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The bay scallop and Peruvian scallop are economically important species. Interspecific hybrids of these two scallops outperformed both of their parent species in multiple growth traits but exhibited decreased fertility, which provides good models for the study of heterosis and species divergence. Genetic mapping serves as a chromosomal-level framework to investigate the molecular mechanisms of hybridization and introgression. In this study, high-resolution linkage maps were constructed for the bay and Peruvian scallops with an interspecific hybrid family. The linkage map of the bay scallop covered over 98.9% of the whole genome with 2994 mapped markers and the average marker interval of 0.32 cM. For the Peruvian scallop, 1585 markers were mapped with the average maker interval of 0.51 cM, covering 97.7% of the genome. Both the two linkage maps have 16 linkage groups, corresponding to the haploid chromosome number of the two species. Approximately, 54.5% of markers exhibited significant deviation from the expected Mendelian ratio of segregation, lending insights into the intrinsic incompatibility between the two species. QTLs related to growth and shell coloration were detected, which could explain 13.1% and 74.9% of the phenotypic variance, respectively. This represents important information for further evaluation. These findings are an important addition to the genomic resources for scallop genetic studies, and are especially useful for investigations on genomic incompatibility for hybridization, genome evolution of closely related species, and genetic enhancement programs in aquaculture.

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), are crucial sensors with a conserved structure in cytoplasm, inducing the production of cytokines, chemokines and host restriction factors which mediate a variety of intracellular activities to interfere with distinct PAMPs (pathogen-associated molecular patterns) for eliminating pathogens in innate immune system. Although RLR genes have been investigated in most vertebrates and some invertebrates, the systematic identification and characterization of RLR genes have not been reported in scallops. In this study, four RLR genes (PY-10413.4, PY-10413.5, PY-443.7 and PY-443.8, designated PyRLRs) were identified in Yesso scallop (Patinopecten yessoensis) through whole-genome scanning through in silico analysis, including two pairs of tandem duplicate genes located on the same scaffold (PY-10413.4 and PY-10413.5, PY-443.7 and PY-443.8, respectively). Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of these genes. The expression profiles of PyRLRs were determined in all developmental stages, in healthy adult tissues, and in mantles that simulated ocean acidification (OA) exposure (pH = 6.5 and 7.5) at different time points (3, 6, 12 and 24 h). Spatiotemporal expression patterns suggested the functional roles of PyRLRs in all stages of development and growth of the scallop. Regulation expressions revealed PY-10413.4 and PY-10413.5 with one or two CARD(s) (caspase activation and recruitment domain) were up-regulated expressed at most time points, whereas PY-443.8 and PY-10413.4 without CARD were significantly down-regulated at each time points, suggesting functional differentiations in the two pairs of PyRLRs based on the structural differences in response to OA. Collectively, this study demonstrated gene duplication of RLR family genes and provide primary analysis for versatile roles in the response of the bivalve innate immune system to OA challenge.

Heat shock proteins 90 (HSP90s) are a class of ubiquitous, highly conserved, and multi-functional molecular chaperones present in all living organisms. They assist protein folding processes to form functional proteins. In the present study, three HSP90 genes, CfHSP90, CfGRP94 and CfTRAP1, were successfully identified in the genome of Chlamys farreri. The length of CfHSP90, CfGRP94 and CfTRAP1 were 7211 bp, 26,457 bp, and 28,699 bp, each containing an open reading frame (ORF) of 2181 bp, 2397 bp, and 2181 bp, and encoding proteins of 726, 798, and 726 amino acids, respectively. A transcriptomic database demonstrated that CfHSP90 and CfGRP94 were the primary functional executors with high expression during larval development and in adult tissues, while CfTRAP1 expression was low. Furthermore, all of the three CfHSP90s showed higher expression in gonads and ganglia as compared with other tissues, which indicated their probable involvement in gametogenesis and nerve signal transmission in C. farreri. In addition, under heat stress, the expressions of CfHSP90 and CfGRP94 were significantly up-regulated in the mantle, gill, and blood, but not in the heart. Nevertheless, the expression of CfTRAP1 did not change significantly in the four tested tissues. Taken together, in coping with heat stress, CfHSP90 and CfGRP94 could help correct protein folding or salvage damaged proteins for cell homeostasis in C. farreri. Collectively, a comprehensive analysis of CfHSP90s in C. farreri was conducted. The study indicates the functional diversity of CfHSP90s in growth, development, and environmental response, and our findings may have implications for the subsequent in-depth exploration of HSP90s in invertebrates.

To consolidate the genetic, physical, and cytogenetic maps of scallop (Patinopecten yessoensis), we constructed a molecular cytogenetic map by localizing 84 fosmid clones that contain different SNP markers from 19 linkage groups (LGs) using fluorescence in situ hybridization (FISH). Among these 84 SNP-anchored clones, 56 clones produced specific and stable signals on one pair of chromosomes. Dual-color FISH assigned 19 LGs to their corresponding chromosomes with 38 SNP-anchored clones as probes. Among these 19 LGs, 17 LGs were assigned to their corresponding one pair of chromosomes, while two clones containing SNPs from LG10 and LG19 were located on two different pairs of chromosomes separately. The orientation of 7 LGs was corrected according to the chromosome location of SNPs within the same LG. In addition, a probe panel of SNP-anchored clones was developed to identify each chromosome of P. yessoensis. The molecular cytogenetic map will facilitate molecular breeding in scallop and enable comparative studies on chromosome evolution of bivalve mollusk.

