Genome miniaturization drives key evolutionary innovations of adaptive traits in verte-brates,such as the flight evolution of birds.However,whether similar evolutionary processes exist in invertebrates remains poorly understood.Derived from the second-largest animal phylum,scallops are a special group of bivalve molluscs and acquire the evolutionary novelty of the swimming lifestyle,providing excellent models for investigating the coordinated genome and lifestyle evolution.Here,we show for the first time that genome sizes of scallops exhibit a generally negative correlation with loco-motion activity.To elucidate the co-evolution of genome size and swimming lifestyle,we focus on the Asian moon scallop(Amusium pleuronectes)that possesses the smallest known scallop genome while being among scallops with the highest swimming activity.Whole-genome sequencing of A.pleuronectes reveals highly conserved chromosomal macrosynteny and microsynteny,suggestive of a highly con-tracted but not degenerated genome.Genome reduction of A.pleuronectes is facilitated by significant inactivation of transposable elements,leading to reduced gene length,elevated expression of genes involved in energy-producing pathways,and decreased copy numbers and expression levels of biomineralization-related genes.Similar evolutionary changes of relevant pathways are also observed for bird genome reduction with flight evolution.The striking mimicry of genome miniaturization underlying the evolution of bird flight and scallop swimming unveils the potentially common,pivotal role of genome size fluctuation in the evolution of novel lifestyles in the animal kingdom.

Bivalves are species-rich mollusks with prominent protective roles in coastal ecosystems.Across these ancient lineages,colony-founding larvae anchor themselves either by byssus produc-tion or by cemented attachment.The latter mode of sessile life is strongly molded by left-right shell asymmetry during larval development of Ostreoida oysters such as Crassostrea hongkongensis.Here,we sequenced the genome of C.hongkongensis in high resolution and compared it to reference bivalve genomes to unveil genomic determinants driving cemented attachment and shell asymmetry.Importantly,loss of the homeobox gene Antennapedia(Antp)and broad expansion of lineage-specific extracellular gene families are implicated in a shift from byssal to cemented attachment in bivalves.Comparative transcriptomic analysis shows a conspicuous divergence between left-right asymmetrical C.hongkongensis and symmetrical Pinctada fucata in their expression profiles.Especially,a couple of orthologous transcription factor genes and lineage-specific shell-related gene families including that encoding tyrosinases are elevated,and may cooperatively govern asymmet-rical shell formation in Ostreoida oysters.

Objective    To summarize and analyze the risk factors and management of artificial valve slippage in transcatheter aortic valve implantation (TAVI). Methods    We retrospectively analyzed the clinical data of 131 patients undergoing TAVI surgery in our center from September 2017 to May 2019, including 62 patients through transapical approach and 69 patients through transfemoral artery approach. Results    A total of 131 patients received TAVI surgery, among whom 4 patients had slipped during the operation, 2 patients via transfemoral artery approach, and another 2 patients via transapical. The average age was 77±9 years with one female (25%). Preoperative evaluation, higher position and poor coaxial were main risk factors for valve slip in TAVI. Conclusion    Valve slippage is also a serious complication in TAVI surgery. Reasonable and effective treatment can avoid thoracotomy.

Objective To explore the clinic results of our new designed transcatheter valve in valve for the mitral biopro-thesis deterioration.Methods Mitral bioprothesis deterioration patients with high risk for the routine bypass surgery got con-sent.After general anesthesia in the hybrid operation the left ventricle apical puncture was performed with guidance of 3D echo and X-ray.The retro-preset J Valve system was guided into the left atrium and the mitral bioprothesis with the beating heart . Results There were total 9 cases between Jan 2019 to Mar 2019 which had STS score above 6-8.The mitral bioprothesis in-cluded Hancock valve 3 cases, Perimount valve 3 cases, Epic valve 2 cases, Baxiter valve 1 case.The mitral bioprosthesis size included 27 for 6 cases and 25 for 3 cases.The successful implant rate was 100％, mortality rate 0, and all the patients recov-ered well without any main complications.The mean tran-valular pressure was only(8 ±2) mmHg (1 mmHg=0.133 kPa). Conclusion This innovative mitral valve in valve technique with retro-preset J Valve system got very good clinic results and worthy of deep research.

Non-alcoholic fatty liver disease (NAFLD) has become one of the major metabolic diseases.In view of the defects of traditional animal models, this study was the first to establish the NAFLD model of Mongolian gerbil (Meriones unguiculatus) with simple feed formula which is similar to human (from simple fatty liver to steatohepatitis, fibrosis,Liver cirrhosis).This study discussed the mechanism of rapid fatty liver deposition in Mongolian gerbil, revealed its molecular mechanism,main regulatory target and network function of fatty liver susceptibility.We provide a new animal model of NAFLD with relatively clear background and less time-consuming for clinical treatment and new drug development.The theoretical and practical basis for the breeding of inbred strain NAFLD gerbil was established.

