A first complete catalog of highly expressed genes in eight chicken tissues reveals uncharacterized gene families specific for the chicken testis.

Based on next-generation sequencing, we established a repertoire of differentially overexpressed genes (DoEGs) in eight adult chicken tissues: the testis, brain, lung, liver, kidney, muscle, heart, and intestine. With 4,499 DoEGs, the testis had the highest number and proportion of DoEGs compared with the seven somatic tissues. The testis DoEG set included the highest proportion of long noncoding RNAs (lncRNAs; 1,851, representing 32% of the lncRNA genes in the whole genome) and the highest proportion of protein-coding genes (2,648, representing 14.

The paralogs' enigma of germ-cell specific genes dispensable for fertility: the case of 19 oogenesin genes†.

Gene knockout experiments have shown that many genes are dispensable for a given biological function. In this review, we make an assessment of male and female germ cell-specific genes dispensable for the function of reproduction in mice, the inactivation of which does not affect fertility. In particular, we describe the deletion of a 1 Mb block containing nineteen paralogous genes of the oogenesin/Pramel family specifically expressed in female and/or male germ cells, which has no consequences in both sexes.

Expanding duplication of the testis PHD Finger Protein 7 (PHF7) gene in the chicken genome.

Gene duplications increase genetic and phenotypic diversity and occur in complex genomic regions that are still difficult to sequence and assemble. PHD Finger Protein 7 (PHF7) acts during spermiogenesis for histone-to-histone protamine exchange and is a determinant of male fertility in Drosophila and the mouse. We aimed to explore and characterise in the chicken genome the expanding family of the numerous orthologues of the unique mouse Phf7 gene (highly expressed in the testis), observing the fact that this information is unclear and/or variable according to the versions of databases.

Protein expression reveals a molecular sexual identity of avian primordial germ cells at pre-gonadal stages.

In poultry, in vitro propagated primordial germ cells (PGCs) represent an important tool for the cryopreservation of avian genetic resources. However, several studies have highlighted sexual differences exhibited by PGCs during in vitro propagation, which may compromise their reproductive capacities. To understand this phenomenon, we compared the proteome of pregonadal migratory male (ZZ) and female (ZW) chicken PGCs propagated in vitro by quantitative proteomic analysis using a GeLC-MS/MS strategy.

A comparative genomic approach using mouse and fruit fly data to discover genes involved in testis function in hymenopterans with a focus on Nasonia vitripennis.

Background: Spermatogenesis appears to be a relatively well-conserved process even among distantly related animal taxa such as invertebrates and vertebrates. Although Hymenopterans share many characteristics with other organisms, their complex haplodiploid reproduction system is still relatively unknown. However, they serve as a complementary insect model to Drosophila for studying functional male fertility.

An evolutionary approach to recover genes predominantly expressed in the testes of the zebrafish, chicken and mouse.

Background: Previously, we have demonstrated that genes involved in ovarian function are highly conserved throughout evolution. In this study, we aimed to document the conservation of genes involved in spermatogenesis from flies to vertebrates and their expression profiles in vertebrates.

Results: We retrieved 379 Drosophila melanogaster genes that are functionally involved in male reproduction according to their mutant phenotypes and listed their vertebrate orthologs.

The seminal acrosin-inhibitor ClTI1/SPINK2 is a fertility-associated marker in the chicken.

The seminal plasma is a very complex fluid, which surrounds sperm in semen. It contains numerous proteins including proteases and protease inhibitors that regulate proteolytic processes associated with protein activation and degradation. We previously identified a seminal protein, chicken liver trypsin inhibitor 1 (ClTI-1) over expressed in semen of roosters with high fertility, suggesting a role in male fertility.

Genes Encoding Mammalian Oviductal Proteins Involved in Fertilization are Subjected to Gene Death and Positive Selection.

Oviductal proteins play an important role in mammalian fertilization, as proteins from seminal fluid. However, in contrast with the latter, their phylogenetic evolution has been poorly studied. Our objective was to study in 16 mammals the evolution of 16 genes that encode oviductal proteins involved in at least one of the following steps: (1) sperm-oviduct interaction, (2) acrosome reaction, and/or (3) sperm-zona pellucida interaction.

Genes Involved in Drosophila melanogaster Ovarian Function Are Highly Conserved Throughout Evolution.

