[Sex determination, it is all about timing].

The sex of an individual is determined at the time of fertilization. The mother passes on one sex chromosome, the X chromosome, and the father transmits the second sex chromosome, X or Y. Thus, an XX embryo becomes a female, whereas an XY individual becomes a male.

and act redundantly for ovarian-to-testicular fate reprogramming in the absence of in mouse sex reversals.

In mammals, testicular differentiation is initiated by transcription factors SRY and SOX9 in XY gonads, and ovarian differentiation involves R-spondin1 (RSPO1) mediated activation of WNT/β-catenin signaling in XX gonads. Accordingly, the absence of in XX humans and mice leads to testicular differentiation and female-to-male sex reversal in a manner that does not require or in mice. Here we show that an alternate testis-differentiating factor exists and that this factor is .

R-spondin2 signaling is required for oocyte-driven intercellular communication and follicular growth.

R-spondin2 (RSPO2) is a member of the R-spondin family, which are secreted activators of the WNT/β-catenin (CTNNB1) signaling pathway. In the mouse postnatal ovary, WNT/CTNNB1 signaling is active in the oocyte and in the neighboring supporting cells, the granulosa cells. Although the role of Rspo2 has been previously studied using in vitro experiments, the results are conflicting and the in vivo ovarian function of Rspo2 remains unclear.

Chemical variability and antioxidant activity of Limbarda crithmoides L. essential oil from Corsica.

The chemical compositions of 25 Corsican Limbarda crithmoides ssp. longifolia essential oils were investigated for the first time using GC-FID, GC/MS, and NMR analyses. Altogether, 65 compounds were identified, accounting for 90.

Cotranscriptional exon skipping in the genotoxic stress response.

Pre-mRNA splicing is functionally coupled to transcription, and genotoxic stresses can enhance alternative exon inclusion by affecting elongating RNA polymerase II. We report here that various genotoxic stress inducers, including camptothecin (CPT), inhibit the interaction between Ewing's sarcoma proto-oncoprotein (EWS), an RNA polymerase II-associated factor, and YB-1, a spliceosome-associated factor. This results in the cotranscriptional skipping of several exons of the MDM2 gene, which encodes the main p53 ubiquitin ligase.

Morphological, chemical and genetic differentiation of two subspecies of Cistus creticus L. (C. creticus subsp. eriocephalus and C. creticus subsp. corsicus).

Cistus creticus L., an aromatic species from the Mediterranean area, contains various diterpenes bearing the labdane skeleton. The production of essential oil from this species has potential economic value, but so far, it has not been optimized.

PKC zeta controls DNA topoisomerase-dependent human caspase-2 pre-mRNA splicing.

Caspase-2 exists as two main isoforms: the caspase-2L long isoform, which is pro-apoptotic, and the caspase-2S short isoform, which may be anti-apoptotic. Topoisomerase inhibitors drive inclusion of exon 9, specific for Casp-2S mRNA, and lower Casp-2L [corrected] mRNA and protein. With cell lines engineered to express various PKC isoforms, we demonstrate that PKC zeta, but not PKCalpha, positively regulates Casp-2S mRNA assembly triggered by topoisomerase inhibitors.

Characterization of carbonic anhydrases from Riftia pachyptila, a symbiotic invertebrate from deep-sea hydrothermal vents.

The symbiotic hydrothermal vent tubeworm Riftia pachyptila needs to supply its internal bacterial symbionts with carbon dioxide, their inorganic carbon source. Our aim in this study was to characterize the carbonic anhydrase (CA) involved in CO(2) transport and conversion at various steps in the plume and the symbiotic tissue, the trophosome. A complete 1209 kb cDNA has been sequenced from the trophosome and identified as a putative alpha-CA based on BLAST analysis and the similarities of total deduced amino-acid sequence with those from the GenBank database.

Expression and localization of carbonic anhydrase and ATPases in the symbiotic tubeworm Riftia pachyptila.

The symbiotic tubeworm Riftia pachyptila needs to fuel its chemoautotrophic symbiotic bacteria with inorganic carbon. CO(2) is transported from the surrounding water to the bacteriocytes located in the trophosome, through the branchial plume and the body fluids. Previous studies have demonstrated the implication of carbonic anhydrase (CA) and proton pumps (ATPases) at various steps of CO(2) transport.