Template:2019 New References: Difference between revisions
From Embryology
mNo edit summary |
mNo edit summary |
||
(12 intermediate revisions by the same user not shown) | |||
Line 13: | Line 13: | ||
{{BMP}} | {{BMP}} | ||
* '''BMP controls dorsoventral and neural patterning in indirect-developing hemichordates providing insight into a possible origin of chordates'''{{#pmid:31189599|PMID31189599}} "A defining feature of chordates is the unique presence of a dorsal hollow neural tube that forms by internalization of the ectodermal neural plate specified via inhibition of BMP signaling during gastrulation. While BMP controls dorsoventral (DV) patterning across diverse bilaterians, the BMP-active side is ventral in chordates and dorsal in many other bilaterians. How this phylum-specific DV inversion occurs and whether it is coupled to the emergence of the dorsal neural plate are unknown. Here we explore these questions by investigating an indirect-developing enteropneust from the hemichordate phylum, which together with echinoderms form a sister group of the chordates. We found that in the hemichordate larva, BMP signaling is required for DV patterning and is sufficient to repress neurogenesis. We also found that transient overactivation of BMP signaling during gastrulation concomitantly blocked mouth formation and centralized the nervous system to the ventral ectoderm in both hemichordate and sea urchin larvae. Moreover, this mouthless, neurogenic ventral ectoderm displayed a medial-to-lateral organization similar to that of the chordate neural plate. Thus, indirect-developing deuterostomes use BMP signaling in DV and neural patterning, and an elevated BMP level during gastrulation drives pronounced morphological changes reminiscent of a DV inversion. These findings provide a mechanistic basis to support the hypothesis that an inverse chordate body plan emerged from an indirect-developing ancestor by tinkering with BMP signaling." | * '''BMP controls dorsoventral and neural patterning in indirect-developing hemichordates providing insight into a possible origin of chordates'''{{#pmid:31189599|PMID31189599}} "A defining feature of chordates is the unique presence of a dorsal hollow neural tube that forms by internalization of the ectodermal neural plate specified via inhibition of BMP signaling during gastrulation. While BMP controls dorsoventral (DV) patterning across diverse bilaterians, the BMP-active side is ventral in chordates and dorsal in many other bilaterians. How this phylum-specific DV inversion occurs and whether it is coupled to the emergence of the dorsal neural plate are unknown. Here we explore these questions by investigating an indirect-developing enteropneust from the hemichordate phylum, which together with echinoderms form a sister group of the chordates. We found that in the hemichordate larva, BMP signaling is required for DV patterning and is sufficient to repress neurogenesis. We also found that transient overactivation of BMP signaling during gastrulation concomitantly blocked mouth formation and centralized the nervous system to the ventral ectoderm in both hemichordate and sea urchin larvae. Moreover, this mouthless, neurogenic ventral ectoderm displayed a medial-to-lateral organization similar to that of the chordate neural plate. Thus, indirect-developing deuterostomes use BMP signaling in DV and neural patterning, and an elevated BMP level during gastrulation drives pronounced morphological changes reminiscent of a DV inversion. These findings provide a mechanistic basis to support the hypothesis that an inverse chordate body plan emerged from an indirect-developing ancestor by tinkering with BMP signaling." | ||
{{cartilage}} | |||
* '''L-type voltage-gated Ca2+ channel CaV1.2 regulates chondrogenesis during {{limb}} development{'''{#pmid:31591237|PMID31591237}} "All cells, including nonexcitable cells, maintain a discrete transmembrane potential (V mem), and have the capacity to modulate V mem and respond to their own and neighbors' changes in V mem Spatiotemporal variations have been described in developing embryonic tissues and in some cases have been implicated in influencing developmental processes. Yet, how such changes in V mem are converted into intracellular inputs that in turn regulate developmental gene expression and coordinate patterned tissue formation, has remained elusive. Here we document that the V mem of limb mesenchyme switches from a hyperpolarized to depolarized state during early chondrocyte differentiation. This change in V mem increases intracellular Ca2+ signaling through Ca2+ influx, via CaV1.2, 1 of L-type voltage-gated Ca2+ channels (VGCCs). We find that CaV1.2 activity is essential for chondrogenesis in the developing limbs. Pharmacological inhibition by an L-type VGCC specific blocker, or limb-specific deletion of CaV1.2, down-regulates expression of genes essential for chondrocyte differentiation, including Sox9, Col2a1, and Agc1, and thus disturbs proper cartilage formation. The Ca2+-dependent transcription factor NFATc1, which is a known major transducer of intracellular Ca2+ signaling, partly rescues Sox9 expression. These data reveal instructive roles of CaV1.2 in limb development, and more generally expand our understanding of how modulation of membrane potential is used as a mechanism of developmental regulation." | |||
{{cerebellum}} | {{cerebellum}} | ||
Line 28: | Line 32: | ||
{{ductus deferens}} | {{ductus deferens}} | ||
