Human sperm pattern of movement during chemotactic re-orientation towards a progesterone source

Human spermatozoa may chemotactically find out the egg by following an increasing gradient of attractant molecules. Although human spermatozoa have been observed to show several of the physiological characteristics of chemotaxis, the chemotactic pattern of movement has not been easy to describe. However, it is apparent that chemotactic cells may be identified while returning to the attractant source. This study characterizes the pattern of movement of human spermatozoa during chemotactic re-orientation towards a progesterone source, which is a physiological attractant candidate. By means of videomicroscopy and image analysis, a chemotactic pattern of movement was identified as the spermatozoon returned towards the source of a chemotactic concentration of progesterone (10 pmol l 21 ). First, as a continuation of its original path, the spermatozoon swims away from the progesterone source with linear movement and then turns back with a transitional movement that can be characterized by an increased velocity and decreased linearity. This sperm behaviour may help the spermatozoon to re-orient itself towards a progesterone source and may be used to identify the few cells that are undergoing chemotaxis at a given time

Spag17 Deficiency Results in Skeletal Malformations and Bone Abnormalities

Height is the result of many growth and development processes. Most of the genes associated with height are known to play a role in skeletal development. Single-nucleotide polymorphisms in the SPAG17 gene have been associated with human height. However, it is not clear how this gene influences linear growth. Here we show that a targeted mutation in Spag17 leads to skeletal malformations. Hind limb length in mutants was significantly shorter than in wild-type mice. Studies revealed differences in maturation of femur and tibia suggesting alterations in limb patterning. Morphometric studies showed increased bone formation evidenced by increased trabecular bone area and the ratio of bone area to total area, leading to reductions in the ratio of marrow area/total area in the femur. Micro-CTs and von Kossa staining demonstrated increased mineral in the femur. Moreover, osteocalcin and osterix were more highly expressed in mutant mice than in wild-type mice femurs. These data suggest that femur bone shortening may be due to premature ossification. On the other hand, tibias appear to be shorter due to a delay in cartilage and bone development. Morphometric studies showed reduction in growth plate and bone formation. These defects did not affect bone mineralization, although the volume of primary bone and levels of osteocalcin and osterix were higher. Other skeletal malformations were observed including fused sternebrae, reduced mineralization in the skull, medial and metacarpal phalanges. Primary cilia from chondrocytes, osteoblasts, and embryonic fibroblasts (MEFs) isolated from knockout mice were shorter and fewer cells had primary cilia in comparison to cells from wild-type mice. In addition, Spag17 knockdown in wild-type MEFs by Spag17 siRNA duplex reproduced the shorter primary cilia phenotype. Our findings disclosed unexpected functions for Spag17 in the regulation of skeletal growth and mineralization, perhaps because of its role in primary cilia of chondrocytes and osteoblasts

SPAG17 Mediates Nuclear Translocation of Protamines During Spermiogenesis

Protamines (PRM1 and PRM2) are small, arginine-rich, nuclear proteins that replace histones in the final stages of spermiogenesis, ensuring chromatin compaction and nuclear remodeling. Defects in protamination lead to increased DNA fragmentation and reduced male fertility. Since efficient sperm production requires the translocation of protamines from the cytoplasm to the nucleus, we investigated whether SPAG17, a protein crucial for intracellular protein trafficking during spermiogenesis, participates in protamine transport. Initially, we assessed the protein-protein interaction between SPAG17 and protamines using proximity ligation assays, revealing a significant interaction originating in the cytoplasm and persisting within the nucleus. Subsequently, immunoprecipitation and mass spectrometry (IP/MS) assays validated this initial observation. Sperm and spermatids fro

Progesterone at the picomolar range is a chemoattractant for mammalian spermatozoa

By means of a videomicroscopy system and a computer image analysis, we performed chemotaxis assays to detect true chemotaxis in human spermatozoa, in parallel to immunohistochemistry detection of progesterone inside the cumulus cells. Progesterone indeed chemotactically guides mammalian spermatozoa at very low hormone concentrations, and the cumulus oophorus could be a potential place for sperm chemotaxis mediated by progesterone in vivo.Fil: Teves, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; ArgentinaFil: Barbano, María Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; ArgentinaFil: Guidobaldi, Héctor Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; ArgentinaFil: Sánchez, Raúl. Universidad de La Frontera; ChileFil: Miska, Werner. Justus Liebig University; AlemaniaFil: Giojalas, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentin

