Histone H1t is not replaced by H1.1 or H1.2 in pachytene spermatocytes or spermatids of H1t-deficient mice

2003 ◽  
Vol 103 (3-4) ◽  
pp. 307-313 ◽  
Keyword(s):  
Pachytene Spermatocytes ◽  
Deficient Mice ◽  
Histone H1t

scholarly journals Defects in Meiotic Recombination Delay Progression Through Pachytene in Mouse Spermatocytes

2017 ◽  
Author(s):  
James H. Crichton ◽  
David Read ◽  
Ian R. Adams
Keyword(s):  
Meiotic Recombination ◽  
Model Organisms ◽  
Chromatin Modifications ◽  
Meiotic Progression ◽  
Chromosome Synapsis ◽  
Successful Execution ◽  
Axis Elongation ◽  
Pachytene Spermatocytes ◽  
Delay Progression ◽  
Histone H1t

AbstractDuring meiosis, recombination, synapsis, chromosome segregation and gene expression are coordinately regulated to ensure successful execution of this specialised cell division. In many model organisms, checkpoint controls can delay meiotic progression to allow defects or errors in these processes to be repaired or corrected. Mouse spermatocytes possess quality control checkpoints that eliminate cells with persistent irreparable defects in chromosome synapsis or recombination, and here we show that a spermatocyte checkpoint regulates progression through pachytene to accommodate delays in meiotic recombination. We have previously show that the appearance of early recombination foci is delayed in Tex19.1-/- spermatocytes during leptotene/zygotene, but some Tex19.1-/- spermatocytes still successfully synapse their chromosomes. Therefore, we have used autosomally synapsed Tex19.1-/- mouse spermatocytes to assess the consequences of delayed recombination on progression through pachytene. We show that these pachytene spermatocytes are enriched for early recombination foci. This skew is not accompanied by cell death and likely reflects delays in the generation and/or maturation of recombination foci. Moreover, patterns of axis elongation, chromatin modifications, and histone H1t expression are also all skewed towards earlier substages of pachytene suggesting these events are co-ordinately regulated. Importantly, the delay in histone H1t expression in response to loss of Tex19.1 does not occur in a Spo11 mutant background, suggesting that histone H1t expression is being delayed by a recombination-dependent checkpoint. These data indicate that a recombination-dependent checkpoint operates in mouse spermatocytes that can alter progression through pachytene to accommodate spermatocytes with some types of recombination defect.

scholarly journals Distinct functions of TBP and TLF/TRF2 during spermatogenesis: requirement of TLF for heterochromatic chromocenter formation in haploid round spermatids

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 945-955 ◽  
Author(s):  
Igor Martianov ◽  
Stefano Brancorsini ◽  
Anne Gansmuller ◽  
Martti Parvinen ◽  
Irwin Davidson ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Early Stage ◽  
Centromeric Heterochromatin ◽  
Intracellular Location ◽  
C Elegans ◽  
Targeted Mutation ◽  
Transcription Initiation Complex ◽  
Temporal Expression Pattern ◽  
Pachytene Spermatocytes ◽  
Deficient Mice

TLF (TBP-like factor) is a protein commonly thought to belong to the general transcription initiation complex. TLF is evolutionarily conserved and has been shown to be essential for early development in C. elegans, zebrafish and Xenopus. In mammals however, TLF has a specialised function, as revealed by targeted mutation of the gene in the mouse germline. The TLF mutation elicits a complete arrest of late spermiogenesis and increased haploid cell apoptosis. We explored in more detail the molecular function that TLF plays in the differentiation program of male germ cells. A comparison of TBP and TLF reveals drastic differences, both in their temporal expression pattern and in their intracellular location. While TBP is ubiquitously expressed, TLF expression is strictly developmentally regulated, being very high in late pachytene spermatocytes, suggesting a function prior to the apoptosis of the haploid cells. A refined study of TLF-deficient mice reveals defective acrosome formation in early stage spermatids. Most importantly, our results uncover an unsuspected function of TLF in chromatin organisation. Indeed, early spermatids in TLF-deficient mice display a fragmentation of the chromocenter, a condensed structure formed by the association of centromeric heterochromatin and containing the HP1 proteins. This defect is likely to be the primary cause of spermatogenic failure in the TLF mutant mice.

scholarly journals piRNA-associated proteins and retrotransposons are differentially expressed in murine testis and ovary of aryl hydrocarbon receptor deficient mice

Open Biology ◽  
2016 ◽  
Vol 6 (12) ◽  
pp. 160186 ◽  
Author(s):  
Eva M. Rico-Leo ◽  
Nuria Moreno-Marín ◽  
Francisco J. González-Rico ◽  
Eva Barrasa ◽  
Cristina Ortega-Ferrusola ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Germ Cell ◽  
Aryl Hydrocarbon Receptor ◽  
Cell Maturation ◽  
Ovary Development ◽  
Aryl Hydrocarbon ◽  
Sperm Counts ◽  
Associated Proteins ◽  
Pachytene Spermatocytes ◽  
Deficient Mice

