Molecular Reproduction and Development最新文献

The role of Sex reversal Y (gene symbols Sry for mice, SRY for humans) in gonadal phase sexual differentiation and maintenance is well established. Sex reversal Y is expressed in the preimplantation embryo, and some of the many genes differentially expressed by sex in such embryos do so because of it (with the majority controlled by the sex chromosomal ratio). However, its role in pregonadal differentiation of the sexes has not been resolved. This review examines possibilities for the mechanisms by which Sex reversal Y could exert an influence on those differences, including a role in regulating non-coding RNAs. The possibility that these mechanisms vary between these two species, long separated by evolution, is also raised.

Male infertility accounts for approximately 50% of infertility cases, with nearly 30% remaining unexplained after standard evaluations. This highlights the need for a better understanding of sperm function to advance diagnostic and therapeutic strategies. Sperm were long considered translationally quiescent; however, emerging evidence suggests that sperm translate messenger RNAs (mRNAs) to synthesize proteins crucial for sperm functions. However, mRNA translation during capacitation remains poorly understood, despite its potential importance for fertility diagnostics. RNA-binding proteins (RBPs), small noncoding RNAs (sncRNAs), and epitranscriptomic marks regulate mRNA stability, localization, and translation initiation, modulating gene expression across reproductive tissues. Ejaculated sperm harbor initiation and elongation factors, ribosomal proteins, and other translation components, such as RBPs. Several cytoskeletal proteins and metabolic enzymes exhibit mRNA-binding activity, with the interaction of some RBPs modulated by phosphorylation during capacitation. Sperm RNA is abundant in sncRNAs, whose altered profile has been implicated in various forms of male infertility. Understanding the interplay among RBPs, the epitranscriptome, and sncRNAs could reveal mechanisms underlying sperm function and identify molecular biomarkers for infertility diagnosis. Disruptions in RNA-protein interactions may underlie idiopathic infertility, presenting opportunities for therapeutic intervention. This review highlights emerging research on sperm mRNA translation as a promising avenue for improving fertility diagnosis and treatment.

Semen evaluation in human and animal reproduction relies on sperm motility and morphology; however, these often fail to predict fertility. The domestic boar (Sus scrofa) serves as a biomedical model for male reproduction due to similarities in sperm size, capacitation dynamics, and acrosomal structure to humans in comparison to traditional rodent models. This study evaluated sperm capacitation biomarkers, particularly zinc signatures, to predict cleavage success after in vitro fertilization (IVF). Semen from 20 boars (3 replicates each) was analyzed at 0, 1 and 4 h post-in vitro capacitation (IVC) using image-based flow cytometry to assess 4 zinc signatures, plasma membrane integrity, and acrosomal remodeling. Capacitation kinetics were quantified between timepoints. Motility was measured by computer-assisted semen analysis, and IVF cleavage percentages were determined. Zinc signature 1 at 4 h post-IVC negatively correlated with cleavage percentage (r = −0.366), indicating higher noncapacitated sperm proportions reduce fertilization potential. The delta of zinc signature 3 from 1 to 0 h also negatively correlated (r = −0.441), suggesting excessively rapid capacitation impairs fertilization. Models combining capacitation biomarkers, motility, kinetics, and morphology parameters had higher predictive power (R² = 0.469) than motility models alone. Zinc signatures may serve as mechanistic fertility biomarkers in a translational boar model applicable to animal breeding and human-assisted reproduction.

Exposure to low temperature prior to insemination increases the likelihood of polyspermy in Lytechinus variegatus eggs. Electrophysiological recordings reveal that cold shock partially disrupts the egg's action potential, producing a subthreshold depolarization during the fertilization response. This attenuated shift in membrane potential appears insufficient to activate the fast block to polyspermy, allowing entry of multiple sperm. These findings identify a temperature-sensitive vulnerability in the electrical barrier to polyspermy in sea urchin eggs.

Sponges (phylum Porifera) are an early-branching lineage of Metazoa. The long independent evolution of sponges makes them an essential group for comparative studies of the emergence and early evolution of various aspects of metazoan biology, including asexual reproduction. This review provides a current critical overview of the modes of asexual reproduction in sponges with an emphasis on the morphogeneses accompanying it. Asexual reproduction occurs in all poriferan clades and has three modes: fragmentation, budding, and gemmulation. Fragmentation seems to be a universal, but unspecialized and passive form of asexual reproduction; it relies on the pronounced regeneration capabilities of sponges. Budding and gemmulation are processes that are triggered by endogenous factors and are an integral part of the life cycle in many species. Budding seems to occur in all poriferan classes but differs in its mechanisms between classes: buds in Demospongiae are formed through mesenchymal morphogeneses, while in Homoscleromorpha and Calcarea—through epithelial ones. In contrast to other modes of asexual reproduction, gemmulation is restricted to freshwater demosponges and a few brackish-water marine demosponges. Gemmules represent compact groups of dormant cells, thesocytes, coated by a thick protective coat; in favorable conditions, these cells give rise to a new individual. Gemmulation represents not only a reproduction mechanism but also a mechanism for enduring adverse environmental conditions becoming a very important alternative reproduction strategy for sponges living in discontinuous-fragmented and/or unstable environments.

Effective January 2025, it is with great honor and excitement that I have assumed the role of Editor-in-Chief for Molecular Reproduction and Development (MRD). This marks an important new chapter for the journal, and I am deeply committed to building on its strong reputation within the scientific community

First, I want to sincerely thank Professor Harvey Florman. He led MRD with incredible dedication and vision. Prof. Florman always championed scientific excellence, making sure our journal maintained its high standards. His deep commitment to top-notch reproductive biology research was key to making MRD a go-to place for cutting-edge work. Under his leadership, MRD didn't just report on the field; it helped shape it, consistently publishing discoveries that moved our understanding of gamete biology and early development forward. His contributions have had a lasting impact, and we're truly grateful.

Looking ahead, our goal stays the same: to keep MRD a top journal known for its quality and rigor. We'll continue to make sure MRD plays a big role in advancing reproductive biology, serving as an important place for high-quality, peer-reviewed research. This commitment follows the path set by our founding editor, Ralph B.L. Gwatkin, who wanted a place for easy information sharing on gametes and early development. It also builds on the strong foundation created by past leaders, including Gary M. Wessel, whose decade as editor expanded the journal's focus and brought the community closer.

As the new editor, I'll make sure MRD keeps innovating while staying true to its core values. We'll actively look for research that not only improves our basic understanding of reproduction but also covers new areas like genomics, epigenetics, developmental programming, and how environmental factors affect reproductive health. We'll also welcome studies using advanced methods, such as single-cell analysis and advanced imaging, to keep MRD at the leading edge of science. Plus, we'll work on making the journal more accessible and engaging, creating a more inclusive and collaborative space for everyone involved.

I'm really excited about what's next for Molecular Reproduction and Development. I encourage researchers worldwide to keep sending their important work to our journal. Together, we'll keep pushing the boundaries of reproductive biology, making sure MRD stays a vital resource for scientists for years to come. Thank you for your continued support.

Ivan Cunha Bustamante-Filho: writing – original draft, writing – review and editing.