Purpose: Spermatogenesis requires a large amount of energy, which is primarily produced by the mitochondrial electron transfer chain. Mitochondrial dysfunction affects male infertility, suggesting a relationship between the electron transfer chain and male infertility. COXFA4L3 (C15ORF48) is an emerging subunit protein of cytochrome oxidase specifically expressed in germ cells during spermatogenesis, and it may be involved in male infertility.
View Article and Find Full Text PDFBesides ubiquitous poly(A)-binding protein, cytoplasmic 1 (PABPC1), testis-specific PABPC2/PABPt (in humans, referred to as PABPC3), and female and male germline-specific PABPC1L/ePAB, have been reported in the mouse testis. Recent in silico analysis additionally identified testis-specific Pabpc6 in the mouse. In this study, we characterized PABPC6 and its mutant mice.
View Article and Find Full Text PDFTestis-brain RNA-binding protein (TB-RBP/Translin) is known to contribute to the translational repression of a subset of haploid cell-specific mRNAs, including protamine 2 (Prm2) mRNA. Mutant mice lacking TB-RBP display abnormal spermatogenesis, despite normal male fertility. In this study, we carried out functional analysis of TB-RBP in mammalian cultured cells to understand the mechanism of translational repression by this RNA-binding protein.
View Article and Find Full Text PDFPrecise regulation of RNA metabolism is crucial for dynamic gene expression and controlling cellular functions. In the nervous system, defects in RNA metabolism are implicated in the disturbance of brain homeostasis and development. Here, we report that deubiquitinating enzyme, ubiquitin specific peptidase 15 (USP15), deubiquitinates terminal uridylyl transferase 1 (TUT1) and changes global RNA metabolism.
View Article and Find Full Text PDFRecently, gradual decline in human sperm production has become a serious worldwide concern because it leads to increased rates of infertility. Endocrine disrupters, lifestyle changes, and varicocele, all of which elevate testicular temperature, are thought to be the main causes of this decline. The present study aimed to determine whether the dietary phytochemicals Angelica keiskei (Ashitaba) powder (57.
View Article and Find Full Text PDFMutant mice lacking a testis-specific cytoplasmic poly(A) polymerase, PAPOLB/TPAP, exhibit spermiogenesis arrest and male infertility. However, the mechanism by which PAPOLB regulates spermiogenesis remains unclear. In this study, we examined the relationships between PAPOLB and other spermiogenesis regulators present in the chromatoid body (CB).
View Article and Find Full Text PDFThe testis-specific cytoplasmic poly(A) polymerase PAPOLB/TPAP is essential for spermatogenesis. Although this enzyme is responsible for poly(A) tail extension of a subset of mRNAs in round spermatids, the stability and translational efficiency of these mRNAs are unaffected by the absence of PAPOLB. To clarify the functional importance of this enzyme's adenylation activity, we produced PAPOLB-null mice expressing a polyadenylation-defective PAPOLB mutant (PAPOLB), in which the catalytic Asp at residue 114 was mutated to Ala.
View Article and Find Full Text PDFZfp318, a mouse gene with a Cys2/His2 zinc finger motif, is mainly expressed in germ cells in the testis. It encodes two alternative transcripts, which regulate androgen receptor-mediated transcriptional activation or repression by overexpression of them. However, the role of Zfp318 is still obscure in vivo, especially in spermatogenesis.
View Article and Find Full Text PDFProper biogenesis of a sperm-specific organelle, the acrosome, is essential for gamete interaction. An acrosomal matrix protein, ACRBP, is known as a proacrosin-binding protein. In mice, two forms of ACRBP, wild-type ACRBP-W and variant ACRBP-V5, are generated by pre-mRNA alternative splicing of Acrbp Here, we demonstrate the functional roles of these two ACRBP proteins.
View Article and Find Full Text PDFMouse testes contain several isoforms of cytoplasmic poly(A)-binding proteins (PABPCs), including ubiquitous PABPC1 and testis-specific PABPC2/PABPt. PABPC2 is characterized by its absence from translationally active polyribosomes and elongating spermatids. To elucidate the function of PABPC2 in spermatogenesis, we produced mutant mice lacking PABPC2.
View Article and Find Full Text PDFACRBP/sp32 is a binding protein specific for the precursor (pro-ACR) and intermediate forms of sperm serine protease ACR. In this study, we examined the expression pattern, localization, and possible role of mouse ACRBP in spermatogenic cells and epididymal sperm. Unlike other mammalian ACRBPs, two forms of Acrbp mRNA-wild-type Acrbp-W and variant Acrbp-V5 mRNAs-were generated by alternative splicing of Acrbp in the mouse.
View Article and Find Full Text PDFTanpakushitsu Kakusan Koso
December 2009
In mammalian spermiogenesis, sperm mature during epididymal transit to get fertility. The pig sharing many physiological similarities with humans is considered a promising animal model in medicine. We examined the expression profiles of proteins from boar epididymal caput, corpus, and cauda sperm by two-dimensional gel electrophoresis and peptide mass fingerprinting.
View Article and Find Full Text PDFAlthough sperm entry into the oocyte-cumulus complex and subsequent sperm penetration through the cumulus matrix to reach the oocyte zona pellucida are essential for mammalian fertilization, the molecular mechanism remains controversial. Previously, we have shown that mouse sperm lacking SPAM1 are capable of penetrating the cumulus matrix despite a delayed dispersal of cumulus cells. We also have identified another sperm hyaluronidase, HYAL5, as a candidate enzyme involved in sperm penetration through the cumulus.
