MesP1: a novel basic helix-loop-helix protein expressed in the nascent mesodermal cells during mouse gastrulation

Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2769-2778 ◽  
Author(s):  
Y. Saga ◽  
N. Hata ◽  
S. Kobayashi ◽  
T. Magnuson ◽  
M.F. Seldin ◽  
...  
Keyword(s):  
Germ Cells ◽  
Southern Hybridization ◽  
Primordial Germ Cells ◽  
Primitive Streak ◽  
Subtractive Hybridization ◽  
Hybridization Study ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Deficiency Gene ◽  
Extraembryonic Mesoderm

A subtractive hybridization strategy was used to isolate putative genes involved in the development of mouse primordial germ cells (PGC). Complimentary DNA was amplified on RNA isolated from the base of the allantois where PGC are located in the 7.5 days post coitum (dpc) mouse embryo. It was then subtracted by hybridization with cDNA amplified on RNA of the anterior region where PGC are absent. A novel gene thus isolated is designated as Mesp1 and encodes a possible transcription factor MesP1 containing a basic helix-loop-helix motif. Its earliest expression was observed at the onset of gastrulation, as early as 6.5 dpc, in the nascent mesodermal cells that first ingressed at the end of the primitive streak. These expressing cells in the lateral and extraembryonic mesoderm showed a wing-shaped distribution. Its initial expression was soon down-regulated at 7.5 dpc before the completion of gastrulation, except at the proximal end of the primitive streak which included the extraembryonic mesoderm and the base of allantois. At 8 dpc, the expression at the base of the allantois moved laterally. This distribution between 7.0 and 8.0 dpc was similar to that of PGC detected by the alkaline phosphatase activity. However, the expression of Mesp1 was down-regulated thereafter, when PGC entered in the migration stage. After birth, Mesp1 expression was detected only in mature testes, but in a different isoform from that expressed in the embryo. Mesp1 was mapped to the mid region of chromosome 7, near the mesodermal deficiency gene (mesd). However, a Southern hybridization study clearly showed that Mesp1 was distinctly different from mesd. The amino acid sequence and its expression pattern suggest that MesP1 plays an important role in the development of the nascent mesoderm including PGC.

Primordial germ cells in the mouse embryo during gastrulation

Development ◽  
1990 ◽  
Vol 110 (2) ◽  
pp. 521-528 ◽  
Author(s):  
M. Ginsburg ◽  
M.H. Snow ◽  
A. McLaren
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primitive Streak ◽  
Cell Types ◽  
Mesodermal Cell ◽  
Alp Activity ◽  
Cluster Area ◽  
Extraembryonic Mesoderm ◽  
Excised Tissue ◽  
Number Of Cells

With the aid of a whole-mount technique, we have detected a small cluster of alkaline phosphatase (ALP)-positive cells in whole mounts of mid-primitive-streak-stage embryos, 7–7 1/4 days post coitum (dpc). Within the cluster, about 8 cells contain a small cytoplasmic spot, intensely stained for ALP activity and possibly associated with an active Golgi complex. The cluster lies just posterior to the definitive primitive streak in the extraembryonic mesoderm, separated from the embryo by the amniotic fold. Towards the end of gastrulation, the number of cells containing the ALP-positive spot rises to between 50 and 80. Thereafter the number of cells in the extraembryonic cluster declines, and similar cells start to be seen in the mesoderm of the primitive streak and then in the endoderm. At 8 dpc, about 125 ALP-stained cells are found, mainly in the hindgut endoderm and also at the base of the allantois, their appearance and location at this stage agreeing closely with previous reports on primordial germ cells (PGCs). Embryos from which the cluster area has been removed at the 7-day stage are devoid of PGCs after culture for 48 h, whereas the excised tissue is rich in PGCs. We argue that the cells in the cluster are indeed primordial germ cells, at a stage significantly earlier than any reported previously. This would indicate that the PGC lineage in the mouse is set aside at least as early as 7 dpc, possibly as one of the first ‘mesodermal’ cell types to emerge, and that its differentiation, as expressed by ALP activity, is gradual.

