Embryonic Stages Research Articles

Empowering sustainable manufacturing: Unleashing digital innovation in spool fabrication industries

In industrial landscapes, spool fabrication industries play a crucial role in the successful completion of numerous industrial projects by providing prefabricated modules. However, the implementation of digitalized sustainable practices in spool fabrication industries is progressing slowly and is still in its embryonic stage due to several challenges. To implement digitalized sustainable manufacturing (SM), digital technologies such as Internet of Things, Cloud computing, Big data analytics, Cyber-physical systems, Augmented reality, Virtual reality, and Machine learning are required in the context of sustainability. The scope of the present study entails prioritization of the enablers that promote the implementation of digitalized sustainable practices in spool fabrication industries using the Improved Fuzzy Stepwise Weight Assessment Ratio Analysis (IMF-SWARA) method integrated with Triangular Fuzzy Bonferroni Mean (TFBM). The enablers are identified through a systematic literature review and are validated by a team of seven experts through a questionnaire survey. Then the finally identified enablers are analyzed by the IMF-SWARA and TFBM integrated approach. The results indicate that the most significant enablers are management support, leadership, governmental policies and regulations to implement digitalized SM. The study provides a comprehensive analysis of digital SM enablers in the spool fabrication industry and offers guidelines for the transformation of conventional systems into digitalized SM practices.

Growth Dynamics of Flexor Muscle Fibers in Developing Male White Leghorn Chicks

The study examines the relationship between fiber orientation, functional activity, and growth dynamics in the flexor muscle of a male white Leghorn chick. It tests three hypotheses: similar histochemical fiber typing in muscle mass, distribution patterns influenced by species' functional activities, and fiber growth dynamics related to somatic growth rate. The study confirmed the hypothesis that all three basic fiber types (red, pink, and white) grow exclusively through hypertrophy. True hyperplasia was not evident in any age group, possibly in the late embryonic stage. Some cases of pink and white fibers showed splitting into smaller ones. All three basic fiber types grew by hypertrophy, regardless of location or functional activity. Muscle fiber growth in this muscle mass was directly related to the chick's somatic growth rate.

Normal table of embryonic development in the Anji salamander Hynobius amjiensis (Hynobiidae)

We established a normal embryonic development table for the Anji salamander Hynobius amjiensis, a critically endangered tailed amphibian of the family Hynobiidae with a very limited distribution in East China, following the standards set by the early developmental table of vertebrates. Put together 32 embryonic stages for the Anji salamander was defined. The total embryonic period from oviposition to hatching is approximately 30 days at 9 °C. Stages 1–16 represent early development from cleavage to neurulation. Stages 17–32 represent organogenesis documenting later developmental events such as tail, gill, and limb formation, and hatching (Stage 32). We provided a detailed description of the external morphology and color changes of the head, trunk, limbs, tail, external gills, and balancers at various stages from egg-laying to hatching. We also described several cases of abnormal embryonic development. The establishment of the embryonic development table in H. amjiensis contributes to better understanding of the ontogeny in tailed amphibians, distinguishing closely related species, and identifying abnormal embryonic amphibians.

HH5 double-carrier embryos fail to progress through early conceptus elongation

Massive genotyping in cattle has uncovered several deleterious haplotypes that cause preterm mortality. Holstein haplotype 5 (HH5) is a deleterious haplotype present in the Holstein Friesian population that involves the ablation of the transcription factor B1 mitochondrial (TFB1M) gene. The developmental stage at which HH5 double-carrier (DC, homozygous) embryos or fetuses die remains unknown and this is a relevant information to estimate the economic losses associated with the inadvertent cross between carriers. To determine whether HH5 DC survive to maternal recognition of pregnancy, embryonic day (E) 14 embryos were flushed from superovulated carrier cows inseminated with a carrier bull. Double-carrier E14 conceptuses were recovered at Mendelian rates but they failed to achieve early elongation, as evidenced by a drastic reduction of their extra-embryonic membranes, which were >26-fold shorter than those of carrier or noncarrier embryos. To assess development at earlier stages, TFB1M knockout (KO) embryos-functionally equivalent to DC embryos-were generated by clustered regularly interspaced short palindromic repeats (CRISPR) technology and cultured to the blastocyst stage, in vitro culture day (D) 8, and to the early embryonic disc stage, D12. No significant effect of TFB1M ablation was observed on the differentiation and proliferation of embryonic lineages and relative mitochondrial DNA (mtDNA) content up to D12. In conclusion, HH5 DC embryos are able to develop to early embryonic disc stage but fail to undergo early conceptus elongation, which is required for pregnancy recognition.

