Metagenomics and metabolomics reveal that gut microbiome adapts to the diet transition in Hyla rabbits

There is still a lack of longitudinal dynamic studies on the taxonomic features, functional reserves, and metabolites of the rabbit gut microbiome. An experiment was conducted to characterize the bacterial community of rabbits. By combining metagenomics and metabolomics, we have comprehensively analyzed the longitudinal dynamics of the rabbit gut microbiota and its effect on host adaptability. Our data reveal an overall increasing trend in microbial community and functional gene diversity and richness during the pre-harvest lifespan of rabbits. The introduction of solid feed is an important driving factor affecting rabbit gut microbiological compositions. Clostridium and Ruminococcus had significantly higher relative abundances in the solid feed stage. Further, the starch and fiber in solid feed promote the secretion of carbohydrate-degrading enzymes, which helps the host adapt to dietary changes. The rabbit gut microbiota can synthesize lysine, and the synthase is gradually enriched during the diet transformation. The gut microbiota of newborn rabbits has a higher abundance of lipid metabolism, which helps the host obtain more energy from breast milk lipids. The rabbit gut microbiota can also synthesize a variety of secondary bile acids after the introduction of solid feed. These findings provide a novel understanding of how the gut microbiota mediates adaptability to environment and diet in rabbits and provide multiple potential strategies for regulating intestinal health and promoting higher feed efficiency.

Dynamics of α-glucan from Agrocybe cylindracea water extract at different developmental stages and its structure characteristics

Polysaccharides are the important bioactive macromolecules in Agrocybe cylindracea, but their changes are as yet elusive during developmental process. This study investigated the dynamic changes of polysaccharides from A. cylindracea fruiting body water extract at four developmental stages and its structure characteristics. Results revealed that the polysaccharides from A. cylindracea water extract significantly increased at the pileus expansion stage and the increased fraction could be α-glucan. The further purification and identification indicated that this α-glucan was a glycogen. It had typical morphology of β particles with a molecular weight of 1375 kDa. Its backbone comprised α-D-(1 → 4)-Glcp and α-D-(1 → 4,6)-Glcp residues at a ratio of 5:1, terminated by α-D-Glcp residue. Rheological behavior suggested that it was a Newtonian fluid at the concentration of 1 %. In addition, despite both the glycogen and natural starch were composed of d-glucose, they exhibited the entirely distinct Maltese cross characteristic and unique crystalline structure. This study is the first to demonstrate the presence of abundant glycogen in the pileus expansion stage of A. cylindracea, which provides new insights on the change patterns of fungal polysaccharides.

Transcriptome analysis reveals immune function-related mRNA expression in donkey mammary glands during four developmental stages

The low susceptibility to mastitis of female donkey (jenny) mammary glands and the strong immune properties of donkey milk are acknowledged, but little is known about the genes involved in mammary gland immunity in jennies. Herein, we used RNA-sequencing and bioinformatics analyses to explore jenny mammary gland transcriptomes and detect potential functional differentially expressed (DE) mRNAs related to immunity during four specific developmental stages: foetal (F), pubertal (P), adult parous nonlactation (N) and lactation (L). A total of 2497, 583 and 1820 DE mRNAs were identified in jenny mammary glands at F vs. P, P vs. N, and N vs. L, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) analyses revealed numerous GO terms related to immune function, especially between F and P. Seven significantly enriched profiles were identified, among which 497 and 1261 DE mRNAs were upregulated in profiles 19 and 17. Eleven mRNAs were enriched in over 10 KEGG pathways. β-2-microglobulin (B2M), immunoglobulin heavy constant mu (IGHM), toll like receptor 2 (TLR2), toll like receptor 4 (TLR4) and myeloid differentiation factor 88 (MYD88) were mainly involved in phosphoinositide 3-kinase (PI3K)-Akt signalling, phagosome and nuclear factor kappa-B (NF-kappa B) signalling pathways. The findings provide insight into the molecular features underpinning the low prevalence of intramammary infections (i.e., mastitis) in donkeys.

Untangling the role of leaf age specific osmoprotectant and antioxidant responses of two poplar clones under increasing ozone concentrations

Plants possess different degrees of tolerance to abiotic stress, which can mitigate the detrimental effect of environmental inputs affecting carbon balance. Less is known about the functions of osmoprotectants in scavenging of reactive oxygen species (ROS), generated at different sites depending on leaf age. This study aimed to clarify the osmotic adjustments adopted by old and young leaves of Oxford and I-214 poplar clones [differing in ozone (O3) sensitivity] to cope with three levels of O3 [ambient (AA), and two elevated O3 levels]. In both clones, the impact of intermediate O3 concentrations (1.5 × AA) on ROS production appeared to be leaf age-specific, given the accumulation of hydrogen peroxide (H2O2) observed only in old leaves of the Oxford plants and in young leaves of the I-214 ones (2- fold higher than AA and +79%, respectively). The induction of an oxidative burst was associated with membrane injury, indicating an inadequate response of the antioxidative systems [decrease of lutein and β-carotene (-37 and -85% in the old leaves of the Oxford plants), accumulation of proline and tocopherols (+60 and +12% in the young leaves of the I-214 ones)]. Intermediate O3 concentrations reacted with unsaturated lipids of the plasma membrane in old and young leaves of the Oxford plants, leading to an increase of malondialdehyde by-products (more than 2- fold higher than AA), while no effect was recorded for I-214. The impact of the highest O3 concentrations (2.0 × AA) on ROS production did not appear clone-specific, which may react with cell wall components by leading to oxidative pressure. Outcomes demonstrated the ability of young leaves of I-214 plants in contain O3 phytotoxic effects.

Cellular dynamics in the maize leaf growth zone during recovery from chilling depends on the leaf developmental stage

KEY MESSAGE

A novel non-steady-state kinematic analysis shows differences in cell division and expansion determining a better recovery from a 3-day cold spell in emerged compared to non-emerged maize leaves. Zea mays is highly sensitive to chilling which frequently occurs during its seedling stage. Although the direct effect of chilling is well studied, the mechanisms determining the subsequent recovery are still unknown. Our goal is to determine the cellular basis of the leaf growth response to chilling and during recovery of leaves exposed before or after their emergence. We first studied the effect of a 3-day cold spell on leaf growth at the plant level. Then, we performed a kinematic analysis to analyse the dynamics of cell division and elongation during recovery of the 4th leaf after exposure to cold before or after emergence. Our results demonstrated cold more strongly reduced the final length of non-emerged than emerged leaves (- 13 vs. - 18%). This was not related to growth differences during cold, but a faster and more complete recovery of the growth of emerged leaves. This difference was due to a higher cell division rate on the 1st and a higher cell elongation rate on the 2nd day of recovery, respectively. The dynamics of cell division and expansion during recovery determines developmental stage-specific differences in cold tolerance of maize leaves.

Core gut microbes Cloacibacterium and Aeromonas associated with different gastropod species could be persistently transmitted across multiple generations

BACKGROUND

Studies on the gut microbiota of animals have largely focused on vertebrates. The transmission modes of commensal intestinal bacteria in mammals have been well studied. However, in gastropods, the relationship between gut microbiota and hosts is still poorly understood. To gain a better understanding of the composition of gut microbes and their transmission routes in gastropods, a large-scale and long-term experiment on the dynamics and transmission modes of gut microbiota was conducted on freshwater snails.

RESULTS

We analyzed 244 microbial samples from the digestive tracts of freshwater gastropods and identified Proteobacteria and Bacteroidetes as dominant gut microbes. Aeromonas, Cloacibacterium, and Cetobacterium were identified as core microbes in the guts, accounting for over 50% of the total sequences. Furthermore, both core bacteria Aeromonas and Cloacibacterium, were shared among 7 gastropod species and played an important role in determining the gut microbial community types of both wild and cultured gastropods. Analysis of the gut microbiota at the population level, including wild gastropods and their offspring, indicated that a proportion of gut microbes could be consistently vertically transmitted inheritance, while the majority of the gut microbes resulted from horizontal transmission. Comparing cultured snails to their wild counterparts, we observed an increasing trend in the proportion of shared microbes and a decreasing trend in the number of unique microbes among wild gastropods and their offspring reared in a cultured environment. Core gut microbes, Aeromonas and Cloacibacterium, remained persistent and dispersed from wild snails to their offspring across multiple generations. Interestingly, under cultured environments, the gut microbiota in wild gastropods could only be maintained for up to 2 generations before converging with that of cultured snails. The difference observed in gut bacterial metabolism functions was associated with this transition. Our study also demonstrated that the gut microbial compositions in gastropods are influenced by developmental stages and revealed the presence of Aeromonas and Cloacibacterium throughout the life cycle in gastropods. Based on the dynamics of core gut microbes, it may be possible to predict the health status of gastropods during their adaptation to new environments. Additionally, gut microbial metabolic functions were found to be associated with the adaptive evolution of gastropods from wild to cultured environments.

CONCLUSIONS

Our findings provide novel insights into the dynamic processes of gut microbiota colonization in gastropod mollusks and unveil the modes of microbial transmission within their guts. Video Abstract.

