A Quantitative Study of Primordial Germ Cells in the Male Rat

Development ◽  
1963 ◽  
Vol 11 (4) ◽  
pp. 715-740
Author(s):  
Heather M. Beaumont ◽  
Anita M. Mandl
Keyword(s):  
Quantitative Study ◽  
Germ Cells ◽  
Total Population ◽  
Developmental Stages ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Male Rat ◽  
Female Rat ◽  
Mitotic Proliferation ◽  
Prophase Of Meiosis

In mammals, as in other vertebrates, primordial germ cells arise extra-gonadally and migrate to the genital ridges (see Franchi, Mandl & Zuckerman, 1962). In the rat, the gonads undergo sex differentiation on the 14th day of gestation, i.e. some 2 days after the arrival of the primordial germ cells. In the female rat, the number of oögonia increases sharply, due to active mitotic proliferation, between the 14th and 18th day of gestation. Thereafter, the majority of germ cells enter the prophase of meiosis, and thus, by definition, become oöcytes. A large number of oöcytes undergo spontaneous degeneration, with the result that the total population decreases from a peak of about 75,000 (at 18·5 days) to about a third that number 2 days after birth. The decrease in the population is due to three distinct ‘waves’ of degeneration occurring at specific developmental stages (Beaumont & Mandl, 1962).

scholarly journals XY oocytes of sex-reversed females with a Sry mutation deviate from the normal developmental process beyond the mitotic stage†

2018 ◽  
Vol 100 (3) ◽  
pp. 697-710 ◽  
Author(s):  
Akihiko Sakashita ◽  
Takuya Wakai ◽  
Yukiko Kawabata ◽  
Chiaki Nishimura ◽  
Yusuke Sotomaru ◽  
...  
Keyword(s):  
Germ Cells ◽  
Developmental Process ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Primordial Follicle ◽  
Genetic Ablation ◽  
Female Mice ◽  
Meiotic Progression ◽  
Molecular Etiology ◽  
Mitotic Proliferation

Abstract 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.

Early gonadal development and sex differentiation in rosy barb (Puntius conchonius)

2006 ◽  
Vol 56 (3) ◽  
pp. 335-350 ◽  
Author(s):  
Şehriban Çek
Keyword(s):  
Germ Cells ◽  
Smooth Surface ◽  
Developmental Stages ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Posterior Part ◽  
Gonadal Development ◽  
Male And Female ◽  
Males And Females ◽  
Early Developmental

AbstractThe main objective of this study was to describe the early gonadal development and to examine the process of sex differentiation in male and female P. conchonius under laboratory conditions. First evidence of primordial germ cells was observed on the day of hatching. The sex differentiation in leptotene, zygotene, pachytene and diplotene stages was clearly detected. Differentiation started from the mid-mid posterior part of the gonads. Actual sex differentiation occurred between 18-21 days and 36-40 days post-hatching in females and males, respectively. Histological sex differentiation differences were clear between males and females; in males, gonads had a smooth surface, were less stained, arrow-shaped, with germ cells located alone in the stroma, and number of germ cells ranging from two to ten per section, whereas in females, gonads had a rough surface, were more stained, wider, with germ cells multiplying rapidly and forming clusters, and number of germ cells ranged from 2 to 58 per section. The numbers of germ cells within the two gonad types were significantly different in favour of females (P < 0.05). Here early developmental stages of the gonads from 0 to 56 days post-hatch are explained.

scholarly journals Comparison of the Transcriptomic and Epigenetic Profiles of Gonadal Primordial Germ Cells of White Leghorn and Green-Legged Partridgelike Chicken Embryos

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1090
Author(s):  
Aleksandra Dunislawska ◽  
Maria Siwek ◽  
Katarzyna Stadnicka ◽  
Marek Bednarczyk
Keyword(s):  
Embryonic Development ◽  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Genetic Material ◽  
Reproductive Traits ◽  
Germline Stem Cells ◽  
White Leghorn ◽  
Methylation Analysis ◽  
Global Methylation

The Green-legged Partridgelike fowl is a native, dual-purpose Polish chicken. The White Leghorn has been intensively selected for several decades to mainly improve reproductive traits. Primordial germ cells (PGCs) represent the germline stem cells in chickens and are the only cells that can transfer the information stored in the genetic material from generation to generation. The aim of the study was to carry out a transcriptomic and an epigenetic comparison of the White Leghorn and Green-legged Partridgelike gonadal PGCs (gPGCs) at three developmental stages: days 4.5, 8, and 12 of the embryonic development. RNA and DNA were isolated from collected gPGCs. The RNA was further subjected to microarray analysis. An epigenetic analysis was performed based on the global methylation analysis and qMSP method for the particular silenced genes demonstrated in transcriptomic analysis. Statistically significant differences between the gPGCs from both breeds were detected on the day 8 of embryonic development. Global methylation analysis showed significant changes at the methylation level in the White Leghorn gPGCs on day 8 of embryonic development. The results suggest faster development of Green-legged Partridgelike embryos as compared to White Leghorn embryos. Changes in the levels of gene expression during embryonic development are determined by genetic and environmental factors, and this variability is influenced by breed and gender.

