Transgenic rescue of ataxia mice reveals a male-specific sterility defect (original) (raw)
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Disruption of Usp26 gene causes male subfertility associated with spermatogenesis defects in mice§
Biology of Reproduction
Ubiquitin-specific protease 26 (USP26) is an X-linked gene exclusively expressed in the testis and codes for the USP26, a peptidase enzyme that belongs to the deubiquitinating enzyme family. Recent studies have indicated that mutations in USP26 affect spermatogenesis and are associated with male infertility in humans and mice. However, the exact role of USP26 in spermatogenesis and how it affects male reproduction remains unknown. In this study, we generated a conventional Usp26 knockout mouse model and found that deletion of Usp26 in male mice (Usp26−/Y) leads to significantly reduced pup numbers per litter and significantly increased intervals between two consecutive offspring. We also found that the serum follicle stimulating hormone and testosterone levels of adult Usp26−/Y mice were significantly decreased compared to those of Usp26+/Y mice. Histological examination results showed that Usp26−/Y mice had significantly increased percentage of abnormal seminiferous tubules at diff...
The deubiquitinating gene Usp29 is dispensable for fertility in male mice
Science China Life Sciences, 2019
The balanced actions between ubiquitination and deubiquitination precisely control the levels of various proteins vital for spermatogenesis. Ubiquitin-specific processing proteases (USPs) are the largest family of deubiquitinatingenzymes(DUBs), containing more than 50 members. So far, the functions of only a few USPs in male fertility have been studied, the roles of the majority are yet unknown. The present study aimed to explore the function of Usp29 (ubiquitin-specific protease 29) in male fertility. We found that Usp29 showed predominant expression in mouse testis, and its mRNA expression started to increase at 14 days postpartum (dpp), with a peak at 28 and 35 dpp. Using CRISPR/Cas9 technology, we generated Usp29 knockout mice (Usp29-/-). Usp29-/mice exhibited no overt developmental anomalies. Further examination revealed that Usp29-/mice had normal fertility and showed no detectable difference in the testis/body weight ratio, testicular and epididymal histology as well as epididymal sperm count from the wild-type littermates. Moreover, Usp29 is not a pseudogene in mice. Taken together, our study first reported that though Usp29 is predominantly expressed in the testis, it is not essential for male fertility in mice.
Ubiquitin-specific protease 26 (USP26) is not essential for mouse gametogenesis and fertility
Chromosoma, 2019
USP26 is a deubiquitylating enzyme belonging to the ubiquitin-specific proteases (USPs) family with a transcription pattern restricted to the male germline. Since protein ubiquitination is an essential regulatory mechanism during meiosis, many efforts have been focused on elucidating the function of USP26 and its relationship with fertility. During the last decade, several studies have reported the presence of different polymorphisms in USP26 in patients with non-obstructive azoospermia (NOA) or severe oligozoospermia suggesting that this gene may be associated with human infertility. However, other studies have revealed the presence of these and novel polymorphisms, including nonsense mutations, in men with normal spermatogenesis as well. Thus, the results remain controversial and its function is unknown. In the present study, we describe the in vivo functional analysis of mice lacking USP26. The phenotypic analysis of two different Usp26-null mutants showed no overt-phenotype with both males and females being fertile. Cytological analysis of spermatocytes showed no defects in synapsis, chromosome dynamics, DNA repair or recombination. Histopathological analysis revealed a normal distribution and number of the different cell types in both male and female mice. Finally, normal counts were observed in fertility assessments. These results represent the first in vivo evidence showing that USP26 is not essential for mouse gametogenesis.
Abnormal sperm development in pcd 3J-/- mice: the importance of Agtpbp1 in spermatogenesis
Molecules and Cells, 2010
Homozygous Purkinje cell degeneration (pcd) mutant males exhibit abnormal sperm development. Microscopic examination of the testes from pcd 3J-/-mice at postnatal days 12, 15, 18 and 60 revealed histological differences, in comparison to wild-type mice, which were evident by day 18. Greatly reduced numbers of spermatocytes and spermatids were found in the adult testes, and apoptotic cells were identified among the differentiating germ cells after day 15. Our immunohistological analysis using an antihuman AGTPBP1 antibody showed that AGTPBP1 was expressed in spermatogenic cells between late stage primary spermatocytes and round spermatids. A global gene expression analysis from the testes of pcd 3J-/-mice showed that expression of cyclin B3 and de-ubiquitinating enzymes USP2 and USP9y was altered by >1.5-fold compared to the expression levels in the wild-type. Our results suggest that the pcd mutant mice have defects in spermatogenesis that begin with the pachytene spermatocyte stage and continue through subsequent stages. Thus, Agtpbp1, the gene responsible for the pcd phenotype, plays an important role in spermatogenesis and is important for survival of germ cells at spermatocytes stage onward.
