Requirement for nuclear autoantigenic sperm protein mRNA expression in bovine preimplantation development

Effect of 3D and 2D cell culture systems on trophoblast extracellular vesicle physico-chemical characteristics and potency

The growing understanding of the role of extracellular vesicles (EVs) in embryo-maternal communication has sparked considerable interest in their therapeutic potential within assisted reproductive technology, particularly in enhancing implantation success. However, the major obstacle remains the large-scale production of EVs, and there is still a gap in understanding how different culture systems affect the characteristics of the EVs. In the current study, trophoblast analogue human chorionic carcinoma cell line was cultivated in both conventional monolayer culture (2D) and as spheroids in suspension culture (3D) and how the cell growth environment affects the physical, biochemical and cellular signalling properties of EVs produced by them was studied. Interestingly, the 3D system was more active in secreting EVs compared to the 2D system, while no significant differences were observed in terms of morphology, size, and classical EV protein marker expression between EVs derived from the two culture systems. There were substantial differences in the proteomic cargo profile and cellular signalling potency of EVs derived from the two culture systems. Notably, 2D EVs were more potent in inducing a cellular response in endometrial epithelial cells (EECs) compared to 3D EVs. Therefore, it is essential to recognize that the biological activity of EVs depends not only on the cell of origin but also on the cellular microenvironment of the parent cell. In conclusion, caution is warranted when selecting an EV production platform, especially for assessing the functional and therapeutic potential of EVs through in vitro studies.

Strategies for successful designing of immunocontraceptive vaccines and recent updates in vaccine development against sexually transmitted infections - A Review

Background

Objective

Methods

Results

Conclusion

Mitochondrial maturation in the trophectoderm and inner cell mass regions of bovine blastocysts

Cellular differentiation induces various morphological changes, including elongation, in mitochondria. Preimplantation embryos have round-shaped mitochondria, characteristic of undifferentiated cells. However, there is controversy regarding the precise mitochondrial morphology in blastocyst embryos, which are generated from two cell lineages: undifferentiated inner cell mass (ICM) and differentiated trophectoderm (TE). This study attempted to precisely determine mitochondrial morphology in these two blastocyst regions. Transmission electron microscopy analyses were conducted using more than 1000 mitochondria from blastocyst embryos. No significant differences were observed in the configuration of mitochondrial cristae and frequencies of hooded mitochondria, which are specific to embryos of livestock animals, between the ICM and TE. To accurately compare mitochondrial roundness between the ICM and TE, oblateness was calculated based on both the major and minor axes. Average oblateness was significantly greater in the TE than in the ICM (P < 0.01). These results indicate tissue-specific mitochondrial maturation with complete elongation in the TE at the blastocyst stage. Since mitochondrial elongation is closely associated with cellular metabolism and differentiation, the present study provides new insights for better understanding of early embryonic development in cattle.

Pathogenetic factors involved in recurrent pregnancy loss from multiple aspects

Recurrent pregnancy loss (RPL) is a common complication in obstetrics, affecting about 5% of women of childbearing age. An increase in the number of abortions results in escalation in the risk of miscarriage. Although concentrated research has identified numerous causes for RPL, about 50% of them remain unexplained. Pregnancy is a complex process, comprising fertilization, implantation, organ and tissue differentiation, and fetal growth, which is effectively controlled by a number of both maternal and fetal factors. An example is the immune response, in which T cells and natural killer cells participate, and inflammation mediated by tumor necrosis factor or colony-stimulating factor, which hinders embryo implantation. Furthermore, vitamin D affects glucose metabolism and inhibits embryonic development, whereas microRNA has a negative effect on the gene expression of embryo implantation and development. This review examines the causes of RPL from multiple perspectives, and focuses on the numerous factors that may result in RPL.

Divergent evolution in the genomes of closely related lacertids, Lacerta viridis and L. bilineata, and implications for speciation

BACKGROUND

Lacerta viridis and Lacerta bilineata are sister species of European green lizards (eastern and western clades, respectively) that, until recently, were grouped together as the L. viridis complex. Genetic incompatibilities were observed between lacertid populations through crossing experiments, which led to the delineation of two separate species within the L. viridis complex. The population history of these sister species and processes driving divergence are unknown. We constructed the first high-quality de novo genome assemblies for both L. viridis and L. bilineata through Illumina and PacBio sequencing, with annotation support provided from transcriptome sequencing of several tissues. To estimate gene flow between the two species and identify factors involved in reproductive isolation, we studied their evolutionary history, identified genomic rearrangements, detected signatures of selection on non-coding RNA, and on protein-coding genes.

FINDINGS

Here we show that gene flow was primarily unidirectional from L. bilineata to L. viridis after their split at least 1.15 million years ago. We detected positive selection of the non-coding repertoire; mutations in transcription factors; accumulation of divergence through inversions; selection on genes involved in neural development, reproduction, and behavior, as well as in ultraviolet-response, possibly driven by sexual selection, whose contribution to reproductive isolation between these lacertid species needs to be further evaluated.

CONCLUSION

The combination of short and long sequence reads resulted in one of the most complete lizard genome assemblies. The characterization of a diverse array of genomic features provided valuable insights into the demographic history of divergence among European green lizards, as well as key species differences, some of which are candidates that could have played a role in speciation. In addition, our study generated valuable genomic resources that can be used to address conservation-related issues in lacertids.

Reciprocal regulation of TEAD4 and CCN2 for the trophectoderm development of the bovine blastocyst

The first segregation at the blastocyst stage is the symmetry-breaking event to characterize two cell components; namely, inner cell mass (ICM) and trophectoderm (TE). TEA domain transcription factor 4 (TEAD4) is a well-known regulator to determine TE properties of blastomeres in rodent models. However, the roles of bovine TEAD4 in blastocyst development have been unclear. We here aimed to clarify the mechanisms underlining TE characterization by TEAD4 in bovine blastocysts. We first found that theTEAD4mRNA expression level was greater in TE than in ICM, which was further supported by TEAD4 immunofluorescent staining. Subsequently, we examined the expression patterns of TE-expressed genes;CDX2,GATA2andCCN2, in theTEAD4-knockdown (KD) blastocysts. These expression levels significantly decreased in theTEAD4KD blastocysts compared with controls. Of these downregulated genes, theCCN2expression level decreased the most. We further analyzed the expression levels of TE-expressed genes;CDX2,GATA2andTEAD4in theCCN2KD blastocysts. Strikingly, theCCN2KD blastocysts showed the downregulation ofCDX2,GATA2andTEAD4. Furthermore, the ratio of TE-to-ICM cell numbers in theCCN2KD blastocysts significantly decreased compared to controls. To our knowledge, this is the first study showing the regulation ofCCN2expression thoroughTEAD4in mammalian embryos. Not only that, this study also provides evidence that reciprocal regulation ofTEAD4andCCN2is required for TE development with appropriate gene expression in bovine blastocysts.