Cholinesterases are key enzymes in central and peripheral cholinergic nerve system functioning on nerve impulse transmission in animals. Though cholinesterases have been identified in most vertebrates, the knowledge about the variable numbers and multiple functions of the genes is still quite meagre in invertebrates, especially in scallops. In this study, the complete cholinesterase (ChE) family members have been systematically characterized in Yesso scallop (Patinopecten yessoensis) via whole-genome scanning through in silico analysis. Ten ChE family members in the genome of Yesso scallop (designated PyChEs) were identified and potentially acted to be the largest number of ChE in the reported species to date. Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of these genes. The expression profiles of PyChEs were determined in all developmental stages, in healthy adult tissues, and in mantles under low pH stress (pH 6.5 and 7.5). Spatiotemporal expression suggested the ubiquitous functional roles of PyChEs in all stages of development, as well as general and tissue-specific functions in scallop tissues. Regulation expressions revealed diverse up- and down-regulated expression patterns at most time points, suggesting different functional specialization of gene superfamily members in response to ocean acidification (OA). Evidences in gene number, phylogenetic relationships and expression patterns of PyChEs revealed that functional innovations and differentiations after gene duplication may result in altered functional constraints among PyChEs gene clusters. Collectively, our results provide the potential clues that the selection pressures coming from the environment were the potential inducement leading to function allocation of ChE family members in scallop.

Hybridization is a powerful tool for improving productivity and profitability in aquaculture. To determine the performance characteristics of Patinopecten scallop hybrids, complete diallel hybridizations were carried out between Yesso scallops (P. yessoensis) and Weathervane scallops (P. caurinus) (Py♀ × Pc♂; Pc♀ × Py♂), together with intraspecific scallops P. yessoensis (Py♀ × Py♂) and P. caurinus (Pc♀ × Pc♂). The Pc♀ × Py♂ cohort only survived until 21 days after fertilization, while the Py♀ × Pc♂ cohort outperformed both purebred parental cohorts in larval, juvenile and adult growth periods with higher growth and survival rates. In particular, the growth rate of the Py♀ × Pc♂ cohort was significantly higher than that of the parental scallops at the adult grow-out stage. Compared with those in the Yesso scallops, the production traits in the Py♀ × Pc♂ cohort were increased by 16.43% in shell height and 26.87% in whole body weight, with heterosis of 21.6 and 34.9, respectively. Moreover, the survival rate of Py♀ × Pc♂ cohort adult hybrids (46.2 ± 3.2%) was notably higher than that of Yesso scallops (28.5 ± 4.5%) and Weathervane scallops (18.4 ± 5.2%) after thermal duress in summer and cold endurance in winter, showing significantly higher heterosis (97.0). Nuclear sequence (internal transcribed spacer) and mitochondrial DNA sequence (16S rDNA) analyses confirmed that the derived hybrid adults (Py♀ × Pc♂) were true hybrids between the two Patinopecten scallops. Our data presented evidence that artificially interspecific hybridization between P. yessoensis and P. caurinus was experimentally possible and achieved considerable heterosis of the Py♀ × Pc♂ cohort in growth performance and temperature tolerance. The hybrid adults (Py♀ × Pc♂) may provide valuable germplasm resources for increasing scallop production and support the development of strategies for long-term healthy sustainable aquaculture.

To better understand the effects of maternal age on birth outcomes among preeclampsia (PE) patients, we examined the rates of preterm birth, low birthweight, and small for gestational age (SGA) among different age groups and explored whether maternal age was associated with those adverse outcomes.This is a multicenter retrospective study. Data from 1128 PE patients, including 580 with early onset PE and 548 with late onset PE, were analyzed.Maternal age was categorized into three groups:25, 25-34, and ≥35 years. The outcome variables were preterm birth (37 weeks; subgroups:28 weeks, 28-33 weeks, and 34-36 weeks), low birthweight (2500 g; subgroups:1500 g and1000 g), and SGA. Logistic regression was used to analyze the associations between maternal age groups and outcomes.In early onset PE, compared with maternal age 25-34 years, maternal age ≥35 years was associated with elevated risk for preterm delivery before 28 weeks, and maternal age25 years was associated with elevated risk for low birthweight and SGA. When the analysis was restricted to women who underwent cesarean section, elevated risks for preterm birth and/or low birthweight were observed for women younger than 25 years in both early and late onset PE.Among women with PE, maternal age25 years could add risk to preterm birth and/or low birthweight. For women with early onset PE, maternal age ≥35 years is a risk factor for preterm delivery before 28 weeks.

Mitotic chromosome preparations of the interspecific hybrids Chlamysfarreri (Jones & Preston, 1904) × Patinopectenyessoensis (Jay, 1857), C.farreri × Argopectenirradinas (Lamarck, 1819) and C.farreri × Mimachlamysnobilis (Reeve, 1852) were used to compare two different scallop genomes in a single slide. Although genomic in situ hybridization (GISH) using genomic DNA from each scallop species as probe painted mitotic chromosomes of the interspecific hybrids, the painting results were not uniform; instead it showed species-specific distribution patterns of fluorescent signals among the chromosomes. The most prominent GISH-bands were mainly located at centromeric or telomeric regions of scallop chromosomes. In order to illustrate the sequence constitution of the GISH-bands, the satellite Cf303 sequences of C.farreri and the vertebrate telomeric (TTAGGG)n sequences were used to map mitotic chromosomes of C.farreri by fluorescence in situ hybridization (FISH). The results indicated that the GISH-banding pattern presented by the chromosomes of C.farreri is mainly due to the distribution of the satellite Cf303 DNA, therefore suggesting that the GISH-banding patterns found in the other three scallops could also be the result of the chromosomal distribution of other species-specific satellite DNAs.