Interactions between primordial germ cells play a role in their migration in mouse embryos

Development ◽  
1994 ◽  
Vol 120 (1) ◽  
pp. 135-141 ◽  
Author(s):  
M. Gomperts ◽  
M. Garcia-Castro ◽  
C. Wylie ◽  
J. Heasman
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primitive Streak ◽  
Carbohydrate Antigen ◽  
Mature Stage ◽  
Conventional View ◽  
Embryonic Antigen ◽  
Hind Gut ◽  
Extraembryonic Mesoderm ◽  
Dorsal Mesentery

Primordial germ cells (PGCs) are the founder cell population of the gametes which form during the sexually mature stage of the life cycle. In the mouse, they arise early in embryogenesis, first becoming visible in the extraembryonic mesoderm, posterior to the primitive streak, at 7.5 days post coitum (d.p.c.). They subsequently become incorporated into the epithelium of the hind gut, from which they emigrate (9.5 d.p.c.) and move first into the dorsal mesentery (10.5 d.p.c.), and then into the genital ridges that lie on the dorsal body wall (11.5 d.p.c.). We have used confocal microscopy to study PGCs stained with an antibody that reacts with a carbohydrate antigen (Stage-Specific Embryonic Antigen-1, SSEA-1) carried on the PGC surface. This allows the study of the whole PGC surface, at different stages of their migration. The appearance of PGCs in tissue sections has given rise to the conventional view that they migrate as individuals, each arriving in turn at the genital ridge. In this paper, we show that PGCs leave the hind gut independently, but then extend long (up to 40 microns) processes, with which they link up to each other to form extensive networks. During the 10.5-11.5 d.p.c. period, these networks of PGCs aggregate into groups of tightly apposed cells in the genital ridges. As this occurs, their processes are lost, and their appearance suggests they are now non-motile. Furthermore, we find that PGCs taken from the dorsal mesentery at 10.5 d.p.c. perform the same sequence of movements in culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Primordial germ cells in normal and transected duck blastoderms

Development ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 247-260
Author(s):  
Teresa Rogulska
Keyword(s):  
Chick Embryo ◽  
Blood Vessels ◽  
Germ Cells ◽  
Anterior Part ◽  
Primordial Germ Cells ◽  
Primitive Streak ◽  
Experimental Investigations ◽  
Suggestive Evidence ◽  
Area Pellucida

Suggestive evidence for the extragonadal origin of germ cells in birds was first presented by Swift (1914), who described primordial germ cells in the chick embryo at as early a stage as the primitive streak. According to Swift, primordial germ cells are originally located extra-embryonically in the anterior part of the blastoderm and occupy a crescent-shaped region (‘germinal crescent’) on the boundary between area opaca and area pellucida. Swift also found that primordial germ cells later enter into the blood vessels, circulate together with the blood throughout the whole blastoderm and finally penetrate into the genital ridges, where they become definitive germ cells. Swift's views have been confirmed in numerous descriptive and experimental investigations. Among the latter, the publications of Willier (1937), Simon (1960) and Dubois (1964a, b, 1965a, b, 1966) merit special attention. Dubois finally proved that the genital ridges exert a strong chemotactic influence on the primordial germ cells.

Proliferation and migration of primordial germ cells during compensatory growth in mouse embryos

Development ◽  
1981 ◽  
Vol 64 (1) ◽  
pp. 133-147
Author(s):  
P. P. L. Tam ◽  
M. H. L. Snow
Keyword(s):  
Mitomycin C ◽  
Germ Cells ◽  
Compensatory Growth ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Primitive Streak ◽  
Mouse Embryos ◽  
Newborn Mice ◽  
Embryonic Life ◽  
And Migration

