SPIN-4/Spinster supports sperm activation in C. elegans via sphingosine-1-phosphate transport.

Spermiogenesis, a sperm-activation step, is crucial for the transformation of immotile spermatids into motile sperm. Though membrane transport of ions and molecules across the sperm plasma membrane has been implicated in this process, the full repertoire of transporters involved, and their respective substrates, is unclear. Here, we report that the major facilitator superfamily transporter SPIN-4/Spinster governs efficient spermiogenesis and fertility in the hermaphrodite nematode Caenorhabditis elegans. Unlike other C. elegans Spinster paralogs, SPIN-4 is germline-expressed. Moreover, SPIN-4 expression is gamete-specific; it is strongly expressed in developing sperm, where it localizes to the plasma membrane, but it is absent from oocytes. Consistent with these expression data, we demonstrate that knocking out spin-4 impairs sperm development, leading to the formation of non-motile sperm that lack pseudopodia. Consequently, hermaphrodites homozygous for the spin-4(knu1099) knockout allele show extensive sperm wasting and reduced self-progeny. We observe similar defects when we genetically inhibit production of sphingosine-1-phosphate, a lipid molecule that stimulates cell motility when exported extracellularly by Spinster homologs in other contexts. Remarkably, extracellular supplementation with sphingosine-1-phosphate rescues sperm activation and motility in the absence of SPIN-4, suggesting that Spinster-dependent efflux of sphingosine-1-phosphate plays a key role in sperm mobilization. These findings identify a new signaling mechanism in C. elegans spermiogenesis entailing Spinster and sphingosine-1-phosphate.

Two Stem Cell Populations Including VSELs and CSCs Detected in the Pericardium of Adult Mouse Heart.

Adult mammalian heart is considered to be one of the least regenerative organs as it is not able to initiate endogenous regeneration in response to injury unlike in lower vertebrates and neonatal mammals. Evidence is now accumulating to suggest normal renewal and replacement of cardiomyocytes occurs even in middle-aged and old individuals. But underlying mechanisms leading to this are not yet clear. Do tissue-resident stem cells exist or somatic cells dedifferentiate leading to regeneration? Lot of attention is currently being focused on epicardium as it is involved in cardiac development, lodges multipotent progenitors and is a source of growth factors. Present study was undertaken to study the presence of stem cells in the pericardium. Intact adult mouse heart was subjected to partial enzymatic digestion to collect the pericardial cells dislodged from the surface. Pericardial cells suspension was processed to enrich the stem cells using our recently published protocol. Two populations of stem cells were successfully enriched from the pericardium of adult mouse heart along with distinct 'cardiospheres' with cytoplasmic continuity (formed by rapid proliferation and incomplete cytokinesis). These included very small embryonic-like stem cells (VSELs) and slightly bigger 'progenitors' cardiac stem cells (CSCs). Expression of pluripotent (Oct-4A, Sox-2, Nanog), primordial germ cells (Stella, Fragilis) and CSCs (Oct-4, Sca-1) specific transcripts was studied by RT-PCR. Stem cells expressed OCT-4, NANOG, SSEA-1, SCA-1 and c-KIT. c-KIT was expressed by cells of different sizes but only smaller CD45-c-KIT+ VSELs possess regenerative potential. Inadvertent loss of stem cells while processing for different experiments has led to misperceptions & controversies existing in the field of cardiac stem cells and requires urgent rectification. VSELs/CSCs have the potential to regenerate damaged cardiac tissue in the presence of paracrine support provided by the mesenchymal stromal cells.

Exploring Probiotic Activity of Lactobacillus sp. Isolated from Indigenous Breeds of Cattle Milk and Fecal Samples in Bhatan Village, MH., IN.

Probiotics are defined as live organisms that are able to confer health benefits to the host by improving their intestinal microbial balance. In the last decade, there has been an increasing interest to reveal health benefits associated with them. The objective of this study was to isolate indigenous probiotic organisms and assess their probiotic activity and therapeutic characteristics. The isolates were identified as Lactobacillus fermentum (isolates 2, 4, 6, 7, 8, and 9), Lactobacillus salivarius (isolate 13), and Lactobacillus plantarum (isolates 32 and 36). Five isolates showed growth at pH 2.5, while all isolates could grow at pH 8.5. All isolates showed good growth upto 5% NaCl concentration while two isolates showed growth in 7% NaCl concentration. All the isolates were susceptible to most of the broad-spectrum antibiotics. Cell-free suspensions from the isolates showed antimicrobial activity against the tested strains of Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Staphylococcus aureus. Two of the isolates 32 and 36 showed good revival after long-term storage, without any change in the morphology. Hence among all the other isolates these two isolates could have a good marketable potential. These strains can further be formulated into a probiotic drink that can be used as a health supplement.