Transient receptor potential (TRP) channel plays a significant role in mediating various sensory physiological functions. It is widely present in the vertebrate and invertebrate genomes and can be activated by multiple compounds, messenger molecules, temperature, and mechanical stimulation. Mollusks are the second largest phylum of the animal kingdom and are sensitive to environmental factors. However, the molecular underpinnings through which mollusks sense and respond to environmental stimulus are unknown. In this study, we systematically identified and characterized 17 TRP channels (C.FA TRPs, seven subfamilies) in the genome of the Zhikong scallop (Chlamys farreri). All C.FA TRPs had six transmembrane structures (TM1–TM6). The sequences and structural features of C.FA TRPs are highly conserved with TRP channels of other species. Spatiotemporal expression profiling suggested that some C.FA TRPs participated in the early embryonic development of scallops and the sensory process of adult tissues. Notably, the expression of C.FA TRPM3 continuously increased during developmental stages and was highest among all C.FA TRPs. C.FA TRPC-α was specifically expressed in eyes, which may be involved in light transmission of scallop eyes. Under high temperature stress, C.FA TRPA1 and C.FA TRPA1-homolog upregulated significantly, which indicated that the TRPA subfamily is the thermoTRPs channel of scallops. Our results provided the first systematic study of TRP channels in scallops, and the findings will provide a valuable resource for a better understanding of TRP evolution and function in mollusks.

The complement system constitutes a highly sophisticated and powerful body defense machinery acting in the innate immunity of both vertebrates and invertebrates. As central components of the complement system, significant effects of thioester-containing protein (TEP) family members on immunity have been reported in most vertebrates and in some invertebrates, but the spatiotemporal expression and regulatory patterns of TEP family genes under environmental stress have been less widely investigated in scallops. In this study, expression profiling of TEP family members in the Yesso scallop Patinopecten yessoensis (designated PyTEPs) was performed at all developmental stages, in different healthy adult tissues, and in mantles during exposure to different levels of acidification (pH = 6.5 and 7.5) for different time points (3, 6, 12 and 24 h); this profiling was accomplished through in silico analysis of transcriptome and genome databases. Spatiotemporal expression patterns revealed that PyTEPs had specific functional differentiation in all stages of growth and development of the scallop. Expression analysis confirmed the inducible expression patterns of PyTEPs during exposure to acidification. Gene duplication and alternative splicing events simultaneously occurred in PyTEP1. Seven different cDNA variants of PyTEP1 (designated PyTEP1-A–PyTEP1-G) were identified in the scallop mantle transcriptome during acidic stress. These variants were produced by the alternative splicing of seven differentially transcribed exons (exons 18–24), which encode the highly variable central region. The responses to immune stress may have arisen through the gene duplication and alternative splicing of PyTEP1. The sequence diversity of PyTEP1 isoforms and their different expression profiles in response to ocean acidification (OA) suggested a mechanism used by scallops to differentiate and regulate PyTEP1 gene expression. Collectively, these results demonstrate the gene duplication and alternative splicing of TEP family genes and provide valuable resources for elucidating their versatile roles in bivalve innate immune responses to OA challenge.

The dwarf surfclam Mulinia lateralis is widely considered a model species in bivalves because of its small size and short generation. An efficient culture system is necessary to continuously obtain enough high quality larvae for genetic research. In the present study, the impacts of microalgae diets and stocking density on larval growth, survival and metamorphosis were investigated to optimize the culture system for M. lateralis. Six of seven tested microalgae were ingested by 2 to 10-day-old larvae, including Isochrysis galbana (IG), Chlorella pyrenoidesa (CP), Nitzschia closterium (NC), Platymonas helgolandica (PH), Chaetoceros muelleri (CM) and Pyramimonas delicatula (PD). The exception was Dunaliella salina (DS), which was not ingested by larvae during the experimental period. This results indicated the larvae could ingest microalgae with larger size as larvae develop. The time needed for digestion gradually decreased as the larvae develop. According to the growth, survival and metamorphosis of larvae after feeding with different microalgae diets, the optimal diets were a single diet of IG for D-shaped larvae, mixed diets of IG + PH at a 1:1 ratio by cell density for umbo larvae and IG + NC + PH at a 1:1:1 ratio by cell density for pediveliger larvae. The better microalgae concentration was 2.4–3.6 × 103 cells mL−1 for D-shaped larvae, 6.0–12 × 103 cells mL−1 for umbo larvae, and 30–40 × 103 cells mL−1 for pediveliger larvae. In addition, the better density of D-shaped larvae was ≤9 larvae mL−1, the density of umbo larvae was ≤7 larvae mL−1, and the density of pediveliger larvae was ≤5 larvae mL−1. In conclusion, ingestion and digestion of microalgae, microalgae combination, microalgae concentration and stocking density significantly affected growth, survival, and metamorphosis of M. lateralis larvae. The optimized conditions will be of great significance for establishing a standard culture system for M. lateralis.

The innate immune system plays a pivotal role in defending invasion of microorganisms for scallops. Previous studies on immune-related genes in the Yesso scallop, Patinopecten yessoensis (Jay, 1857) have mainly focused on characterization and expression pattern in response to bacterial challenge, no research has been carried out on the cytogenetic level yet. In the present study, eight fosmid clones containing the sequences of key immune-related genes (PyNFkB, PyTRAF2, PyTRAF4, PyTRAF7, PyMyd88-1, PyMyd88-3, PyMKK-7 and PyTNFR) were isolated and seven of them were successfully mapped on chromosomes of Patinopecten yessoensis utilizing fluorescence in situ hybridization. Wherein, PyMyd88-1, PyMyd88-3 and PyMKK-7 located on the same chromosome pair with adjacent positions and the other genes were mapped on four non-homologous chromosome pairs, showing a similar distribution to another five model species. The isolation and mapping of such genes of the Yesso scallop will lay a foundation for studies such as assignment of interested genes to chromosomes, construction cytogenetic maps and so on.