Identification and expression analysis of the KNOX genes during organogenesis and stress responseness in Camellia sinensis (L.) O. Kuntze

Tea plant (Camellia sinensis L.), whose leaves are the major reproductive organs, has been cultivated and consumed widely for its economic and health benefits. The Knotted1-like Homeobox (KNOX) proteins play significant roles in leaf morphology formation and development. However, the functions of KNOX proteins in tea plants are still unknown. Here, 11 CsKNOX genes from the tea plants were cloned and divided into Class I, II, and KNATM clades based on their protein sequences. These 11 CsKNOX genes were mapped on 8 out of 15 tea plant chromosomes, all localized in the nucleus. Specific spatiotemporal expression patterns of CsKNOX genes were found in various tissues and different development periods of buds, flowers, and roots of tea plants. Meanwhile, transcript levels of CsKNOX in tea leaves were strongly correlated with the accumulation of flavan-3-ols and proanthocyanidins. It was found that most of the CsKNOX genes could respond to drought, salt, cold, and exogenous MeJA and GA3 by analysis of transcriptomics data and promoter elements. The protein interaction analysis showed that CsKNOX could cooperate with CsAS1 and other critical functional proteins. In conclusion, this research provided the basic information for the functions of the CsKNOX family during organogenesis and stress response in tea plants, which was necessary for further functional characterization verification.

Dynamic characteristics of soil aggregate stability and related carbon and nitrogen pools at different developmental stages of plantations in northern China

The carbon and nitrogen reserves of forest soil play a key role in combating global climate change. Afforestation is considered an effective measure for increasing carbon and nitrogen reserves in terrestrial forest ecosystems. However, the mechanisms governing how different developmental stages of plantations affect soil carbon and nitrogen stability and storage remain unclear. In this study, we selected three developmental stages of the Larix principis-rupprechtii plantations: medium mature forest (30 yr), near mature forest (40 yr) and mature forest (50 yr). We studied the distribution and stability of soil aggregates at distinct developmental stages, the distribution of carbon and nitrogen pools related to aggregates, and their relationship to environmental factors. We found that with increasing forest age, the soil sand particles became finer. In each developmental stage, the proportion of aggregates >0.25 mm reached more than 85%. The concentrations of carbon and nitrogen in the soil aggregates were lower in the near mature forest (40 a) than in the medium mature forest (30 a), but reached a maximum in the mature forest (50 a). There were significant positive correlations between soil carbon and nitrogen concentrations and soil relative water content (RWC), forest age, and stand density. Soil texture strongly affected the distribution of aggregates. TOC/TN was mainly influenced by aggregate distribution, which was most vulnerable to environmental factors. Environmental factors have a significant negative impact on soil texture, and the path coefficient was -0.812. Environmental factors indirectly affected the concentrations of soil carbon and nitrogen by influencing the distribution and stability of soil aggregates. Therefore, different developmental stages of plantations strongly affected forest carbon and nitrogen pools by changing the soil structure and environmental factors. This study provides a basis for understanding the mechanisms of forest soil carbon and nitrogen storage.

RNA-Seq analysis reveals the important co-expressed genes associated with polyphyllin biosynthesis during the developmental stages of Paris polyphylla

Background

Plants synthesize metabolites to adapt to a continuously changing environment. Metabolite biosynthesis often occurs in response to the tissue-specific combinatorial developmental cues that are transcriptionally regulated. Polyphyllins are the major bioactive components in Paris species that demonstrate hemostatic, anti-inflammatory and antitumor effects and have considerable market demands. However, the mechanisms underlying polyphyllin biosynthesis and regulation during plant development have not been fully elucidated.

Results

Tissue samples of P. polyphylla var. yunnanensis during the four dominant developmental stages were collected and investigated using high-performance liquid chromatography and RNA sequencing. Polyphyllin concentrations in the different tissues were found to be highly dynamic across developmental stages. Specifically, decreasing trends in polyphyllin concentration were observed in the aerial vegetative tissues, whereas an increasing trend was observed in the rhizomes. Consistent with the aforementioned polyphyllin concentration trends, different patterns of spatiotemporal gene expression in the vegetative tissues were found to be closely related with polyphyllin biosynthesis. Additionally, molecular dissection of the pathway components revealed 137 candidate genes involved in the upstream pathway of polyphyllin backbone biosynthesis. Furthermore, gene co-expression network analysis revealed 74 transcription factor genes and one transporter gene associated with polyphyllin biosynthesis and allocation.

Conclusions

Our findings outline the framework for understanding the biosynthesis and accumulation of polyphyllins during plant development and contribute to future research in elucidating the molecular mechanism underlying polyphyllin regulation and accumulation in P. polyphylla.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08792-2.

Secretory immunoglobulin A (s-IgA) reactivity to acute psychosocial stress in children and adolescents: The influence of pubertal development and history of maltreatment

BACKGROUND

Mucosal secretory immunoglobulin A (s-IgA) is an antibody protein-complex that plays a crucial role in immune first defense against infection. Although different immune biomarkers have been associated with stress-related psychopathology, s-IgA remains poorly studied, especially in youth.

OBJECTIVES

The present study investigated how s-IgA behaves in front of acute psychosocial stress in children and adolescents, including possible variability associated with developmental stage and history of childhood maltreatment (CM).

METHODS

94 children and adolescents from 7 to 17 years (54 with a current psychiatric diagnostic and 40 healthy controls) drawn from a larger Spanish study were explored (EPI-Young Stress Project). To assess biological reactivity, participants provided five saliva samples during an acute laboratory-based psychosocial stressor, the Trier Social Stress Test for Children (TSST-C). Samples were assayed for s-IgA, as well as for cortisol. Pubertal development was ascertained by Tanner stage and CM following TASSCV criteria.

RESULTS

We observed s-IgA fluctuations throughout the stressor, indicating the validity of TSST-C to stimulate s-IgA secretion (F(4,199) = 6.200, p <.001). Although s-IgA trajectories followed a reactivity and recovery pattern in adolescents, children exhibited no s-IgA response when faced with stress (F(4,197) = 3.406, p =.010). An interaction was found between s-IgA and CM (F(4,203) = 2.643, p =.035). Interestingly, an interaction between developmental stage, CM history and s-IgA reactivity was identified (F(12,343) = 2.036, p =.017); while children non-exposed to maltreatment exhibited no s-IgA changes to acute stress, children with a history of CM showed a similar response to adolescents, increasing their s-IgA levels after the psychosocial stressor.

CONCLUSION

Acute psychosocial stress stimulates s-IgA secretion, but only after puberty. However, children with a history of maltreatment exhibited a response resembling that of adolescents, suggesting an early maturation of the immune system. Further studies are needed to clarify the validity of s-IgA as an acute stress biomarker, including additional measures during stress exposure.

Metallothionein-1 gene from Exopalaemon carinicauda and its response to heavy metal ions challenge

Metallothioneins (MTs) belong to a conserved low-molecular-weight protein family that participates in heavy metal binding and detoxification. EcMT-1 was amplified by PCR from genomic DNA of Exopalaenon carinicauda. It contained a 180 bp open reading frame and encoded 59 amino acids. A total of 18 cysteine (Cys) residues were found in the deduced amino acid sequence, which was consistent with the Cys-rich characteristics of MTs. EcMT-1 was mainly expressed in hepatopancreas, followed by stomach and gill. The expression profiles of EcMT-1 indicated that EcMT-1 was significantly increased at 24, 48 h and 12, 24, and 48 h under the treatment of 2.5 μmol/L CdCl₂ and 50 μmol/L CuSO₄. The expression of EcMT-1 at gastrula stage was very low; it was detectable until nauplius stage, and the highest expression level appeared in the postlarvae stage.

Vitrification of manually stage-selected embryos of Drosophila have significantly higher survival and emergence - Consequences for insect germplasm storage

Embryonic selection for vitrification and cryostorage in Drosophila and other dipterans is generally carried out by gross observation of the embryonic development at a constant temperature. In this study, the effect of embryo developmental temperature (19, 20 and 21 °C) on the stage specific convergence of the embryonic development to the developmental stages 15-17, that is useful for cryopreservation, was studied in a flightless mutant strain of Drosophila melanogaster and compared with the Ore-R strain. The temperature that allowed for the best convergence to stage 16 was chosen for further selection and treatment of the embryos. The converged embryos (SS) were directly treated or further manually sorted (MS) for the requisite developmental stage to reduce the number of non-convergent embryos. These selected embryos were then permeabilized and cryopreserved. While at all the three incubation temperatures the embryos exhibited convergence peaks, it was only at 20 °C and at hour 22 that a maximum number of stage 16 embryos converged and remained at a much higher proportion than the other developmental stages in both the strains. When permeabilized, MS embryos showed higher mean viability and hatching proportion compared to SS embryos (wingless: ∼0.70 vs. ∼0.58; Ore-R: ∼0.77 versus 0.54). Upon vitrification, the manually selected embryos hatched and survived at significantly higher mean rates than the converged embryos at stage 16 (wingless: 0.32 vs. ∼0.08; Ore-R: 0.47 vs. 0.15) after adjusting for permeabilization mortality. The maximum proportion hatch after vitrified storage that could be obtained by this method was 0.74 for both the wingless and Ore-R strains. More than 55% of the larvae pupated and >72% of the pupae eclosed in MS and vitrified wingless stage 16. In Ore-R, well over 85% of the larvae pupariated and eclosed as flight capable flies.

