Expression of theSox9,Foxl2,Vasa, andTRPV4genes in the ovaries and testes of the Morelet's crocodile,Crocodylus moreletii

Enhancing differentiation of menstrual blood-derived stem cells into female germ cells using a bilayer amniotic membrane and nano-fibrous fibroin scaffold

Three-dimensional nanofiber scaffolds offer a promising method for simulating in vivo conditions within the laboratory. This study aims to investigate the influence of a bilayer amniochorionic membrane/nanofibrous fibroin scaffold on the differentiation of human menstrual blood mesenchymal stromal/stem cells (MenSCs) into female germ cells. MenSCs were isolated and assigned to four culture groups: (i) MenSCs co-cultured with granulosa cells (GCs) using the scaffold (3D-T group), (ii) MenSCs using the scaffold alone (3D-C group), (iii) MenSCs co-cultured only with GCs (2D-T group), and (iv) MenSCs without co-culture or scaffold (2D-C group). Both MenSCs and GCs were independently cultured for two weeks before co-culturing was initiated. Flow cytometry was employed to characterize MenSCs based on positive markers (CD73, CD90, and CD105) and negative markers (CD45 and CD133). Additionally, flow cytometry and immunocytochemistry were used to characterize the GCs. Differentiated MenSCs were analyzed using real-time PCR and immunostaining. The real-time PCR results demonstrated significantly higher levels of VASA expression in the 3D-T group compared to the 3D-C, 2D-T, and 2D-C groups. Similarly, the SCP3 mRNA level in the 3D-T group was notably elevated compared to the 3D-C, 2D-T, and 2D-C groups. Moreover, the expression of GDF9 was significantly higher in the 3D-T group when compared to the 3D-C, 2D-T, and 2D-C groups. Immunostaining results revealed a lack of signal for VASA, SCP3, or GDF9 markers in the 2D-T group, while some cells in the 3D-T group exhibited positive staining for all these proteins. These findings suggest that the combination of a bilayer amniochorionic membrane/nanofibrous fibroin scaffold with co-culturing GCs facilitates the differentiation of MenSCs into female germ cells.

How do maternal androgens and estrogens affect sex determination in reptiles with temperature-dependent sex?

Temperature sex determination (TSD) in reptiles has been studied to elucidate the mechanisms by which temperature is transformed into a biological signal that determines the sex of the embryo. Temperature is thought to trigger signals that alter gene expression and hormone metabolism, which will determine the development of female or male gonads. In this review, we focus on collecting and discussing important and recent information on the role of maternal steroid hormones in sex determination in oviparous reptiles such as crocodiles, turtles, and lizards that possess TSD. In particular, we focus on maternal androgens and estrogens deposited in the egg yolk and their metabolites that could also influence the sex of offspring. Finally, we suggest guidelines for future research to help clarify the link between maternal steroid hormones and offspring sex.

Histology study and transcriptome analysis of the testis of Loach(Misgurnus anguillicaudatus) in response to phenanthrene exposure

Phenanthrene (PHE) is one of the most abundant polycyclic aromatic hydrocarbon compounds (PAHs) in the aquatic environment. The loaches were exposed at concentrations of 0.30、1.00、3.00 mg L^-1 for 60 days. The effects of PHE on the testis development were evaluated by calculating the survival rate, observing the structure of testis and analyzing transcriptome. Firstly, PHE markedly decreased the survival rate in a dose-dependent manner. Then, the number and density of spermatogonia, primary spermatocytes, secondary spermatocytes and spermatids were substantially reduced under PHE exposure. The space in the seminiferous tubule obviously increased in the high PHE concentration group. Meanwhile, transcriptome comparative analysis identified 5329 differentially expressed genes (DEGs) including 2928 up-regulated and 2401 down-regulated in the testis of loach exposed PHE for 60 days. Meiotic cell cycle, arganelle fission, ATPase activity and adenylate nucleotide binding were significantly differences by GO (Gene Ontology) enrichment. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis revealed that TNF (Tumor Necrosis Factor) signaling pathway, CAMs (Cell Adhesion Molecules), cytochrome P450 and lipid metabolism were markedly regulated. In addition, eight DEGs were randomly selected from the testis transcriptomics results for qPCR verification, the results were consistent with RNA-Seq. Finally, related genes (piwil2, dmc1, vasa, ubr2, dnd, rnf17, plcb2, c-fos, gpx4) of testis development were further confirmed and they were differentially regulated after PHE exposure. In summary, a survey of the mechanism of loach testis response to PHE was performed, and a large number of gene expression levels regarding metabolism, spermatogenesis and immunity genes were acquired from RNA-seq. This study provide informations for elucidating the molecular mechanism of PHE affected the testis development of loach.