Primitive-streak-stage mouse embryos were treated with Mitomycin C injected intraperitoneally into pregnant females at 6·75–7·0 days post coitum. The newborn mice developed poorly and mortality was high during the suckling period. Many weaned survivors showed impaired fertility and poor breeding performance. Histological examination revealed a paucity of germ cells in the adult gonads. The deficiency was mainly caused by a severe reduction of the primordial germ cell population in early embryonic life, which was not fully compensated for during the compensatory growth phase of the Mitomycin C-treated embryo. Also contributing to such impaired fertility were retarded migration of the primordial germ cells into the genital ridges, poor development of the foetal gonad and secondary loss of the germ cells during gametogenesis in males.

scholarly journals Primordial germ cells are capable of producing cells of the hematopoietic system in vitro

Blood ◽  
1995 ◽  
Vol 86 (2) ◽  
pp. 463-472 ◽  
Author(s):  
IN Rich
Keyword(s):  
Stem Cell ◽  
Cell Population ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Methyl Cellulose ◽  
Primitive Streak ◽  
Stem Cell Population ◽  
Hematopoietic Stem ◽  
Hematopoietic System

The identity of the cells giving rise to the hematopoietic system in the mouse embryo are unknown. The results presented here strongly suggest that hematopoietic cells are derived from a nonhematopoietic cell population that has been previously thought to give rise to the germ cells. These cells are called primordial germ cells (PGCs) and can be recognized as large cells showing blebbing and pseudopodial extrusions on their surface. They are alkaline phosphatase (AP) positive and possess a stage-specific embryonic antigen (SSEA-1) on their surface. They represent a small pool of cells in the extraembryonic mesoderm at the base of the allantois in late day-6 embryos. Primordial germ cells from 7.5- and 8.5-day visceral yolk sac and embryo proper form AP+ and SSEA-1+ colonies within 5 days when grown on an embryonic fibroblast feeder cell layer in the presence of leukemia inhibitory factor (LIF), stem cell factor (SCF), and interleukin-3 (IL-3). Individual colonies taken from day-5 cultures can be shown to differentiate into erythroid lineage cells in secondary methyl cellulose culture and produce secondary and tertiary PGCs in the presence of LIF, SCF, and IL-3. Cells taken from the region of the allantois and primitive streak can form colonies on hydrophilic Teflon (DuPont, Wilmington, DE) foils precoated with collagen and fibronectin. The cells from these colonies were then shown to form cobblestone areas on irradiated adult bone marrow stromal layers, indicating that the most primitive in vitro hematopoietic stem cell, the cobblestone-area forming cell (CAFC), was present. PGC colonies were grown in methyl cellulose in the presence of LIF, SCF, and IL-3 for 5 days, and the colonies were removed and passaged 3 times on pretreated extracellular matrix hydrophilic Teflon foils. After each passage, the cells were assayed for their differentiation capacity and PGC content. After the last passage, the number of CAFCs was also determined. It was found that, under these conditions, the PGC population expanded more than 400- fold and also contained CAFCs. It is postulated that the PGC represents a totipotent stem cell population capable of producing a variety of different cell types including cells of the hematopoietic system.

Dual role of the basic helix-loop-helix transcription factor scleraxis in mesoderm formation and chondrogenesis during mouse embryogenesis

Development ◽  
1999 ◽  
Vol 126 (19) ◽  
pp. 4317-4329 ◽  
Author(s):  
D. Brown ◽  
D. Wagner ◽  
X. Li ◽  
J.A. Richardson ◽  
E.N. Olson
Keyword(s):  
Transcription Factor ◽  
Target Genes ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Axial Skeleton ◽  
Bhlh Transcription Factor ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Mesoderm Formation ◽  
Cell Layers