Characterization of reference genes for qRT-PCR normalization in rice-field eel (Monopterus albus) to assess differences in embryonic developmental stages, the early development of immune organs, and cells infected with rhabdovirus

Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) has become a popular technique to assess gene expression. Suitable reference genes are normally identified first to ensure accurate normalization. The aim of the present study was to select the most stable genes in embryonic developmental stages, the early development of immune organs, and cells infected with Chinese rice-field eel rhabdovirus (CrERV) of the rice-field eel (Monopterus albus). Four reference genes, including those encoding 18S ribosomal RNA (18SrRNA), beta actin (β-actin), elongation factor 1 alpha (EF1ɑ), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were assessed using geNorm, NormFinder, BestKeeper, and RefFinder software. Analyses indicated the stability ranking was 18SrRNA > β-actin > GAPDH > EF1α in the embryonic stage, with 18SrRNA as the most stable reference gene. For immunity-related organs at different developmental stages, the order in the thymus was β-actin > GAPDH > EF1α > 18SrRNA, with β-actin as the most stable gene. In both spleen and kidney tissues, the rank order was EF1ɑ > GAPDH > β-actin > 18SrRNA, with EF1α as the most stable gene. Furthermore, in rice-field eel kidney (CrE-K) cells infected with CrERV, the ranking was EF1ɑ > β-actin > GAPDH > 18SrRNA, with EF1α as the most stable gene. The results for cells infected with CrERV were verified by testing signaling pathway genes catenin beta 1 (CTNNB1) and NOTCH1 based on the above four genes after virus infection in CrE-K cells. This study laid the foundation for choosing suitable reference genes for immunity-related gene expression analysis in rice-field eel.

Tissue-specific distribution of primary and secondary metabolites of Baemoochae (×Brassicoraphanus) and its changes as a function of developmental stages

The distribution and changes in the primary and secondary metabolite profiles of Baemoochae, an inter-generic hybrid of Chinese cabbage and radish, during the plant's developmental stages were investigated. Metabolites were analyzed using gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight (UHPLC-ESI-qTOF MS). Free sugar, organic acid, and amino acid composition depended on the tissue type and developmental stage of Baemoochae. For example, glucose and alanine levels were higher in mature leaves than in young leaves; citric acid content in mature roots was lower than that in young roots. Several glucosinolates were identified for the first time in Baemoochae. Glucoraphasatin was predominant in both leaves and roots, regardless of plant maturity. Total glucosinolate content was significantly higher in roots than in leaves and in mature than in young plants. The roots of mature Baemoochae could be used as a rich source of glucosinolates, with several potential health-promoting effects.

Differences in third molar development and angulation in class II subdivision malocclusions

PURPOSE

To assess and compare the developmental stages and angulations of third molars between the class II and class I sides in class II subdivision malocclusions.

METHODS

This retrospective study was performed using panoramic x‑rays of 38 individuals (mean age: 15.5 years; 24 females, 14 males) with class II subdivision malocclusions, which were further divided into type 1 and 2 subgroups according to midline deviation, and a control group of 42 individuals (mean age: 17.0 years; 30 females, 12 males) with normal occlusion. Third molars were categorized using the developmental stages defined by the Demirjian method. Angles between the third molars and horizontal reference lines and also to the second molars were measured.

RESULTS

No difference was found in developmental stages or angulations between the left and right third molars in the control group. In the class II subdivision malocclusion cases, no difference in third molar developmental stages was observed, but the angle between the long axes of the mandibular third and second molars was significantly greater on the class II side. In the type 2 subgroup, developmental stage of the maxillary third molar was more advanced on the class II side. In both subgroups, the angles of the maxillary third molars' long axis to the interorbital plane differed significantly between the two sides.

CONCLUSION

Class II subdivision malocclusion may cause differences in third molar development and angulations between the two sides. Orthodontic treatment should be planned considering the third molars in this malocclusion.

Comprehensive transcriptome and methylome analysis delineates the biological basis of hair follicle development and wool-related traits in Merino sheep

Background

Characterization of the molecular mechanisms underlying hair follicle development is of paramount importance in the genetic improvement of wool-related traits in sheep and skin-related traits in humans. The Merino is the most important breed of fine-wooled sheep in the world. In this study, we systematically investigated the complexity of sheep hair follicle development by integrating transcriptome and methylome datasets from Merino sheep skin.

Results

We analysed 72 sequence datasets, including DNA methylome and the whole transcriptome of four gene types, i.e. protein-coding genes (PCGs), lncRNAs, circRNAs, and miRNAs, across four embryonic days (E65, E85, E105, and E135) and two postnatal days (P7 and P30) from the skin tissue of 18 Merino sheep. We revealed distinct expression profiles of these four gene types across six hair follicle developmental stages, and demonstrated their complex interactions with DNA methylation. PCGs with stage-specific expression or regulated by stage-specific lncRNAs, circRNAs, and miRNAs were significantly enriched in epithelial differentiation and hair follicle morphogenesis. Regulatory network and gene co-expression analyses identified key transcripts controlling hair follicle development. We further predicted transcriptional factors (e.g. KLF4, LEF1, HOXC13, RBPJ, VDR, RARA, and STAT3) with stage-specific involvement in hair follicle morphogenesis. Through integrating these stage-specific genomic features with results from genome-wide association studies (GWAS) of five wool-related traits in 7135 Merino sheep, we detected developmental stages and genes that were relevant with wool-related traits in sheep. For instance, genes that were specifically upregulated at E105 were significantly associated with most of wool-related traits. A phenome-wide association study (PheWAS) demonstrated that candidate genes of wool-related traits (e.g. SPHK1, GHR, PPP1R27, CSRP2, EEF1A2, and PTPN1) in sheep were also significantly associated with dermatological, metabolic, and immune traits in humans.

Conclusions

Our study provides novel insights into the molecular basis of hair follicle morphogenesis and will serve as a foundation to improve breeding for wool traits in sheep. It also indicates the importance of studying gene expression in the normal development of organs in understanding the genetic architecture of economically important traits in livestock. The datasets generated here are useful resources for functionally annotating the sheep genome, and for elucidating early skin development in mammals, including humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-01127-9.

Age-associated changes in caecal microbiome and their apparent correlations with growth performances of layer pullets

The microbiome in gastrointestinal tracts play an important role in regulating nutrient utilization and absorption, gut immune function, and host growth or development. This study was conducted to investigate the composition and dynamic distribution of caecal microbiota in pullets during the first 16 weeks. Growth performance, immune organs index, and intestinal morphology of pullets were analyzed at 3, 6, 12 and 16 weeks of age. The caecal contents were collected for microbiota analysis by 16S rRNA gene sequencing method. With advancing ages in pullets, the gradually increased average daily feed intake (ADFI), feed conversion ratio (FCR) and intestinal villus height, but the gradually decreased organs index of thymus and bursa were determined. Meanwhile, more abundant caecal bacterial communities were determined from pullets at 12 and 16 weeks of age than those at 3 and 6 weeks of age. Furthermore, the dominant microflora of pullets from different weeks of age were analyzed by using LEfSe: The higher abundance of Blautia, Prevotella, Alistipes, and Eggerthella were found at 6 weeks; Anaerostipes, Oscillospira, Enterococcus and Methanobrevibacter were determined at 12 weeks; and the higher abundance of Parabacteroides, Anaerofustis, Lactobacillus and Butyricimonas were determined at 16 weeks. Further functional predicted analysis by PICRUSt revealed that the endocrine system and carbohydrate metabolism were significantly developed at 3 weeks. The development of the immune system was predicted to be mainly during 6 to 12 weeks, while cardiovascular diseases and circulatory system were during 12 to 16 weeks. In addition, the significantly negative correlation between Bacteroides and villus height, the significantly negative correlation between growth parameters (ADFI and FCR) and Bacteroides, Oscillospira and Alistipes; and the significantly positive relations between growth parameters (ADFI and FCR) and Bilophila, Lactobacillus, Rikenella and Anaerofustis were determined by using Pearson analyses. In conclusion, our data demonstrated that growth performance and intestinal morphology correlate well with caecal microbiota, which could provide new insights to establish or develop nutritional strategies to manage the intestinal health or development of laying pullets.

Sex- and Developmental Stage-Related Differences in the Hepatic Transcriptome of Japanese Quail (Coturnix japonica) Exposed to 17β-Trenbolone

Endocrine-disrupting chemicals can cause transcriptomic changes that may disrupt biological processes associated with reproductive function including metabolism, transport, and cell growth. We investigated effects from in ovo and dietary exposure to 17β-trenbolone (at 0, 1, and 10 ppm) on the Japanese quail (Coturnix japonica) hepatic transcriptome. Our objectives were to identify differentially expressed hepatic genes, assess perturbations of biological pathways, and examine sex- and developmental stage-related differences. The number of significantly differentially expressed genes was higher in embryos than in adults. Male embryos exhibited greater differential gene expression than female embryos, whereas in adults, males and females exhibited similar numbers of differentially expressed genes (>2-fold). Vitellogenin and apovitellenin-1 were up-regulated in male adults exposed to 10 ppm 17β-trenbolone, and these birds also exhibited indications of immunomodulation. Functional grouping of differentially expressed genes identified processes including metabolism and transport of biomolecules, enzyme activity, and extracellular matrix interactions. Pathway enrichment analyses identified as perturbed peroxisome proliferator-activated receptor pathway, cardiac muscle contraction, gluconeogenesis, growth factor signaling, focal adhesion, and bile acid biosynthesis. One of the primary uses of 17β-trenbolone is that of a growth promoter, and these results identify effects on mechanistic pathways related to steroidogenesis, cell proliferation, differentiation, growth, and metabolism of lipids and proteins. Environ Toxicol Chem 2021;40:2559-2570. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Social Stress and Aggression in Murine Models

Throughout life, animals engage in a variety of social interactions ranging from the affiliative mother-offspring interaction and juvenile play to aggressive conflict. Deprivation of the appropriate social interaction during early development is stressful and disrupts the development of appropriate social behaviors and emotional responses later in life. Additionally, agonistic encounters can induce stress responses in both dominant and subordinate individuals. This review focuses on the social stress that escalates aggressive behavior of animals and discusses the known neurobiological and physiological mechanisms underlying the link between social stress and aggression. Social instigation, a brief exposure to a rival without physical contact, induces aggressive arousal in dominant animals and escalates aggressive behaviors in the following agonistic encounter. Furthermore, the experience of winning an aggressive encounter is known to be as rewarding as addictive drugs, and the experience of repeatedly winning induces addiction-like behavioral and neurobiological changes and leads to abnormal aggressive behaviors. Social isolation stress in early development from neonatal to juvenile and adolescent periods also affects aggressive behavior, but these effects largely depend on the strain, sex, and species as well as the stage of development in which isolation stress is experienced. In conclusion, understanding neurobiological mechanisms underlying the link between social stress and aggression will provide an important insight for the development of more effective and tolerable treatments for maladaptive aggression in humans.