Activation of TRPV4 stimulates transepithelial K+ secretion in rat epididymal epithelium

The maturation of sperms is dependent on the coordinated interactions between sperm and the unique epididymal luminal milieu, which is characterized by high K+ content. This study investigated the involvement of transient receptor potential vanilloid 4 (TRPV4) in the K+ secretion of epididymal epithelium. The expression level and cellular localization of TRPV4 and Ca2+- activated K+ channels (KCa) were analyzed via RT-PCR, real-time quantitative PCR, western blot, and immunofluorescence. The functional role of TRPV4 was investigated using short circuit current (ISC) and intracellular Ca2+ imaging techniques. We found a predominant expression of TRPV4 in the corpus and cauda epididymal epithelium. Activation of TRPV4 with a selective agonist, GSK1016790A, stimulated a transient decrease in the ISC of the epididymal epithelium. The ISC response was abolished by either the TRPV4 antagonists, HC067047 and RN-1734, or the removal of basolateral K+. Simultaneously, the application of GSK1016790A triggered Ca2+ influx in epididymal epithelial cells. Our data also indicated that the big conductance KCa (BK), small conductance KCa (SK), and intermediate conductance KCa (IK) were all expressed in rat epididymis. Pharmacological studies revealed that BK, but not SK and IK, mediated TRPV4-elicited transepithelial K+ secretion. Finally, we demonstrated that TRPV4 and BK were localized in the epididymal epithelium, which showed an increased expression level from caput to cauda regions of rat epididymis. This study implicates that TRPV4 plays an important role in the formation of high K+ concentration in epididymal intraluminal fluid via promoting transepithelial K+ secretion mediated by BK.

Identification and evaluation of antioxidant and reference genes for quantitative real-time PCR in blood of Caiman latirostris

The quantitative real-time polymerase chain reaction (qPCR) has been one of the most promising approaches to perform rapid and accurate quantification of DNA in various biological systems. The aim of this study was to standardized the qPCR technique for the analysis of important genes involved in the main routes of antioxidant defense against reactive oxygen species (catalase: cat and superoxide dismutase: sod) and evaluate the stability of different reference genes in blood of Caiman latirostris hatchlings. The stability of the reference genes, β-actin, glyceraldehyde 3-phosphate dehydrogenase (gapdh) and ribosomal protein L8 (rpl8) was determined using the comparative ΔCt, NormFinder, geNorm, BestKeeper and RefFinder. Then, cat and sod genes were normalized with each reference gene and their mRNA abundances were determined through the qPCR. Stability of genes was ranked through the different methods in the following order: β-actin, rpl8 and gapdh , under normal physiological conditions. The results reveal that cat and sod genes present a similar relative mRNA abundance with β-actin and rpl8. This is the first report of the analysis of antioxidant mRNA as potential biomarkers of oxidative stress in blood for all crocodilians species. Besides, we determined the stability of different reference genes that can be used for normalization of mRNA abundance patterns in blood of C. latirostris, without the need to sacrifice the animals.

Mechanisms related to sexual determination by temperature in reptiles

A number of strategies have emerged that appear to relate to the evolution of mechanisms for sexual determination in vertebrates, among which are genetic sex determination caused by sex chromosomes and environmental sex determination, where environmental factors influence the phenotype of the sex of an individual. Within the reptile group, some orders such as: Chelonia, Crocodylia, Squamata and Rhynchocephalia, manifest one of the most intriguing and exciting environmental sexual determination mechanisms that exists, comprising temperature-dependent sex determination (TSD), where the temperature of incubation that the embryo experiences during its development is fundamental to establishing the sex of the individual. This makes them an excellent model for the study of sexual determination at the molecular, cellular and physiological level, as well as in terms of their implications at an evolutionary and ecological level. There are different hypotheses concerning how this process is triggered and this review aims to describe any new contributions to particular TSD hypotheses, analyzing them from the "eco-evo-devo" perspective.

Insights into Germline Development and Differentiation in Molluscs and Reptiles: The Use of Molecular Markers in the Study of Non-model Animals

When shifting research focus from model to non-model species, many differences in the working approach should be taken into account and usually methodological modifications are required because of the lack of genetics/genomics and developmental information for the vast majority of organisms. This lack of data accounts for the largely incomplete understanding of how the two components-genes and developmental programs-are intermingled in the process of evolution. A deeper level of knowledge was reached for a few model animals, making it possible to understand some of the processes that guide developmental changes during evolutionary time. However, it is often difficult to transfer the obtained information to other, even closely related, animals. In this chapter, we present and discuss some examples, such as the choice of molecular markers to be used to characterize differentiation and developmental processes. The chosen examples pertain to the study of germline in molluscs, reptiles, and other non-model animals.