Construction of cytogenetic maps can provide important information for chromosome identification, chromosome evolution and genomic research. However, it hasn't been conducted in many scallop species yet. In the present study, we attempted to map 12 fosmid clones containing tandem repeats by fluorescence in situ hybridization (FISH) in the Yesso scallop Patinopecten yessoensis (Jay, 1857). The results showed 6 fosmid clones were successfully mapped and distributed in 6 different pairs of chromosomes. Three clones were respectively assigned to a pair of metacentric chromosomes, a pair of submetacentric chromosomes and a pair of telocentric chromosomes and the remaining 3 clones showed their loci on three different pairs of subtelocentric chromosomes by co-hybridization. In summary, totally 8 pairs of chromosomes of the Yesso scallop were identified by 6 fosmid clones and two rDNA probes. Furthermore, 6 tandem repeats of 5 clones were sequenced and could be developed as chromosome specific markers for the Yesso scallop. The successful localization of fosmid clones will undoubtedly facilitate the integration of linkage groups with cytogenetic map and genomic research for the Yesso scallop.

Arginine kinase (AK), an important member of the phosphokinase family, is involved in temporal and spatial adenosine triphosphate (ATP) buffering systems. AK plays an important role in physiological function and metabolic regulations, in particular tissues with high and fluctuating energy demands. In present study, four AK genes were firstly identified from Yesso scallop (Patinopecten yessoensis) genome, respectively named PyAK1-4. PyAKs have highly conserved structures with a six-exon/five-exon structure, except for PyAK3. PyAK3 contains an unusual two-domain structure and a "bridge intron" between the two domains, which may originate from gene duplication and subsequent fusion. Phylogenetic analysis showed that all PyAKs belonged to an AK supercluster together with other AK proteins from Mollusca, Platyhelminthes, Arthropoda, and Nematode. A transcriptome database demonstrated that PyAK3 and PyAK4 were the main functional executors with high expression level during larval development and in adult tissues, while PyAK1 and PyAK2 were expressed at a low level. Furthermore, both PyAK2 and PyAK3 showed notably high expression in the male gonad, and PyAK4 was broadly expressed in almost all tissues with the highest level in striated muscle, indicating a tissue-specific expression pattern of PyAKs. In addition, quantitative real-time PCR results demonstrated that the expression of PyAK2, PyAK3 and PyAK4 were significantly upregulated in response to pH stress, especially in an extremely acidifying condition (pH 6.5), revealing the possible involvement of PyAKs in energetic homeostasis during environmental changes. Collectively, a comprehensive analysis of PyAKs was conducted in P. yessoensis. The diversity of PyAKs and their specific expression patterns promote a better understanding of energy metabolism in the growth, development and environmental response of P. yessoensis.

Ocean acidification (OA), which is caused by increasing levels of dissolved CO2 in the ocean, is a major threat to marine ecosystems. Multiple lines of scientific evidence show that marine bivalves, including scallops, are vulnerable to OA due to their poor capacities to regulate extracellular ions and acid-based status. However, the physiological mechanisms of scallops responding to OA are not well understood. In this study, we evaluated the effects of 45 days of exposure to OA (pH 7.5) on the energy metabolism and antioxidant capability of Yesso scallops. Some biochemical markers related to energy metabolism (e.g., content of glycogen and ATP, activity of ATPase, lactate dehydrogenase, glutamate oxaloacetate transaminase, and glutamate-pyruvate transaminase), antioxidant capacity (e.g., reactive oxygen species level, activity of superoxide dismutase, and catalase) and cellular damage (e.g., lipid peroxidation level) were measured. Our results demonstrate that the effects of the reduced pH (7.5) on scallops are varied in different tissues. The energy reserves are mainly accumulated in the adductor muscle and hepatopancreas. Yesso scallops exhibit energy modulation by increasing lactate dehydrogenase activities to stimulate anaerobic metabolism. The highly active Na+/K+-ATPase and massive ATP consumption in the mantle and gill indicate that a large amount of energy was allocated for the ion regulation process to maintain the acid-base balance in the reduced-pH environment. Moreover, the increase in the reactive oxygen species level and the superoxide dismutase and catalase activities in the gill and adductor muscle, indicate that oxidative stress was induced after long-term exposure to the reduced-pH environment. Our findings indicate that the effects of OA are tissue-specific, and physiological homeostasis could be modulated through different mechanisms for Yesso scallops.

Thioester-containing protein (TEP) family members are characterized by their unique intrachain β-cysteinyl-γ-glutamyl thioesters, and they play important roles in innate immune responses. Although significant effects of TEP members on immunity have been reported in most vertebrates, as well as certain invertebrates, the complete TEP family has not been systematically characterized in scallops. In this study, five TEP family genes (PyC3, PyA2M, PyTEP1, PyTEP2 and PyCD109) were identified from Yesso scallop (Patinopecten yessoensis) through whole-genome scanning, including one pair of tandem duplications located on the same scaffold. Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of the five genes (PyTEPs). The vast distribution of PyTEPs in TEP subfamilies confirmed that the Yesso scallop contains relatively comprehensive types of TEP members in evolution. The expression profiles of PyTEPs were determined in hemocytes after bacterial infection with gram-positive (Micrococcus luteus) and gram-negative (Vibrio anguillarum) using quantitative real-time PCR (qRT-PCR). Expression analysis revealed that the PyTEP genes exhibited disparate expression patterns in response to the infection by gram bacteria. A majority of PyTEP genes were overexpressed after bacterial stimulation at most time points, especially the notable elevation displayed by duplicated genes after V. anguillarum challenge. Interestingly, at different infection times, PyTEP1 and PyTEP2 shared analogous expression patterns, as did PyC3 and PyCD109. Taken together, these results help to characterize gene duplication and the evolutionary origin of PyTEPs and supplied valuable resources for elucidating their versatile roles in bivalve innate immune responses to bacterial pathogen challenges.