The Culture in vitro of Urogenital Organs of Pleurodeles waltlii

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 465-470
Author(s):  
Charles L. Foote ◽  
Florence M. Foote
Keyword(s):  
Organ Culture ◽  
Germ Cells ◽  
Culture Medium ◽  
Developmental Stages ◽  
Rana Catesbeiana ◽  
Sex Differentiation ◽  
Organ Cultures ◽  
Tissue And Organ Culture ◽  
Pleurodeles Waltlii

Earlier reports (Foote & Foote, 1958a, b, 1959) describe growth and maintenance in vitro of larval organs, particularly gonads, of Rana catesbeiana and Xenopus laevis. Immature germ cells of both testes and ovaries are well maintained in vitro, especially if the culture medium is supplemented with watersoluble sex-hormonal substances, although germ cells in process of maturation become necrotic. Recently some urogenital organs from the salamander, Pleurodeles waltlii, have been grown in vitro. Tissues and organs from this amphibian might prove to be more suitable for tissue and organ culture investigations than those of Anurans. Animals at three different ages were used in this study: recently hatched larvae, metamorphosing animals, and adults. To determine whether sex differentiation would occur in vitro, trunk portions of young larvae of Pleurodeles waltlii of developmental stages 37–38 (Gallien & Durocher, 1957) were placed in organ cultures.

Sex differentiation of germ cells in the teleost, Oryzias latipes, during normal embryonic development

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 385-395
Author(s):  
Noriyuki Satoh ◽  
Nobuo Egami
Keyword(s):  
Germ Cells ◽  
Meiotic Prophase ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Oryzias Latipes ◽  
The Other ◽  
Histological Structure ◽  
The Mean ◽  
Further Development ◽  
Normal Embryonic Development

Mitotic and meiotic activities of germ cells during early development in the medaka, Oryzias latipes, are dealt with in this report. Primordial germ cells were obviously distinguishable from somatic cells 3 days after fertilization and began to proliferate about 7 days after fertilization. The mean number of primordial germ cells increased during a period of 7–10 days after fertilization, reaching about 90 immediately before hatching. Newly hatched fry could be classified into two types according to the number and the nucleic activity of germ cells in the gonadal rudiment. One type consisted of fry containing about 100 germ cells and no cells in the meiotic prophase. In the other type of fry the number of germ cells increased by mitotic divisions and some of the cells began to enter into the meiotic prophase. During the course of further development the fry of the former type differentiated into males and the latter into females. Therefore it can be concluded that the morphological sex differentiation of germ cells occurs at the time of hatching. However, no sexual differences in the histological structure of somatic elements in the gonad are observable at that time.

scholarly journals Regulators of mitotic proliferation in mouse primordial germ cells

Reproduction ◽  
2009 ◽  
Vol 138 (1) ◽  
pp. 185
Author(s):  
Massimo De Felici ◽  
Eleonora Sorrentino ◽  
Francesca Klinger ◽  
Cecilia De Felici ◽  
Donatella Farini
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Mitotic Proliferation

scholarly journals When Regenerative Medicine Faces the Challenges of Reproductive Medicine: A Review Study on Recent Advances in the Strategies for Derivation of Gametes from Stem Cells

2020 ◽  
pp. 42-52
Author(s):  
María Gil Juliá ◽  
José V. Medrano
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Differentiation Strategy ◽  
Stem Cell Source ◽  
Potential Applications ◽  
Key Events

The murine model has allowed for the replication of all developmental stages of the mammalian germline in vitro, from embryonic stem cells to epiblast cells, primordial germ cells, and finally into functional haploid gametes. However, because of interspecies differences between mice and humans, these results are yet to be replicated in our species. Reports on the use of stem cells as a source of gametes, retrieved from public scientific databases, were analysed and classified according to the animal model used, the stem cell source and type, the differentiation strategy, and its potential application. This review offers a comprehensive compilation of recent publications of key events in the derivation of germ cells and gametogenesis in vitro, in both mice and human models. Additionally, studies intending to replicate the different stages in human cells in vitro, in order to obtain cells with a phenotype akin to functional human gametes, are also depicted. The authors present options for deriving gametes from stem cells in vitro and different reproductive options for specific groups of patients. Lastly, the potential applications of in vitro human gametogenesis are evaluated as well as the main limitations of the techniques employed. Even though it appears that we are far from being able to obtain gametes from pluripotent stem cells in vitro as a viable reproductive option, its current academic and clinical implications are extremely promising.