* '''[https://www.omim.org/entry/182307 SLC9A3] Affects Vas Deferens Development and Associates with Taiwanese Congenital Bilateral Absence of the Vas Deferens'''{{#pmid:30956978|PMID30956978}} "The pathophysiology of Taiwanese congenital bilateral absence of the vas deferens (CBAVD) is different from that in Caucasians. In particular, major cystic fibrosis transmembrane conductance regulator (CFTR) mutations and cystic fibrosis are absent in the former. DISCUSSION: Our findings build upon previous data associated with CBAVD pathogenesis. Here, we now report for the first time an association between CBAVD and loss of SLC9A3 and propose that specific defects in the reproductive duct due to SLC9A3 variants drive CBAVD development. CONCLUSION: The data implicate loss of SLC9A3 as a basis of Taiwanese CBAVD and highlight SLC9A3 function in reproduction." [https://www.omim.org/entry/182307 OMIM - SLC9A3] | * '''[https://www.omim.org/entry/182307 SLC9A3] Affects Vas Deferens Development and Associates with Taiwanese Congenital Bilateral Absence of the Vas Deferens'''{{#pmid:30956978|PMID30956978}} "The pathophysiology of Taiwanese congenital bilateral absence of the vas deferens (CBAVD) is different from that in Caucasians. In particular, major cystic fibrosis transmembrane conductance regulator (CFTR) mutations and cystic fibrosis are absent in the former. DISCUSSION: Our findings build upon previous data associated with CBAVD pathogenesis. Here, we now report for the first time an association between CBAVD and loss of SLC9A3 and propose that specific defects in the reproductive duct due to SLC9A3 variants drive CBAVD development. CONCLUSION: The data implicate loss of SLC9A3 as a basis of Taiwanese CBAVD and highlight SLC9A3 function in reproduction." [https://www.omim.org/entry/182307 OMIM - SLC9A3] | ||
{{epithelial mesenchymal transition}} | |||
* '''p120-catenin regulates {{WNT}} signaling and EMT in the mouse embryo.'''{{#pmid:31371508|PMID31371508}} "{{epithelial mesenchymal transition}}s (EMTs) require a complete reorganization of cadherin-based cell-cell junctions. p120-catenin binds to the cytoplasmic juxtamembrane domain of classical cadherins and regulates their stability, suggesting that p120-catenin may play an important role in EMTs. Here, we describe the role of p120-catenin in {{mouse}} {{gastrulation}}, an EMT that can be imaged at cellular resolution and is accessible to genetic manipulation. Mouse embryos that lack all p120-catenin, or that lack p120-catenin in the embryo proper, survive to midgestation. However, mutants have specific defects in gastrulation, including a high rate of p53-dependent cell death, a bifurcation of the posterior axis, and defects in the migration of mesoderm; all are associated with abnormalities in the primitive streak, the site of the EMT. In embryonic day 7.5 (E7.5) mutants, the domain of expression of the streak marker Brachyury (T) expands more than 3-fold, from a narrow strip of posterior cells to encompass more than one-quarter of the embryo. After {{ME7.5}}, the enlarged T+ domain splits in 2, separated by a mass of {{mesoderm}} cells. Brachyury is a direct target of canonical WNT signaling, and the domain of {{WNT}} response in p120-catenin mutant embryos, like the T domain, is first expanded, and then split, and high levels of nuclear β-catenin levels are present in the cells of the posterior embryo that are exposed to high levels of WNT ligand. The data suggest that p120-catenin stabilizes the membrane association of β-catenin, thereby preventing accumulation of nuclear β-catenin and excessive activation of the WNT pathway during EMT." | |||
{{fetal growth restriction}} | {{fetal growth restriction}} | ||
* '''Outcomes in patients with early-onset fetal growth restriction without fetal or genetic anomalies'''{{#pmid:29478342|PMID29478342}} "Early-onset fetal growth restriction is associated with poor pregnancy outcomes, but frequently is due to fetal structural or chromosomal abnormalities. The objective of this study was to determine outcomes in patients with early-onset fetal growth restriction without diagnosed fetal or genetic anomalies and to identify additional risk factors for poor outcomes in these patients. This was retrospective cohort study of singleton pregnancies in women with early-onset growth restriction defined as a sonographic estimated fetal weight <10% diagnosed between 16-28 weeks' gestation. We excluded all women with a fetal structural or chromosomal abnormality diagnosed prenatally. Data on pregnancy characteristics and outcomes were collected and analyzed for estimated fetal weight <10% and ≤5%. A nested case-control study within the cohort of patients with ongoing pregnancies was then performed to identify risk factors associated with poor pregnancy outcome using chi-squared test. One hundred forty-two patients were identified who met inclusion and exclusion criteria and 20 patients were found to have fetal structural or chromosomal abnormalities. In the remaining 122 patients, the incidence of intrauterine fetal demise was 5.7% and there were high rates of preterm birth <37 weeks (20%), birth weight <10% (59.3%), and gestational hypertension (14.1%). Later gestational age at diagnosis and the presence of echogenic bowel and abnormal initial umbilical artery Dopplers were associated with poor pregnancy outcome (22.56 versus 20.86 weeks, p = .046), (17.4 versus 2.2%, OR 9.68, 95%CI 1.65-56.73), and (35.3 versus 0%, OR 4.46, 95%CI 2.65-7.50) respectively. Patients with early-onset fetal growth restriction with no fetal structural or genetic abnormality have a high risk of poor pregnancy outcomes. Gestational age at diagnosis and certain ultrasound findings are associated with poor pregnancy outcome." | * '''Outcomes in patients with early-onset fetal growth restriction without fetal or genetic anomalies'''{{#pmid:29478342|PMID29478342}} "Early-onset fetal growth restriction is associated with poor pregnancy outcomes, but