Scleraxis is a basic helix-loop-helix (bHLH) transcription factor shown previously to be expressed in developing chondrogenic cell lineages during embryogenesis. To investigate its function in embryonic development, we produced scleraxis-null mice by gene targeting. Homozygous mutant embryos developed normally until the early egg cylinder stage (embryonic day 6.0), when they became growth-arrested and failed to gastrulate. Consistent with this early embryonic phenotype, scleraxis was found to be expressed throughout the embryo at the time of gastrulation before becoming restricted to chondrogenic precursor cells at embryonic day 9.5. At the time of developmental arrest, scleraxis-null embryos consisted of ectodermal and primitive endodermal cell layers, but lacked a primitive streak or recognizable mesoderm. Analysis of molecular markers of the three embryonic germ layers confirmed that scleraxis mutant embryos were unable to form mesoderm. By generating chimeric embryos, using lacZ-marked scleraxis-null and wild-type embryonic stem cells, we examined the ability of mutant cells to contribute to regions of the embryo beyond the time of lethality of homozygous mutants. Scleraxis-null cells were specifically excluded from the sclerotomal compartment of somites, which gives rise to the axial skeleton, and from developing ribs, but were able to contribute to most other regions of the embryo, including mesoderm-derived tissues. These results reveal an essential early role for scleraxis in mesoderm formation, as well as a later role in formation of somite-derived chondrogenic lineages, and suggest that scleraxis target genes mediate these processes.

scholarly journals Role of the Basic Helix-Loop-Helix Transcription Factor, Scleraxis, in the Regulation of Sertoli Cell Function and Differentiation

2005 ◽  
Vol 19 (8) ◽  
pp. 2164-2174 ◽  
Author(s):  
Tera Muir ◽  
Ingrid Sadler-Riggleman ◽  
Michael K. Skinner
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Antisense Oligonucleotide ◽  
Cell Function ◽  
Gene Products ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix

Abstract Sertoli cells are a postmitotic terminally differentiated cell population in the adult testis that form the seminiferous tubules and provide the microenvironment and structural support for developing germ cells. The transcription factors that regulate Sertoli cell differentiation remain to be elucidated. The basic helix-loop-helix transcription factors are involved in the differentiation of a variety of cell lineages during development and are expressed in pubertal Sertoli cells. A yeast-two-hybrid procedure was used to screen a Sertoli cell library from 20-d-old pubertal rats to identify dimerization partners with the ubiquitous E47 basic helix-loop-helix transcription factor. Scleraxis was identified as one of the interacting partners. Among the cell types of the testis, scleraxis expression was found to be specific to Sertoli cells. Analysis of the expression pattern of scleraxis mRNA in developing Sertoli cells revealed an increase in scleraxis message at the onset of puberty. Sertoli cells respond to FSH to promote expression of differentiated gene products such as transferrin that aid in proper development of the germ cells. Analysis of the hormonal regulation of scleraxis expression revealed a 4-fold increase in scleraxis mRNA in response to the presence of FSH or dibutryl cAMP in cultured Sertoli cells. An antisense oligonucleotide procedure and overexpression analysis were used to determine whether scleraxis regulates the expression of Sertoli cell differentiated gene products. An antisense oligonucleotide to scleraxis down-regulated transferrin promoter activity in Sertoli cells. A transient overexpression of scleraxis in Sertoli cells stimulated transferrin and androgen binding protein promoter activities and the expression of a number of differentiated genes. Observations suggest scleraxis functions in a number of adult tissues and is involved in the regulation and maintenance of Sertoli cell function and differentiation. This is one of the first adult and nontendon/chondrocyte-associated functions described for scleraxis.

scholarly journals FIGLA, a Basic Helix-Loop-Helix Transcription Factor, Balances Sexually Dimorphic Gene Expression in Postnatal Oocytes

2010 ◽  
Vol 30 (14) ◽  
pp. 3661-3671 ◽  
Author(s):  
Wei Hu ◽  
Lyn Gauthier ◽  
Boris Baibakov ◽  
Maria Jimenez-Movilla ◽  
Jurrien Dean
Keyword(s):  
Transcription Factor ◽  
Germ Cell ◽  
Germ Cells ◽  
Sexually Dimorphic ◽  
Newborn Mice ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Age Related ◽  
Posttranscriptional Processing ◽  
Dimorphic Gene Expression