Progesterone sperm chemoattraction may be modulated by its corticosteroid-binding globulin carrier protein

Progesterone, the main steroidal component secreted by the cumulus cells that surround the egg, chemotactically guides human spermatozoa. The aim of this work was to evaluate whether the carrier protein corticosteroid-binding globulin also participates in the sperm P chemotactic response. By means of videomicroscopy and image analysis, we observed that corticosteroid-binding globulin modulates the chemotactic activity of P, when a solution of corticosteroid-binding globulin + P is at the nanomolar range.Fil: Teves, Maria Eugenia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guidobaldi, Héctor Alejandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Uñates, Diego Rafael. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanchez, Raúl. Universidad de la Frontera; ChileFil: Miska, Werner. Justus Liebig University; AlemaniaFil: Giojalas, Laura Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Draft Genome Sequences of Burkholderia contaminans FFI-28, a Strain Isolated from a Contaminated Pharmaceutical Solution

Burkholderia contaminans is a species of the Burkholderia cepacia complex, a group of bacteria that can grow in pharmaceutical products and are capable of infecting the immunocompromised and people with cystic fibrosis. Here, we report draft genome sequences for Burkholderia contaminans FFI-28, a strain isolated from a contaminated pharmaceutical solution.Fil: Haim, Maria Sol. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mollerach, Marta Eugenia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Van Domselaar, Gary. Public Health Agency of Canada; CanadáFil: Teves, Sergio A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Degrossi, Jose. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Cardona, Silvia T.. University of Manitoba; Canad

Picomolar gradients of progesterone select functional human sperm even in subfertile samples

More than 1 million infertility treatments are practiced around the world per year, but only 30% of the couples succeed in taking a baby home. Reproductive technology depends in part on sperm quality, which influences not only fertilization but also embryo development and implantation. In order to provide a better quality sperm subpopulation, innovative sperm selection techniques based on physiological sperm features are needed. Spermatozoa at an optimum state may be selected by following an increasing concentration gradient of picomolar progesterone, a steroid secreted by the cumulus cells at the time of ovulation. In this study we developed a method to recruit spermatozoa at the best functional state, based on sperm guidance toward progesterone. The sperm selection assay (SSA) consists of a device with two wells connected by a tube.One well was filled with the sperm suspension and the other with picomolar progesterone, which diffused inside the connecting tube as a gradient. The sperm quality after the SSA was analyzed in normal and subfertile semen samples. Several sperm parameters indicative of sperm physiological state were determined before and after the SSA: capacitation, DNA integrity and oxidative stress. After the SSA, the mean level of capacitated spermatozoa increased three times in normal and in subfertile samples. The level of sperm with intact DNA was significantly increased, while sperm oxidative stress was decreased after sperm selection. Interestingly, the exposure to a progesterone gradient stimulated the completion of capacitation in some spermatozoa that could not do it by themselves. Thus, the SSA supplies a sperm population enriched with spermatozoa at an optimum physiological state that may improve the assisted reproductive technology outcome.Fil: Gatica, Laura Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Guidobaldi, Héctor Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Montesinos, Maria del Mar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Teves, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Moreno, Ignacio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Uñates, Diego Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Molina, R. I.. Laboratorio de Andrología y Reproducción; ArgentinaFil: Giojalas, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin

Ca2+ signalling in the control of motility and guidance in mammalian sperm

Ca2+ signalling in the sperm plays a key role in the regulation of events preceding fertilisation. Control of motility, including hyperactivation and chemotaxis, is particularly dependent upon [Ca2+]i signalling in the principal piece of the flagellum and the midpiece. Here we briefly review the processes that contribute to regulation of [Ca2+]i in mammalian sperm and then examine two areas: (i) the regulation of hyperactivation by [Ca2+]i and the pivotal roles played by CatSpers (sperm-specific, Ca2+-permeable membrane channels) and intracellular Ca2+ stores in this process and (ii) the elevation of [Ca2+]i and consequent modulation of motility caused by progesterone including the ability of progesterone at micromolar concentrations to cause sperm hyperactivation and/or accumulation and the recent discovery that progesterone, at picomolar concentrations, acts as a chemoattractant for mammalian sperm..</p