Journal of Developmental Biology最新文献

The germline stem cells (GSCs) in the male gonad of Drosophila can increase their division frequency in response to a demand for more sperm caused by repeated mating. However, the molecules and mechanisms regulating and mediating this response have yet to be fully explored. Here, we present the results of a transcriptome analysis comparing expression from the testis tips from non-mated and mated males. An overlapping set of 18 differentially expressed genes (DEGs) from two independent wild-type (wt) strains revealed that the majority of the DEGs encode secreted proteins, which suggests roles for them in cell-cell interactions. Consistent with a role for secretion in regulating GSC divisions, knocking down Signal Recognition Particle (SRP) components within the germline cells using RNA Interference (RNAi), prevented the increase in GSC division frequency in response to mating. The major class of DEGs encodes polypeptides below the size of 250 amino acids, also known as small proteins. Upon reducing germline expression of small proteins, males no longer increased GSC division frequency after repeated mating. We hypothesize that mating induces cellular interactions via small proteins to ensure continued GSC divisions for the production of sperm.

Endocannabinoid signaling plays a significant role in neurogenesis and nervous system physiology, but its roles in the development of other tissues are just beginning to be appreciated. Previous reports have shown the presence of the key endocannabinoid receptor Cannabinoid receptor 1 (CB1 or Cnr1) in multiciliated (MCC) tissues and its upregulation in kidney diseases, yet the relationship between Cnr1 and renal MCC development is unknown. Here, we report that Cnr1 is essential for cilia development across tissues and regulates renal MCCs via cyclic AMP (cAMP) signaling during zebrafish embryogenesis. Using a combination of genetic and pharmacological studies, we found that the loss of function, agonism and antagonism of cnr1 all lead to reduced mature renal MCC populations. cnr1 deficiency also led to reduced cilia development across tissues, including the pronephros, ear, Kupffer's vesicle (KV), and nasal placode. Interestingly, treatment with the cAMP activator Forskolin (FSK) restored renal MCC defects in agonist-treated embryos, suggesting that cnr1 mediates cAMP signaling in renal MCC development. Meanwhile, treatment with the cAMP inhibitor SQ-22536 alone or with cnr1 deficiency led to reduced MCC populations, suggesting that cnr1 also mediates renal MCC development independently of cAMP signaling. Our findings indicate that cnr1 has a critical role in controlling renal MCC development both via cAMP signaling and an independent pathway, further revealing implications for ciliopathies and renal diseases.

Previously, we reported that mammalian cells, specifically human dermal fibroblasts (HDFs), could be transdifferentiated by lactic acid bacteria (LAB). Later, we observed that HDFs incorporated LAB-derived ribosomes, forming the ribosome-induced cell clusters (RICs) and transdifferentiating into cells derived from all three germ layers. Based on this insight, we hypothesized that incorporating ribosomes into non-mammalian cells could reveal the universality of this mechanism and open the door to commercial applications. Our current study demonstrates that ribosome incorporation can transdifferentiate chick primary muscle-derived cells (CMCs) into adipocytes, osteoblasts, and chondrocytes. Furthermore, the culture medium supernatant from ribosome-incorporated CMCs was found to significantly enhance CMC's proliferation. RNA-seq analysis revealed that RICs-CMC exhibit increased expression of genes related to multi-lineage cell growth. In addition, we developed a novel technological shift in meat production-the "CulNet System"-which replicates organ interactions within mechanical systems for cell-cultured meat production. While significant efforts are still required to implement this technology in a cost-effective manner, we believe that combining the "CulNet System" with ribosome-incorporated multipotent cells that have prolonged culture capability could substantially improve the scalability and cost-effectiveness of cultured chicken meat production. This report highlights a promising approach for cell-culture-based meat production, offering a sustainable alternative to traditional methods.