frequently is due to fetal structural or chromosomal abnormalities. The objective of this study was to determine outcomes in patients with early-onset fetal growth restriction without diagnosed fetal or genetic anomalies and to identify additional risk factors for poor outcomes in these patients. This was retrospective cohort study of singleton pregnancies in women with early-onset growth restriction defined as a sonographic estimated fetal weight <10% diagnosed between 16-28 weeks' gestation. We excluded all women with a fetal structural or chromosomal abnormality diagnosed prenatally. Data on pregnancy characteristics and outcomes were collected and analyzed for estimated fetal weight <10% and ≤5%. A nested case-control study within the cohort of patients with ongoing pregnancies was then performed to identify risk factors associated with poor pregnancy outcome using chi-squared test. One hundred forty-two patients were identified who met inclusion and exclusion criteria and 20 patients were found to have fetal structural or chromosomal abnormalities. In the remaining 122 patients, the incidence of intrauterine fetal demise was 5.7% and there were high rates of preterm birth <37 weeks (20%), birth weight <10% (59.3%), and gestational hypertension (14.1%). Later gestational age at diagnosis and the presence of echogenic bowel and abnormal initial umbilical artery Dopplers were associated with poor pregnancy outcome (22.56 versus 20.86 weeks, p = .046), (17.4 versus 2.2%, OR 9.68, 95%CI 1.65-56.73), and (35.3 versus 0%, OR 4.46, 95%CI 2.65-7.50) respectively. Patients with early-onset fetal growth restriction with no fetal structural or genetic abnormality have a high risk of poor pregnancy outcomes. Gestational age at diagnosis and certain ultrasound findings are associated with poor pregnancy outcome." | ||
{{gastrulation}} | |||
* '''A single-cell molecular map of {{mouse}} {{gastrulation}} and early organogenesis'''{{#pmid:30787436|PMID30787436}} "Across the animal kingdom, gastrulation represents a key developmental event during which embryonic pluripotent cells diversify into lineage-specific precursors that will generate the adult organism. Here we report the transcriptional profiles of 116,312 single cells from mouse embryos collected at nine sequential time points ranging from {{ME6.5}} to {{ME8.5}} days post-fertilization. We construct a molecular map of cellular differentiation from pluripotency towards all major embryonic lineages, and explore the complex events involved in the convergence of visceral and primitive streak-derived {{endoderm}}. Furthermore, we use single-cell profiling to show that Tal1-/- chimeric embryos display defects in early {{mesoderm}} diversification, and we thus demonstrate how combining temporal and transcriptional information can illuminate gene function." | |||
{{genital}} | {{genital}} | ||
* '''Bmp4 is an essential growth factor for the initiation of genital tubercle (GT) outgrowth'''{{#pmid:30714224|PMID30714224}} "The external genitalia are appendage organs outgrowing from the posterior body trunk. Murine genital tubercle (GT), anlage of external genitalia, initiates its outgrowth from embryonic day (E) {{ME10.5}} as a bud structure. Several growth factors such as fibroblast growth factor (FGF), Wnt and Sonic hedgehog ({{Shh}}) are essential for the GT outgrowth. However, the mechanisms of initiation of GT outgrowth are poorly understood. We previously identified bone morphogenetic protein ({{Bmp}}) signaling as a negative regulator for GT outgrowth. We show here novel aspects of Bmp4 functions for GT outgrowth. We identified the Bmp4 was already expressed in cloaca region at E9.5, before GT outgrowth. To analyze the function of Bmp4 at early stage for the initiation of GT outgrowth, we utilized the Hoxa3-Cre driver and Bmp4 flox/flox mouse lines. Hoxa3 Cre/+ ; Bmp4 flox/flox mutant mice showed the hypoplasia of GT with reduced expression of outgrowth promoting genes such as Wnt5a, Hoxd13 and p63, whereas Shh expression was not affected. Formation of distal urethral epithelium (DUE) marked by the Fgf8 expression is essential for controlling mesenchymal genes expression in GT and subsequent its outgrowth. Furthermore, Fgf8 expression was dramatically reduced in such mutant mice indicating the defective DUE formation. Hence, current results indicate that Bmp4 is an essential growth factor for the initiation of GT outgrowth independent of Shh signaling. Thus, Bmp4 positively regulates for the formation of DUE. The current study provides new insights into the function of Bmp signaling at early stage for the initiation of GT outgrowth." {{BMP}} | * '''Bmp4 is an essential growth factor for the initiation of genital tubercle (GT) outgrowth'''{{#pmid:30714224|PMID30714224}} "The external genitalia are appendage organs outgrowing from the posterior body trunk. Murine genital tubercle (GT), anlage of external genitalia, initiates its outgrowth from embryonic day (E) {{ME10.5}} as a bud structure. Several growth factors such as fibroblast growth factor (FGF), Wnt and Sonic hedgehog ({{Shh}}) are essential for the GT outgrowth. However, the mechanisms of initiation of GT outgrowth are poorly understood. We previously identified bone morphogenetic protein ({{Bmp}}) signaling as a negative regulator for GT outgrowth. We show here novel aspects of Bmp4 functions for GT outgrowth. We identified the Bmp4 was already expressed in cloaca region at E9.5, before GT outgrowth. To analyze the function of Bmp4 at early stage for the initiation of GT outgrowth, we utilized the Hoxa3-Cre driver and Bmp4 flox/flox mouse lines. Hoxa3 Cre/+ ; Bmp4 flox/flox mutant mice showed the hypoplasia of GT with reduced expression of outgrowth promoting genes such as Wnt5a, Hoxd13 and p63, whereas Shh expression was not affected. Formation of distal urethral epithelium (DUE) marked by the Fgf8 expression is essential for controlling mesenchymal genes expression in GT and subsequent its outgrowth. Furthermore, Fgf8 expression was dramatically reduced in such mutant mice indicating the defective DUE formation. Hence, current results indicate that Bmp4 is an essential growth factor for the initiation of GT outgrowth independent of Shh signaling. Thus, Bmp4 positively regulates for the formation of DUE. The current study provides new insights into the function of Bmp signaling at early stage for the initiation of GT outgrowth." {{BMP}} | ||