Using multilevel models to explore the impact of abiotic and biotic conditions on the efficacy of pirimiphos-methyl against Tenebrio molitor L

In this study, we utilized a hierarchical multilevel modeling approach to test the hypothesis that the activity of the organophosphate insecticide pirimiphos-methyl against the cosmopolitan serious secondary pest of stored products, the yellow mealworm, Tenebrio molitor (Coleoptera: Tenebrionidae), is affected by temperature, relative humidity (RH), and developmental stage (adults, small larvae, large larvae). Our results showed that as temperature increased from 20 to 25 °C, the observed mortality of T. molitor was significantly higher. Furthermore, mortality at 25 °C did not significantly differ from that of 30 °C. An ultimate increase at 35 °C resulted in the highest mortality rate of T. molitor. However, an increase of RH from 55 to 75% adversely affected the efficacy of pirimiphos-methyl. In our study, it is also shown that the insect developmental stage is a critical feature of pirimiphos-methyl efficacy. Tenebrio molitor adults exhibited significantly higher mortality than larvae. In addition, small larvae showed significantly higher mortality than large larvae. Thus, adult is the most susceptible developmental stage of T. molitor to pirimiphos-methyl treatment. Our results could be useful tools for the management of T. molitor by indicating the optimum combination of temperature and RH that favors the insecticidal treatment against this species. In addition, we expect that the percentage of developmental stages in a whole population of T. molitor affects the insecticidal efficacy of pirimiphos-methyl.

Effect of biochar on the accumulation and distribution of cadmium in tobacco (Yunyan 87) at different developmental stages

Cadmium (Cd) easily accumulates in tobacco, which endangers public health through Cd exposure from smoking. However, its uptake, translocation, and distribution in tobacco plants during plant development or its response to biochar application are poorly understood. A pot experiment was conducted with tobacco (Yunyan 87) grown in soil severely contaminated with Cd (30 mg kg-1) amended with 0, 1, and 2% (w/w) tobacco stem-derived biochar (BC). The absorption and accumulation of Cd in all parts of the tobacco plants were most active from the rosette stage to the fast growing stage, during which approximately 90% of the Cd deposited in the tobacco leaves occurred, especially in the lower leaves. The Cd concentrations in most plant parts without added biochar decreased significantly by 52.61-78.30% due to the rapid increase in biomass (dilution effect), although the Cd concentration in the lower leaves increased by 48.89% (P < 0.05). However, with the slowdown of the growth rate of tobacco at the maturity stage, the proportion of Cd accumulation in roots and stems without biochar addition increased by 29.01%, resulting in an increased Cd concentration in roots and stems by 63.29-86.80% (P < 0.05). In the different growth stages, the application of biochar reduced the contents of DTPA-extractable and exchangeable Cd in the soil by 5.11-35.14% and 9.20-54.05%, respectively, thus reducing the absorption, accumulation and concentration of Cd in all parts of the tobacco plant. In addition, the inhibitive effect of biochar on the Cd concentration in the leaves was weak at the rosette stage (22.17-53.72%) compared with the other stages (46.14-78.88%), and the degree of inhibition of biochar on the Cd concentration in the middle leaves (37.94-59.24%) was lower than that in the upper and lower leaves (49.04-73.54%) at all developmental stages. However, the long-term remediation effect of biochar on soil Cd contamination needs to be further verified, and the combination of biochar and other technologies should receive additional attention.

Embryonic heart rate correlates with maternal temperature and developmental stage in viviparous snakes

Interactions between the environment and maternal and embryonic physiology can have critical ramifications for early-life phenotypes and survival in a range of species. A major component of the environment-maternal-embryonic nexus is the regulation of embryonic heart rate, which can have important ramifications for developmental phenology, but remains relatively unexplored in viviparous reptiles. The goal of this study was to test for a relationship between embryonic heart rate and maternal body temperature in two species of viviparous garter snakes. The embryonic heart rates of Thamnophis elegans and T. sirtalis were assessed using a field-portable ultrasound. For both T. elegans and T. sirtalis, embryonic heart rate was strongly correlated to maternal temperature. Interestingly, there was also a strong correlation between embryonic and maternal heart rate that was most likely mediated by a common response to maternal body temperature, in spite of the effects of handling during ultrasound on maternal heart rate. Furthermore, embryos at earlier developmental stages had lower heart rates. To our knowledge, this study is the first to explore embryonic heart rate in viviparous reptiles, providing a foundation for future work using ultrasonography to test ecological and evolutionary hypotheses related to developmental dynamics in free-ranging viviparous species.

The legacy of climate variability over the last century on populations' phenotypic variation in tree height

Phenotypic plasticity and local adaptation are the two main processes underlying trait variability. Under rapid environmental change, phenotypic plasticity, if adaptive, could increase the odds for organisms to persist. However, little is known on how environmental variation has shaped plasticity across species ranges over time. Here, we assess whether the portion of phenotypic variation of tree populations linked to the environment is related to the inter-annual climate variability of the last century and how it varies among populations across species ranges and age. To this aim, we used 372,647 individual tree height measurements of three pine species found in low elevation forests in Europe: Pinus nigra Arnold, P. pinaster Aiton and P. pinea L. Measurements were taken in a network of 38 common gardens established in Europe and North Africa with 315 populations covering the distribution range of the species. We fitted linear mixed-effect models of tree height as a function of age, population, climate and competition effects. Models allowed us to estimate tree height response curves at the population level and indexes of populations' phenotypic variation, as a proxy of phenotypic plasticity, at 4, 8 and 16 years old, and relate these indexes to the inter-annual climate variability of the last century. We found that phenotypic variation in tree height was higher in young trees than in older ones. We also found that P. pinea showed the highest phenotypic variation in tree height compared with P. pinaster and P. nigra. Finally, phenotypic variation in tree height may be partly adaptive, and differently across species, as climate variability during the last century at the origin of the populations explained between 51 and 69% of the current phenotypic variation of P. nigra and P. pinea, almost twice of the levels of P. pinaster. MAIN CONCLUSIONS: Populations' phenotypic variation in tree height is largely explained by the climate variability that the populations experienced during the last century, which we attribute to the genetic diversity among populations.

DNA methylation patterns of β-globin cluster in β-thalassemia patients

BACKGROUND

Reactivation of fetal hemoglobin (HbF, α₂γ₂) holds a therapeutic target for β-thalassemia and sickle cell disease. Although many HbF regulators have been identified, the methylation patterns in β-globin cluster driving the fetal-to-adult hemoglobin switch remains to be determined.

RESULTS

Here, we evaluated DNA methylation patterns of the β-globin cluster from peripheral bloods of 105 β⁰/β⁰ thalassemia patients and 44 normal controls. We also recruited 15 bone marrows and 4 cord blood samples for further evaluation. We identified that the CpG sites in the locus control region (LCR) DNase I hypersensitive site 4 and 3 (HS4-3) regions, and γ- and β-globin promoters displayed hypomethylation in β⁰/β⁰-thalassemia patients, especially for the patients with high HbF level, as compared with normal controls. Furthermore, hypomethylations in most of CpG sites of the HS4-3 core regions were also observed in bone marrows (BM) of β⁰/β⁰-patients compared with normal controls; and methylation level of γ-globin promoter -50 and + 17 CpG sites showed lower methylation level in patients with high HbF level compared with those with low HbF level and a negative correlation with HbF level among β⁰-thalassemia patients. Finally, γ-globin promoter + 17 and + 50 CpG sites also displayed significant hypomethylation in cord blood (CB) tissues compared with BM tissues from normal controls.

CONCLUSIONS

Our findings revealed methylation patterns in β-globin cluster associated with β⁰ thalassemia disease and γ-globin expression, contributed to understand the epigenetic modification in β⁰ thalassemia patients and provided candidate targets for the therapies of β-hemoglobinopathies.