Objective To study the effect of drinking water at different pH on intestinal microbial diversity in SPF mice.Methods Ninety 21-day-old SPF mice were randomly divided into three groups: drinking acidified water (pH 3.0), neutral water (pH 7.0) and alkaline water (pH 9.0), respectively, for 3 months, 30 mice in each group.10 mice were sacrificed at the end of 4, 8 and 12 weeks in each group.Bacteria, virus and parasites in serum were detected according to the national standard for SPF.Then, primer sequences were designed according to the conservativeness of bacteria 16S rRNA, and libraries were constructed.Subsequently, the ileocecal contents were subjected to high-throughput sequencing (Illumina).10 G data were obtained and analyzed.Results The sequencing results revealed that the intestinal microbial abundance of the mice receiving pH 3.0 drinking water was moderate with a high stability.Conclusions Under the conditions of large-scale breeding, the mice receiving pH 3.0 drinking water can maintain the intestinal microbial diversity for a long time, and reach a stable platform.This study provides theoretical and technical support for the stable long-term maintenance of animal quality production.It is also a specific application of gastrointestinal macrogenomics in animal quality control.

Objective To report the clinical and peripheral neuropathological findings in two patients with autosomal recessive Charcot-Marie-Tooth disease 2K(AR-CMT2K).Methods Case one was a nine year-old girl.She had distal weakness of lower limbs for six years, with calf atrophy and contracture of Achilles tendon for three years.Case two was an eight year-old boy.He had distal weakness of lower limbs with contracture of Achilles tendon and calf muscle atrophy for three years, and proximal weakness of low limbs for two years.The motor nerve conduction velocities in median nerves were 48.1 m/s in case one and 47.6 m/s in case two.The compound motor action potential amplitude of median nerves decreased by 46% in case one and 69% in case two.Sural nerve biopsies and gene targeted next-generation sequencing were performed in both patients.Results Density of myelinated fibers was 8 407/mm2 in case one and 7 714/mm2 in case two.The ratio of myelinated fibers with diameter over 8 μm was 2.6% in case one and 0 in case two.Both patients had small regenerating cluster of myelinated fibers.Thin myelinated fibers appeared in case one.In case two, atypical onion bulb formations with focal folded myelin appeared, and electromicroscopy revealed mitochondrial aggregate in axons.Compound heterozygous mutations of ganglioside-induced differentiation associated protein 1 gene were detected in both patients, including c.767A>G(p.H256R) and c.466G>A (p.A156T) in case one and c.767A>G and 845G>A(p.R282H) in case two.Conclusions Contracture of Achilles tendon may appear in early childhood of AR-CMT2K patients.The main pathological changes in sural nerve are loss of large myelinated fibers, mitochondrial aggregate in axons and myelin abnormalities.

Objective To summarize the clinical features of Chinese patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes ( MELAS).Methods A total of 190 patients with MELAS who presented to Peking University First Hospital between 1997 and 2015 were recruited.Among 190 patients, 175 were identified carrying mitochondrial DNA mutations, and the remaining 15 patients were diagnosed by muscle biopsy.The clinical features, including predisposing factors of stroke-like episodes, the onset symptoms and frequencies of various manifestations were analyzed and reported.Results In our cohort of MELAS patients, the male-to-female ratio was 1.44∶1.The median age of onset was 14 years ( from 7 months to 45 years).The peak onset ages were 8-12 years.The median onset age of the first stroke-like episode was 16 years ( from 1 to 53 years ).There were 66 ( 46.15%) patients who had predisposing factors before the onset, and fatigue and upper respiratory tract infection were the most common predisposing factors of stroke-like episodes in these patients ( 37.88%, 25/66 and 34.85%, 23/66, respectively).Other predisposing factors included emotional agitation, drinking alcohol, trauma, withdrawal of antiepileptic drugs, being frightened, satiation and hunger.Stroke-like episodes appeared in 70.53%(134/190) patients as an onset symptom and developed in all patients with disease progression.The neurological manifestations included seizure ( 89.42%, 169/189 ) , mental retardation or dementia (82.87%, 150/181), headache (74.30%, 133/179), hemianopia or cortical blindness (67.72%, 107/158), exercise intolerance (50.87%, 88/173), hemiplegia or hemianesthesia (47.44%, 74/156), sensorineural deafness (46.20%, 85/184), aphasia (39.47%, 60/152), behaviour disorder (17.71%, 31/175) and ophthalmoplegia ( 9.60%, 17/177 ).The manifestations of extra-nervous systems included hirsutism (67.57%, 100/148), vomiting (65.58%, 101/154), fever (62.07%, 90/145), short stature (45.32%, 63/139), diarrhea or constipation (43.48%, 70/161), low body mass index (26.62%, 37/139), diabetes mellitus (20.79%, 37/178) and kidney disease (3.16%, 6/190).Conclusions The majority of the patients in this study have the disease onset during childhood.There are more male MELAS patients than females.Most common clinical manifestations are seizure, mental retardation or dementia, headache, cortical blindness, hirsutism, vomiting and fever in this patient group.