{{Hox}} | |||
* '''{{Hox}} genes in the pharyngeal region: how Hoxa3 controls early embryonic development of the pharyngeal organs'''{{#pmid:30604847|PMID30604847}} "The pharyngeal organs, namely the {{thyroid}}, {{thymus}}, {{parathyroid}}s, and ultimobranchial bodies, derive from the pharyngeal {{endoderm}} during embryonic development. The pharyngeal region is a segmented structure comprised of a series of reiterated structures: the pharyngeal arches on the exterior surface, the pharyngeal pouches on the interior, and a mesenchymal core. It is well known that {{Hox}} genes control spatial identity along the anterior-posterior axis of the developing vertebrate embryo, and nowhere is this is more evident than in the pharyngeal region. Each of the distinct segmented regions has a unique pattern of Hox expression, which conveys crucial positional information to the cells and tissues within it. In the context of pharyngeal organ development, molecular data suggest that HOXA3 is responsible for specifying organ identity within the third pharyngeal pouch, and in its absence, {{thymus}} and {{parathyroid}} organogenesis fails to proceed normally" | |||
{{Hypothalamus}} | {{Hypothalamus}} | ||
* '''Development of the Basal Hypothalamus through Anisotropic Growth'''{{#pmid:31050853|PMID31050853}} "The adult hypothalamus is subdivided into distinct domains: pre-optic, anterior, tuberal and mammillary. Each domain harbours an array of neurons that act together to regulate homeostasis. The embryonic origins and development of hypothalamic neurons, however, remains enigmatic. Here we summarise recent studies in model organisms that challenge current views of hypothalamic development, which traditionally have attempted to map adult domains to correspondingly-located embryonic domains that expand isotropically. Instead, new studies indicate that hypothalamic neurons arise from progenitor cells that undergo anisotropic growth in different dimensions. Here we describe how a multipotent Shh/ Fgf10-expressing progenitor population gives rise to progenitors that grow anisotropically, expanding to a greater extent than other progenitors and giving rise to cells throughout the basal hypothalamus. Further, Shh/Fgf10+ive -derived progenitors grow sequentially in different directions from the multipotent Shh/ Fgf10 population: first, a subset displaced rostrally give rise to anterior-ventral/tuberal neuronal progenitors, then a subset displaced caudally give rise to mammillary neuronal progenitors; finally, a subset(s) displaced ventrally give rise to tuberal infundibular glial progenitors. As this occurs, stable populations of Shh+ive and Fgf10+ive progenitors form. We describe current understanding of the mechanisms that induce Shh/Fgf10+ive progenitors, and begin to direct their differentiation to anterior-ventral/tuberal neuronal progenitors, mammillary neuronal progenitors and tuberal infundibular progenitors. Together these studies suggest a new model for hypothalamic development that we term the Anisotropic growth model. We discuss the implications of the model for understanding the origins of adult hypothalamic neurons." | * '''Development of the Basal Hypothalamus through Anisotropic Growth'''{{#pmid:31050853|PMID31050853}} "The adult hypothalamus is subdivided into distinct domains: pre-optic, anterior, tuberal and mammillary. Each domain harbours an array of neurons that act together to regulate homeostasis. The embryonic origins and development of hypothalamic neurons, however, remains enigmatic. Here we summarise recent studies in model organisms that challenge current views of hypothalamic development, which traditionally have attempted to map adult domains to correspondingly-located embryonic domains that expand isotropically. Instead, new studies indicate that hypothalamic neurons arise from progenitor cells that undergo anisotropic growth in different dimensions. Here we describe how a multipotent Shh/ Fgf10-expressing progenitor population gives rise to progenitors that grow anisotropically, expanding to a greater extent than other progenitors and giving rise to cells throughout the basal hypothalamus. Further, Shh/Fgf10+ive -derived progenitors grow sequentially in different directions from the multipotent Shh/ Fgf10 population: first, a subset displaced rostrally give rise to anterior-ventral/tuberal neuronal progenitors, then a subset displaced caudally give rise to mammillary neuronal progenitors; finally, a subset(s) displaced ventrally give rise to tuberal infundibular glial progenitors. As this occurs, stable populations of Shh+ive and Fgf10+ive progenitors form. We describe current understanding of the mechanisms that induce Shh/Fgf10+ive progenitors, and begin to direct their differentiation to anterior-ventral/tuberal neuronal progenitors, mammillary neuronal progenitors and tuberal infundibular progenitors. Together these studies suggest a new model for hypothalamic development that we term the Anisotropic growth model. We discuss the implications of the model for understanding the origins of adult hypothalamic neurons." | ||
