scholarly journals Quantification of healthy and atretic germ cells and follicles in the developing and post-natal ovary of the South American plains vizcacha, Lagostomus maximus: evidence of continuous rise of the germinal reserve

Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. 199-209 ◽  
Author(s):  
P I F Inserra ◽  
N P Leopardo ◽  
M A Willis ◽  
A L Freysselinard ◽  
A D Vitullo
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Cell Number ◽  
South American ◽  
The South ◽  
Foetal Life ◽  
Female Germ Line ◽  
Lagostomus Maximus ◽  
Mitotic Proliferation

The female germ line in mammals is subjected to massive cell death that eliminates 60–85% of the germinal reserve by birth and continues from birth to adulthood until the exhaustion of the germinal pool. Germ cell demise occurs mainly through apoptosis by means of a biased expression in favour of pro-apoptotic members of theBCL2gene family. By contrast, the South American plains vizcacha,Lagostomus maximus, exhibits sustained expression of the anti-apoptoticBCL2gene throughout gestation and a low incidence of germ cell apoptosis. This led to the proposal that, in the absence of death mechanisms other than apoptosis, the female germ line should increase continuously from foetal life until after birth. In this study, we quantified all healthy germ cells and follicles in the ovaries ofL. maximusfrom early foetal life to day 60 after birth using unbiased stereological methods and detected apoptosis by labelling with TUNEL assay. The healthy germ cell population increased continuously from early-developing ovary reaching a 50 times higher population number by the end of gestation. TUNEL-positive germ cells were <0.5% of the germ cell number, except at mid-gestation (3.62%). Mitotic proliferation, entrance into prophase I stage and primordial follicle formation occurred as overlapping processes from early pregnancy to birth. Germ cell number remained constant in early post-natal life, but a remnant population of non-follicular VASA- and PCNA-positive germ cells still persisted at post-natal day 60.L. maximusis the first mammal so far described in which female germ line develops in the absence of constitutive massive germ cell elimination.Free Spanish abstractSpanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/147/2/199/suppl/DC1

Germ cell differentiation and proliferation in the developing testis of the South American plains viscacha, Lagostomus maximus (Mammalia, Rodentia)

Zygote ◽  
2011 ◽  
Vol 20 (3) ◽  
pp. 219-227 ◽  
Author(s):  
C.R. Gonzalez ◽  
M.L. Muscarsel Isla ◽  
N.A. Fraunhoffer ◽  
N.P. Leopardo ◽  
A.D. Vitullo
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Late Gestation ◽  
Nuclear Antigen ◽  
South American ◽  
The South ◽  
Pluripotency Marker ◽  
Germ Cell Differentiation ◽  
Lagostomus Maximus

SummaryCell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH.

scholarly journals The developing ovary of the South American plains vizcacha, Lagostomus maximus (Mammalia, Rodentia): massive proliferation with no sign of apoptosis-mediated germ cell attrition

Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 633-641 ◽  
Author(s):  
N P Leopardo ◽  
F Jensen ◽  
M A Willis ◽  
M B Espinosa ◽  
A D Vitullo
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Tissue ◽  
Tunel Assay ◽  
South American ◽  
Follicular Atresia ◽  
The South ◽  
Cell Degeneration ◽  
Lagostomus Maximus ◽  
Apoptotic Activity

Apoptosis-dependent massive germ cell death is considered a constitutive trait of the developing mammalian ovary that eliminates 65–85% of the germinal tissue depending on the species. After birth and during adult lifetime, apoptotic activity moves from the germ cell proper to the somatic compartment, decimating germ cells through follicular atresia until the oocyte reserve is exhausted. In contrast, the South American rodent Lagostomus maximus shows suppressed apoptosis-dependent follicular atresia in the adult ovary, with continuous folliculogenesis and massive polyovulation, which finally exhausts the oocyte pool. The absence of follicular atresia in adult L. maximus might arise from a failure to move apoptosis from the germinal stratum to the somatic compartment after birth or being a constitutive trait of the ovarian tissue with no massive germ cell degeneration in the developing ovary. We tested these possibilities by analysing oogenesis, expression of germ cell-specific VASA protein, apoptotic proteins BCL2 and BAX, and DNA fragmentation by TUNEL assay in the developing ovary of L. maximus. Immunolabelling for VASA revealed a massive and widespread colonisation of the ovary and proliferation of germ cells organised in nests that disappeared at late development when folliculogenesis began. No sign of germ cell attrition was found at any time point. BCL2 remained positive throughout oogenesis, whereas BAX was slightly detected in early development. TUNEL assay was conspicuously negative throughout the development. These results advocate for an unrestricted proliferation of germ cells, without apoptosis-driven elimination, as a constitutive trait of L. maximus ovary as opposed to what is normally found in the developing mammalian ovary.

