Omics-based analysis of honey bee (Apis mellifera) response to Varroa sp. parasitisation and associated factors reveals changes impairing winter bee generation.

The extensive annual loss of honey bees (Apis mellifera L.) represents a global problem affecting agriculture and biodiversity. The parasitic mite Varroa destructor, associated with viral co-infections, plays a key role in this loss. Despite years of intensive research, the complex mechanisms of Varroa - honey bee interaction are still not fully defined. Therefore, this study employed a unique combination of transcriptomic, proteomic, metabolomic, and functional analyses to reveal new details about the effect of Varroa mites and naturally associated factors, including viruses, on honey bees. We focused on the differences between Varroa parasitised and unparasitised ten-day-old worker bees collected before overwintering from the same set of colonies reared without anti-mite treatment. Supplementary comparison to honey bees collected from colonies with standard anti-Varroa treatment can provide further insights into the effect of a pyrethroid flumethrin. Analysis of the honey bees exposed to mite parasitisation revealed alterations in the transcriptome and proteome related to immunity, oxidative stress, olfactory recognition, metabolism of sphingolipids, and RNA regulatory mechanisms. The immune response and sphingolipid metabolism were strongly activated, whereas olfactory recognition and oxidative stress pathways were inhibited in Varroa parasitised honey bees compared to unparasitised ones. Moreover, metabolomic analysis confirmed the depletion of nutrients and energy stores, resulting in a generally disrupted metabolism in the parasitised workers. The combined omics-based analysis conducted on strictly parasitised bees revealed the key molecular components and mechanisms underlying the detrimental effects of Varroa sp. and its associated pathogens. This study provides the theoretical basis and interlinked datasets for further research on honey bee response to biological threats and the development of efficient control strategies against Varroa mites.

HGTree v2.0: a comprehensive database update for horizontal gene transfer (HGT) events detected by the tree-reconciliation method.

HGTree is a database that provides horizontal gene transfer (HGT) event information on 2472 prokaryote genomes using the tree-reconciliation method. HGTree was constructed in 2015, and a large number of prokaryotic genomes have been additionally published since then. To cope with the rapid rise of prokaryotic genome data, we present HGTree v2.0 (http://hgtree2.snu.ac.kr), a newly updated version of our HGT database with much more extensive data, including a total of 20 536 completely sequenced non-redundant prokaryotic genomes, and more reliable HGT information results curated with various steps. As a result, HGTree v2.0 has a set of expanded data results of 6 361 199 putative horizontally transferred genes integrated with additional functional information such as the KEGG pathway, virulence factors and antimicrobial resistance. Furthermore, various visualization tools in the HGTree v2.0 database website provide intuitive biological insights, allowing the users to investigate their genomes of interest.

1H NMR Profiling of Honey Bee Bodies Revealed Metabolic Differences between Summer and Winter Bees.

In temperate climates, honey bee workers of the species Apis mellifera have different lifespans depending on the seasonal phenotype: summer bees (short lifespan) and winter bees (long lifespan). Many studies have revealed the biochemical parameters involved in the lifespan differentiation of summer and winter bees. However, comprehensive information regarding the metabolic changes occurring in their bodies between the two is limited. This study used proton nuclear magnetic resonance (1H NMR) spectroscopy to analyze the metabolic differences between summer and winter bees of the same age. The multivariate analysis showed that summer and winter bees could be distinguished based on their metabolic profiles. Among the 36 metabolites found, 28 metabolites have displayed significant changes from summer to winter bees. Compared to summer bees, trehalose in winter bees showed 1.9 times higher concentration, and all amino acids except for proline and alanine showed decreased patterns. We have also detected an unknown compound, with a CH3 singlet at 2.83 ppm, which is a potential biomarker that is about 13 times higher in summer bees. Our results show that the metabolites in summer and winter bees have distinctive characteristics; this information could provide new insights and support further studies on honey bee longevity and overwintering.

Clinical Implication of Liquid Biopsy in Colorectal Cancer Patients Treated with Metastasectomy.

BACKGROUND & AIMS: The application of circulating tumor DNA (ctDNA) has been studied for predicting recurrent disease after surgery and treatment response during systemic treatment. Metastasectomy can be curative for well-selected patients with metastatic colorectal cancer (mCRC). This prospective study investigated the ctDNA level before and after metastasectomy in patients with mCRC to explore its potential as a predictive biomarker. METHODS: We collected data on 98 metastasectomies for mCRC performed from March 2017 to February 2020. Somatic mutations in the primary and metastatic tumors were identified and tumor-informed ctDNAs were selected by ultra-deep targeted sequencing. Plasma samples were mandatorily collected before and 3-4 weeks after metastasectomy and serially, if patients agreed. RESULTS: Data on 67 of 98 metastasectomies (58 patients) meeting the criteria were collected. ctDNA was detected in 9 (29%) of 31 cases treated with upfront metastasectomy and in 7 (19.4%) of 36 cases treated with metastasectomy after upfront chemotherapy. The detection rate of ctDNA was higher in liver metastasis (p = 0.0045) and tumors measuring ≥1 cm (p = 0.0183). ctDNA was less likely to be detected if the response to chemotherapy was good. After metastasectomy, ctDNA was found in 4 (6%) cases with rapid progressive disease. CONCLUSION: The biological factors affecting the ctDNA shedding from the tumor should be considered when applying ctDNA assays in a clinical setting. After metastasectomy for oligometastatic lesions in good responders of chemotherapy, most ctDNA was cleared or existed below the detection level. To assist clinical decision making after metastasectomy for mCRC using ctDNA, further studies for improving specific outcomes are needed.