Keratins and keratin-associated proteins (KRTAPs) are the main components of mammalian nails and hair. Comparative genomics and gene expression studies have revealed that keratins are conserved in all vertebrates, whereas KRTAPs exist only in mammals. Recently, we found hair keratin-like cysteine-rich keratins in jawless vertebrates with confirmed expression in the cornified epithelial teeth of the sea lamprey (Petromyzon marinus). Here, we report that KRTAP-like proteins are also present in the horny teeth of the lamprey. Mass spectrometry-based proteomics identified proteins that share features with KRTAPs, such as high contents of cysteine and tyrosine residues, which support intermolecular interactions, and abundant glycine residues, which endow the proteins with flexibility. Genes encoding KRTAP-like proteins are arranged in a cluster in P. marinus, and the presence of at least one KRTAP-like protein is conserved in phylogenetically diverse species of lamprey, including Lampetra fluviatilis, Lethenteron reissneri, Geotria australis, and Mordacia mordax. The KRTAP-like genes of lampreys contain two exons, whereas mammalian KRTAPs have only a single exon. Although KRTAPs and KRTAP-like proteins are products of independent evolution, their common expression in cornified skin appendages suggests that they fulfill similar functions.

Assisted reproductive technology (ART)such as in vitro embryo culture (IVC), is widely used in human infertility treatments; however, its long-term effects on the cardiac health of offspring remain unclear. This study aimed to determine whether the effects of IVC on cardiac metabolism and associated signaling pathways persist after birth into adolescence. Embryos were either transferred to an intermediate ewe (ET) or cultured in vitro in the absence (IVC) or presence of human serum (IVCHS) with methionine supplementation (IVCHS+M) for 6 days after mating. Naturally mated (NM) ewes were used as controls. Protein expression and hormone concentrations in the left ventricle (LV) were analyzed using Western blot and LC-MS/MS analyses, respectively. IVC was associated with sex-specific alterations in cardiac mitochondria, with males exhibiting reduced mitochondrial abundance. Cardiac protein expression of oxidative phosphorylation (OXPHOS) complexes 1 and 4 was reduced by IVC. Additionally, IVC reduced protein expression of PDK-4 and Mn-SOD in the IVCHS+M group, which may impact energy efficiency and defense against oxidative stress. These changes may predispose IVC offspring to cardiac oxidative stress and mitochondrial dysfunction, particularly in males. This study provides insights into the sex-dependent effects of IVC on cardiac health, emphasizing the importance of evaluating long-term cardiovascular risks associated with IVC protocols.

Background: The process of prenatal hematopoiesis occurs in various anatomical locations, including the placenta. The placenta is not merely a temporary hematopoietic reservoir, but it is one of the key sites for the synthesis of hematopoietic stem cells (HSCs). This study aimed to investigate the presence, distribution, and immunoprofiles of HSCs in the human placenta during different gestational periods. Materials and Methods: Placental samples of different gestational ages (first, second, and third trimesters) were analyzed using classical hematoxylin and eosin staining and immunohistochemical staining for CD34, CD117, and CD41 markers, with HSC quantification through numerical areal density (N_A). Results: Highly immunoreactive CD34 HSCs were present in placentas throughout gestation, while highly immunoreactive CD117 and CD41 HSCs were observed during the first two trimesters. In the first trimester, HSCs were found within the lumen of blood vessels and as individual cells in the mesenchyme of chorionic villi. With advancing gestation, the number of HSCs in the mesenchyme of chorionic villi increased. Conclusions: Immunoreactive CD34, CD117, and CD41 cells are present in significant proportions in various parts of the placenta throughout gestation, indicating that the placenta provides a substantial proportion of HSCs for hematopoiesis.

Lizards are distinguished as the only amniotes, and closest relatives of mammals, capable of multilineage epimorphic regeneration. Tail blastemas of green anole lizards (Anolis carolinensis) consist of col3a1⁺ fibroblastic connective tissue cells enclosed in krt5⁺ wound epidermis (WE), both of which are required for regeneration. Blastema and WE formation are known to be closely associated with phagocytic cell populations, including macrophages and osteoclasts. However, it remains unclear what specific phagocytic cell types are required to stimulate regeneration. Here, we explicitly assess the roles of osteoclast activity during blastema and WE formation in regenerating lizard tails. First, probe sequencing was performed at regenerative timepoints on fibroblasts isolated based on col3a1 expression toward establishing pathways involved in stimulating blastema formation and subsequent tail regrowth. Next, treatments with osteoclast inhibitor zoledronic acid (ZA) were used to assess the roles of osteoclast activity in lizard tail regeneration and fibroblast signaling. ZA treatment stunted lizard tail regrowth, suggesting osteoclast activity was required for blastema formation and regeneration. Transcriptomic profiling of fibroblasts isolated from ZA-treated and control lizards linked inhibition of osteoclast activity with limitations in fibroblasts to form pro-regenerative extracellular matrix and support WE formation. These results suggest that crosstalk between osteoclasts and fibroblasts regulates blastema and WE formation during lizard tail regeneration.