scholarly journals VIABILITY OF FEMALE GERM-LINE CELLS HOMOZYGOUS FOR ZYGOTIC LETHALS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 235-247
Author(s):  
Antonio Garcia-Bellido ◽  
Leonard G Robbins
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Epidermal Cells ◽  
Chromosome Band ◽  
X Chromosomes ◽  
Different Types ◽  
Complementation Groups ◽  
Female Germ Line ◽  
Embryonic Arrest

ABSTRACT We have analyzed the viability of different types of X chromosomes in homozygous clones of female germ cells. The chromosomes carried viable mutations, single-cistron zygotic-lethal and semi-lethal mutations, or small (about six chromosome band) deletions. Homozygous germ-line clones were produced by recombination in females heterozygous for an X-linked, dominant, agametic female sterile. All the zygotic-viable mutants are also viable in germ cells. Of 16 deletions tested (uncovering a total of 93 bands) only 2 (of 4 and 5 bands) are germ-cell viable. Mutations in 15 lethal complementation groups in the zeste-white region were tested. When known, the most extreme alleles at each locus were tested. Only in five loci (33%) were the mutants viable in the germ line. Similar studies of the same deletions and point-mutant lethals in epidermal cells show that 42% of the bands and 77% of the lethal alleles are viable. Thus, germ-line cells have more stringent cell-autonomous genetic requirements than do epidermal cells. The eggs recovered from clones of three of the germ-cell viable zw mutations gave embryos arrested early in embryogenesis, although genotypically identical embryos derived from heterozygous oogonia die as larvae or even hatch as adult escapers. For two genes, homozygosis of the mutations tested also caused embryonic arrest of heterozygous female embryos, and in one case, the eggs did not develop at all. Germ-line clones of one quite leaky mutation gave eggs that were indistinguishable from normal. The abundance of genes whose products are required for oogenesis, whose products are required in the oocyte, and whose activity is required during zygotic development is discussed.

scholarly journals BCL2-modifying factor promotes germ cell loss during murine oogenesis

Reproduction ◽  
2016 ◽  
Vol 151 (5) ◽  
pp. 553-562 ◽  
Author(s):  
Kavitha Vaithiyanathan ◽  
Seng H Liew ◽  
Nadeen Zerafa ◽  
Thilini Gamage ◽  
Michele Cook ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Cell Loss ◽  
Regulatory Proteins ◽  
Primordial Follicles ◽  
Large Numbers ◽  
Female Germ Line ◽  
Low Levels

Abstract Apoptosis plays a prominent role during ovarian development by eliminating large numbers of germ cells from the female germ line. However, the precise mechanisms and regulatory proteins involved in germ cell death are yet to be determined. In this study, we characterised the role of the pro-apoptotic BH3-only protein, BCL2-modifying factor (BMF), in germ cell apoptosis in embryonic and neonatal mouse ovaries. BMF protein was immunohistochemically localised to germ cells at embryonic days 15.5 (E15.5) and E17.5 and postnatal day 1 (PN1), coincident with entry into the meiotic prophase, but was undetectable at E13.5, and only present at low levels at PN3 and PN5. Consistent with this expression pattern, loss of BMF in female mice was associated with a decrease in apoptosis at E15.5 and E17.5. Furthermore, increased numbers of germ cells were found in ovaries from Bmf−/− mice compared with WT animals at E15.5 and PN1. However, germ cell numbers were comparable between Bmf−/− and WT ovaries at PN3, PN5 and PN10. Collectively, these data indicate that BMF mediates foetal oocyte loss and its action limits the maximal number of germ cells attained in the developing ovary, but does not influence the number of primordial follicles initially established in ovarian reserve.