The mosaic genome of indigenous African cattle as a unique genetic resource for African pastoralism.

Cattle pastoralism plays a central role in human livelihood in Africa. However, the genetic history of its success remains unknown. Here, through whole-genome sequence analysis of 172 indigenous African cattle from 16 breeds representative of the main cattle groups, we identify a major taurine × indicine cattle admixture event dated to circa 750-1,050 yr ago, which has shaped the genome of today's cattle in the Horn of Africa. We identify 16 loci linked to African environmental adaptations across crossbred animals showing an excess of taurine or indicine ancestry. These include immune-, heat-tolerance- and reproduction-related genes. Moreover, we identify one highly divergent locus in African taurine cattle, which is putatively linked to trypanotolerance and present in crossbred cattle living in trypanosomosis-infested areas. Our findings indicate that a combination of past taurine and recent indicine admixture-derived genetic resources is at the root of the present success of African pastoralism.

Gene copy number variation and protein overexpression of EGFR and HER2 in distal extrahepatic cholangiocarcinoma.

EGFR and HER2 are among the most promising therapeutic targets in solid cancers. The expression status of EGFR and HER2 are associated with the prognosis, and with a number of clinicopathological factors, in many cancers. However, few studies have examined this association in distal extrahepatic cholangiocarcinoma (EHCC). Therefore, we investigated EGFR and HER2 protein expression and gene copy number variation (CNV) in distal EHCC. We also studied the association of these factors with clinicopathological parameters and prognosis. Immunostaining, using antibodies against EGFR and HER2, was performed on 84 cases of distal EHCC. All positive (3+) and equivocal (2+) EGFR and HER2 expression cases, together with randomly selected negative (1+ and 0) cases, were evaluated for EGFR and HER2 CNV. Among distal EHCC samples, 6.0% (n=5) were positive (3+) for EGFR expression and 6.0% (n=5) were equivocal (2+). HER2 expression was positively identified in 2.4% of samples (n=2), and was equivocal in 1.2% of samples (n=1). All cases of positive EGFR expression showed amplification (n=1) or high polysomy (n=4) involving the EGFR gene; three cases (60%) of equivocal EGFR expression showed high polysomy of the EGFR gene. All cases of positive or equivocal HER2 expression (n=3, 3.6%) showed amplification of the HER2 gene. In univariate analysis, EGFR expression and CNV were associated with shorter cancer-specific overall survival (p=0.003 and p=0.018, respectively). Multivariate analysis also showed that EGFR CNV was a significant prognostic factor in distal EHCC (p=0.015). Although further study is warranted, our findings suggest that EGFR expression and CNV are factors associated with poor prognosis, and that anticancer therapeutics against EGFR and HER2 receptors may be promising therapeutic options for patients with distal EHCC.

Genome sequence of pacific abalone (Haliotis discus hannai): the first draft genome in family Haliotidae.

Background: Abalones are large marine snails in the family Haliotidae and the genus Haliotis belonging to the class Gastropoda of the phylum Mollusca. The family Haliotidae contains only one genus, Haliotis, and this single genus is known to contain several species of abalone. With 18 additional subspecies, the most comprehensive treatment of Haliotidae considers 56 species valid [ 1 ]. Abalone is an economically important fishery and aquaculture animal that is considered a highly prized seafood delicacy. The total global supply of abalone has increased 5-fold since the 1970s and farm production increased explosively from 50 mt to 103 464 mt in the past 40 years. Additionally, researchers have recently focused on abalone given their reported tumor suppression effect. However, despite the valuable features of this marine animal, no genomic information is available for the Haliotidae family and related research is still limited. To construct the H . discus hannai genome, a total of 580-G base pairs using Illumina and Pacbio platforms were generated with 322-fold coverage based on the 1.8-Gb estimated genome size of H . discus hannai using flow cytometry. The final genome assembly consisted of 1.86 Gb with 35 450 scaffolds (>2 kb). GC content level was 40.51%, and the N50 length of assembled scaffolds was 211 kb. We identified 29 449 genes using Evidence Modeler based on the gene information from ab initio prediction, protein homology with known genes, and transcriptome evidence of RNA-seq. Here we present the first Haliotidae genome, H . discus hannai , with sequencing data, assembly, and gene annotation information. This will be helpful for resolving the lack of genomic information in the Haliotidae family as well as providing more opportunities for understanding gastropod evolution.

Altered PLCß-1 expression in the gerbil hippocampal complex following spontaneous seizure.

Although the phospholipase C (PLC)ß-1 isoform is associated with spontaneous seizure and distinctively expressed in the telencephalon, the distribution of PLCß-1 expression in the epileptic gerbil hippocampus remains controversial. Therefore, we determined whether PLCß-1 is associated with spontaneous seizure in an animal model of genetic epilepsy. In the present study, PLCß-1 immunoreactivity was down-regulated in seizure-sensitive (SS) gerbils more than in seizure-resistant (SR) gerbils. The expression of PLCß-1 within calretinin (CR)- positive neurons was rarely detected within the dentate hilar region of SS gerbils. PLCß-1 immunoreactivity in the hippocampus was significantly elevated as compared to that in pre-seizure SS gerbil 3 h post-ictal. These findings suggest that alterations in PLCß-1 immunoreactivity in the SS gerbil hippocampus may be closely related to the epileptic state of the gerbil brain and transiently elevated PLCß-1 protein levels following seizure episodes. Such alterations may be compensatory responses in the SS gerbil hippocampus.