proximal scaphoid and articulate with the concave scaphoid fossa of the radius. A magnetic resonance imaging (MRI) comparison of the shape of the MFT as it relates to the native proximal scaphoid has not been previously performed. Our study aimed to quantifiably compare the shape of the MFT, proximal scaphoid, and scaphoid fossa. METHODS: Using imaging processing software, we measured radius of curvature of the articular segments in MRI scans of 10 healthy subjects' wrists and knees. RESULTS: Compared with the scaphoid fossa, average ratio of the radius of circumference of the proximal scaphoid was 0.79 and 0.78 in the coronal and sagittal planes, respectively. Compared with the scaphoid fossa, average ratio of the radius of circumference of the MFT was 0.98 and 1.31 in the coronal and sagittal planes, respectively. The radius of curvature of the MFT was larger than the proximal scaphoid, in the coronal and sagittal planes. In the coronal plane, the MFT radius of curvature is nearly identical to the scaphoid fossa, a closer match than the scaphoid itself. In the sagittal plane, the radius of curvature of the MFT was larger than the radius of curvature of the scaphoid fossa. CONCLUSIONS: Our data suggest that the radius of curvature, in the sagittal and coronal planes, of the MFT and proximal scaphoid is disparate.

Arterial Perfusion of the Proximal Phalanx Revisited: New Insights Based on Micro-Computed Tomography.

PURPOSE: To characterize the periosteal and endosteal arterial perfusion of the proximal phalanx using micro-computed tomography angiography (micro-CTA). METHODS: Cadaveric upper extremities were injected with a barium sulfate/gelatin suspension. Phalanges were imaged using micro-CTA and analyzed with a focus on osseous arterial anatomy. Periosteal and endosteal perfusion was characterized by number of vessels, length, anatomic course, and caliber. RESULTS: The base of the proximal phalanx had a significantly greater number (8.0 ± 3.5) of periosteal vessels than those of the shaft (4.1 ± 1.6) and head (1.3 ± 1.1). One-third (34.4%) of the specimens demonstrated a complete absence of periosteal vessels in the head. A nutrient endosteal vessel was noted in 100% of the specimens. Entering at the junction of the middle and distal third of the bone (25.8 ± 3.9 mm from base), the nutrient vessel entered the proximal phalanx of the index finger along its ulnar aspect (8 of 8 specimens), the middle finger along its radial aspect (6 of 8), the ring finger along its ulnar aspect (5 of 8), and the little finger along its radial aspect (7 of 8). The nutrient vessel branched into proximal and distal extensions toward the shaft and head, respectively, with an average endosteal length of 10.7 ± 5.2 mm and average diameter of 0.36 ± 0.11 mm. CONCLUSIONS: Periosteal contributions to the perfusion of the proximal phalanx appear to diminish distally. The endosteal arterial anatomy remains consistent, with a single nutrient vessel entering the intramedullary canal with reliable laterality on each digit. This is often the only vessel supplying the head of the proximal phalanx, making this area particularly susceptible to vascular compromise. CLINICAL RELEVANCE: An understanding of the patterns of perfusion of the proximal phalanx provides some insight into clinically observed pathology, as well as guidance for operative management.

Lateral Femoral Trochlea Osteochondral Flap Reconstruction of Proximal Pole Scaphoid Nonunions.

PURPOSE: The medial femoral trochlea flap has been described as a method of scaphoid proximal pole nonunion reconstruction when the proximal pole is deemed nonsalvageable. The lateral femoral trochlea (LFT) is an alternative donor site providing a comparable vascularized convex osteochondral flap. We describe the technique and outcomes of our first 17 cases of LFT flap reconstruction of the proximal scaphoid pole with a minimum follow-up of 14 months. METHODS: Seventeen of the first 24 patients who underwent LFT scaphoid reconstruction at 3 institutions were able to be contacted for clinical follow-up and chart reviews. We recorded patient age and sex, duration of nonunion, number of previous surgical procedures, details of surgical technique, achievement of osseous union, complications, additional postoperative procedures, preoperative and postoperative pain, and range of motion. Preoperative and postoperative scapholunate and radiolunate angles were analyzed on x-rays and achievement of osseous union on computerized tomography scans. RESULTS: The average age of patients included was 35 years (range, 16-55 years). Follow-up data were recorded at an average of 33 months (range, 14-62 months). Ten patients had previous procedures (average, 1; range, 0-2). Median duration from trauma to LFT was 3.4 years (range, 8 months-12 years) among patients who had a recognized date of injury. Osseous healing was achieved in 16 of 17 patients and confirmed by computerized tomograpy scan. Twelve patients reported complete pain relief, while 5 reported partial pain relief. Final postoperative range of motion was 59°extension (range, 30°-85°) and 50° flexion (range, 10°-80°), which was comparable to preoperative values. Preoperative (59°) and postoperative (55°) scapholunate angles were similar to normal wrists. CONCLUSION: Vascularized LFT flaps provide an alternative donor site for vascularized osteochondral reconstruction of proximal pole scaphoid nonunion. Rate of union, range of motion, and pain relief are similar to reported results with medial femoral trochlea flap reconstruction. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

An Algorithmic Approach to the Treatment of Kienböck Disease.

The algorithm and rationale described is a reflection of our own surgical experience for this challenging disorder and can be compared with other publications. Our algorithm has evolved from treatment of a large volume of patients with Kienböck disease in a referral practice. However, it is limited to the management that we have found logical, effective, and within our scope of experience. The treatment guidelines for our specialty as a whole will evolve as our understanding of the etiology and our ability to quantify efficacy improves.

Unravelling mechanisms that govern meiotic crossover formation in wheat.

Wheat is a major cereal crop that possesses a large allopolyploid genome formed through hybridisation of tetraploid and diploid progenitors. During meiosis, crossovers (COs) are constrained in number to 1-3 per chromosome pair that are predominantly located towards the chromosome ends. This reduces the probability of advantageous traits recombining onto the same chromosome, thus limiting breeding. Therefore, understanding the underlying factors controlling meiotic recombination may provide strategies to unlock the genetic potential in wheat. In this mini-review, we will discuss the factors associated with restricted CO formation in wheat, such as timing of meiotic events, chromatin organisation, pre-meiotic DNA replication and dosage of CO genes, as a means to modulate recombination.