View Article and Find Full Text PDFThe steady-state levels of microRNAs (miRNAs) and their activities are regulated by the post-transcriptional processes. It is known that 3' ends of several miRNAs undergo post-dicing adenylation or uridylation. We isolated the liver-specific miR-122 from human hepatocytes and mouse livers.
View Article and Find Full Text PDFMouse spermatogenic cells are known to contain at least two isoforms of cytoplasmic poly(A)-binding proteins, PABPC1 and PABPC2 (previously known as PABPT). In this study, we have characterized PABPC1 and PABPC2. PABPC2 was present in pachytene spermatocytes and round spermatids, whereas elongating spermatids still included PABPC1.
View Article and Find Full Text PDFAlthough the acrosome reaction and subsequent penetration of sperm through the egg zona pellucida (ZP) are essential for mammalian fertilization, the molecular mechanism is still controversial. We have previously identified serine protease Tesp5 identical to Prss21 on the mouse sperm surface as a candidate enzyme involved in sperm penetration through the ZP. Here we show that despite normal fertility of male mice lacking Prss21/Tesp5, the epididymal sperm penetrates the ZP only at a very low rate in vitro, presumably owing to the reduced ability to bind the ZP and undergo the ZP-induced acrosome reaction.
View Article and Find Full Text PDFMammalian fertilization requires sperm to penetrate the cumulus mass and egg zona pellucida prior to fusion with the egg. Although sperm penetration through these physical barriers is essential, the molecular mechanism has not yet been completely elucidated. In addition to sperm motility, hyaluronan-hydrolyzing and proteolytic enzymes of sperm have been suggested to participate in the penetration events.
View Article and Find Full Text PDFSperm-specific phospholipase C, PLCzeta, is a candidate for the Ca(2+) oscillation-inducing factor that is introduced into the ooplasm upon sperm-egg fusion. In addition to the 647-residue full-length PLCzeta, s-PLCzeta lacking the N-terminal 110 amino acids is known to be present in the mouse testis. In this study, we attempted to obtain full-term offspring from s-PLCzeta-activated eggs by round spermatid injection.
View Article and Find Full Text PDFPolyadenylation of mRNA precursors initially occurs in the nucleus of eukaryotic cells, and the polyadenylated mRNAs are then transported into the cytoplasm. Because the length of the poly(A) tail is implicated in various aspects of mRNA metabolism, including the transport into the cytoplasm, stability, and translational control, processing of mRNA precursors at the 3'-end is important for post-transcriptional gene regulation. In particular, the lengthening, maintenance, and shortening of poly(A) tails in the cytoplasm are all essential for modulation of gametogenesis.
View Article and Find Full Text PDFThe elongation of poly(A) tails in cytoplasm is essential for oogenesis and early embryogenesis in Xenopus laevis. mGLD-2 is a mouse homologue of Xenopus cytoplasmic poly(A) polymerase xGLD-2. We found an association of mGLD-2 with cytoplasmic polyadenylation components, CPEB and CPSF described in Xenopus oocytes.
View Article and Find Full Text PDFBacillus stearothermophilus alpha-1,4-glucosidase (BS) is highly specific for alpha-1,4-glucosidic bonds of maltose, maltooligosaccharides and alpha-glucans. Bacillus thermoglucosdasius oligo-1,6-glucosidase (BT) can specifically hydrolyse alpha-1,6 bonds of isomaltose, isomaltooligosaccharides and alpha-limit dextrin. The two enzymes have high homology in primary structure and belong to glycoside hydrolase family 13, which contain four conservative regions (I, II, III and IV).
View Article and Find Full Text PDFBHC80 is a component of BRAF-HDAC complex (BHC) involved in transcriptional repression of neuron-specific genes in non-neuronal cells. However, BHC80 is present in both neuronal and non-neuronal cells. To explore the physiological importance of BHC80 in vivo, and the precise mechanism underlying neuron-specific gene repression by BHC80, we have produced mutant mice lacking Bhc80.
View Article and Find Full Text PDFFertilin, a heterodimeric protein complex composed of alpha (ADAM1) and beta (ADAM2) subunits on the sperm surface, is believed to mediate adhesion and fusion between the sperm and egg plasma membranes. Here we have shown that mutant male mice lacking ADAM1b are fertile and that the loss of ADAM1b results in no significant defect in sperm functions such as migration from the uterus into oviduct, binding to egg zona pellucida, and fusion with zona pellucida-free eggs. ADAM1b-deficient epididymal sperm showed a severe reduction of ADAM2 on the cell surface, despite the normal presence of ADAM2 in testicular germ cells.
View Article and Find Full Text PDFA glycosylphosphatidylinositol (GPI)-anchored hyaluronidase, PH-20, on the sperm surface has long been believed to assist sperm penetration through the cumulus mass surrounding the eggs. However, mouse sperm lacking PH-20 were still capable of penetrating the cumulus mass despite a delayed dispersal of cumulus cells. Intriguingly, a 55-kDa hyaluronan-hydrolyzing protein was abundantly present in wild-type and PH-20-deficient mouse sperm.
View Article and Find Full Text PDF