Single-cell transcriptome atlas in C57BL/6 mice encodes morphological phenotypes in the aging kidneys

C57BL/6 mice are frequently utilized as murine models with the desired genetic background for altertion in multiple research contexts. So far, there is still a lack of comprehensive kidney morphology and single-cell transcriptome atlas at all stages of growth of C57BL/6 mice. To provide an interactive set of reference standards for the scientific community, we performed the current study to investigate the kidney’s development throughout the capillary-loop stage until senescence. Eight groups, with five to six mice each, represented embryonic stage (embryos 18.5 days), suckling period (1 day after birth), juvenile stage (1 month old), adulthood (containing 3 months old, 6 months old and 10 months old), reproductive senescence stage (20 months old), and post-senescence stage (30 months old), respectively. With age, the thickness of the glomerular basement membrane (GBM) was increased. Notably, GBM knobs appeared at three months and became frequent with age. Using single-cell transcriptome data, we evaluated how various biological process appear in particular cell types and investigated the potential mechanism of formation of GBM konbs. In conclusion, having access to detailed kidney morphology and single-cell transcriptome maps from C57BL/6 mice at various developmental stages of C57BL/6 mice would be a novel and major resource for biological research and testing of prospective therapeutic approaches.

Using qPCR to Identify Potential Effects of Thermal Conditions during Embryogenesis on Mitochondrial DNA Copy Number in Juvenile Brown Trout Salmo trutta

Changes in the number, structure, and function of mitochondria during the early life stages of animals can play an important role for an organism’s metabolic rate, growth, and health. Previous studies have shown that juvenile brown trout (Salmo trutta) subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced metabolic rate. The aim of this study was to explore if embryonic temperature affects the mitochondria content of young brown trout and as such explains the previously found differences in metabolic rates. Here, we optimize a quantitative PCR (qPCR) method for the mitochondria cytochrome c oxidase subunit I gene, and then use the method as a proxy for mitochondrial DNA content. We hypothesize that young trout subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced mitochondrial DNA content. To test this hypothesis, we subjected brown trout to either control ambient (4.4 ± 1.5 °C) or elevated temperatures (7.1 ± 0.6 °C) during embryogenesis. Subsequently, we extracted DNA from liver and white muscle tissue of juvenile brown trout from the two different incubation temperature treatments and successively optimized qPCR for mitochondrial DNA. We found that the amount of mitochondria DNA in liver tissue was 18 times higher than in white muscle tissue, but there was no significant difference in mitochondria content in liver or muscle tissue between brown trout exposed to elevated and ambient control temperatures during embryogenesis. We conclude that reduced metabolic rate is not likely associated with mitochondria DNA content. We also suggest that qPCR is a simple and cost-effective method to quantify mitochondria DNA in frozen and partly degraded tissue from different treatment groups and a useful proxy for identification of differences in mitochondria number.

Elucidating the Role of Transcriptomic Networks and DNA Methylation in Collagen Deposition of Dezhou Donkey Skin.