ABSTRACT Maintenance of sex-specific germ cells requires balanced activation and repression of genetic hierarchies to ensure gender-appropriate development in mammals. Figla (factor in the germ line, alpha) encodes a germ cell-specific basic helix-loop-helix transcription factor first identified as an activator of oocyte genes. In comparing the ovarian proteome of normal and Figla null newborn mice, 18 testis-specific or -enhanced proteins were identified that were more abundant in Figla null ovaries than in normal ovaries. Transgenic mice, ectopically expressing Figla in male germ cells, downregulated a subset of these genes and demonstrated age-related sterility associated with impaired meiosis and germ cell apoptosis. Testis-associated genes, including Tdrd1, Tdrd6, and Tdrd7, were suppressed in the transgenic males with a corresponding disruption of the sperm chromatoid body and mislocalization of MVH and MILI proteins, previously implicated in posttranscriptional processing of RNA. These data demonstrate that physiological expression of Figla plays a critical dual role in activation of oocyte-associated genes and repression of sperm-associated genes during normal postnatal oogenesis.

147 IDENTIFICATION OF PRIMORDIAL GERM CELLS IN PORCINE EMBRYOS FROM THE PRIMITIVE STREAK STAGE

2006 ◽  
Vol 18 (2) ◽  
pp. 181 ◽  
Author(s):  
M. Vejlsted ◽  
H. Offenberg ◽  
P. Maddox-Hyttel
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Primitive Streak ◽  
Posterior Pole ◽  
Embryonic Cells ◽  
Somite Stage ◽  
Mesodermal Origin ◽  
A Site

In embryonic stem cell research, Oct-4 is one of the most widely used markers of pluripotency. Moreover, at least in the mouse, this marker is restricted to primordial germ cells (PGCs) after gastrulation. Vimentin is often used as a marker of mesoderm/mesenchyme in embryonic tissues and appears to localize to the same embryonic cells as Oct-4, at least in the bovine epiblast. The expression of neither of these markers has been completely addressed in the pig. Therefore, the purpose of the present study was to examine the expression of Oct-4 and vimentin in the porcine epiblast during differentiation and establishment of the three germ layers, i.e. the process of gastrulation. A total of 410 porcine embryos were collected at 8 to 17 days post-insemination from 29 sows of the Danish Landrace breed. Embryos were categorized based on stereo-microscopic observations into the following stages: pre-streak stages 1 and 2, primitive streak stage, neural groove stage, and somite stage. Specimens were fixed at all stages, dehydrated and embedded in paraffin wax. Selected embryos at each stage (n = 28) were completely cut into serial sections for immunohistochemical evaluation of Oct-4 and vimentin. Pre-streak stage 1 embryos were defined by lack of polarization of the embryonic disk, whereas in pre-streak stage 2 embryos a crescent shaped thickening was seen at the posterior pole of the disk. This thickening, marking the first morphological anterior-posterior polarization of the embryo proper, was shown to be a site of incipient ingression of cells from the epiblast. Immunohistochemical analyses localized Oct-4 to nuclei and vimentin to cytoplasm of both founding and ingressing epiblast cells. During formation of mesoderm and endoderm, at the primitive streak stage, solitary Oct-4 positive cells, i.e. potential PGCs, were seen scattered in the endoderm. Cells of the epiblast displayed positive labeling for Oct-4 until specification for the ectoderm cell lineage at the subsequent neural groove stage. In mesoderm, Oct-4 likewise disappeared by the time of formation of the first somites, defining the following somite stage. Thus, at this stage the only cells labeled for Oct-4, i.e. potential PGCs, were seen solitarily scattered in the endoderm. By the 15-somite stage, such cells were no longer visible in the endoderm but were seen located in the mesoderm, spreading from the stalk of the yolk sac and allantois and extending through the mid- and hindgut areas into the incipient genital ridge. Vimentin localized to the mesenchyme and most other derivatives of neural crest and mesodermal origin. In conclusion, based on Oct-4 labeling and distribution pattern, we strongly believe that we have identified the porcine PGCs from the primitive streak stage.

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