Objective To analyze the differences of the clinical and neuropathological features among the common Charcot-Marie-Tooth disease (CMT) subtypes.Methods There were 81 CMT patients confirmed by genetic testing from 2005 to 2015 in Department of Neurology,Peking University First Hospital,including 31 cases of CMT1A (38.3％),19 cases of CMTX1 (23.5％),16 cases of CMT2A2 (19.8％) and 15 cases of 9 rare types of CMT (1.2％-4.9％).We compared the onset age,duration,muscles weakness of legs,frequency of pes cavus,and main pathological changes of the sural nerve biopsy in 48 cases of the common CMT subtypes.Results The mean age of the onset was (12.00 ± 6.77) years in CMT1A patients,(11.81 ±4.65) years in CMTX1 patients and (5.00 ±2.68) years in CMT2A2 patients (Brown-Forsythe test,P =0.001).The duration was (12.00 ± 6.75) years in CMT1A patients,(8.50 ± 4.75) years in CMTX1 patients and (5.00 ± 2.73) years in CMT2A2 patients (Brown-Forsythe test,P =0.001).The muscle force of the dorsi flexors was Ⅳ (0,Ⅴ) in CMT1A patients,Ⅲ + (0,Ⅳ) in CMTX1 patients and 0 (0,Ⅳ) in CMT2A2 patients (H =11.359,P =0.020).The pes cavus appeared in 15/23 cases of CMT1A,10/16 cases of CMTX1 and 1/9 cases of CMT2A2 (Fisher test,P=0.017).The leukoencephalopathy appeared only in 3 cases of CMTX1 and the visual loss appeared only in 3 cases of CMT2A2.The onion-bulb formations of myelinated fibers appeared in 23/23 cases of CMT1 A,5/16 cases of CMTX1 and 2/9 cases of CMT2A2(Fisher test,P =0.000).The axonal regeneration appeared in 16/23 cases of CMT1A,16/16 cases of CMTX1 and 9/9 cases of CMT2A2 (x2 =7.666,P =0.016).There were significant differences among the three common CMT subtypes in the above parameters.Conclusions CMT1A,CMT2A2 and CMTX1 are the most common subtypes of CMT in the present study.For the clinical diagnosis,more attention should be paid to the onset of the disease,duration,muscles weakness,pes cavus,cerebral symptoms and visual loss.The present frequency of onion-bulb and the axonal regeneration of myelinated fibers help the different pathological diagnosis among them.

Objective To investigate the effects of dried whey on the intestinal bacterial community and probiotics in weaned laboratory rabbits .Methods A single factor design was employed to investigate the effects of dried whey supplemented at levels of 0%, 2%, 5%and 10%, respectively, on 48 weaned (40-day-old) laboratory rabbits.At the day 30, eight rabbits in each group were taken and sacrificed after anesthesia .The total bacterial DNA from the ceacal content of each selected rabbit was drew to analyze the bacterial community and intestinal probiotics ( Bifidobacterium and Lactobacillius) population by PCR-DGGE and real-time fluorescence quantitative PCR, respectively.Results 1) The DGGE parameters of ceacal bacterial community were increased with the increasing dried whey supplemental levels .The number of DGGE band in 2%, 5%and 10%dried whey supplement groups (P<0.05, P<0.01), the Shannon index in 5%and 10% supplement groups ( P<0.01 ) were significantly higher than that in the 0% supplement group , but the indices of DGGE band and Shannon index had no significant differences among the 2%, 5% and 10% dried whey supplement groups (P>0.05).Supplying dried whey has no significant effects on the homogeneity index (P>0.05).2) The population of Bifidobacterium and Lactobacillius in ceacal content had a trend of increase with the rising dried whey supplement levels .Compared with the 0% supplement group , the Lactobacillius population in the 2%, 5% and 10%supplement groups ( P <0.05 ) , the Bifidobacterium population in the 10% supplement group ( P <0.05 ) were significantly increased .Conclusions The results of our study indicate that: 1 ) Supplying dried whey in the feed of laboratory rabbit can effectively increase the diversity of ceacal bacterial community .2) Dried whey may effectively improve the intestinal probiotics population .