DNA methylation represents a predominant epigenetic modification with broad implications in various biological functions. Its role is particularly significant in the process of collagen deposition, a fundamental aspect of dermal development in donkeys. Despite its critical involvement, the mechanistic insights into how DNA methylation influences collagen deposition in donkey skin remain limited. In this study, we employed whole genome bisulfite sequencing (WGBS) and RNA sequencing (RNA-seq) to investigate the epigenetic landscape and gene expression profiles in the dorsal skin tissues of Dezhou donkeys across three developmental stages: embryonic (YD), juvenile (2-year-old, MD), and mature (8-year-old, OD). Our analysis identified numerous differentially methylated genes that play pivotal roles in skin collagen deposition and overall skin maturation, including but not limited to COL1A1, COL1A2, COL3A1, COL4A1, COL4A2, GLUL, SFRP2, FOSL1, SERPINE1, MMP1, MMP2, MMP9, and MMP13. Notably, we observed an inverse relationship between gene expression and DNA methylation proximal to transcription start sites (TSSs), whereas a direct correlation was detected in regions close to transcription termination sites (TTSs). Detailed bisulfite sequencing analyses of the COL1A1 promoter region revealed a low methylation status during the embryonic stage, correlating with elevated transcriptional activity and gene expression levels. Collectively, our findings elucidate key genetic markers associated with collagen deposition in the skin of Dezhou donkeys, underscoring the significant regulatory role of DNA methylation. This research work contributes to the foundational knowledge necessary for the genetic improvement and selective breeding of Dezhou donkeys, aiming to enhance skin quality attributes.

Maternal supplementation with mulberry-leaf flavonoids improves the development of skeletal muscle in the offspring of chickens

The development of skeletal muscle is a crucial factor in determining the meat yield and economic benefits of broiler production. Recent research has shown that mulberry leaves and their extracts can be used to significantly improve the growth performance of livestock and poultry. The present study aims to elucidate the mechanisms involved in the regulation of skeletal muscle development in broiler offspring by dietary mulberry-leaf flavonoids (MLF) supplementation from the perspective of maternal effect theory. A total of 270 Qiling broiler breeder hens were randomly assigned to 3 treatments with different doses of MLF (0, 30, 60 mg/kg) for 8 weeks before collecting their fertilized eggs. The chicken offspring at 13 and 19 d of embryonic stage, and from 1 to 28 d old after hatching were included in this study. The results showed that maternal supplementation increased the breast muscle weight and body weight of the offspring at the embryo and chick stages (P < 0.05). This was followed by increased cross-sectional area of pectoral muscle fibres at 14 d (P < 0.05). Further determination revealed a tendency towards increased serum levels of insulin-like growth factor 1 (IGF-1) (P = 0.092) and muscle fibre count (P = 0.167) at 1 d post-hatching following maternal MLF treatment, while serum uric acid (UA) was decreased at 14 d after hatching (P < 0.05). Moreover, maternal MLF supplementation significantly up-regulated the mRNA expression of the myogenic regulatory factor Myf5 in skeletal muscle at the both embryonic and growth stages (P < 0.05). The relative abundance of the downstream protein of BMPR2, Smad1 and p-Smad1/5/9 in the TGFβ signalling pathway was significantly increased by maternal MLF treatment. Meanwhile, the increased expression of the target protein p-mTOR in the breast muscle of the offspring chicks is in accordance with the improved growth rate of the breast and the body. In conclusion, maternal MLF supplementation can promote muscle protein metabolism and muscle fibre development of chick embryos through upregulation of Myf5 expression and BMP/p-Smad1/5/9 axis, thereby improving growth performance of slow growing broiler.

Mucopolysaccharidosis type II zebrafish model exhibits early impaired proteasomal-mediated degradation of the axon guidance receptor Dcc.

Most of the patients affected by neuronopathic forms of Mucopolysaccharidosis type II (MPS II), a rare lysosomal storage disorder caused by defects in iduronate-2-sulfatase (IDS) activity, exhibit early neurological defects associated with white matter lesions and progressive behavioural abnormalities. While neuronal degeneration has been largely described in experimental models and human patients, more subtle neuronal pathogenic defects remain still underexplored. In this work, we discovered that the axon guidance receptor Deleted in Colorectal Cancer (Dcc) is significantly dysregulated in the brain of ids mutant zebrafish since embryonic stages. In addition, thanks to the establishment of neuronal-enriched primary cell cultures, we identified defective proteasomal degradation as one of the main pathways underlying Dcc upregulation in ids mutant conditions. Furthermore, ids mutant fish-derived primary neurons displayed higher levels of polyubiquitinated proteins and P62, suggesting a wider defect in protein degradation. Finally, we show that ids mutant larvae display an atypical response to anxiety-inducing stimuli, hence mimicking one of the characteristic features of MPS II patients. Our study provides an additional relevant frame to MPS II pathogenesis, supporting the concept that multiple developmental defects concur with early childhood behavioural abnormalities.