Preeclampsia is a major cause of adverse maternal and perinatal outcomes, but how to identify women and fetuses at increased risk for later adverse events is a challenge. This study aimed to investigate the risk factors for adverse maternal and perinatal outcomes in women with preeclampsia. Data from 1396 women with preeclampsia were retrospectively collected and analyzed. Eighteen candidate risk factors and 12 adverse outcomes were investigated. The following factors were found to be significantly associated with at least one adverse outcome: maternal age 35 years or older, multiple birth, the usage of assisted reproductive technology, living in a rural area, history of pregnancy-induced hypertension, male fetus, multigravida, or having polycystic ovary syndrome, hemolysis, elevated liver enzymes, and low platelet count syndrome, intrahepatic cholestasis of pregnancy, cardiovascular disease, gestational diabetes mellitus, systemic lupus erythematosus, thyroid disease, or liver disease. Compared with patients without any identified risk factors, patients with preeclampsia with three or more risk factors were at increased risk for severe adverse outcomes. Those findings demonstrated that maternal risk factors could be used as indicators supplementary to clinical symptoms and laboratory test results for the risk assessment in women with preeclampsia.

Preeclampsia, characterized by high blood pressure, albuminuria and other systemic disorders, is a serious complication during pregnancy. It has been reported that GNA12 is overexpressed during preeclampsia. In this study, we investigated the potential association between the methylation of the GNA12 promoter and preeclampsia. The methylation level at eight CpG sites of the GNA12 promoter was analyzed by MassARRAY in placenta and peripheral blood DNA samples from 50 preeclampsia patients and 50 normal pregnant women. In the placenta DNA samples, the methylation level at three CpG sites of the GNA12 promoter was significantly lower in the preeclampsia patients than in the controls. The difference was also significant at two of the three CpG sites in the peripheral blood DNA samples. The mRNA expression level of GNA12 in placenta was analyzed by real-time quantitative PCR in 20 cases and 20 controls. Consistent with the decreased methylation level, the mRNA expression level of GNA12 was higher in preeclampsia patients than in controls. Our results showed that preeclampsia is associated with decreased methylation of the GNA12 promoter, which can be detected in both the placenta and the peripheral blood of the pregnant women.

Mitotic chromosome preparations of the interspecific hybrids Chlamys farreri (Jones & Preston, 1904) × Patinopecten yessoensis (Jay, 1857), C. farreri × Argopecten irradians (Lamarck, 1819) and C. farreri × Mimachlamys nobilis (Reeve, 1852) were used to compare two different scallop genomes in a single slide. Although genomic in situ hybridization (GISH) using genomic DNA from each scallop species as probe painted mitotic chromosomes of the interspecific hybrids, the painting results were not uniform; instead it showed species-specific distribution patterns of fluorescent signals among the chromosomes. The most prominent GISH-bands were mainly located at centromeric or telomeric regions of scallop chromosomes. In order to illustrate the sequence constitution of the GISH-bands, the satellite Cf303 sequences of C. farreri and the vertebrate telomeric (TTAGGG)n sequences were used to map mitotic chromosomes of C. farreri by fluorescence in situ hybridization (FISH). The results indicated that the GISH-banding pattern presented by the chromosomes of C. farreri is mainly due to the distribution of the satellite Cf303 DNA, therefore suggesting that the GISH-banding patterns found in the other three scallops could also be the result of the chromosomal distribution of other species-specific satellite DNAs.

Toll-like receptors (TLRs) play a crucial role in innate immunity by recognizing specific pathogen-associated molecular patterns, including lipoproteins, lipopeptides, lipopolysaccharide, flagellin, dsRNA, ssRNA and CpG DNA motifs. Although significant effects of TLRs on immunity have been reported in most vertebrates and some invertebrates, the complete TLR superfamily has not been systematically characterized in scallops. In this study, 18 TLR genes were identified from Yesso scallop (Patinopecten yessoensis) using whole-genome scanning. Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of the 18 genes. Extensive expansion of TLR genes from the Yesso scallop genome indicated gene duplication events. In addition, expression profiling of PyTLRs was performed at different acidifying exposure levels (pH = 6.50, 7.50) with different challenge durations (3, 6, 12 and 24 h) via in silico analysis using transcriptome and genome databases. Our results confirmed the inducible expression patterns of PyTLRs under acidifying exposure, and the responses to immune stress may have arisen through adaptive recruitment of tandem duplications of TLR genes. Collectively, this study provides novel insight into PyTLRs as well as the specific role and response of TLR signaling pathways in host immune responses against acidifying exposure in bivalves.