{{implantation}} - {{trophoblast}} | |||
* '''Dynamics of {{trophoblast}} differentiation in peri-{{implantation}}-stage human embryos'''{{#pmid:31636193|PMID31636193}} "Single-cell RNA sequencing of cells from cultured human blastocysts has enabled us to define the transcriptomic landscape of placental trophoblast (TB) that surrounds the epiblast and associated embryonic tissues during the enigmatic day 8 (D8) to D12 peri-implantation period before the villous placenta forms. We analyzed the transcriptomes of 3 early placental cell types, cytoTB (CTB), syncytioTB (STB), and migratoryTB (MTB), picked manually from cultured embryos dissociated with trypsin and were able to follow sublineages that emerged from proliferating CTB at the periphery of the conceptus. A unique form of CTB with some features of STB was detectable at D8, while mature STB was at its zenith at D10. A form of MTB with a mixed MTB/CTB phenotype arose around D10. By D12, STB generation was in decline, CTB had entered a new phase of proliferation, and mature MTB cells had begun to move from the main body of the conceptus. Notably, the MTB transcriptome at D12 indicated enrichment of transcripts associated with IFN signaling, migration, and invasion and up-regulation of HLA-C, HLA-E, and HLA-G. The STB, which is distinct from the STB of later villous STB, had a phenotype consistent with intense protein export and placental hormone production, as well as migration and invasion. The studies show that TB associated with human embryos is in rapid developmental flux during peri-implantation period when it must invade, signal robustly to the mother to ensure that the pregnancy continues, and make first contact with the maternal immune system." | |||
{{induced stem cells}} | |||
* '''Directing differentiation of human induced pluripotent stem cells toward androgen-producing {{Leydig cell}}s rather than {{adrenal}} cells'''{{#pmid:31591190|PMID31591190}} "Reduced serum {{testosterone}} (T), or hypogonadism, affects millions of men and is associated with many pathologies, including infertility, cardiovascular diseases, metabolic syndrome, and decreased libido and sexual function. Administering T-replacement therapy (TRT) reverses many of the symptoms associated with low T levels. However, TRT is linked to side effects such as infertility and increased risk of prostate cancer and cardiovascular diseases. Thus, there is a need to obtain T-producing cells that could be used to treat hypogonadism via transplantation and reestablishment of T-producing cell lineages in the body. T is synthesized by Leydig cells (LCs), proposed to derive from mesenchymal cells of mesonephric origin. Although mesenchymal cells have been successfully induced into LCs, the limited source and possible trauma to donors hinders their application to clinical therapies. Alternatively, human induced pluripotent stem cells (hiPSCs), which are expandable in culture and have the potential to differentiate into all somatic cell types, have become the emerging source of autologous cell therapies. We have successfully induced the differentiation of hiPSCs into either human Leydig-like (hLLCs) or adrenal-like cells (hALCs) using chemically defined culture conditions. Factors critical for the development of LCs were added to both culture systems. hLLCs expressed all steroidogenic genes and proteins important for T biosynthesis, synthesized T rather than cortisol, secreted steroid hormones in response to dibutyryl-cAMP and 22(R)-hydroxycholesterol, and displayed ultrastructural features resembling LCs. By contrast, hALCs synthesized cortisol rather than T. The success in generating hiPSC-derived hLLCs with broad human LC (hLC) features supports the potential for hiPSC-based hLC regeneration." | |||
{{limb}} | |||
* '''Analysis of a {{limb}}-specific regulatory element in the promoter of the link protein gene'''{{#pmid:31470976|PMID31470976}} "Link protein is encoded by the Hapln1 gene and is a prototypical protein found in the {{cartilage}} matrix. It acts as an important component of the endochondral skeleton during early development. To study its transcriptional regulation, promoter fragments derived from the link protein gene were coupled to the β-galactosidase reporter and used to study in vivo transgene expression in mice. In day 15.5 mouse embryos, a link promoter fragment spanning -1020 to +40 nucleotides demonstrated highly specific β-galactosidase staining of skeletal structures, including the appendicular and axial cartilaginous tissues. Two shorter promoter fragments, spanning -690 to +40 and -315 to +40 nucleotides, demonstrated limb- and genitalia-specific expression resembling that of homeodomain-regulated tissues. Bioinformatic analysis revealed a highly conserved, {{Hox}}-like binding site (HLBS) at approximately -220 bp of the promoter, shared by both constructs, which contained the Hox-core consensus sequence TAATTA. Electromobility shift assays demonstrated binding of {{Hox}}-B4 recombinant protein to the HLBS, which was eliminated with nucleotide substitutions within the core-binding element. Co-transfection analysis of the HLBS demonstrated a 22-fold transcriptional activation by HoxA9 expression, which was ablated with a substitution within the core HLBS element. Together these findings establish promoter regions within the link protein gene that are important for in vivo expression and identify the potential role of homeodomain-containing proteins in controlling {{cartilage}} and {{limb}} gene expression." | |||
{{liver}} | {{liver}} | ||
Line 45: | Line 68: | ||
{{lizard}} | {{lizard}} | ||