Local and global stressors as major drivers of the drastic regression of brown macroalgae forests in an oceanic island

Similar to other coastal regions worldwide, forests created by brown macroalgae have severely declined in recent decades across the Macaronesian oceanic archipelagos (northeastern Atlantic), eroding the provision of ecosystem services. However, the putative effects of natural and anthropogenic stressors (both local and global) on such declines across spatial and temporal scales remain unresolved. Our research endeavored to investigate the connection between local and global stressors and the distribution and extent of the brown macroalgae Gongolaria abies-marina in the rocky intertidal and adjacent subtidal zones of Gran Canaria over the past four decades. We also quantified the presence of populations at small scales, according to local micro-habitat topography (“open rock” versus “refuge”). Through herbarium records, we additionally analyzed the historical variation in the thallus size of the species. Finally, we experimentally assessed the thermotolerance of embryonic stages to warming. The main environmental drivers explaining the regression of G.abies-marina were the increasing number of marine heatwaves, while the number of local human impacts (quantified through the HAPI index) also accounted for further regression in the extent of marine forests. Warming experimentally reduced the survival and size of macroalgal embryos. A progressive miniaturization of the species, currently restricted to micro-habitat refuges as a survival strategy, seems likely to be the final stage in the progressive disappearance of this macroalgae from the island’s rocky shores.

A Case of a Eustachian Tube Hairy Polyp Misdiagnosed as an Adenoid Residual in a Child.

Hairy polyps, considered a highly unusual congenital anomaly of the pharynx, are believed by many scholars to arise from the ectoderm and mesoderm during the embryonic stage. These growths often have a pear or sausage shape, are pedunculated, and their size ranges between 0.5 and 6 cm. They are typically grayish white or pink in color. This article discusses a 12-year-old female who had a growth at the Eustachian tube's entrance on the left side of the nasopharyngeal wall, as identified by a computed tomography scan of the neck soft tissue; it was suspected to be a hairy polyp originating from the left Eustachian tube. The diagnosis of a hairy polyp was confirmed through pathology. The hairy polyp at the Eustachian tube, in this case, showed an irregular form with a wide base, making it look similar to an adenoid; thus, increasing the risk of it being misdiagnosed as residual adenoid tissue.

Epithelial development of the urinary collecting system in the human embryo.

The urinary collecting system (UCS) consists of organized ducts that collect urine from the nephrons and transport it to the ureter and bladder. Understanding the histogenesis of the UCS is critical. Thirty human embryos between the Carnegie stages (CS) 18 and 23 were selected from the Congenital Anomaly Research Center, Kyoto, Japan. Epithelia of the UCS, ureter, and bladder of each sample were randomly selected. Histological findings of the epithelia were analyzed according to the following criteria: type of epithelium, presence or absence of glycogen, percentage of migrated nuclei, percentage of cells in mitosis, and the surrounding mesenchyme. A thickened epithelium lining a narrow luminal cavity was observed in the pre-expanded pelvic specimens at CS18-CS23. At CS23, after pelvic expansion, the UCS showed a thin epithelium with a large luminal cavity mainly located on the early branches, whereas the epithelium covering the subsequent branches had medium thickness. Histological characteristics differed depending on the UCS part and sample stage. The degree of differentiation was evaluated, revealing that in CS18-CS23 pre-expanded pelvis specimens, the undifferentiated epithelium was found in the zeroth to third/fifth generation, whereas at CS23, after pelvic expansion, a differentiated epithelium covered the UCS zeroth to seventh generation. In a comparison of the urothelial epithelium between the UCS, ureter, and bladder, we found that urinary tract differentiation may be initiated in the bladder, followed by the ureter, UCS zeroth to seventh generations, and finally, UCS eighth to end generations. An understanding of the histogenesis of embryonic stage UCS can aid in the clinical management of congenital urinary tract defects and other diseases.