This work presents a systematic approach to study the conservation of genes between fruit flies and mammals. We have listed 971 Drosophila genes involved in female reproduction at the ovarian level and systematically looked for orthologs in the Ciona, zebrafish, coelacanth, lizard, chicken, and mouse. Depending on the species, the percentage of these Drosophila genes with at least one ortholog varies between 69% and 78%.

Loss of oocytes due to conditional ablation of Murine double minute 2 (Mdm2) gene is p53-dependent and results in female sterility.

Murine double minute 2 and 4 (Mdm2, Mdm4) are major p53-negative regulators, preventing thus uncontrolled apoptosis induction in numerous cell types, although their function in the female germ line has received little attention. In the present work, we have generated mice with specific invalidation of Mdm2 and Mdm4 genes in the mouse oocyte (Mdm2(Ocko) and Mdm4(Ocko) mice), to test their implication in survival of these germ cells. Most of the Mdm2(Ocko) but not Mdm4(Ocko) mice were sterile, with a dramatic reduction of the weight of ovaries and genital tract, a strong increase in follicle-stimulating hormone and luteinizing hormone serum levels, and a reduction of anti-mullerian hormone serum levels.

Expression of dominant-negative thyroid hormone receptor alpha1 in Leydig and Sertoli cells demonstrates no additional defect compared with expression in Sertoli cells only.

Background: In the testis, thyroid hormone (T3) regulates the number of gametes produced through its action on Sertoli cell proliferation. However, the role of T3 in the regulation of steroidogenesis is still controversial.

Methods: The TRαAMI knock-in allele allows the generation of transgenic mice expressing a dominant-negative TRα1 (thyroid receptor α1) isoform restricted to specific target cells after Cre-loxP recombination.

Direct and indirect consequences on gene expression of a thyroid hormone receptor alpha 1 mutation restricted to Sertoli cells.

Thyroid hormone is required for the timely transition of Sertoli cells from proliferative to differentiating and maturing. This transition takes place during a critical developmental period in mammals, which in mice is the first post-natal week. In order to identify the underlying molecular mechanisms of this differentiation process, we used Cre/loxP technology to selectively block the function of the thyroid hormone receptor TRα1 in Sertoli cells.

Depletion of the p43 mitochondrial T3 receptor increases Sertoli cell proliferation in mice.

Among T3 receptors, TRα1 is ubiquitous and its deletion or a specific expression of a dominant-negative TRα1 isoform in Sertoli cell leads to an increase in testis weight and sperm production. The identification of a 43-kDa truncated form of the nuclear receptor TRα1 (p43) in the mitochondrial matrix led us to test the hypothesis that this mitochondrial transcription factor could regulate Sertoli cell proliferation. Here we report that p43 depletion in mice increases testis weight and sperm reserve.

Thyroid hormone limits postnatal Sertoli cell proliferation in vivo by activation of its alpha1 isoform receptor (TRalpha1) present in these cells and by regulation of Cdk4/JunD/c-myc mRNA levels in mice.

Hypo- and hyperthyroidism alter testicular functions in the young. Among T3 receptors, TRalpha1 is ubiquitous, and its previously described knockout leads to an increase in testis weight and sperm production. We tested, for the first time, the hypothesis that TRalpha1-dependent regulation of Sertoli cell (SC) proliferation was directly regulated by TRalpha1 present in these cells.

Missense mutation in the second RNA binding domain reveals a role for Prkra (PACT/RAX) during skull development.

Random chemical mutagenesis of the mouse genome can causally connect genes to specific phenotypes. Using this approach, reduced pinna (rep) or microtia, a defect in ear development, was mapped to a small region of mouse chromosome 2. Sequencing of this region established co-segregation of the phenotype (rep) with a mutation in the Prkra gene, which encodes the protein PACT/RAX.

FSH-stimulated PTEN activity accounts for the lack of FSH mitogenic effect in prepubertal rat Sertoli cells.

Follicle-stimulating hormone (FSH) controls the proliferation and differentiation of Sertoli cells of the testis. FSH binds a G protein-coupled receptor (GPCR) to stimulate downstream effectors of the phosphoinositide-3 kinase (PI3K)-dependent pathway, without enhancing PI3K activity. To clarify this paradox, we explored the activity of phosphatase and tensin homolog deleted in chromosome 10 (PTEN), the PI3K major regulator, in primary cultures of rat Sertoli cells.