* '''Egg incubation temperature influences the growth and foraging behaviour of juvenile lizards'''{{#pmid:31170461|PMID31170461}} "After laying their eggs, oviparous reptiles are reliant on the external environment to provide the required incubation conditions for successful embryonic development. Egg incubation temperature can impact the behaviour of various species of reptiles, but previous experiments have focused on the impact of incubation environment on hatchlings, with only a limited number of studies focussing on the longer-term behavioural consequences of incubation environment. This study investigated the effects of developmental environment on bearded dragon lizards (Pogona vitticeps) that were incubated at different temperatures within the natural range; half of them were incubated at a 'hot' temperature (30 ± 3 °C) and half at a 'cold' temperature (27 ± 3 °C). The growth and foraging behaviour of the lizards was then compared over 18 weeks of development. Although the lizards incubated at a cool temperatures grew more quickly, those incubated at the hotter temperature completed the foraging task more often and had significantly faster running speeds. These results show that egg incubation temperature impacts the foraging behaviour of juvenile lizards and suggest a potential trade-off between growth and foraging speed, which could influence an animal's life history trajectory." {{DOHAD}} | * '''Egg incubation temperature influences the growth and foraging behaviour of juvenile lizards'''{{#pmid:31170461|PMID31170461}} "After laying their eggs, oviparous reptiles are reliant on the external environment to provide the required incubation conditions for successful embryonic development. Egg incubation temperature can impact the behaviour of various species of reptiles, but previous experiments have focused on the impact of incubation environment on hatchlings, with only a limited number of studies focussing on the longer-term behavioural consequences of incubation environment. This study investigated the effects of developmental environment on bearded dragon lizards (Pogona vitticeps) that were incubated at different temperatures within the natural range; half of them were incubated at a 'hot' temperature (30 ± 3 °C) and half at a 'cold' temperature (27 ± 3 °C). The growth and foraging behaviour of the lizards was then compared over 18 weeks of development. Although the lizards incubated at a cool temperatures grew more quickly, those incubated at the hotter temperature completed the foraging task more often and had significantly faster running speeds. These results show that egg incubation temperature impacts the foraging behaviour of juvenile lizards and suggest a potential trade-off between growth and foraging speed, which could influence an animal's life history trajectory." {{DOHAD}} | ||
{{maternal diabetes}} | |||
* '''Maternal diabetes induces autism-like behavior by hyperglycemia-mediated persistent oxidative stress and suppression of superoxide dismutase 2'''{{#pmid:31685635}} "Epidemiological studies show that maternal diabetes is associated with an increased risk of autism spectrum disorders (ASDs), although the detailed mechanisms remain unclear. The present study aims to investigate the potential effect of maternal diabetes on autism-like behavior in offspring. The results of in vitro study showed that transient hyperglycemia induces persistent reactive oxygen species (ROS) generation with suppressed superoxide dismutase 2 (SOD2) expression. Additionally, we found that SOD2 suppression is due to oxidative stress-mediated histone methylation and the subsequent dissociation of early growth response 1 (Egr1) on the SOD2 promoter. Furthermore, in vivo rat experiments showed that maternal diabetes induces SOD2 suppression in the amygdala, resulting in autism-like behavior in offspring. SOD2 overexpression restores, while SOD2 knockdown mimics, this effect, indicating that oxidative stress and SOD2 expression play important roles in maternal diabetes-induced autism-like behavior in offspring, while prenatal and postnatal treatment using antioxidants permeable to the blood-brain barrier partly ameliorated this effect. We conclude that maternal diabetes induces autism-like behavior through hyperglycemia-mediated persistent oxidative stress and SOD2 suppression. Here we report a potential mechanism for maternal diabetes-induced ASD." | |||
{{mouse}} | {{mouse}} | ||
* '''Molecular recording of mammalian embryogenesis'''{{#pmid:31086336|PMID31086336}} "Ontogeny describes the emergence of complex multicellular organisms from single totipotent cells. This field is particularly challenging in mammals, owing to the indeterminate relationship between self-renewal and differentiation, variation in progenitor field sizes, and internal gestation in these animals. Here we present a flexible, high-information, multi-channel molecular recorder with a single-cell readout and apply it as an evolving lineage tracer to assemble mouse cell-fate maps from fertilization through gastrulation. By combining lineage information with single-cell RNA sequencing profiles, we recapitulate canonical developmental relationships between different tissue types and reveal the nearly complete transcriptional convergence of endodermal cells of extra-embryonic and embryonic origins. Finally, we apply our cell-fate maps to estimate the number of embryonic progenitor cells and their degree of asymmetric partitioning during specification. Our approach enables massively parallel, high-resolution recording of lineage and other information in mammalian systems, which will facilitate the construction of a quantitative framework for understanding developmental processes." | * '''Molecular