Stem Cell and its Applications in Medical Biotechnology

Stem cells are undifferentiated cells in multicellular organisms that can be specialized into many types of cells and multiply into different types of cells. Stem cells can be produced from many sources in the body such as early embryos, embryonic tissue, foetal membranes i e; chorion and amnion, umbilical cord, and amniotic fluid. Stem cells are also present in organs of adult organisms like blood, skin, skeletal muscle, bone marrow, etc., Stem cells can be totipotent, pluripotent, multipotent, and unipotent. Stem cells are used to regenerate injured cells in the body, and repair the cells due to any kind of disease. From all types of cells, totipotent stem cells can generate any kind of cells in the body so they are the most important type of cells. Along with this, pluripotent stem cells also produce all types of cells, except the placenta or embryonic cells. These cells can be isolated from the body from the late embryonic stage after 1 week of the birth of a child, from the miscarriage of 12 weeks, and also from the umbilical cord of the child. These can be stored for another 2 decades. Another type is multipotent stem cells, which can generate a limited number of cells in a specific type; the last fourth type is unipotent stem cells, which can only produce cells of their own type. Diagnosis with stem cells is a useful technique to treat patients with many blood-related diseases for example blood cancer, thalassemia, etc., It also cures diseases like diabetes, liver disease, bone and cartilage, and organ transplantation.

The embryonic role of juvenile hormone in the firebrat, Thermobia domestica, reveals its function before its involvement in metamorphosis.

To gain insights into how juvenile hormone (JH) came to regulate insect metamorphosis, we studied its function in the ametabolous firebrat, Thermobia domestica. Highest levels of JH occur during late embryogenesis, with only low levels thereafter. Loss-of-function and gain-of-function experiments show that JH acts on embryonic tissues to suppress morphogenesis and cell determination and to promote their terminal differentiation. Similar embryonic actions of JH on hemimetabolous insects with short germ band embryos indicate that JH's embryonic role preceded its derived function as the postembryonic regulator of metamorphosis. The postembryonic expansion of JH function likely followed the evolution of flight. Archaic flying insects were considered to lack metamorphosis because tiny, movable wings were evident on the thoraces of young juveniles and their positive allometric growth eventually allowed them to support flight in late juveniles. Like in Thermobia, we assume that these juveniles lacked JH. However, a postembryonic reappearance of JH during wing morphogenesis in the young juvenile likely redirected wing development to make a wing pad rather than a wing. Maintenance of JH then allowed wing pad growth and its disappearance in the mature juvenile then allowed wing differentiation. Subsequent modification of JH action for hemi- and holometabolous lifestyles are discussed.

The SoxE factor Sox9 is selectively expressed in indirect pathway striatal projection neurons and regulates synaptogenesis

Striatum, as the largest structure of the basal ganglia, serves as a center for information transmission and is critical for motor function and reward perception. However, the genetic mechanisms underlying its development require further exploration. Here, we found that Sox9, traditionally recognized as a glial marker, is uniquely expressed in striatal medium spiny neurons (MSNs), especially in Drd2-expressing indirect pathway MSNs (D2-MSNs). Intriguingly, Sox9 expression in the striatum, which is conserved in humans, is a dynamic process. It maintains a high level during the perinatal stage, and exhibits low expression levels or vanishes at the embryonic and postnatal stages, respectively. The peak period of Sox9 expression coincides with the transition from neurogenesis to synaptogenesis. Importantly, gene regulatory network analysis and gain-of-function experiments confirmed Sox9 is strongly correlated with synaptogenesis. Moreover, we identified that Sox9 regulates synaptogenesis by repressing Foxp2, a well-known synapse regulator. Furthermore, we demonstrated that the biased expression pattern of Sox9 in D2-MSNs is, at least in part, regulated by another SoxE family member Sox8, which is specifically expressed in Drd1-expressing direct pathway MSNs (D1-MSNs). Taken together, our findings reveal a new marker of D2-MSNs and identify its distinctive function in striatal development.