Effect of Embryo Developmental Stage, Morphological Grading, and Ploidy Status on Live Birth Rate in Frozen Cycles of Single Blastocyst Transfer

To determine whether embryo developmental stage or morphological grading can predict live birth rate (LBR) from a single blastocyst in nonbiopsied and biopsied frozen embryo transfer (FET) cycles. This retrospective study included 1336 nonbiopsied and 360 euploid FET cycles. Blastocysts were divided according to developmental stage (day 5 [D5] and day 6 [D6]) and morphology (good quality and low quality). Nonbiopsied cycles in which D5 blastocysts were transferred were associated with a significantly higher LBR than those in the D6 group (48.5 vs. 24.3%; p < 0.001), as well as in good-quality embryo transfer cycles than that in low-quality embryo cycles (52.6 vs. 25.3%; p < 0.001). Embryos reaching good-quality blastocysts on D5 yielded significantly higher LBR than those similar quality blastocysts on D6. The same trend was seen in low-quality embryos. Concerning only D5 or D6 blastocyst transfer, the LBRs of good-quality embryos were still superior to those of low-quality embryos. In the case of euploid embryo transfers, the LBR (48.9 vs. 44.9%, p = 0.444) of D5 blastocysts did not significantly differ from that of D6 blastocysts. Good-quality embryos showed a higher LBR than low-quality embryos (51.6 vs. 40.0%, p = 0.030); the adjusted odds ratio remained insignificant after controlling for confounders (aOR 1.56; 95% CI 0.99-2.45; p = 0.056). The LBRs in the same developmental stage or morphology subgroups were not statistically significant. Embryo developmental stage and morphological grade are useful predictors of LBR in nonbiopsied FET cycles. However, no association was found in euploid transfer cycles.

Impedance flow cytometry allows the early prediction of embryo yields in wheat (Triticum aestivum L.) microspore cultures

Haplomethods are key biotechnological tools that make it possible to rapidly produce perfectly homozygous lines, speeding up plant breeding programs. Under specific stress conditions, microspores are reprogrammed toward sporophytic pathways, leading to embryo formation. Various endogenous and exogenous factors affect embryo yield in androgenesis, so the improvement of androgenesis efficiency requires the development of early, reliable and robust reactivity markers. During the last decade, numerous cytological, cellular and biochemical approaches were carried out to finely characterize microspore development and fate during androgenesis. However, the different available markers are often species-dependent, and their development and application are time-consuming and cumbersome. In this study, we show the suitable use of impedance flow cytometry (IFC) to develop new robust, reliable and strong markers of androgenesis reactivity in wheat, leading to: (i) routine monitoring of the viability of heterogeneous cell cultures; (ii) quick and simple evaluation of stress treatment efficiency; and (iii) early prediction of embryo yields from microspore suspensions. IFC can therefore provide the fine characterization of all of the microspore developmental pathways that occur in a cell suspension, for embryogenic microspores as well as pollen-like microspores. IFC technology has become a very useful tool to track and characterize wheat microspores in androgenesis, but can also be adapted to other species and other in vitro cell culture systems.

An integrative gene network-based approach to uncover the cellular and molecular infrastructures of schizophrenia

AIMS

High phenotypic and endophenotypic heritability of schizophrenia indicates substantial involvement of genetic elements in the occurrence of this disorder. Multiplicity of hypotheses about the genetic basis of schizophrenia pathogenesis suggests that there is still no integrated image from cellular and molecular infrastructure of this disorder.

MATERIALS AND METHODS

Here, we aimed to gain an integrated insight into the genetic basis of schizophrenia through gene set enrichment and network analysis to find the most important developmental stages/brain regions, chromosomal locations and metabolic pathways involved in the pathogenesis of schizophrenia. We investigated major mental disorders whose genetic bases are significantly overlapping with the schizophrenia gene set.

KEY FINDINGS

Enrichment analyses uncovered 60 developmental stages/brain regions, 21 chromosomal hotspots and 16 pathways which are significantly associated with the found gene set. Our results demonstrated early mid-fetal/cortex as the most prominent developmental stage/brain region, chr16q22 as the most significant cytoband and the neuroactive ligand-receptor interaction as the most central pathway associated with schizophrenia. Further analyses revealed that autistic disorder has the most shared genes with schizophrenia. Moreover, mitogen-activated protein kinase-3 (MAPK3), calcium voltage-gated channel subunit alpha1 C (CACNA1C), solute carrier family 6 member 4 (SLC6A4) and 5-hydroxytryptamine receptor 2A (HTR2A) genes are the most central genes in the pathogenesis of schizophrenia.

SIGNIFICANCE

In addition to summarizing what has been found on schizophrenia-associated genes in an integrative holistic framework, our results may help identify principle schizophrenia-associated cellular and molecular infrastructures, and provide support for further investigation on potential diagnostic and therapeutic biomarkers for schizophrenia.

Towards fully automated third molar development staging in panoramic radiographs

Staging third molar development is commonly used for age assessment in sub-adults. Current staging techniques are, at most, semi-automated and rely on manual interactions prone to operator variability. The aim of this study was to fully automate the staging process by employing the full potential of deep learning, using convolutional neural networks (CNNs) in every step of the procedure. The dataset used to train the CNNs consisted of 400 panoramic radiographs (OPGs), with 20 OPGs per developmental stage per sex, staged in consensus between three observers. The concepts of transfer learning, using pre-trained CNNs, and data augmentation were used to mitigate the issues when dealing with a limited dataset. In this work, a three-step procedure was proposed and the results were validated using fivefold cross-validation. First, a CNN localized the geometrical center of the lower left third molar, around which a square region of interest (ROI) was extracted. Second, another CNN segmented the third molar within the ROI. Third, a final CNN used both the ROI and the segmentation to classify the third molar into its developmental stage. The geometrical center of the third molar was found with an average Euclidean distance of 63 pixels. Third molars were segmented with an average Dice score of 93%. Finally, the developmental stages were classified with an accuracy of 54%, a mean absolute error of 0.69 stages, and a linear weighted Cohen's kappa coefficient of 0.79. The entire automated workflow on average took 2.72 s to compute, which is substantially faster than manual staging starting from the OPG. Taking into account the limited dataset size, this pilot study shows that the proposed fully automated approach shows promising results compared with manual staging.

Cryopreservation of oil palm (Elaeis guineensis Jacq.) polyembryoids via encapsulation-desiccation

The current report assesses the efficiency of encapsulation–desiccation protocol to cryopreserve oil palm (Elaeis guineensis Jacq.) polyembryoids. Specifically identified polyembryoids, comprising of haustorium and torpedo-shaped structures, were encapsulated [comprising 3% (w/v) sodium alginate and 100 mM CaCl₂]. Calcium alginate-encapsulated and sucrose-precultured polyembryoids were subjected to different spans of desiccation in a laminar air-flow cabinet, followed by freezing in liquid nitrogen. The effect of sucrose preculture (with gradual exposure to 0.3, 0.5, 0.75 and 1 M for 7 days) and dehydration periods (0–10 h) under sterile air-flow on post-freezing survival and regrowth of encapsulated polyembryoids were studied. Cryopreserved and thawed polyembryoids (initially precultured in sucrose, followed by 9 h air-desiccated to 23.3% moisture content) displayed the highest survival percentage (73.3%) and regeneration (of shoot, root and secondary somatic embryo) on Murashige and Skoog regrowth medium containing sucrose (0.3–1 M) and 0.2 mg/l 2,4-dichlorophenoxy acetic acid. In addition, ultrastructural study using scanning electron microscopy exhibited successful revival of cryopreserved polyembryoids, owing to retention of cellular membrane stability through optimized and protected (encapsulated) desiccation. The present study thus substantiates the potential of this encapsulation–desiccation procedure in cryopreservation of oil palm polyembryoids for long-term conservation programs.

Effects of Tropilaelaps mercedesae on midgut bacterial diversity of Apis mellifera

Tropilaelaps mercedesae is an ectoparasite of Apis mellifera in Asia and is considered a major threat to honey bee health. Herein, we used the Illumina MiSeq platform 16S rDNA Amplicon Sequencing targeting the V3-V4 regions and analysed the effects on the midgut bacterial communities of honey bees infested with T. mercedesae. The overall bacterial community in honey bees infested with T. mercedesae were observed at different developmental stages. Honey bee core intestinal bacterial genera such as Gilliamella, Lactobacillus and Frischella were detected. Tropilaelapsmercedesae infestation changed the bacterial communities in the midgut of A. mellifera. Tropilaelapsmercedesae-infested pupae had greatly increased relative abundances of Micrococcus and Sphingomonas, whereas T. mercedesae-infested 15-day-old workers had significantly reduced relative abundance of non-core microbes: Corynebacterium, Sphingomonas, Acinetobacter and Enhydrobacter compared to T. mercedesae-infested newly emerged bees. The bacterial community was significantly changed at the various T. mercedesae-infested developmental stages of A. mellifera. Tropilaelapsmercedesae infestation also changed the non-core bacterial community from larvae to newly emerged honey bees. Bacterial communities were significantly different between T. mercedesa-infested and non-mite-infested 15-day-old workers. Lactobacillus was dominant in T. mercedesae-infested 15-day-old workers compared to non-mite-infested 15-day-old workers.

Fine-tuning blastocyst selection based on morphology: a multicentre analysis of 2461 single blastocyst transfers

RESEARCH QUESTION

Which blastocyst morphology parameter is associated with live birth after controlling for female age and endometrial receptivity?

DESIGN

Retrospective study including fresh single blastocyst transfers (n = 2461) where the value of serum progesterone on day of human chorionic gonadotrophin trigger (PdHCG) was available. Generalized estimating equation regression models evaluated the independent effects of developmental stage (DevSt), inner cell mass (ICM) and trophectoderm grade on live birth rates while controlling for the confounding effects of female age and PdHCG.

RESULTS

DevSt was strongly associated with the probability of live birth (P < 0.0001) independently of female age (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.87-0.91) and PdHCG (OR 0.80, 95% CI 0.74-0.87). For full blastocysts, expanded blastocysts and hatching blastocysts, addition of ICM and trophectoderm grading in the multivariable analysis suggested that besides female age (OR 0.92, 95% CI 0.90-0.94) and PdHCG (OR 0.80, 95% CI 0.73-0.87), only DevSt (P = 0.001) and trophectoderm quality (P = 0.004) were independent predictors of live birth, while the predictive capacity of ICM was no longer significant. The mean probability of live birth was highest for AA blastocysts (35.0%), followed by BA blastocysts (31.2%) and AB blastocysts (27.7%).