The Relation of the Interrenal Blastema to the Origin of the Somatic Tissues of the Gonad in Frog Tadpoles

Development ◽  
1954 ◽  
Vol 2 (4) ◽  
pp. 275-289
Author(s):  
Enrico Vannini ◽  
Armando Sabbadin
Keyword(s):  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Lateral Position ◽  
Medullary Tissue ◽  
Somatic Tissues ◽  
Frog Tadpoles ◽  
Dorsal Mesentery

As long ago as 1941 and 1942 one of us (Vannini) found in a series of developmental stages of frog tadpoles that the somatic components of the medullary tissue of the gonad have their origin in the interrenal blastema, and not, as was then generally supposed, in the mesonephric blastema. In the earliest stages examined at that time the gonad rudiment had the structure of ‘paired genital ridges’, lying at each side of the dorsal mesentery, and were furnished with primordial germ-cells, but were still without medullary tissue. The interrenal blastema occupied a median site in the tadpole's body, ventral to the aorta and dorsal to the two subcardinal veins. The mesonephric blastemata appeared distinctly separate from the interrenal rudiment, because they were situated in a more lateral position, contiguous with the Wolffian ducts. In later stages the medullary tissue (‘medulla’) penetrated within the genital ridges.

SEX DIFFERENTIATION IN THE PACIFIC SALMON ONCORHYNCHUS KETA (WALBAUM)

1953 ◽  
Vol 31 (2) ◽  
pp. 73-79 ◽  
Author(s):  
J. G. Robertson
Keyword(s):  
Germ Cells ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
The Other ◽  
Oncorhynchus Keta ◽  
Progressive Development ◽  
The Pacific ◽  
Female Phase

The differentiation of the gonad is described in chum salmon embryos and alevins. Contrary to classical findings in teleosts, sex differentiation in the chum salmon proceeds in the male or female direction without an intermediate female phase. From an initially indifferent gonad there is a progressive development of one sex or the other. The organ forms as a fold from the splanchnic mesoderm and, at the time of first appearance, contains primordial germ cells. These enlarge to form the definitive germ cells which, after a series of divisions, form smaller oogonia or spermatogonia. Oogonia are followed by primary and secondary (growing) oocytes, the appearance of which is the criterion of sex distinction. Spermatogonia continue to multiply but do not undergo growth in the alevin. The ovary develops an open endovarial canal and is supported by a prominent mesovarium. The testis remains small and, in the alevin, develops no ducts. It is suspended by a mesorchium.

Gnrh3 Regulates PGC Proliferation and Sex Differentiation in Developing Zebrafish

Endocrinology ◽  
2019 ◽  
Vol 161 (1) ◽  
Author(s):  
Ke Feng ◽  
Xuefan Cui ◽  
Yanlong Song ◽  
Binbin Tao ◽  
Ji Chen ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Mek Inhibitor ◽  
Gonadotropin Releasing Hormone ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Hormone Release ◽  
Wild Type ◽  
Gnrh Analog ◽  
Biased Sex Ratio

Abstract Gonadotropin-releasing hormone (Gnrh) plays important roles in reproduction by stimulating luteinizing hormone release, and subsequently ovulation and sperm release, ultimately controlling reproduction in many species. Here we report on a new role for this decapeptide. Surprisingly, Gnrh3-null zebrafish generated by CRISPR/Cas9 exhibited a male-biased sex ratio. After the dome stage, the number of primordial germ cells (PGCs) in gnrh3-/- fish was lower than that in wild-type, an effect that was partially rescued by gnrh3 overexpression. A terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) analysis revealed no detectable apoptosis of PGCs in gnrh3-/- embryos. Proliferating PGCs could be detected in wild-type embryos, while there was no detectable signal in gnrh3-/- embryos. Compared with wild type, the phosphorylation of AKT was not significantly different in gnrh3-/- embryos, but the phosphorylation of ERK1/2 decreased significantly. Treatment with a Gnrh analog (Alarelin) induced ERK1/2 phosphorylation and increased PGC numbers in both wild-type and gnrh3-/- embryos, and this was blocked by the MEK inhibitor PD0325901. The relative expression of sox9a, amh, and cyp11b were significantly upregulated, while cyp19a1a was significantly downregulated at 18 days post-fertilization in gnrh3-/- zebrafish. Taken together, these results indicate that Gnrh3 plays an important role in early sex differentiation by regulating the proliferation of PGCs through a MAPK-dependent path.

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