Previous studies suggested that the aryl hydrocarbon receptor (AhR) contributes to mice reproduction and fertility. However, the mechanisms involved remain mostly unknown. Retrotransposon silencing by Piwi-interacting RNAs (piRNAs) is essential for germ cell maturation and, remarkably, AhR has been identified as a regulator of murine B1-SINE retrotransposons. Here, using littermate AhR +/+ and AhR −/− mice, we report that AhR regulates the general course of spermatogenesis and oogenesis by a mechanism likely to be associated with piRNA-associated proteins, piRNAs and retrotransposons. piRNA-associated proteins MVH and Miwi are upregulated in leptotene to pachytene spermatocytes with a more precocious timing in AhR −/− than in AhR +/+ testes. piRNAs and transcripts from B1-SINE , LINE-1 and IAP retrotransposons increased at these meiotic stages in AhR-null testes. Moreover, B1-SINE transcripts colocalize with MVH and Miwi in leptonema and pachynema spermatocytes. Unexpectedly, AhR −/− males have increased sperm counts, higher sperm functionality and enhanced fertility than AhR +/+ mice. In contrast, piRNA-associated proteins and B1-SINE and IAP -derived transcripts are reduced in adult AhR −/− ovaries. Accordingly, AhR-null female mice have lower numbers of follicles when compared with AhR +/+ mice. Thus, AhR deficiency differentially affects testis and ovary development possibly by a process involving piRNA-associated proteins, piRNAs and transposable elements.

GPAT2 is required for piRNA biogenesis, transposon silencing, and maintenance of spermatogonia in mice†

2019 ◽  
Vol 101 (1) ◽  
pp. 248-256 ◽  
Author(s):  
Yusuke Shiromoto ◽  
Satomi Kuramochi-Miyagawa ◽  
Ippei Nagamori ◽  
Shinichiro Chuma ◽  
Tatsuhiko Arakawa ◽  
...  
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Critical Role ◽  
Mitochondrial Outer Membrane ◽  
Germline Stem Cells ◽  
Neonatal Stage ◽  
Pachytene Spermatocytes ◽  
Vitro Analysis ◽  
Deficient Mice

Abstract PIWI-interacting RNAs (piRNAs), a subclass of germ cell-specific noncoding small RNAs, are essential for de novo DNA methylation of retrotransposon genes in embryonic testes. PIWIL2/MILI, one of three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably via piRNA, and normal spermatogenesis. In vitro analysis using germline stem cells (GS cells) revealed that glycerol-3-phosphate acyltransferase 2 (GPAT2), which is a mitochondrial outer membrane protein involved in generation of lysophosphatidic acid (LPA) and highly expressed in testes, plays important roles in spermatogenesis. Namely, GPAT2 binds to PIWIL2 and is closely involved in the biogenesis of piRNAs; this process is independent of its enzymatic activity on LPA. However, GS cells recapitulate only a limited phase of spermatogenesis and the biological functions of GPAT2 remain largely unknown. In this study, we generated GPAT2-deficient mice and conducted comprehensive analyses. The deficient mice showed defective piRNA production and subsequent de-silencing of IAP and Line-1 retrotransposons in fetal testes. In addition, apoptosis of pachytene spermatocytes was observed. These abnormalities were all common to the phenotype of PIWIL2-deficient mice, in which piRNA production was impaired. GPAT2-deficient mice exhibited apoptosis in spermatogonia at the neonatal stage, which was not observed in PIWIL2-deficient mice. These data show that GPAT2 plays a critical role in preventing apoptosis in spermatogonia.

scholarly journals Hspa4l-Deficient Mice Display Increased Incidence of Male Infertility and Hydronephrosis Development

2006 ◽  
Vol 26 (21) ◽  
pp. 8099-8108 ◽  
Author(s):  
Torsten Held ◽  
Ilona Paprotta ◽  
Janchiv Khulan ◽  
Bernhardt Hemmerlein ◽  
Lutz Binder ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sperm Count ◽  
Physiological Role ◽  
Heat Shock Gene ◽  
Seminiferous Tubules ◽  
Genes Encoding ◽  
Null Mutant Mice ◽  
Pachytene Spermatocytes ◽  
Deficient Mice

ABSTRACT The Hspa4l gene, also known as Apg1 or Osp94, belongs to the HSP110 heat shock gene family, which includes three genes encoding highly conserved proteins. This study shows that Hspa4l is expressed ubiquitously and predominantly in the testis. The protein is highly expressed in spermatogenic cells, from late pachytene spermatocytes to postmeiotic spermatids. In the kidney, the protein is restricted to cortical segments of distal tubules. To study the physiological role of this gene in vivo, we generated mice deficient in Hspa4l by gene targeting. Hspa4l-deficient mice were born at expected ratios and appeared healthy. However, approximately 42% of Hspa4l −/− male mice suffered from fertility defects. Whereas the seminiferous tubules of Hspa4l −/− testes contained all stages of germ cells, the number of mature sperm in the epididymis and sperm motility were drastically reduced. The reduction of the sperm count was due to the elimination of a significant number of developing germ cells via apoptosis. No defects in fertility were observed in female mutants. In addition, 12% of null mutant mice developed hydronephrosis. Concentrations of plasma and urine electrolytes in Hspa4l −/− mice were similar to wild-type values, suggesting that the renal function was not impaired. However, Hspa4l −/− animals were preferentially susceptible to osmotic stress. These results provide evidence that Hspa4l is required for normal spermatogenesis and suggest that Hspa4l plays a role in osmotolerance.