CONCLUSION

This large study analyses for the first time the independent role of blastocyst morphology in predicting live birth while controlling for female age and PdHCG. Its findings suggest that DevSt and then trophectoderm grade are stronger predictors of live birth over ICM grade when selecting a single blastocyst for transfer.

Comprehensive expression analysis of Arabidopsis GA2-oxidase genes and their functional insights

Bioactive gibberellins (GAs) play multiple roles in plant development and stress responses. GA2-oxidases (GA2oxs) are a class of 2-oxoglutarate-dependent dioxygenases that regulate the deactivation of bioactive GAs. In this study, we investigated the phylogeny and domain structures of the seven GA2ox genes present in the Arabidopsis thaliana genome. Comprehensive expression analysis using translational reporter lines showed that the seven GA2ox genes are differentially expressed during Arabidopsis growth and development: GA2ox1 is specifically expressed in the hypocotyl and lateral root primordium; GA2ox2 is highly expressed in aboveground tissues; GA2ox3 is expressed in the chalazal endosperm of the early embryo sac and inflorescences; GA2ox4 is expressed in the shoot apical meristem and during lateral root initiation; GA2ox6 is expressed in the maturation zone, but not in the meristem or elongating zone of the root; GA2ox7 is constitutively expressed during almost all developmental stages; and GA2ox8 is exclusively expressed in stomatal cells. Overexpression of each of these GA2ox genes inhibited high temperature-induced hypocotyl elongation in both wild-type and elongated hypocotyl 5 plants, which have an elongated hypocotyl phenotype, suggesting that these genes negatively regulate hypocotyl elongation by reducing bioactive GA levels. This study provides a valuable resource for further elucidating the roles of GA2ox genes during different stages of development.

Characterization of genes encoding small heat shock proteins from Bemisia tabaci and expression under thermal stress

Small heat shock proteins (sHSPs) are probably the most diverse in structure and function among the various super-families of stress proteins, and they play essential roles in various biological processes. The sweet potato whitefly, Bemisia tabaci (Gennadius), feeds in the phloem, transmits several plant viruses, and is an important pest on cotton, vegetables and ornamentals. In this research, we isolated and characterized three α-crystallin/sHSP family genes (Bthsp19.5, Bthsp19.2, and Bthsp21.3) from Bemisia tabaci. The three cDNAs encoded proteins of 171, 169, and 189 amino acids with calculated molecular weights of 19.5, 19.2, and 21.3 kDa and isoelectric points of 6.1, 6.2, and 6.0, respectively. The deduced amino acid sequences of the three genes showed strong similarity to sHSPs identified in Hemiptera and Thysanoptera insects species. All three sHSPs genes from Bemisia tabaci lacked introns. Quantitative real-time PCR analyses revealed that the three BtsHSPs genes were significantly up-regulated in Bemisia tabaci adults and pupae during high temperature stress (39, 41, 43, and 45 °C) but not in response to cold temperature stress (-6, -8, -10, and -12 °C). The expression levels of Bthsp19.2 and Bthsp21.3 in pupae was higher than adults in response to heat stress, while the expression level of Bthsp19.5 in adults was higher than pupae. In conclusion, this research results show that the sHSP genes of Bemisia tabaci had shown differential expression changes under thermal stress.

Spatiotemporal expression pattern of Sjfz7 and its expression comparison with other frizzled family genes in developmental stages of Schistosoma japonicum

Wnts are secreted signaling molecules that are implicated in a variety of growth-related processes. Frizzled proteins have been identified as receptors for Wnt ligands in vertebrates and invertebrates, but a functional role for dioecious flatworm Frizzleds has not been determined. To evaluate the endogenous role of Frizzled proteins during development, we have identified and characterized a Schistosoma japonicum frizzled gene (Sjfz7). We found that Sjfz7 encodes a 698 amino acid protein with typical characteristics of Frizzled proteins. The immunohistochemical localization pattern showed that Sjfz7 protein was extensively distributed in almost all tissues of S. japonicum, including subtegumental muscle cells, parenchymal cells, intestinal epithelial cells and male and female germ cells. This indicated that Sjfz7-mediated Wnt signaling might be associated with the development of musculature, intestinal tract and reproductive organs in schistosome. Comparing mRNA levels between frizzled family members showed that Sjfz7 mRNA was consistently higher in the developmental stages analyzed, suggesting that Sjfz7 may be responsible for more functional tasks than other frizzled family members. Comparing frizzled mRNA levels between not fully developed and normal worms suggested that Wnt signaling might be abnormal in not fully developed worms.

Genome-wide analysis of developmental stage-specific transcriptome in Bradysia odoriphaga

Bradysia odoriphaga is a serious pest of the Chinese chive; however, detailed information regarding the developmental stage-specific gene expression patterns of B. odoriphaga is not yet available. In this study, RNA sequencing (RNA-seq) was performed to determine the gene expression patterns of developmental stages including the eggs, second instar larvae, fourth instar larvae, pupae, and adults of B. odoriphaga. Analysis of 15 samples revealed an average of 89.56% of the clean reads could be mapped onto the assembled UniGene database. Cluster tree analysis showed that the expression patterns were stage-specific and that samples of the second and fourth instar larvae clustered in one group, while those of eggs, pupae, and adults clustered in another group. Differential expression unigenes (DEUs) for sequential developmental stages were between 3314 and 10,632. A total of 1910-7756 DEUs of sequential developmental stages were assigned into 45-56 gene ontology categories and 1165-3845 DEUs were mapped into Kyoto Encyclopedia of Genes and Genomes pathways. The expression of DEUs related to growth and development showed that hormone receptors highly expressed in the pupal stage, while chitinases were highly expressed in the larval stage. The results of quantitative real time polymerase chain reaction (qRT-PCR) and RNA-seq expression agreed well for 12 growth- and development-related unigenes. This study identified DEUs for sequential developmental stages of B. odoriphaga. Gene Ontology classifications and KEGG pathway identification of DEUs not only provide information useful for understanding insect growth and development but also for exploring novel approaches to control B. odoriphaga.

The gut bacteria across life stages in the synanthropic fly Chrysomya megacephala

BACKGROUND

Gut bacteria are closely associated with host. Chrysomya megacephala, as a vector and resource insect, can transmit various pathogenic bacteria and consume manure to produce biofertilizer and larva biomass. However, the gut bacteria composition and abundance of C. megacephala remain unclear.

RESULTS

Illumina MiSeq platform was used to compare composition of gut bacterial community in eggs, 1-day-old larvae, 5-day-old larvae, pupae, adult females and males by sequencing with variation in V4 region of 16S ribosomal DNA gene. In total, 928 operational taxonomic units (OTUs) were obtained. These OTUs were annotated into 19 phyla, 42 classes, 77 orders, 153 families and 289 genera. More than 0.5% abundance of 32 OTU core genera were found across all life stages. At class level, Alphaproteobacteria, Bacilli, Bacteroidia, Betaproteobacteria, Flavobacteriia and Gammaproteobacteria were the most abundant in C. megacephala. Eight species were identified to have significantly different abundance between 1-d-larvae and 5-day-larvae and took 28.95% of shared species between these two groups. Sex-specific bacterial species were identified that Faecalibacterium prausnitzii was merely present in females, while Rhodococcus fascians was merely present in males.

CONCLUSION

Gut bacteria of C. megacephala varied across life stages. The composition and community structure of the bacterial community differed from young larvae to mature larvae, while that were similar in adult females and males. These data will provide an overall view of bacterial community across life stages in C. megacephala with attention on manure associated and pathogenic bacteria.

Toxicity of seven insecticides to different developmental stages of the whitefly Bemisia tabaci MED (Hemiptera: Aleyrodidae) in multiple field populations of China

Chemical control is important in the management of the tobacco whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Susceptibility of B. tabaci to insecticides may vary among different developmental stages and geographical populations. In this study, we examined toxicity of seven commonly-used insecticides to B. tabaci MED in four field populations from China. Avermectin has high level of toxicity to all stages of B. tabaci MED in all four populations. Cyantraniliprole and sulfoxaflor have high toxicity to adults. Spirotetramat, cyantraniliprole and flonicamid have high toxicity to nymphs but not adults. Acetamiprid, cyantraniliprole and sulfoxaflor have high toxicity to eggs. However, the relative toxicity of B. tabaci MED to these chemicals varied across different populations, with little consistency in population differences across developmental stages. Our findings together with some instances where LC₉₅ values were higher than field recommended dosages indicate field-evolved resistance to insecticides (such as thiamethoxam and sulfoxaflor) and stage-specific mechanisms that will influence effective control of B. tabaci MED by insecticides.