Impaired fertility in mice deficient for the testicular germ-cell protease PC4
Proceedings of the National Academy of Sciences, 1997
PC4 is a member of the proprotein convertase family of serine proteases implicated in the processing of a variety of polypeptides including prohormones, proneuropeptides, and cell surface proteins. In rodents, PC4 transcripts have been detected in spermatocytes and round spermatids exclusively, suggesting a reproductive function for this enzyme. In an effort to elucidate this function, we have disrupted its locus (Pcsk4) by homologous recombination in embryonic stem cells and have produced mice carrying the mutation. In intercrosses of heterozygous mutant mice, there was low transmission of the mutant Pcsk4 allele to the progeny, resulting in lower than expected incidence of heterozygosity and null homozygosity. The in vivo fertility of homozygous mutant males was severely impaired in the absence of any evident spermatogenic abnormality. In vitro, the fertilizing ability of Pcsk4 null spermatozoa was also found to be significantly reduced. Moreover, eggs fertilized by these spermatozoa failed to grow to the blastocyst stage. These results suggest that PC4 in the male may be important for achieving fertilization and for supporting early embryonic development in mice.
Adult Apaf-1-Deficient Mice Exhibit Male Infertility
Developmental Biology, 2000
Release of cytochrome c from the mitochondria, and subsequent binding to apoptotic protease-activating factor-1 (Apaf-1), is a key trigger of apoptotic events. A complex composed of Apaf-1, dATP, and cytochrome c activates a series of cytoplasmic proteases called caspases, leading to apoptotic cell death. We have disrupted the Apaf-1 gene in the mouse. Like previous reports on this knockout model, we find that most Apaf-1 mutants die perinatally and frequently exhibit exencephaly and cranioschesis. We additionally find that the neural lesions that develop in the knockout are due to an excess of neural progenitor cells that manifests as early as embryonic day 9.5 in development. In contrast to previous reports on the Apaf-1 knockout mice, we find that 5% of the mutants successfully survive to adulthood. In these survivors, the brain develops normally, but in males, there is degeneration of spermatogonia resulting in the virtual absence of sperm. Thus, cytochrome c-mediated apoptosis is not absolutely required for normal neural development, but is essential for spermatogenesis. These findings strongly suggest that alternative apoptotic pathways work in conjunction with and parallel to Apaf-1 and can modify its effect on programmed cell death.
The expression of Usp26 gene in mouse testis and brain
Asian Journal of Andrology, 2009
Deubiquitinating enzymes (DUBs) play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 (USP26) is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription (RT)-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids (steps 9-16), Leydig cells and nerve fi bers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial cells, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.
Molecular and Cellular Biology, 2003
Substrates of the ubiquitin-dependent N-end rule pathway include proteins with destabilizing N-terminal residues. UBR1 −/− mice, which lacked the pathway's ubiquitin ligase E3α, were viable and retained the N-end rule pathway. The present work describes the identification and analysis of mouse UBR2, a homolog of UBR1. We demonstrate that the substrate-binding properties of UBR2 are highly similar to those of UBR1, identifying UBR2 as the second E3 of the mammalian N-end rule pathway. UBR2 −/− mouse strains were constructed, and their viability was found to be dependent on both gender and genetic background. In the strain 129 (inbred) background, the UBR2 −/− genotype was lethal to most embryos of either gender. In the 129/B6 (mixed) background, most UBR2 −/− females died as embryos, whereas UBR2 −/− males were viable but infertile, owing to the postnatal degeneration of the testes. The gross architecture of UBR2 −/− testes was normal and spermatogonia were intact as well, but UB...
An X-to-autosome retrogene is required for spermatogenesis in mice
Nature genetics, 2004
We identified the gene carrying the juvenile spermatogonial depletion mutation (jsd), a recessive spermatogenic defect mapped to mouse chromosome 1 (refs. 1,2). We localized jsd to a 272-kb region and resequenced this area to identify the underlying mutation: a frameshift that severely truncates the predicted protein product of a 2.3-kb genomic open reading frame. This gene, Utp14b, evidently arose through reverse transcription of an mRNA from an X-linked gene and integration of the resulting cDNA into an intron of an autosomal gene, whose promoter and 5′ untranslated exons are shared with Utp14b. To our knowledge, Utp14b is the first protein-coding retrogene to be linked to a recessive mammalian phenotype. The X-linked progenitor of Utp14b is the mammalian ortholog of yeast Utp14, which encodes a protein required for processing of pre-rRNA 3 and hence for ribosome assembly. Our findings substantiate the hypothesis 4 that mammalian spermatogenesis is supported by autosomal retrogenes that evolved from X-linked housekeeping genes to compensate for silencing of the X chromosome during male meiosis 5-7 . We find that Utp14b-like retrogenes arose independently and were conserved during evolution in at least four mammalian lineages. This recurrence implies a strong selective pressure, perhaps to enable ribosome assembly in male meiotic cells.