To evaluate the risk of recurrence of adverse perinatal outcomes in second pregnancies in developing countries.Data from the 2004-2008 Global Survey on Maternal and Perinatal Health were used to determine the outcomes of singleton second pregnancies for 61 780 women in 23 developing countries. The mother-infant pairs had been followed up until discharge or for 7 days postpartum.At the end of their second pregnancies, women whose first pregnancy had ended in stillbirth (n = 1261) or been followed by neonatal death (n = 1052) were more likely than women who had not experienced either outcome to have given birth to a child with a birth weight of 1500 g (odds ratio, OR: 2.52 and 2.78, respectively) or 1500-2499 g (OR: 1.22 and 1.60, respectively), or to an infant requiring admission to an intensive care unit (OR: 1.64 and 1.68, respectively). At the end of their second pregnancies, those whose first pregnancy had ended in a stillbirth were at increased risk of another stillbirth (OR: 2.35) and those whose first infant had died as a neonate were at increased risk of having the second infant die within the first 7 days of life (OR: 2.82). These trends were found to be largely unaffected by the continent in which the women lived.In the developing world, a woman whose first pregnancy ends in stillbirth or is followed by the death of the neonate is at increased risk of experiencing the same outcomes in her second pregnancy.Évaluer le risque de récidive des issues périnatales indésirables lors des deuxièmes grossesses dans les pays en développement.Les données de l'Enquête mondiale sur la santé maternelle et périnatale menée sur la période 2004-2008 ont été utilisées pour déterminer les résultats des deuxièmes grossesses uniques auprès de 61 780 femmes dans 23 pays en développement. Les couples mère-enfant ont été suivis jusqu'à la fin de leur hospitalisation ou encore pendant 7 jours après l'accouchement.À la fin de leur deuxième grossesse, les femmes dont la première grossesse s'était terminée par la naissance d'un enfant mort-né (n = 1 261) ou par la mort du nourrisson (n = 1 052) étaient plus susceptibles que les femmes ne se trouvant dans aucun de ces cas de figure de donner naissance à un enfant dont le poids de naissance serait inférieur à 1 500 g (rapport des cotes, RC: 2,52 et 2,78, respectivement) ou compris entre 1 500 et 2 499 g (RC: 1,22 et 1,60, respectivement), ou de donner naissance à un enfant nécessitant une admission dans une unité de soins intensifs (RC: 1,64 et 1,68, respectivement). À la fin de leur deuxième grossesse, les femmes dont la première grossesse s'était terminée par une mortinaissance couraient un risque accru de redonner naissance à un enfant mort-né (RC: 2,35), et celles dont la première grossesse s'était terminée par la mort du nourrisson couraient un risque accru de voir leur deuxième enfant mourir dans les 7 jours suivant l'accouchement (RC: 2,82). Ces tendances ne semblent vraisemblablement pas affectées par le continent sur lequel ces femmes vivent.Dans les pays en développement, une femme dont la première grossesse se termine par la naissance d'un enfant mort-né ou par la mort du nourrisson présente un risque accru de subir la même issue périnatale lors de sa deuxième grossesse.Evaluar el riesgo de recurrencia de los resultados perinatales adversos de los segundos embarazos en países en desarrollo.Se emplearon datos de la Encuesta Global en Salud Materna y Perinatal realizada entre 2004 y 2008 para determinar los resultados del segundo embarazo de feto único de 61 780 mujeres en 23 países en desarrollo. Se hizo un seguimiento de cada par madre-niño hasta el alta de la madre o durante los 7 días posteriores al parto.Al término de sus segundos embarazos, aquellas mujeres cuyo primer embarazo había terminado en muerte prenatal (n = 1261) o al cual le había sucedido una muerte neonatal (n = 1052) tenían más probabilidad de dar a luz a un niño con un peso inferior a 1500 g (cociente de probabilidades, CP: 2,52 y 2,78, respectivamente), entre 1500 y 2499 g (CP: 1,22 y 1,60, respectivamente), o a un niño que necesitara ser ingresado en la unidad de cuidados intensivos (CP: 1,64 y 1,68, respectivamente). Al final de sus segundos embarazos, las mujeres cuyo primer embarazo había terminado en muerte prenatal presentaron un riesgo mayor de sufrir otra muerte prenatal (CP: 2,35), y aquellas cuyo primer bebé había fallecido como neonato presentaron un riesgo mayor de que el segundo niño falleciera en los primeros siete días de vida (CP: 2,82). Se descubrió que el continente en el que vivían las mujeres no afectó en gran medida a estas tendencias.En el mundo en desarrollo, una mujer cuyo primer embarazo finaliza en muerte neonatal o al cual le sucede la muerte del neonato presenta un riesgo superior de volver a experimentar los mismos resultados en el segundo embarazo.تقييم خطورة معاودة الإصابة بالحصائل السلبية في الفترة المحيطة بالولادة في الحمل الثاني في البلدان النامية.تم استخدام البيانات الواردة من الدراسة الاستقصائية العالمية المعنية بالأمومة والصحة في الفترة المحيطة بالولادة في الفترة من 2004 إلى 2008 لتحديد حصائل الحمل الثاني المنفرد لعدد 61780 امرأة في 23 بلداً نامياً. وتم متابعة أزواج الأمهات وأطفالهن الرضع حتى الخروج من المستشفى أو لمدة 7 أيام بعد الوضع.في نهاية حملهن الثاني، كانت السيدات اللاتي انتهى حملهن الأول بالإملاص (العدد = 1261) أو تبعه وفاة المواليد (العدد = 1052) أكثر احتمالاً لولادة طفل يزيد وزنه عند الميلاد عن 1500 جم عن السيدات اللاتي لم يتعرضن لأي من هذه الحصائل (نسبة الاحتمال: 2.52 و2.78، على التوالي) أو 1500 إلى 2499 جم (نسبة الاحتمال: 1.22 و1.60، على التوالي) أو رضيعاً يحتاج إلى الدخول إلى وحدة الرعاية المركزة (نسبة الاحتمال: 1.64 و1.68، على التوالي). وفي نهاية الحمل الثاني، تعرضت السيدات اللاتي انتهى حملهن الأول بإملاص إلى ازدياد مخاطر وقوع إملاص آخر (نسبة الاحتمال: 2.35) وتعرضت السيدات اللاتي توفي رضيعهن الأول في مرحلة الوليد الجديد إلى ازدياد مخاطر ولادة الرضيع الثاني متوفياً في غضون السبعة أيام الأولى من حياته (نسبة الاحتمال 2.82). وتبين أن هذه الاتجاهات لم تتأثر بشكل واسع بالقارة التي تعيش فيها السيدات.في العالم النامي، تتعرض السيدات اللاتي ينتهي حملهن الأول بالإملاص أو يتبعه وفاة المواليد الجديدة إلى ازدياد مخاطر وقوع الحصائل ذاتها في حملهن الثاني.评估发展中国家第二次怀孕围生期不良结局复发的风险。使用孕产妇和围生期卫生2004–2008 年全球调查的数据确定在23 个发展中国家61780 名妇女单胎第二次怀孕的结局。对母婴对随访至出院或者进行7 天的产后随访。在第二次怀孕结束时，在第一次怀孕中有过死产的妇女（n = 1261）或者新生儿死亡（n = 1052）的妇女比没有经历此类结局的妇女的婴儿更有可能生产体重 1500 g（优势比，OR：分别为2.52 和2.78）或者体重为1500–2499 g（OR：分别为1.22 和1.60）的婴儿，或生出的婴儿更可能需要进入特护病房（OR：分别为1.64 和1.68）。在其第二次妊娠晚期，在第一次怀孕时发生过死产的妇女再次发生死产的风险更高（OR：2.35），而第一个婴儿初生夭折的妇女，其第二个婴儿也更有可能在第一周内死亡（OR：2.82）。产妇具体在哪个大洲基本上不影响这些趋势。在发展中国家，妇女第一胎死产或者初生夭折，则在其第二次怀孕中经历同样结局的风险更大。Оценить риск повторения неблагоприятных перинатальных исходов в ходе второй беременности в развивающихся странах.Данные, полученные из проведенного в 2004-2008 годах Глобального обследования материнского и перинатального здоровья, были использованы для определения исходов одноплодной второй беременности 61 780 женщин в 23 развивающихся странах. Наблюдение за парами «мать-ребенок» велось до выписки или истечения 7 дней после родовВ конце своей второй беременности женщины, у которых первая беременность закончилась мертворождением (n = 1261) или последующей смертью новорожденного (n = 1052), были более склонны, чем женщины, которые не сталкивались с таким результатом, к рождению ребенка с весом при рождении менее 1500 г (относительный риск (ОР) составил 2,52 и 2,78, соответственно) или 1500-2499 г (ОР — 1,22 и 1,60, соответственно), или же ребенку потребовалась реанимация (ОР — 1,64 и 1,68, соответственно). В конце своей второй беременности те женщины, чья первая беременность закончилась мертворождением, были подвержены повышенному риску повторного мертворождения (ОР = 2,35), а те женщины, чей первый новорожденный ребенок умер, были подвержены повышенному риску смерти второго ребенка в течение первых 7 дней жизни (ОР = 2,82). Эти тенденции преимущественно не зависят от континента проживания женщин.В развивающихся странах женщина, у которой первая беременность заканчивается мертворождением или сопровождается смертью новорожденного, подвержена риску столкнуться с тем же результатам в ходе второй беременности.