Different effects of bisphenol a and its halogenated derivatives on the reproduction and development of Oryzias melastigma under environmentally relevant doses

Bisphenol A (BPA) and its halogenated compounds (H-BPAs) are widely detected in the environmental media and organisms. However, their toxicological effects, especially chronic exposure at low doses, have not been fully compared. In this study, the effects of BPA and H-BPAs on the reproduction and development of Oryzias melastigma were systematically assessed and compared at various developmental stages. BPA and its derivatives tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) elicited the acceleration of embryonic heartbeat. BPA did not show any significant impact on the hatching time and rate of embryos. In contrast, both TBBPA and TCBPA led to the delayed hatching and decreased hatching rate. Accordingly, the expressions of hatching enzyme significantly decreased upon exposure and TCBPA was found to be more toxic than TBBPA. The body weight and gonadsomatic index (GSI) of the treated fish were relatively lower than the control fish upon long-term (four months from larvae to adult) exposure to BPA rather than H-BPAs. Slowed oocyte development occurred in the ovary, and the estrogen level decreased after exposure to BPA rather than H-BPAs. In male fish, no significant alteration was observed in the testis for all groups. The concentration of testosterone significantly decreased upon exposure to BPA rather than H-BPAs. The effects of these three chemicals on the estrogen-related gene expressions were different under various developmental stages. Our study indicated the importance of considering both the exposure stages and structure-activity relationship when assessing the eco-toxicological impact of pollutants.

Lettuce facing microcystins-rich irrigation water at different developmental stages: Effects on plant performance and microcystins bioaccumulation

This study investigated the microcystins (MCs)-rich irrigation water effect on lettuce of different developmental stages, i.e. during a two months period, covering the whole period from seed germination to harvest at marketable size of the plant. We followed four lettuce plant groups receiving MCs-rich water (1.81μgl-1 of dissolved MCs), originating from the Karla Reservoir, central Greece: 1) from seeds, 2) the cotyledon, 3) two true leaves and 4) four true leaves stages, all of which were compared to control plants that received tap water. Lettuce growth, photosynthetic performance, biochemical and mineral characteristics, as well as MCs accumulation in leaves, roots and soil were measured. The overall performance of lettuce at various developmental stages pointed to increased tolerance since growth showed minor alterations and non-enzymatic antioxidants remained unaffected. Plants receiving MCs-rich water from the seed stage exhibited higher photosynthetic capacity, chlorophylls and leaf nitrogen content. Nevertheless, considerable MCs accumulation in various plant tissues occurred. The earlier in their development lettuce plants started receiving MCs-rich water, the more MCs they accumulated: roots and leaves of plants exposed to MCs-rich water from seeds and cotyledons stage exhibited doubled MCs concentrations compared to respective tissues of the 4 Leaves group. Furthermore, roots accumulated significantly higher MCs amounts than leaves of the same plant group. Concerning human health risk, the Estimated Daily Intake values (EDI) of Seed and Cotyledon groups leaves exceeded Tolerable Daily Intake (TDI) by a factor of 6, while 2 Leaves and 4 Leaves groups exceeded TDI by a factor of 4.4 and 2.4 respectively. Our results indicate that irrigation of lettuce with MCs-rich water may constitute a serious public health risk, especially when contaminated water is received from the very early developmental stages (seed and cotyledon). Finally, results obtained for the tolerant lettuce indicate that MCs bioaccumulation in edible tissues is not necessarily coupled with phytotoxic effects.

Modeling the cis-regulatory modules of genes expressed in developmental stages of Drosophila melanogaster

Because transcription is the first step in the regulation of gene expression, understanding how transcription factors bind to their DNA binding motifs has become absolutely necessary. It has been shown that the promoters of genes with similar expression profiles share common structural patterns. This paper presents an extensive study of the regulatory regions of genes expressed in 24 developmental stages of Drosophila melanogaster. It proposes the use of a combination of structural features, such as positioning of individual motifs relative to the transcription start site, orientation, pairwise distance between motifs, and presence of motifs anywhere in the promoter for predicting gene expression from structural features of promoter sequences. RNA-sequencing data was utilized to create and validate the 24 models. When genes with high-scoring promoters were compared to those identified by RNA-seq samples, 19 (79.2%) statistically significant models, a number that exceeds previous studies, were obtained. Each model yielded a set of highly informative features, which were used to search for genes with similar biological functions.

Effects of three triazine metabolites and their mixture at environmentally relevant concentrations on early life stages of marbled crayfish (Procambarus fallax f. virginalis)

The sensitivity of early life stages of marbled crayfish (Procambarus fallax f. virginalis) to chronic exposure of one out of three triazine metabolites (terbuthylazine 2-hydroxy - T2H, terbuthylazine-desethyl - TD, and atrazine 2-hydroxy - A2H) and their mixture at maximal environmentally real concentrations was evaluated under laboratory conditions. The effects were assessed on the basis of mortality, growth, development, oxidative stress biomarkers, antioxidant enzymes activity and histopathology. Single metabolites (T2H - 0.73 μg/L; TD - 1.80 μg/L; A2H - 0.66 μg/L) and their mixture were not associated with negative effects on mortality, behaviour and early ontogeny, however, two metabolites (TD and A2H) and mixtures caused significantly lower growth and significantly higher catalase activity of early life stages of marbled crayfish. No histopathological changes of gills were observed after exposure to all tested triazine treatments, however, apparent histological differences in structural cells organization such as superiority in numbers of lipid resorptive cells were recorded in after exposition to TD and mixture. In conclusion, this study shows potential risk of using triazine herbicides in agriculture due to effects of their degradation products on non-target organisms.

Characterization of transcriptome in the Indian meal moth Plodia interpunctella (Lepidoptera: Pyralidae) and gene expression analysis during developmental stages

The Indian meal moth Plodia interpunctella (Lepidoptera: Pyralidae) is a worldwide pest that causes serious damage to stored foods. Although many efforts have been conducted on this species due to its economic importance, the study of genetic basis of development, behavior and insecticide resistance has been greatly hampered due to lack of genomic information. In this study, we used high throughput sequencing platform to perform a de novo transcriptome assembly and tag-based digital gene expression profiling (DGE) analyses across four different developmental stages of P. interpunctella (egg, third-instar larvae, pupae and adult). We obtained approximate 9gigabyte (GB) of clean data and recovered 84,938 unigenes, including 37,602 clusters and 47,336 singletons. These unigenes were annotated using BLAST against the non-redundant protein databases and then functionally classified based on Gene Ontology (GO), Clusters of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes databases (KEGG). A large number of differentially expressed genes were identified by pairwise comparisons among different developmental stages. Gene expression profiles dramatically changed between developmental stage transitions. Some of these differentially expressed genes were related to digestion and cuticularization. Quantitative real-time PCR results of six randomly selected genes conformed the findings in the DGEs. Furthermore, we identified over 8000 microsatellite markers and 97,648 single nucleotide polymorphisms which will be useful for population genetics studies of P. interpunctella. This transcriptomic information provided insight into the developmental basis of P. interpunctella and will be helpful for establishing integrated management strategies and developing new targets of insecticides for this serious pest.

Age, pathogen exposure, but not maternal care shape offspring immunity in an insect with facultative family life

Background

To optimize their resistance against pathogen infection, individuals are expected to find the right balance between investing into the immune system and other life history traits. In vertebrates, several factors were shown to critically affect the direction of this balance, such as the developmental stage of an individual, its current risk of infection and/or its access to external help such as parental care. However, the independent and/or interactive effects of these factors on immunity remain poorly studied in insects.

Results

Here, we manipulated maternal presence and pathogen exposure in families of the European earwig Forficula auricularia to measure whether and how the survival rate and investment into two key immune parameters changed during offspring development. The pathogen was the entomopathogenic fungus Metarhiziumbrunneum and the immune parameters were hemocyte concentration and phenol/pro-phenoloxidase enzyme activity (total-PO). Our results surprisingly showed that maternal presence had no effect on offspring immunity, but reduced offspring survival. Pathogen exposure also lowered the survival of offspring during their early development. The concentration of hemocytes and the total-PO activity increased during development, to be eventually higher in adult females compared to adult males. Finally, pathogen exposure overall increased the concentration of hemocytes—but not the total-PO activity—in adults, while it had no effect on these measures in offspring.

Conclusions

Our results show that, independent of their infection risk and developmental stage, maternal presence does not shape immune defense in young earwigs. This reveals that pathogen pressure is not a universal evolutionary driver of the emergence and maintenance of post-hatching maternal care in insects.

Determining the optimal developmental stages of Xenopus laevis for initiating exposures to chemicals for sensitively detecting their feminizing effects on gonadal differentiation

Xenopus laevis is an important model for detecting feminizing effects of endocrine disrupting chemicals (EDCs) on amphibians because its genetic males can be induced to phenotypic females by estrogenic chemicals. It is crucial that chemical exposures begin at sensitive developmental stages for gonadal sex-reversal in X. laevis. To determine the optimal stages for initiating exposures, we investigated gonadal sex-reversal induced by low concentrations of 17α-ethinylestradiol (EE2) when exposures were initiated at different stages (3/4, 45/46, 48 and 50) until stage 58. We found that 0.1nM EE2 resulted in 85%, 86%, 43%, and 19% intersex, whereas 1nM EE2 caused 77%, 81%, 17%, and 8% phenotypic females, when genetic male tadpoles were exposed from stages 3/4, 45/46, 48 and 50, respectively. The data show the sensitivity of X. laevis gonads to EE2 at stages 45/46 is similar with that at stages 3/4, but the sensitivity decreases at stage 48 and stage 50, displaying a developmental stage-dependent manner. In another experiment using the offspring of another pair of frogs, we confirmed high sensitivity of X. laevis gonads at stages 45/46 to low concentrations of EE2. Considering that stages 45/46 tadpoles are easier to manipulate and have higher survival rates than earlier embryos, we propose that stages 45/46 are the optimal stages for initiating exposure for detecting feminizing effects of EDCs on gonadal differentiation in X. laevis. The developmental stages for initiating exposures we determined will guarantee the high sensitivity for detecting feminizing effects of EDCs with low estrogenic activities on gonadal differentiation in X. laevis. Also, our study suggests that gonadal differentiation in X. laevis possibly begins at stages 45/46, but not at later stages.