Brain enlargement with rostral bias in larvae from a spontaneously occurring female variant line of Xenopus; role of aberrant embryonic Wnt/β-catenin signaling

Increased brain size and its rostral bias are hallmarks of vertebrate evolution, but the underlying developmental and genetic basis remains poorly understood. To provide clues to understanding vertebrate brain evolution, we investigated the developmental mechanisms of brain enlargement observed in the offspring of a previously unrecognized, spontaneously occurring female variant line of Xenopus that appears to reflect a genetic variation. Brain enlargement in larvae from this line showed a pronounced rostral bias that could be traced back to the neural plate, the primordium of the brain. At the gastrula stage, the Spemann organizer, which is known to induce the neural plate from the adjacent dorsal ectoderm and give it the initial rostrocaudal patterning, was expanded from dorsal to ventral in a large proportion of the offspring of variant females. Consistently, siamois expression, which is required for Spemann organizer formation, was expanded laterally from dorsal to ventral at the blastula stage in variant offspring. This implies that the active region of the Wnt/β-catenin signaling pathway was similarly expanded in advance on the dorsal side, as siamois is a target gene of this pathway. Notably, the earliest detectable change in variant offspring was in fertilized eggs, in which maternal wnt11b mRNA, a candidate dorsalizing factor responsible for activating Wnt/β-catenin signaling in the dorsal embryonic region, had a wider distribution in the vegetal cortical cytoplasm. Since lateral spreading of wnt11b mRNA, and possibly that of other potential maternal dorsalizing factors in these eggs, is expected to facilitate lateral expansion of the active region of the Wnt/β-catenin pathway during subsequent embryonic stages, we concluded that aberrant Wnt/β-catenin signaling could cause rostral-biased brain enlargement via expansion of siamois expression and consequent expansion of the Spemann organizer in Xenopus. Our studies of spontaneously occurring variations in brain development in Xenopus would provide hints for uncovering genetic mutations that drive analogous morphogenetic variations during vertebrate brain evolution.

The biological modeling of autism spectrum disorders

IntroductionAutism Spectrum Disorders (ASD) are heterogeneous pathological conditions characterized by difficulties in establishing social contacts and the manifestation of repetitive behavior. An atypical trajectory of brain maturation, impaired neurogenesis, synaptogenesis, and an imbalance in the excitatory and inhibitory systems of the CNS form the morphofunctional basis of the ASDObjectivesscientific publicationsMethodsscientific analysisResultsThese pathological changes appear at different stages of brain maturation They are the result of multifactorial environmental influences. To understand the functioning of this complexly organized system in time and space, a three-dimensional model is needed. The closest in vitro model of the human brain from early embryonic stages to aging is brain organoids. Human brain organoids are self-organizing three-dimensional cell aggregates derived from pluripotent stem cells. Organoids summarize neurogenesis, gliogenesis, synaptogenesis, cell migration and cell differentiation, gyrification of the cerebral cortex, reflect the connections of brain regions. The use of a 3D brain model makes it possible to simulate diseases, reactions to drugs in cells obtained from patients. The use of telencephalon organoids in the ASD model revealed that neuronal migration deficiency, acceleration and disruption of cell cycle synchronization, aberrant cell proliferation, abundant synaptogenesis, temporary deviations in the development of the cortex, increased branching of neurons, unbalanced inhibitory differentiation of neurons, high activity of ion channels are the result of impaired activity FOXG1. FOXG1 is responsible for the overproduction of GABAergic neurons. The shift towards GABAergic neurons induced by FOXG1 is positively correlated with the severity of ASD symptoms and is seen as a precursor to the future of ASDConclusionsThus, ASD as a socially significant disease with a heterogeneous type of inheritance, multi-link pathogenesis, realized in different periods of ontogenesis and involving different brain loci, requires special attention of researchers for the personification of diagnosis and therapy. The hiPSCs can provide insight into the cellular mechanisms underlying ASD as a neuropsychiatric disorder, providing access to the development of platforms for in vitro drug screening and patient-tailored therapy.Disclosure of InterestNone Declared

Photoperiod-regulated mitophagy in the germ cells of Brandt's voles (Lasiopodomys brandtii).