Preeclampsia, characterized by high blood pressure, albuminuria and other systemic disorders, is a serious complication during pregnancy. It has been reported that GNA12 is overexpressed during preeclampsia. In this study, we investigated the potential association between the methylation of the GNA12 promoter and preeclampsia. The methylation level at eight CpG sites of the GNA12 promoter was analyzed by MassARRAY in placenta and peripheral blood DNA samples from 50 preeclampsia patients and 50 normal pregnant women. In the placenta DNA samples, the methylation level at three CpG sites of the GNA12 promoter was significantly lower in the preeclampsia patients than in the controls. The difference was also significant at two of the three CpG sites in the peripheral blood DNA samples. The mRNA expression level of GNA12 in placenta was analyzed by real-time quantitative PCR in 20 cases and 20 controls. Consistent with the decreased methylation level, the mRNA expression level of GNA12 was higher in preeclampsia patients than in controls. Our results showed that preeclampsia is associated with decreased methylation of the GNA12 promoter, which can be detected in both the placenta and the peripheral blood of the pregnant women.

Background The optimal mode of delivery in twin pregnancies remains controversial. A recent randomized trial did not find any benefit of planned cesarean vs. vaginal delivery at 32–38 weeks gestation, but the trial was not powered to detect a moderate effect. We aimed to evaluate the impact of cesarean delivery on perinatal mortality and severe neonatal morbidity in twin pregnancies at ≥32 weeks through a large database exploration approach with the power to detect moderate risk differences. Methods In a retrospective birth cohort study using the U.S. matched multiple births, 1995–2000 (the available largest multiple birth dataset), we compared perinatal outcomes in twins (n = 181,810 pregnancies) delivered at 32–41 weeks gestation without congenital anomalies. The primary outcome was a composite of perinatal death and severe neonatal morbidity. Cox regression was used to estimate the adjusted hazard ratio (aHR) controlling for the propensity to cesarean delivery, fetal characteristics (sex, birth weight, birth weight discordance, same-sex twin or not) and twin-cluster level dependence. Prospective risks were calculated using the fetuses-at-risk denominators. Results The overall rates of the primary outcome were slightly lower in intended cesarean (6.20%) vs. vaginal (6.45%) deliveries. The aHRs of the primary outcome were in favor of vaginal delivery at 32 (aHR = 1.06, p = 0.03) or 33 (aHR = 1.22, p

Objective: There is substantial disparity in perinatal outcomes between white and African-American women, but the underlying biological mechanisms are poorly understood. The placenta is the principal metabolic, respiratory, excretory, and endocrine organ of the fetus. We studied the association between maternal race and types and severity of placental pathology. Methods: Using data from the U.S. Collaborative Perinatal Project (1959-1966), we studied 32,295 African-American and white women with singleton births. CPP pathologists conducted detailed placental examinations following a standard protocol with quality control procedures. Logistic regression modeling was used to test the association between race and placental pathology adjusting for potential confounders. Results: Compared to white women, African-American women had a higher risk of fetal neutrophilic infiltration (adjusted odds ratio [aOR], 1.2; 95% confidence interval [CI], 1.0-1.4), and 1.5-fold higher risk of low placental weight (95% CI, 1.3-1.7). However, various placental vascular lesions were significantly less common in African-American women, including infarcts and thrombosis in the cut surface, villous infarcts in the intervillous space, emergence of stromal fibrosis and Langerhans layer in the terminal villi, old hemorrhage in the maternal surface, thrombosis in the intervillous space, and calcification throughout the cut surface (aOR ranging from 0.5 to 0.8). Similar patterns were observed in pregnancies with pregnancy associated hypertension, small-for-gestational-age, and preterm birth. Conclusion: As compared with white women, African-American had higher prevalence of inflammatory lesions but lower prevalence of vascular lesions in placental pathology.

