Gcse, a novel germ-cell-specific gene, is differentially expressed during meiosis and gametogenesis

Use of assisted reproductive technologies (ARTs) to shorten the generational interval in ruminants: current status and perspectives

The challenges posed by climate change and increasing world population are stimulating renewed efforts for improving the sustainability of animal production. To meet such challenges, the contribution of genomic selection approaches, in combination with assisted reproductive technologies (ARTs), to spreading and preserving animal genetics is essential. The largest increase in genetic gain can be achieved by shortening the generation interval. This review provides an overview of the current status and progress of advanced ARTs that could be applied to reduce the generation time in both female and male of domestic ruminants. In females, the use of juvenile in vitro embryo transfer (JIVET) enables to generate offspring after the transfer of in vitro produced embryos derived from oocytes of prepubertal genetically superior donors reducing the generational interval and acceleration genetic gain. The current challenge is increasing in vitro embryo production (IVEP) from prepubertal derived oocytes which is still low and variable. The two main factors limiting IVEP success are the intrinsic quality of prepubertal oocytes and the culture systems for in vitro maturation (IVM). In males, advancements in ARTs are providing new strategies to in vitro propagate spermatogonia and differentiate them into mature sperm or even to recapitulate the whole process of spermatogenesis from embryonic stem cells. Moreover, the successful use of immature cells, such as round spermatids, for intracytoplasmic injection (ROSI) and IVEP could allow to complete the entire process in few months. However, these approaches have been successfully applied to human and mouse whereas only a few studies have been published in ruminants and results are still controversial. This is also dependent on the efficiency of ROSI that is limited by the current isolation and selection protocols of round spermatids. In conclusion, the current efforts for improving these reproductive methodologies could lead toward a significant reduction of the generational interval in livestock animals that could have a considerable impact on agriculture sustainability.

TSGA10 as a Potential Key Factor in the Process of Spermatid Differentiation/Maturation: Deciphering Its Association with Autophagy Pathway

Testis-specific gene antigen 10 (TSGA10) plays an important role in spermatogenesis. However, the exact TSGA10 role and its relationship with the autophagy pathway in the process of spermatids differentiation/maturation is still not clear. Therefore, the present study evaluates the role of TSGA10 gene in the spermatid differentiation/maturation through its effect on autophagy and explores possible underlying pathway(s). Sperm samples from patients with teratospermia were collected. The mRNA and protein level of TSGA10 in these samples were assessed by real-time PCR and western blotting. Using the ingenuity pathway analysis (IPA) software, the gene network and interactions of TSGA10 involved in sperm maturation and autophagy were investigated. Based on these analyses, the expression levels of identified genes in patient's samples and healthy controls were further evaluated. Moreover, using flow cytometry analysis, the levels of reactive oxygen species (ROS( production in teratospermic sperm samples were evaluated. The results showed that the expression levels of TSGA10 mRNA and protein decreased significantly in the teratospermic patients compared to controls (P < 0.05). Moreover, a significant reduction in the expression of the important genes involved in sperm maturation and autophagy was observed (P < 0.05). Also, the levels of ROS production in teratospermic sperm samples were shown to be significantly higher compared to those in normal sperms (P < 0.05). Our findings provide new evidence that simultaneous decrease in TSGA10 and autophagy beside the increased level of ROS production in sperm cells might be associated with the abnormalities in the spermatids differentiation/maturation and the formation of sperms with abnormal morphology.

Double homeobox gene, Duxbl, promotes myoblast proliferation and abolishes myoblast differentiation by blocking MyoD transactivation

Homeobox genes encode transcription factors that regulate embryonic development programs including organogenesis, axis formation and limb development. Previously, we identified and cloned a mouse double homeobox gene, Duxbl, whose homeodomain exhibits the highest identity (67 %) to human DUX4, a candidate gene of facioscapulohumeral muscular dystrophy (FSHD). Duxbl proteins have been shown to be expressed in elongated myocytes and myotubes of trunk and limb muscles during embryogenesis. In this study, we found that Duxbl maintained low expression levels in various adult muscles. Duxbl proteins were induced to express in activated satellite cells and colocalized with MyoG, a myogenic differentiating marker. Furthermore, Duxbl proteins were not detected in quiescent satellite cells but detected in regenerated myocytes and colocalized with MyoD and MyoG following cardiotoxin-induced muscle injury. Ectopic Duxbl overexpressions in C2C12 myoblast cells promoted cell proliferation through mainly enhancing cyclin D1 and hyper-phosphorylated retinoblastoma protein but reducing p21 expression. However, Duxbl overexpression in C2C12 cells inhibited myogenic differentiation by decreasing MyoD downstream gene expressions, including M-cadherin, MyoG, p21 and cyclin D3 but not MyoD itself. Duxbl overexpressions also promoted cell proliferation but blocked MyoD-induced myogenic conversion in multipotent mesenchymal C3H10T1/2 cells. In addition, results of a luciferase reporter assay suggest that Duxbl negatively regulated MyoG promoter activity through the proximal two E boxes. In conclusion, these results indicate that Duxbl may play a crucial role in myogenesis and postnatal muscle regeneration by activating and proliferating satellite and myoblast cells.