An invertebrate signal transducer and activator of transcription 5 (STAT5) ortholog from the disk abalone, Haliotis discus discus: Genomic structure, early developmental expression, and immune responses to bacterial and viral stresses

Signal transducer and activator of transcription (STAT) family members are key signaling molecules that transduce cellular responses from the cell membrane to the nucleus upon Janus kinase (JAK) activation. Although seven STAT members have been reported in mammals, very limited information on STAT genes in molluscans is available. In this study, we identified and characterized a STAT paralog that is homologous to STAT5 from the disk abalone, Haliotis discus discus, and designated as AbSTAT5. Comparison of the deduced amino acid sequence for AbSTAT5 (790 amino acids) with other counterparts revealed conserved residues important for functions and typical domain regions, including the N-terminal domain, coiled-coil domain, DNA-binding domain, linker domain, and Src homology 2 (SH2) domains as mammalian counterparts. Analysis of STAT phylogeny revealed that AbSTAT5 was clustered with the molluscan subgroup in STAT5 clade with distinct evolution. According to the genomic structure of AbSTAT5, the coding sequence was distributed into 20 exons with 19 introns. Immunologically essential transcription factor-binding sites, such as GATA-1, HNF, SP1, C/EBP, Oct-1, AP1, c-Jun, and Sox-2, were predicted at the 5'-proximal region of AbSTAT5. Expression of AbSTAT5 mRNA was detected in different stages of embryonic development and observed at considerably higher levels in the morula and late veliger stages. Tissue-specific expressional studies revealed that the highest level of AbSTAT5 transcripts was detected in hemocytes, followed by gill tissues. Temporal expressions of AbSTAT5 were analyzed upon live bacterial (Vibrio parahemolyticus and Listeria monocytogenes), viral (viral hemorrhagic septicemia virus), and pathogen-associated molecular pattern (lipopolysaccharides and Poly I:C) stimulations, and significant elevations indicated immune modulation. These results suggest that AbSTAT5 may be involved in maintaining innate immune responses from developmental to adult stages in the disk abalone. Further, this study provides a basis for structural and functional exploration of STAT members in the invertebrate JAK/STAT signaling pathway.

Validation of reference genes for quantitative real-time PCR in Périgord black truffle (Tuber melanosporum) developmental stages

The symbiotic fungus Tuber melanosporum Vittad. (Périgord black truffle) belongs to the Ascomycota and forms mutualistic symbiosis with tree and shrub roots. This truffle has a high value in a global market and is cultivated in many countries of both hemispheres. The publication of the T. melanosporum genome has given researchers unique opportunities to learn more about the biology of the fungus. Real-time quantitative PCR (qRT-PCR) is a definitive technique for quantitating differences in transcriptional gene expression levels between samples. To facilitate gene expression studies and obtain more accurate qRT-PCR data, normalization relative to stable housekeeping genes is required. These housekeeping genes must show stable expression under given experimental conditions for the qRT-PCR results to be accurate. Unfortunately, there are no studies on the stability of housekeeping genes used in T. melanosporum development. In this study, we present a morphological and microscopical classification of the developmental stages of T. melanosporum fruit body, and investigate the expression levels of 12 candidate reference genes (18S rRNA; 5.8S rRNA; Elongation factor 1-alpha; Elongation factor 1-beta; α-tubulin; 60S ribosomal protein L29; β-tubulin; 40S ribosomal protein S1; 40S ribosomal protein S3; Glucose-6-phosphate dehydrogenase; β-actin; Ubiquitin-conjugating enzyme). To evaluate the suitability of these genes as endogenous controls, five software-based approaches and one web-based comprehensive tool (RefFinder) were used to analyze and rank the tested genes. We demonstrate here that the 18S rRNA gene shows the most stable expression during T. melanosporum development and that a set of three genes, 18S rRNA, Elongation factor 1-alpha and 40S ribosomal protein S3, is the most suitable to normalize qRT-PCR data from all the analyzed developmental stages; conversely, 18S rRNA, Glucose-6-phosphate dehydrogenase and Elongation factor 1-alpha are the most suitable genes for fruiting body developmental stages.

Expression Analysis of Cathepsin F during Embryogenesis and Early Developmental Stage in Olive Flounder (Paralichthys olivaceus)

Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder.

Stage and Tissue Specific Expression of Four TCR Subunits in Olive Flounder (Paralichthys olivaceus)

TCR subunits are members of membrane-bound receptors which allow the fast and efficient elimination of the specific fish pathogens have regulated function in adaptive immunity. Sequence structure of TCR subunits have been reported for various teleosts, but the information of each TCR subunit functional characterization through expression analysis in fish was unknown. In this study, we examined the gene expression of TCR subunits in the early developmental stages and observed transcript levels in various tissues from healthy adult olive flounder by RT-PCR. The mRNA expression of alpha subunit was already detected in the previous hatching step. But the transcripts of another TCR subunit were not observed during embryo development and increased after hatching and maintained until metamorphosis at the same level. It was found that all TCR subunits mRNAs are commonly expressed in the immune-related organ such as spleen, kidney and gill, also weak expressed in fin and eye. TCR alpha and beta subunit were expressed in brain, whereas gamma and delta were not expressed same tissue. The sequence alignment analysis shows that there are more than 80% sequence homology between TCR subunits. Because it has a high similarity of amino acid sequence to expect similar in function, but expression analysis show that will have may functional diversity due to different time and place of expression.

Family-based treatment with transition age youth with anorexia nervosa: a qualitative summary of application in clinical practice

BACKGROUND

Family based treatment (FBT) has been empirically investigated in adolescents between the ages of 12 and 19 years of age. Although parental control over eating symptoms and the weight gain process are temporary and necessary due to serious medical complications, FBT may be developmentally inappropriate when working with older adolescents. To date, there are no studies identifying how the principles of this model are used differentially across different stages of adolescence. This study aimed to identify how clinicians informed by FBT employ this model with transition age youth (TAY) (16-21) with an eating disorder.

METHODS

Using content analysis, seven individual interviews and six focus groups were conducted with 34 clinicians from specialized Eating Disorder Treatment programs across Ontario, Canada.

RESULTS

Participants consistently reported modifying FBT to increase its developmental appropriateness with TAY in the following ways: working more collaboratively with the patient, increasing individual time spent with the patient prior to the family meeting, providing greater opportunities for the individual to practice eating without parental support and introducing relapse prevention in the latter phase of the treatment.

CONCLUSIONS

In all adaptations of the model, participants in focus groups and individual interviews cited the age of the individual with the eating disorder, their level of autonomy and independence in all areas of their lives, and their pending transfer of care from paediatric to adult eating disorder programs as main factors that influenced the modification of FBT with TAY. While adaptations were made across all three phases of FBT, adherence to the model progressively declined over the course of treatment with adaptations increasing significantly in the later phases. Future research is needed to evaluate the effectiveness of an adapted version of FBT with TAY.

Transcervical collection of bovine embryos up to Day 21: an 8-year overview

Transcervical embryo collection is used routinely in the bovine species throughout the world to collect Day 6 to Day 9 embryos (early embryos) for genetic selection. For research purposes, however, the collection of embryos at later stages of pregnancy, i.e., Days 12 to 21 (late embryos), is needed. So far, for the recovery of late embryos, females are euthanized and embryo collection is performed after recovery of the genital tract. To reduce the number of animals used and still provide valuable material for embryo research, we have therefore developed a transcervical technique to collect late embryos. The objective of this study was to compare embryo recovery results at early and late stages within our laboratory. Altogether, 232 cows were used for this study. One hundred forty-five flushes were performed to collect embryos from Days 6 to 9, and 251 flushes were performed to collect embryos from Days 12 to 21. For the early embryos, a classical three-way collection equipment was used. To collect the late embryos, the same equipment was used, but the extensible flexible catheter that goes inside the external rigid catheter was removed, so that larger embryos could be collected through the remaining larger hole (two-way collection). All females were submitted to ovum pick up to remove the dominant follicle and were subsequently superovulated with FSH. Luteolysis was induced 48 hours before artificial insemination. Two artificial inseminations were performed with frozen semen, 48 and 56 hours after PGF2α injection. Before embryo collection, cows were treated with an epidural injection of a local anesthetic drug. The presence of CL was checked, and they were counted by rectal palpation. For all collections, the cervix was prepared with the initial introduction of a dilator. Then, the catheter was introduced in one horn, and the cuff was inflated as low as possible. For the collection of late embryos, the flushing solution (30 mL) was injected slowly twice to suspend the embryos before flushing the horn with 500 mL, and the same operation was performed on the second horn. There was no significant difference in the number of embryos collected per flush in the early- and late-stage (758 embryos collected, 5.22 ± 6.02 per flush vs. 1238 embryos collected, 4.93 ± 5.07 per flush, respectively). The number of embryos collected per CL, however, was significantly lower in the early versus late group (0.39 ± 0.32% vs. 0.44 ± 0.34%, respectively). The late collection allowed the retrieval of full conceptuses (embryonic and extraembryonic tissues), even at very late stages such as Days 18 to 21. Careful collection is needed, however, so that conceptuses are not damaged or torn: the horn must be massaged gently and the flush should be ideally recovered in one single flow. This technique is a powerful tool to collect the late-stage embryos for research purposes. Because it is not traumatic, animals can be used again for the same procedure.