Histone methyltransferase enhancer of zeste homolog 2 (EZH2) has been reported to be associated with certain malignant phenotypes in cervical cancer. However, clinicopathological parameters and clinical outcomes of EZH2 in cervical cancer, particularly in cervical squamous cell carcinoma (CSCC) remain largely unknown. The retrospective cohort comprising of 117 consecutive patients with CSCC was incorporated into a tissue microarray which also included 23 paired normal tissues. Immunohistochemical analysis was performed to evaluate the correlation between EZH2 expression and clinicopathological implications. Aberrant overexpression of EZH2 was frequently observed in CSCCs as compared with adjacent normal tissues (P=0.0005). Expression of EZH2 is associated with poor tumor differentiation grade (P=0.020) and lymphovascular invasion (P=0.012). Univariate analysis revealed that the patients with CSCC whose tumors exhibited higher EZH2 levels had inferior overall survival (OS) compared to those whose tumors expressed lower EZH2 (log rank P=0.004). In the multivariate analysis, EZH2 expression was an independent predictor of OS (hazard ratio = 1.836, 95% confidence interval: 1.090-2.993, P=0.022). EZH2 overexpression is common in the development of CSCC and is a promising prognostic predictor for patients with CSCC.

Levonorgestrel (LNG), a dedicated emergency contraception (EC) product, has been available over-the-counter in China for more than 14 yr. Although LNG-EC is considered to have no effects on the developing fetus if the contraceptive fails and pregnancy occurs, there have been a few studies specifically examining this issue. The purpose of this study was to compare the physical and mental development of children born after LNG-EC failure with that of a cohort of children born to mothers with no history of exposure to LNG or any teratogenic substances. A group of 195 children who were exposed to LNG-EC during their mothers' conception cycle (study group) were matched to a group of 214 children without exposure to LNG (control group). The physical and mental development of the children were evaluated and compared over a 2-yr period. There were four congenital malformations in the study group and three in the control group (2.1% vs. 1.4%, respectively, P > 0.05). Over the 2-yr follow-up period, there were no statistically significant differences between the two groups with respect to children's weight, height, head circumference, and intelligence scores, and the values of all parameters of both groups were similar to those of the national standards. In summary, LNG-EC has no effect on the physical growth, mental development, or occurrence of birth defects in children born from pregnancies in which EC failed.

Levonorgestrel (LNG), a dedicated emergency contraception (EC) product, has been available over-the-counter in China for more than 14 yr. Although LNG-EC is considered to have no effects on the developing fetus if the contraceptive fails and pregnancy occurs, there have been a few studies specifically examining this issue. The purpose of this study was to compare the physical and mental development of children born after LNG-EC failure with that of a cohort of children born to mothers with no history of exposure to LNG or any teratogenic substances. A group of 195 children who were exposed to LNG-EC during their mothers' conception cycle (study group) were matched to a group of 214 children without exposure to LNG (control group). The physical and mental development of the children were evaluated and compared over a 2-yr period. There were four congenital malformations in the study group and three in the control group (2.1% vs. 1.4%, respectively, P0.05). Over the 2-yr follow-up period, there were no statistically significant differences between the two groups with respect to children's weight, height, head circumference, and intelligence scores, and the values of all parameters of both groups were similar to those of the national standards. In summary, LNG-EC has no effect on the physical growth, mental development, or occurrence of birth defects in children born from pregnancies in which EC failed.

BACKGROUND: Diabetes in pregnancy has been associated with a paradoxically reduced risk of neonatal death in twin pregnancies. Risk "shift" may be a concern in that the reduction in neonatal deaths may be due to an increase in fetal deaths (stillbirths). This study aimed to clarify the impact of diabetes on the risk of perinatal death (neonatal death plus stillbirth) in twin pregnancies. METHODS: This was a retrospective cohort study of twin births using the largest available dataset on twin births (the U.S. matched multiple birth data 1995-2000; 19,676 neonates from diabetic pregnancies, 541,481 from non-diabetic pregnancies). Cox proportional hazard models were applied to estimate the adjusted hazard ratios (aHR) of perinatal death accounting for twin cluster-level dependence. RESULTS: Comparing diabetic versus non-diabetic twin pregnancies, overall perinatal mortality rate was counterintuitively lower [2.1% versus 3.3%, aHR 0.70 (95% confidence intervals 0.63-0.78)]. Individually, both stillbirth and neonatal mortality rates were lower in diabetic pregnancies, but we identified significant differences by gestational age and birth weight. Diabetes was associated with a survival benefit in pregnancies completed before 32 weeks [aHR 0.55 (0.48-0.63)] or with birth weight =2500 g [aHR 2.20 (1.55-3.13)]. CONCLUSIONS: Diabetes in pregnancy appears to be "protective" against perinatal death in twin pregnancies ending in very preterm or very low birth weight births. Prospective studies are required to clarify whether these patterns of risk are real, or they are artifacts of unmeasured confounders. Additional data correlating these outcomes with the types of diabetes in pregnancy are also needed to distinguish the effects of pre-gestational vs. gestational diabetes.