scholarly journals Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sex Differentiation ◽  
Somatic Cells ◽  
Oryzias Latipes ◽  
Cell Number ◽  
Gonadal Differentiation ◽  
Loss Of Function ◽  
Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

ERα and GnRH co-localize in the hypothalamic neurons of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha)

2017 ◽  
Vol 48 (3) ◽  
pp. 259-273 ◽  
Author(s):  
Pablo Ignacio Felipe Inserra ◽  
Santiago Elías Charif ◽  
Noelia Paula Di Giorgio ◽  
Lucía Saucedo ◽  
Alejandro Raúl Schmidt ◽  
...  
Keyword(s):  
South American ◽  
The South ◽  
Hypothalamic Neurons ◽  
Lagostomus Maximus

Distribution of kisspeptin system and its relation with gonadotropin-releasing hormone in the hypothalamus of the South American plains vizcacha, Lagostomus maximus

2021 ◽  
pp. 113974
Author(s):  
Alejandro Raúl Schmidt ◽  
Pablo Ignacio Felipe Inserra ◽  
Santiago Andrés Cortasa ◽  
Sofía Proietto ◽  
Victoria Fidel ◽  
...  
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
South American ◽  
The South ◽  
Releasing Hormone ◽  
Lagostomus Maximus

Melatonin is involved in the modulation of the hypothalamic and pituitary activity in the South American plains vizcacha, Lagostomus maximus

2021 ◽  
Author(s):  
Santiago Elías Charif ◽  
Pablo Ignacio Felipe Inserra ◽  
Alejandro Raúl Schmidt ◽  
Santiago Andrés Cortasa ◽  
Sofía Proietto ◽  
...  
Keyword(s):  
South American ◽  
The South ◽  
Lagostomus Maximus

scholarly journals Unexpected low genetic variation in the South American hystricognath rodent Lagostomus maximus (Rodentia: Chinchillidae)

PLoS ONE ◽  
2019 ◽  
Vol 14 (9) ◽  
pp. e0221559 ◽  
Author(s):  
María Constanza Gariboldi ◽  
Pablo Ignacio Felipe Inserra ◽  
Sergio Lucero ◽  
Mauricio Failla ◽  
Sergio Iván Perez ◽  
...  
Keyword(s):  
Genetic Variation ◽  
South American ◽  
The South ◽  
Lagostomus Maximus

scholarly journals Germ cell fate and seminiferous tubule development in bovine testis xenografts

Reproduction ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Rahul Rathi ◽  
Ali Honaramooz ◽  
Wenxian Zeng ◽  
Stefan Schlatt ◽  
Ina Dobrinski
Keyword(s):  
Germ Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Cell Number ◽  
Sperm Production ◽  
Continuous Increase ◽  
Control Tissue ◽  
Low Efficiency ◽  
Pachytene Spermatocytes ◽  
Testis Tissue

Spermatogenesis can occur in testis tissue from immature bulls ectopically grafted into mouse hosts; however, efficiency of sperm production is lower than in other donor species. To elucidate a possible mechanism for the impaired spermatogenesis in bovine testis xenografts, germ cell fate and xenograft development were investigated at different time points and compared with testis tissue from age-matched calves as controls. Histologically, an initial decrease in germ cell number was noticed in xenografts recovered up to 2 months post-grafting without an increase in germ cell apoptosis. From 2 months onward, the number of germ cells increased. In contrast, a continuous increase in germ cell number was seen in control tissue. Pachytene spermatocytes were observed in some grafts before 4 months, whereas in the control tissue they were not present until 5 months of age. Beyond 4 months post-grafting spermatogenesis appeared to be arrested at the pachytene spermatocyte stage in most grafts. Elongated spermatids were observed between 6 and 8 months post-grafting, similar to the controls, albeit in much lower numbers. Lumen formation started earlier in grafts compared with controls and by 6 months post-grafting tubules with extensively dilated lumen were observed. A donor effect on efficiency of spermatogenesis was also observed. These results indicate that the low efficiency of sperm production in bovine xenografts is due to an initial deficit of germ cells and impaired meiotic and post-meiotic differentiation. The characterization of spermatogenic efficiency will provide the basis to understand the control of spermatogenesis in testis grafts.

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