scholarly journals CCR4-Associated Factor CAF1 Is an Essential Factor for Spermatogenesis

2004 ◽  
Vol 24 (13) ◽  
pp. 5808-5820 ◽  
Author(s):  
Cyril Berthet ◽  
Anne-Marie Morera ◽  
Marie-Jeanne Asensio ◽  
Marie-Agnes Chauvin ◽  
Anne-Pierre Morel ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Germ Cells ◽  
Cell Function ◽  
Essential Factor ◽  
Human Male ◽  
Pachytene Spermatocytes ◽  
Total Disappearance ◽  
Deficient Mice ◽  
Insight Into ◽  
Cell Vacuolization

ABSTRACT The CCR4-associated protein CAF1 has been demonstrated to play several roles in the control of transcription and of mRNA decay. To gain further insight into its physiological function, we generated CAF1-deficient mice. They are viable, healthy, and normal in appearance; however, mCAF1 −/− male mice are sterile. The crossing of mCAF1 +/− mice gave a Mendelian ratio of mCAF1 +/+, mCAF1 +/−, and mCAF1 −/− pups, indicating that haploid mCAF1-deficient germ cells differentiate normally. The onset of the defect occurs during the first wave of spermatogenesis at 19 to 20 days after birth, during progression of pachytene spermatocytes to haploid spermatids and spermatozoa. Early disruption of spermatogenesis was evidenced by Sertoli cell vacuolization and tubular disorganization. The most mature germ cells were the most severely depleted, but progressively all germ cells were affected, giving Sertoli cell-only tubes, large interstitial spaces, and small testes. This phenotype could be linked to a defect(s) in germ cells and/or to inadequate Sertoli cell function, leading to seminiferous tubule disorganization and finally to a total disappearance of germ cells. The mCAF1-deficient mouse provides a new model of failed spermatogenesis in the adult that may be relevant to some cases of human male sterility.

Comparison of localization of metallothionein in tissues of metallothionein-deficient mice

1995 ◽  
Vol 53 ◽  
pp. 1042-1043
Author(s):  
H. Nishimura ◽  
R Nishimura ◽  
D.L. Adelson ◽  
A.E. Michaelska ◽  
K.H.A. Choo ◽  
...  
Keyword(s):  
Metal Binding ◽  
Immunohistochemical Staining ◽  
Squamous Epithelium ◽  
Rabbit Antiserum ◽  
Slight Modification ◽  
Positive Control ◽  
Heavy Metal Binding ◽  
Critical Organ ◽  
Metal Binding Protein ◽  
Deficient Mice

Metallothionein (MT), a cysteine-rich heavy metal binding protein, has several isoforms designated from I to IV. Its major isoforms, I and II, can be induced by heavy metals like cadmium (Cd) and, are present in various organs of man and animals. Rodent testes are a critical organ to Cd and it is still a controversial matter whether MT exists in the testis although it is clear that MT is not induced by Cd in this tissue. MT-IV mRNA was found to localize within tongue squamous epithelium. Whether MT-III is present mainly glial cells or neurons has become a debatable topic. In the present study, we have utilized MT-I and II gene targeted mice and compared MT localization in various tissues from both MT-deficient mice and C57Black/6J mice (C57BL) which were used as an MT-positive control. For MT immunostaining, we have used rabbit antiserum against rat MT-I known to cross-react with mammalian MT-I and II and human MT-III. Immunohistochemical staining was conducted by the method described in the previous paper with a slight modification after the tissues were fixed in HistoChoice and embedded in paraffin.

Alterations during Positive Selection in the Thymus of nackt CD4-Deficient Mice

2000 ◽  
Vol 52 (6) ◽  
pp. 555-562 ◽  
Author(s):  
I. Nepomnaschy ◽  
G. Lombardi ◽  
P. Bekinschtein ◽  
P. Berguer ◽  
V. Francisco ◽  
...  
Keyword(s):  
Positive Selection ◽  
Deficient Mice

Gubernacular development in Müllerian inhibiting substance receptor-deficient mice

2002 ◽  
Vol 89 (1) ◽  
pp. 113-118 ◽  
Author(s):  
J.E. Bartlett ◽  
S.M.Y. Lee ◽  
Y. Mishina ◽  
R.R. Behringer ◽  
N. Yang ◽  
...  
Keyword(s):  
Müllerian Inhibiting Substance ◽  
Deficient Mice ◽  
Mullerian Inhibiting Substance
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