Expression and characterisation of splice variants during folliculogenesis in the rat.

Context: The FMR1 gene consists of 17 exons and codes for the FMRP protein. FMR1 is involved in four genetic disorders depending on the CGG repeats length in its 5'UTR: the full mutation is responsible for the Fragile X syndrome while the premutation is associated with the Fragile X-associated Tremor/Ataxia Syndrome, Fragile X-associated Primary Ovarian Insufficiency (FXPOI) and Fragile X-associated neuropsychiatric disorders. FMR1 presents multiple isoforms resulting from skipping of exons 12 and 14 and the use of alternative splice sites in exons 15 and 17.

TFEB Transcriptional Responses Reveal Negative Feedback by BHLHE40 and BHLHE41.

Transcription factor EB (TFEB) activates lysosomal biogenesis genes in response to environmental cues. Given implications of impaired TFEB signaling and lysosomal dysfunction in metabolic, neurological, and infectious diseases, we aim to systematically identify TFEB-directed circuits by examining transcriptional responses to TFEB subcellular localization and stimulation. We reveal that steady-state nuclear TFEB is sufficient to activate transcription of lysosomal, autophagy, and innate immunity genes, whereas other targets require higher thresholds of stimulation.

Meiotic gatekeeper STRA8 suppresses autophagy by repressing Nr1d1 expression during spermatogenesis in mice.

The transition from mitotic to meiotic cell cycles is essential for haploid gamete formation and fertility. Stimulated by retinoic acid gene 8 (Stra8) is an essential gatekeeper of meiotic initiation in vertebrates; yet, the molecular role of STRA8 remains principally unknown. Here we demonstrate that STRA8 functions as a suppressor of autophagy during spermatogenesis in mice.

Quantitative analysis of male germline stem cell differentiation reveals a role for the p53-mTORC1 pathway in spermatogonial maintenance.

p53 protects cells from DNA damage by inducing cell-cycle arrest upon encountering genomic stress. Among other pathways, p53 elicits such an effect by inhibiting mammalian target of rapamycin complex 1 (mTORC1), the master regulator of cell proliferation and growth. Although recent studies have indicated roles for both p53 and mTORC1 in stem cell maintenance, it remains unclear whether the p53-mTORC1 pathway is conserved to mediate this process under normal physiological conditions.

Hypermaintenance and hypofunction of aged spermatogonia: insight from age-related increase of Plzf expression.

Like stem cells in other tissues, spermatogonia, including spermatogonial stem cells (SSCs) at the foundation of differentiation hierarchy, undergo age-related decline in function. The promyelocytic leukemia zinc finger (Plzf) protein plays an essential role in spermatogonia maintenance by preventing their differentiation. To evaluate whether there is an age-related change in Plzf expression, we found that aged mouse testes exhibited a robust "Plzf overexpression" phenotype, in that they showed not only a higher frequency of Plzf-expressing cells but also an increased level of Plzf expression in these cells.