Photoperiod is a pivotal factor in affecting testicular function and spermatogenesis in seasonal-breeding animals. Mitophagy is essential for spermatogenesis, but its association with seasonal photoperiods has not been studied extensively. To explore this, we exposed male Brandt's voles (Lasiopodomys brandtii) to long-photoperiod (LP, 16 h/day) and short-photoperiod (SP, 8 h/day) conditions from their embryonic stages. Our results indicated that testis weight, volume, and relative testes weight were all significantly increased in LP compared to SP. Additionally, blood testosterone levels were markedly higher in LP than SP. Histological examination revealed that seminiferous diameter and epithelium thickness were greater in LP, with an increased abundance of germ cell types and cell numbers compared to SP. RT-qPCR analysis showed that mitophagy-promoting genes, such as Pink1, Prkn, Tomm7, Mnf2, Lc3, Optn, Gabarap, and Nbr1 were all upregulated in LP. Fluorescence in situ hybridization indicated that Pink1 expression was present in spermatogonia in SP, while in LP, Pink1 expression extended to almost all germ cell types with significantly higher mean optical density. Prkn expression was found in all germ cell types in both LP and SP, with a significantly higher mean optical density of 10-week-old LP males. Transmission electron microscopy showed normal mitochondrial morphology with clear membranes in SP, while the LP group had reduced cristae in mitochondria and damaged mitochondria undergoing autophagy. This study suggests that mitophagy may be involved in the photoperiodic spermatogenesis in Brandt's voles, providing insights into the role of photoperiod in seasonal reproduction in wild animals.

The Effect of Rapamycin on the Cyclin D Expression in Some Tissues of Swiss Albino Mice Mus Masculus Embryos

The current study aimed to investigate the effects of Rapamycin (Rapa) on the cyclin D expression in heart and liver tissues of Swiss albino mice Mus masculus embryos at different Embryonic Developmental stages. The study conducted on Thirty- two pregnant albino mice, were randomly divided into four groups, each group contained eight pregnant mice. Each group received Rapamycin (Rapa) at different doses, via intraperitoneally injection (IP), at different gestational days until the conclusion of the designated times, whereas the control groups received a DMSO. Pregnant mice were administered the desired doses under the same environmental circumstances. According to pharmacological constitutions, body weight was used to establish the dosages. After that, on days 13th and 16th, the mice were put to killing. Current study used another two concentrations from drug, one less than the therapeutic dosage (0.75mg/kg of Rapamycin) and another more than the therapeutic dosage (3mg /kg of Rapamycin). Quantification of the IHC of cytoplasmic proportion and intensity showed cytoplasmic expression of Cyclin D in tissue of mice embryos heart the control group and other treatment groups differed significantly from one another at (P &lt;0.05), while there wasn't a significant difference between the treatment groups which received 0.75 and 1.5mg/kg of Rapamycin, in embryonic liver tissue. At gestation day 16th, there was no significant difference in expression of Cyclin D between control group and treated group with 0.75mg/kg of Rapamycin, while there was a significant difference in Cyclin D expression at (P &lt; 0.05) between treated groups with 0.75mg/kg of and treated group with 1.5 and 3 mg/kg of Rapamycin and from these results we concluded that the use of Rapamycin has been affected on checkpoints of cell cycle during embryogenesis, which appeared through its effects on cyclin D expression.

Aberrant stem cell and developmental programs in pediatric leukemia.

Hematopoiesis is a finely orchestrated process, whereby hematopoietic stem cells give rise to all mature blood cells. Crucially, they maintain the ability to self-renew and/or differentiate to replenish downstream progeny. This process starts at an embryonic stage and continues throughout the human lifespan. Blood cancers such as leukemia occur when normal hematopoiesis is disrupted, leading to uncontrolled proliferation and a block in differentiation of progenitors of a particular lineage (myeloid or lymphoid). Although normal stem cell programs are crucial for tissue homeostasis, these can be co-opted in many cancers, including leukemia. Myeloid or lymphoid leukemias often display stem cell-like properties that not only allow proliferation and survival of leukemic blasts but also enable them to escape treatments currently employed to treat patients. In addition, some leukemias, especially in children, have a fetal stem cell profile, which may reflect the developmental origins of the disease. Aberrant fetal stem cell programs necessary for leukemia maintenance are particularly attractive therapeutic targets. Understanding how hijacked stem cell programs lead to aberrant gene expression in place and time, and drive the biology of leukemia, will help us develop the best treatment strategies for patients.