recording of mammalian embryogenesis'''{{#pmid:31086336|PMID31086336}} "Ontogeny describes the emergence of complex multicellular organisms from single totipotent cells. This field is particularly challenging in mammals, owing to the indeterminate relationship between self-renewal and differentiation, variation in progenitor field sizes, and internal gestation in these animals. Here we present a flexible, high-information, multi-channel molecular recorder with a single-cell readout and apply it as an evolving lineage tracer to assemble mouse cell-fate maps from fertilization through gastrulation. By combining lineage information with single-cell RNA sequencing profiles, we recapitulate canonical developmental relationships between different tissue types and reveal the nearly complete transcriptional convergence of endodermal cells of extra-embryonic and embryonic origins. Finally, we apply our cell-fate maps to estimate the number of embryonic progenitor cells and their degree of asymmetric partitioning during specification. Our approach enables massively parallel, high-resolution recording of lineage and other information in mammalian systems, which will facilitate the construction of a quantitative framework for understanding developmental processes." | ||
{{neural}} {{fly}} | {{neural}} | {{fly}} | ||
* '''N-cadherin orchestrates self-organization of neurons within a columnar unit in the Drosophila medulla'''{{#pmid:31175213|PMID31175213}} "The columnar structure is a basic unit of the brain, but its developmental mechanism remains unknown. The medulla, the largest ganglion of the fly visual center, provides a unique opportunity to reveal the mechanisms of three-dimensional organization of the columns. We reveal that column formation is initiated by three core neurons that establish distinct concentric domains within a column. We demonstrate the in vivo evidence of N-cadherin-dependent differential adhesion among the core columnar neurons within a column along a two-dimensional layer in the larval medulla. The two-dimensional larval columns evolve to form three distinct layers in the pupal medulla. We propose the presence of mutual interactions among the three layers during formation of the three-dimensional structures of the medulla columns." | * '''N-cadherin orchestrates self-organization of neurons within a columnar unit in the Drosophila medulla'''{{#pmid:31175213|PMID31175213}} "The columnar structure is a basic unit of the brain, but its developmental mechanism remains unknown. The medulla, the largest ganglion of the fly visual center, provides a unique opportunity to reveal the mechanisms of three-dimensional organization of the columns. We reveal that column formation is initiated by three core neurons that establish distinct concentric domains within a column. We demonstrate the in vivo evidence of N-cadherin-dependent differential adhesion among the core columnar neurons within a column along a two-dimensional layer in the larval medulla. The two-dimensional larval columns evolve to form three distinct layers in the pupal medulla. We propose the presence of mutual interactions among the three layers during formation of the three-dimensional structures of the medulla columns." | ||
{{neural postnatal}} | {{smell}} | |||
* '''Dynamic changes in ultrastructure of the primary cilium in migrating neuroblasts in the postnatal brain'''{{#pmid:31685650|PMID31685650}} "New neurons, referred to as neuroblasts, are continuously generated in the ventricular-subventricular zone of the brain throughout an animal's life. These neuroblasts are characterized by their unique potential for proliferation, formation of chain-like cell aggregates, and long-distance and high-speed migration through the rostral migratory stream (RMS) toward the olfactory bulb (OB), where they decelerate and differentiate into mature interneurons. ... Together, our results highlight a close mutual relationship between spatiotemporal regulation of the primary cilium and efficient chain migration of neuroblasts in the postnatal brain. Immature neurons (neuroblasts) generated in the postnatal brain have a mitotic potential and migrate in chain-like cell aggregates toward the olfactory bulb. Here we report that migrating neuroblasts possess a tiny cellular protrusion called a primary cilium. Immunohistochemical studies with zebrafish, mouse, and monkey brains suggest that the presence of the primary cilium in migrating neuroblasts is evolutionarily conserved. Ciliogenesis in migrating neuroblasts in the RMS is suppressed during mitosis and promoted after cell cycle exit. Moreover, live imaging and three-dimensional electron microscopy revealed that ciliary localization and orientation change during saltatory movement of neuroblasts. Our results reveal highly organized dynamics in maturation and positioning of the primary cilium during neuroblast migration that underlie saltatory movement of postnatal-born neuroblasts." | |||
{{neural crest}} | {{neural crest}} | ||
Line 64: | Line 93: | ||
{{testis}} | {{testis}} | ||