Gene birth, death, and divergence: the different scenarios of reproduction-related gene evolution.

Reproductive genes are known to evolve more rapidly than genes expressed in other organs. In this paper we present an overview and bring some new data on the evolutionary study of reproduction-related genes by integrating phylogeny with gene genomic localization. We focus on the gene evolutionary processes of gene birth, death, and divergence.

Dimeric transferrin inhibits phagocytosis of residual bodies by testicular rat Sertoli cells.

Transferrin is well known as an iron transport glycoprotein. Dimeric or tetrameric transferrin forms have recently been reported to modulate phagocytosis by human leukocytes. It is mainly synthesized by the liver, and also by other sources, such as Sertoli cells of the testis.

Glial cell-line-derived neurotropic factor and its receptors are expressed by germinal and somatic cells of the rat testis.

Glial cell-line-derived neurotropic factor (GDNF) and its receptors glial cell-line-derived neurotropic factor alpha (GFR1alpha) and rearranged during transformation (RET) have been localized in the rat testis during postnatal development. The three mRNAs, and GDNF and GFR1alpha proteins were detected in testis extracts from 1- to 90-day-old rats by reverse transcriptase PCR and Western blotting respectively. The three mRNAs were present in Sertoli cells from 20- and 55-day-old rats, pachytene spermatocytes (PS), and round spermatids (RS).

Profiling and imaging proteins in the mouse epididymis by imaging mass spectrometry.

Different aspects of matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) have been used as discovery tools to obtain global and time-correlated information on the local proteomic composition of the sexually mature mouse epididymis from both qualitative and semiquantitative points of view. Tissue sections and laser captured microdissected cells and secretory products were analyzed by MALDI-MS and from the recovered protein profiles, over 400 different proteins were monitored. Over 50 of these, some of which have been identified, displayed regionalized behavior from caput to cauda within the epididymis.

Identification of a member of a new RNase a family specifically secreted by epididymal caput epithelium.

In this study, we purified the first member of a new ribonuclease (RNase) A family from fluid of the proximal caput of the boar epididymis. This protein, named "Train A," is the most abundant compound secreted in the anterior part of the boar epididymis. After 2D electrophoresis, it is characterized by more than 10 isoforms ranging in size from 26 to 33 kDa and pI from 5 to 8.

Identification, immunolocalization, regulation, and postnatal development of the lipocalin EP17 (epididymal protein of 17 kilodaltons) in the mouse and rat epididymis.

Several lipocalins are present in the mouse epididymis and are thought to play a role in sperm maturation by transporting lipophilic molecules. We have previously reported that two lipocalin genes, mERABP (mouse epididymal retinoic acid binding protein), and mEP17 (mouse epididymal protein of 17 kDa), derived from an ancestral gene, are specifically expressed in the epididymis. In the present study, a polyclonal antibody was raised against a recombinant protein to investigate the presence and the regulation of mEP17.

Prostaglandin D2 synthase secreted in the caput epididymidis displays spatial and temporal delay between messenger RNA and protein expression during postnatal development.

Highly regionalized protein secretory activity is established progressively throughout the epididymal tubule during postnatal development. Prostaglandin D(2) synthase (PGDS) is a major protein in the ovine epididymis, the secretion of which is restricted to the proximal part of the epididymis. We investigated the mRNA and protein expression of PGDS during ontogenesis.

Epididymal lipocalin-type prostaglandin D2 synthase: identification using mass spectrometry, messenger RNA localization, and immunodetection in mouse, rat, hamster, and monkey.

This study identified prostaglandin D2 synthase (PGDS) in murine epididymal fluid using a proteomic approach combining two-dimensional (2D) gel electrophoresis and mass spectrometry (MS). The caudal epididymal fluid was collected by retroperfusion, and proteins were separated by 2D gel electrophoresis followed by matrix-assisted laser desorption ionization MS analyses after trypsin digestion. The identification was based on the protein-specific peptide map as well as on sequence information generated by nano-electrospray ionization MS/MS.

Mammalian lipocalin-type prostaglandin D2 synthase in the fluids of the male genital tract: putative biochemical and physiological functions.

Prostaglandin D2 synthase (PGDS) is a major epididymal secretory protein in several species. We quantified PGDS in ram and bull semen using a specific antiserum. Strong variations in PGDS concentration existed between animals.