It is not yet understood why cows that exhibit estrus and ovulate are more likely to become pregnant than those that ovulate but do not exhibit estrus during a fixed-time artificial insemination (FTAI) protocol. The objective of this work was to determine whether the follicular fluid from cows that exhibit estrus contributes to the increased likelihood of pregnancy. Lactating crossbred cows were subjected to an FTAI estrous synchronization protocol. Estrous behavior was observed and recorded prior to transvaginal follicle aspiration from cows that did (estrus, n = 7) or did not exhibit estrus (non-estrus, n = 6). Follicular fluid (25%) was then added to in vitro maturation media for the maturation of oocytes (n = 1489) from slaughterhouse ovaries. Cleavage rates were not affected by the estrous status of the cows from which the follicular fluid was collected. Blastocyst rates, however, were greater following maturation in the presence of follicular fluid from estrus cows compared to non-estrus cows (p ≤ 0.01). This difference in blastocyst rates was not related to blastocyst cell numbers (inner cell mass, trophoblast, and total), as they did not differ between estrus and non-estrus animals. This study demonstrates that the follicular fluid, and thus, the follicular environment just prior to ovulation does indeed contribute to improved pregnancy rates following FTAI.

Compartment boundaries divide the embryo into segments with distinct fates and functions. In the vascular system, compartment boundaries organize endothelial cells into arteries, capillaries, and veins that are the fundamental units of a circulatory network. For vascular smooth muscle cells (SMCs), such boundaries produce mosaic patterns of investment based on embryonic origins with important implications for the non-uniform distribution of vascular disease later in life. The morphogenesis of blood vessels requires vascular cell movements within compartments as highly-sensitive responses to changes in fluid flow shear stress and wall strain. These movements underline the remodeling of primitive plexuses, expansion of lumen diameters, regression of unused vessels, and building of multilayered artery walls. Although the loss of endothelial compartment boundaries can produce arterial-venous malformations, little is known about the consequences of mislocalization or the failure to form SMC-origin-specific boundaries during vascular development. We propose that the failure to establish a normal compartment boundary between cardiac neural-crest-derived SMCs of the 6th pharyngeal arch artery (future ductus arteriosus) and paraxial-mesoderm-derived SMCs of the dorsal aorta in mid-gestation embryos leads to aortic coarctation observed at birth. This model raises new questions about the effects of fluid flow dynamics on SMC investment and the formation of SMC compartment borders during pharyngeal arch artery remodeling and vascular development.

Molecules involved in the activation of regeneration in reptiles are almost unknown. MARCK-like proteins are indicated to activate regeneration in some amphibians and fish, and it would be important to know whether this is a general process also present in other vertebrates. To address this problem, the present study reports the immunolocalization of a MARCK-like protein in injured tissues of a lizard. Bioinformatics and immunofluorescence after 5BrdU administration, and detection of MARCK-like proteins, have been performed on regenerating tail and limb of the lizard Podarcis muralis. Transcriptome data indicate up-regulation of MARCKS and MARCK-like1 expression in the initial regenerating tail and limb blastemas, supporting their involvement in the activation of regeneration in both appendages. Immunofluorescence for 5BrdU shows numerous proliferating cells in the blastemas of both appendages. Immunolocalization of a MARCK-like protein, using an antibody generated against a homologous protein from the axolotl, shows that the wound epidermis, nerves, and myotubes accumulate most of the protein in the limb and tail. MARCK-like immunolabeling is also detected in the regenerating spinal cord of the tail. The study indicates that, although the limb later turns into a scar, the MARCK-like protein is also up-regulated in this appendage, like in the regenerating tail. These results indicate that the initial reaction to an injury in lizards, an amniote representative, includes some triggering processes observed in amphibians and fish (anamniotes), with the activation of MARCK-like genes and proteins. This suggests that a MARCK-like-dependant mechanism for tissue repair is likely activated during the initial phases of vertebrate wound healing.