* '''XY oocytes of sex-reversed females with a Sry mutation deviate from the normal developmental process beyond the mitotic stage'''{{#pmid:30289439|PMID30289439}} "The fertility of sex-reversed XY female mice is severely impaired by a massive loss of oocytes and failure of meiotic progression. This phenomenon remains an outstanding mystery. We sought to determine the molecular etiology of XY oocyte dysfunction by generating sex-reversed females that bear genetic ablation of Sry, a vital sex determination gene, on an inbred C57BL/6 background. These mutant mice, termed XYsry- mutants, showed severe attrition of germ cells during fetal development, resulting in the depletion of ovarian germ cells prior to sexual maturation. Comprehensive transcriptome analyses of primordial germ cells (PGCs) and postnatal oocytes demonstrated that XYsry- females had deviated significantly from normal developmental processes during the stages of mitotic proliferation. The impaired proliferation of XYsry- PGCs was associated with aberrant β-catenin signaling and the excessive expression of transposable elements. Upon entry to the meiotic stage, XYsry- oocytes demonstrated extensive defects, including the impairment of crossover formation, the failure of primordial follicle maintenance, and no capacity for embryo development. Together, these results suggest potential molecular causes for germ cell disruption in sex-reversed female mice, thereby providing insights into disorders of sex differentiation in humans, such as "Swyer syndrome," in which patients with an XY karyotype present as typical females and are infertile." | * '''XY oocytes of sex-reversed females with a Sry mutation deviate from the normal developmental process beyond the mitotic stage'''{{#pmid:30289439|PMID30289439}} "The fertility of sex-reversed XY female mice is severely impaired by a massive loss of oocytes and failure of meiotic progression. This phenomenon remains an outstanding mystery. We sought to determine the molecular etiology of XY oocyte dysfunction by generating sex-reversed females that bear genetic ablation of Sry, a vital sex determination gene, on an inbred C57BL/6 background. These mutant mice, termed XYsry- mutants, showed severe attrition of germ cells during fetal development, resulting in the depletion of ovarian germ cells prior to sexual maturation. Comprehensive transcriptome analyses of primordial germ cells (PGCs) and postnatal oocytes demonstrated that XYsry- females had deviated significantly from normal developmental processes during the stages of mitotic proliferation. The impaired proliferation of XYsry- PGCs was associated with aberrant β-catenin signaling and the excessive expression of transposable elements. Upon entry to the meiotic stage, XYsry- oocytes demonstrated extensive defects, including the impairment of crossover formation, the failure of primordial follicle maintenance, and no capacity for embryo development. Together, these results suggest potential molecular causes for germ cell disruption in sex-reversed female mice, thereby providing insights into disorders of sex differentiation in humans, such as "Swyer syndrome," in which patients with an XY karyotype present as typical females and are infertile." | ||
{{trisomy 21}} | |||
* '''First trimester uterine artery pulsatility index levels in euploid and aneuploid pregnancies'''{{#pmid:31616987|PMID31616987}} "To examine whether the uterine artery PI is different in aneuploid and euploid pregnancies. METHODS: Retrospective case-matched study at the department of prenatal medicine at the University of Tuebingen, Germany. The study involved patients with complete data on first trimester screening for trisomies and preeclampsia except PlGF. For each case with trisomy 21 we randomly selected 50 cases with a euploid fetus where complete data on screening for aneuploidy and preeclampsia were also available. The uterine artery pulsatility index and the corresponding MoM values of euploid and the aneuploid population were compared with a Man-Whitney U test. RESULTS: The dataset consisted of 4591 singleton pregnancies. The karyotype was normal in 4500 cases and was abnormal in the remaining 91 pregnancies. There were 50 pregnancies with trisomy 21, 31 with trisomy 18 and 13, and 10 with triploidy. In the group with euploid fetuses, median uterine artery PI was 1.55 (0.99 MoM). In the group with trisomy 21, the median PI (1.42) and MoM (0.89) levels were both significantly lower than in the euploid (p < 0.001). However, the measurements in the trisomy 18 and 13 [1.61 (0.93 MoM)] and in the triploidy [1.99 (1.13 MoM)] groups were not significantly different from those in the euploid group (p = 0.468 and p = 0.632, respectively). CONCLUSION: In conclusion, uterine artery PI levels in the first trimester are slightly lower in pregnancies with trisomy 21. This knowledge may prove to be useful in cases where a low PAPP-A level is seen on the first trimester maternal serum biochemical evaluation to differentiate whether the more likely cause for this finding is placental dysfunction or aneuploidy, specifically trisomy 21." | |||
{{VACTERL}} | |||
* '''VACTERL Association in a Female {{Pig}} (''Sus scrofa domesticus'')'''{{#pmid:31812176|PMID31812176}} "VACTERL/VATER association is a condition defined by the presence of at least three of the following congenital malformations: vertebral defects (V), anal atresia (A), cardiac defects (C), tracheo-oesophageal fistula (TE), renal anomalies (R) and limb abnormalities (L). We describe a stillborn female piglet with cardiac anomalies, renal defects, vertebral anomalies, anal atresia and a single umbilical artery (SUA), which are the main features of VACTERL association. In addition, the piglet had a unilateral abdominal wall defect. This was the only affected animal in a litter of 16 piglets. The molecular inductive mechanisms of this disorder are discussed, as well as the comparative and embryological implications." | |||
{{vein}} | {{vein}} |
Latest revision as of 22:47, 28 December 2019
2019 New References |
---|
Mark Hill (talk) 12:23, 16 June 2019 (AEST) Added this new page to capture updated references added throughout the site in the "Some Recent Findings". Entries are listed alphabetically by topic page. Note that not all new references may be added to this current list. (More? New)
epithelial mesenchymal transition
|